10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-Q

(Mark one)

þ QUARTERLY REPORT PURSUANT TO SECTION 13 or 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the Quarterly Period Ended September 30, 2016

or

o Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934.

For the Transition Period from to .

Commission File Number 1-15202

W. R. BERKLEY CORPORATION

(Exact name of registrant as specified in its charter)

Delaware	22-1867895
(State or other jurisdiction of	(I.R.S. Employer
incorporation or organization)	Identification No.)
475 Steamboat Road, Greenwich, Connecticut	06830
(Address of principal executive offices)	(Zip Code)

	(203) 629-3000
	(Registrant’s telephone number, including area code)
	None
Former name, former address and former fiscal year, if changed since last report.

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes þ     No o

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes þ     No o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer,” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer þ	Accelerated filer o	Non-accelerated filer o	Smaller reporting company o
		(Do not check if a smaller reporting company)

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes o     No þ

Number of shares of common stock, $.20 par value, outstanding as of November 2, 2016: 121,371,880

TABLE OF CONTENTS

Part I — FINANCIAL INFORMATION
	Item 1. Financial Statements
	Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations
	Item 3. Quantitative and Qualitative Disclosure About Market Risk
	Item 4. Controls and Procedures
PART II — OTHER INFORMATION
	Item 1. Legal Proceedings
	Item 1A. Risk Factors
	Item 2. Unregistered Sales of Equity Securities and Use of Proceeds
	Item 6. Exhibits
SIGNATURES
EX-31.1
EX-31.2
EX-32.1
EX-101 INSTANCE DOCUMENT
EX-101 SCHEMA DOCUMENT
EX-101 CALCULATION LINKBASE DOCUMENT
EX-101 LABELS LINKBASE DOCUMENT
EX-101 PRESENTATION LINKBASE DOCUMENT
EX-101 DEFINITION LINKBASE DOCUMENT

Part I — FINANCIAL INFORMATION

Item 1. Financial Statements

W. R. BERKLEY CORPORATION AND SUBSIDIARIES

CONSOLIDATED BALANCE SHEETS

(In thousands, except share data)

	September 30, 2016			December 31, 2015
	(Unaudited)			(Audited)
Assets
Investments:
Fixed maturity securities	$	13,616,671		$	12,444,394
Investment funds	1,231,700			1,170,040
Real estate	1,108,482			936,367
Arbitrage trading account	602,965			376,697
Loans receivable	113,996			273,103
Equity securities available for sale	158,975			150,866
Total investments	16,832,789			15,351,467
Cash and cash equivalents	873,064			763,631
Premiums and fees receivable	1,742,210			1,669,186
Due from reinsurers	1,692,779			1,532,829
Deferred policy acquisition costs	564,663			513,128
Prepaid reinsurance premiums	429,850			394,387
Trading account receivables from brokers and clearing organizations	185,548			383,115
Property, furniture and equipment	348,169			348,224
Goodwill	134,146			153,291
Accrued investment income	133,720			123,164
Federal and foreign income taxes	—			48,952
Other assets	408,718			442,782
Total assets	$	23,345,656		$	21,724,156
Liabilities and Equity
Liabilities:
Reserves for losses and loss expenses	$	11,097,830		$	10,669,150
Unearned premiums	3,408,640			3,137,133
Due to reinsurers	261,622			224,752
Trading account securities sold but not yet purchased	60,959			37,035
Federal and foreign income taxes	96,885			—
Other liabilities	968,019			837,937
Senior notes and other debt	1,762,487			1,844,621
Subordinated debentures	727,390			340,320
Total liabilities	18,383,832			17,090,948
Equity:
Preferred stock, par value $.10 per share:
Authorized 5,000,000 shares; issued and outstanding - none
Common stock, par value $.20 per share:
Authorized 500,000,000 shares, issued and outstanding, net of treasury shares, 121,684,506 and 123,307,837 shares, respectively	47,024			47,024
Additional paid-in capital	1,027,465			1,005,455
Retained earnings	6,519,536			6,178,070
Accumulated other comprehensive loss	(9,808		)	(66,698		)
Treasury stock, at cost,113,433,412 and 111,810,081 shares, respectively	(2,658,452		)	(2,563,605		)
Total stockholders’ equity	4,925,765			4,600,246
Noncontrolling interests	36,059			32,962
Total equity	4,961,824			4,633,208
Total liabilities and equity	$	23,345,656		$	21,724,156

See accompanying notes to interim consolidated financial statements.

1

W. R. BERKLEY CORPORATION AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

(In thousands, except per share data)

	For the Three Months						For the Nine Months
	Ended September 30,						Ended September 30,
	2016			2015			2016			2015
REVENUES:
Net premiums written	$	1,607,365		$	1,571,037		$	4,913,656		$	4,690,364
Change in net unearned premiums	(21,421		)	(39,479		)	(240,584		)	(193,752		)
Net premiums earned	1,585,944			1,531,558			4,673,072			4,496,612
Net investment income	145,668			133,214			404,850			385,036
Insurance service fees	32,135			35,192			109,437			107,652
Net realized investment gains	175,738			66,419			207,508			113,020
Other-than-temporary impairments	—			(12,515		)	(18,114		)	(12,515		)
Revenues from non-insurance businesses	80,242			107,059			305,787			305,261
Other income	—			30			—			335
Total revenues	2,019,727			1,860,957			5,682,540			5,395,401
OPERATING COSTS AND EXPENSES:
Losses and loss expenses	965,856			926,355			2,852,339			2,733,298
Other operating costs and expenses	606,348			573,541			1,770,450			1,698,169
Expenses from non-insurance businesses	78,865			100,500			291,127			288,900
Interest expense	37,043			31,641			104,019			99,210
Total operating costs and expenses	1,688,112			1,632,037			5,017,935			4,819,577
Income before income taxes	331,615			228,920			664,605			575,824
Income tax expense	(110,952		)	(76,184		)	(214,789		)	(181,595		)
Net income before noncontrolling interests	220,663			152,736			449,816			394,229
Noncontrolling interests	(13		)	(129		)	(689		)	(280		)
Net income to common stockholders	$	220,650		$	152,607		$	449,127		$	393,949
NET INCOME PER SHARE:
Basic	$	1.80		$	1.24		$	3.66		$	3.17
Diluted	$	1.72		$	1.18		$	3.50		$	3.02

See accompanying notes to interim consolidated financial statements.

2

W. R. BERKLEY CORPORATION AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED)

(In thousands)

	For the Three Months						For the Nine Months
	Ended September 30,						Ended September 30,
	2016			2015			2016			2015
Net income before noncontrolling interests	$	220,663		$	152,736		$	449,816		$	394,229
Other comprehensive income (loss):
Change in unrealized currency translation adjustments	(19,470		)	(62,535		)	(77,389		)	(76,713		)
Change in unrealized investment gains, net of taxes	(47,676		)	4,497			134,213			(78,832		)
Other comprehensive income (loss)	(67,146		)	(58,038		)	56,824			(155,545		)
Comprehensive income	153,517			94,698			506,640			238,684
Noncontrolling interest	44			(35		)	(623		)	(174		)
Comprehensive income to common stockholders	$	153,561		$	94,663		$	506,017		$	238,510

See accompanying notes to interim consolidated financial statements.

3

W. R. BERKLEY CORPORATION AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (UNAUDITED)

(In thousands)

	For the Nine Months
	Ended September 30,
	2016			2015
COMMON STOCK:
Beginning and end of period	$	47,024		$	47,024
ADDITIONAL PAID-IN CAPITAL:
Beginning of period	$	1,005,455		$	991,512
Restricted stock units issued including tax benefit	(3,421		)	(25,394		)
Restricted stock units expensed	25,431			23,429
End of period	$	1,027,465		$	989,547
RETAINED EARNINGS:
Beginning of period	$	6,178,070		$	5,732,410
Net income to common stockholders	449,127			393,949
Dividends	(107,661		)	(43,239		)
End of period	$	6,519,536		$	6,083,120
ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME
Unrealized investment gains (losses):
Beginning of period	$	180,695		$	306,199
Unrealized gains (losses) on securities not other-than-temporarily impaired	133,866			(78,773		)
Unrealized gains on other-than-temporarily impaired securities	413			47
End of period	314,974			227,473
Currency translation adjustments:
Beginning of period	(247,393		)	(122,649		)
Net change in period	(77,389		)	(76,713		)
End of period	(324,782		)	(199,362		)
Total accumulated other comprehensive (loss) income	$	(9,808	)	$	28,111
TREASURY STOCK:
Beginning of period	$	(2,563,605	)	$	(2,364,551	)
Stock exercised/vested	5,023			23,667
Stock repurchased	(99,870		)	(223,652		)
End of period	$	(2,658,452	)	$	(2,564,536	)
NONCONTROLLING INTERESTS:
Beginning of period	$	32,962		$	34,189
Contributions (distributions)	2,474			(992		)
Net income	689			280
Other comprehensive loss, net of tax	(66		)	(106		)
End of period	$	36,059		$	33,371

See accompanying notes to interim consolidated financial statements.

4

W. R. BERKLEY CORPORATION AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)

(In thousands)

	For the Nine Months
	Ended September 30,
	2016			2015
CASH FROM OPERATING ACTIVITIES:
Net income to common stockholders	$	449,127		$	393,949
Adjustments to reconcile net income to net cash from operating activities:
Net investment gains	(189,394		)	(100,505		)
Depreciation and amortization	69,153			65,384
Noncontrolling interests	689			280
Investment funds	(60,387		)	(50,838		)
Stock incentive plans	27,033			24,052
Change in:
Arbitrage trading account	(4,777		)	(4,157		)
Premiums and fees receivable	(92,372		)	(99,541		)
Reinsurance accounts	(154,939		)	(62,272		)
Deferred policy acquisition costs	(51,795		)	(40,216		)
Income taxes	89,007			80,587
Reserves for losses and loss expenses	440,486			362,854
Unearned premiums	269,287			198,534
Other	(64,608		)	(147,776		)
Net cash from operating activities	726,510			620,335
CASH FROM (USED IN) INVESTING ACTIVITIES:
Proceeds from sale of fixed maturity securities	1,074,630			765,764
Proceeds from sale of equity securities	123,187			23,778
Distributions from investment funds	5,630			198,489
Proceeds from maturities and prepayments of fixed maturity securities	2,189,365			2,727,635
Purchase of fixed maturity securities	(4,280,457		)	(3,387,648		)
Purchase of equity securities	(127,303		)	(37,754		)
Real estate purchased	(207,829		)	(150,940		)
Change in loans receivable	159,128			35,739
Net additions to property, furniture and equipment	(37,895		)	(40,262		)
Change in balances due to security brokers	102,981			43,429
Cash received in connection with business disposition	250,216			—
Payment for business purchased net of cash aquired	(53,524		)	(7,156		)
Net cash from (used in) investing activities	(801,871		)	171,074
CASH FROM (USED IN) FINANCING ACTIVITIES:
Repayment of senior notes and other debt	(70,567		)	(279,204		)
Net proceeds from issuance of debt	386,848			1,891
Cash dividends to common stockholders	(30,654		)	(43,239		)
Purchase of common treasury shares	(99,870		)	(223,652		)
Other, net	(1,376		)	(3,345		)
Net cash from (used in) financing activities	184,381			(547,549		)
Net impact on cash due to change in foreign exchange rates	413			(38,367		)
Net change in cash and cash equivalents	109,433			205,493
Cash and cash equivalents at beginning of year	763,631			674,441
Cash and cash equivalents at end of period	$	873,064		$	879,934

See accompanying notes to interim consolidated financial statements.

5

W. R. Berkley Corporation and Subsidiaries

NOTES TO INTERIM CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)

(1) General

The unaudited consolidated financial statements, which include the accounts of W. R. Berkley Corporation and its subsidiaries (the “Company”) have been prepared on the basis of U.S. generally accepted accounting principles (“GAAP”) for interim financial information. Accordingly, they do not include all the information and notes required by GAAP for annual financial statements. The unaudited consolidated financial statements reflect all adjustments, consisting only of normal recurring items, which are necessary to present fairly the Company’s financial position and results of operations on a basis consistent with the prior audited consolidated financial statements. Operating results for interim periods are not necessarily indicative of the results that may be expected for the year. All significant intercompany accounts and transactions have been eliminated. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the revenues and expenses reflected during the reporting period. For further information related to a description of areas of judgment and estimates and other information necessary to understand the Company’s financial position and results of operations, refer to the audited consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015. Reclassifications have been made in the 2015 financial statements as originally reported to conform to the presentation of the 2016 financial statements.

The income tax provision has been computed based on the Company’s estimated annual effective tax rate. The effective tax rate for the quarter differs from the federal income tax rate of 35% principally because of tax-exempt investment income.

(2) Per Share Data

The Company presents both basic and diluted net income per share (“EPS”) amounts. Basic EPS is calculated by dividing net income by the weighted average number of common shares outstanding during the period. Diluted EPS is based upon the weighted average number of common and common equivalent shares outstanding during the period and is calculated using the treasury stock method for stock incentive plans. Common equivalent shares are excluded from the computation in periods in which they have an anti-dilutive effect. Stock options for which the exercise price exceeds the average market price over the period have an anti-dilutive effect on EPS and, accordingly, are excluded from the calculation.

The weighted average number of common shares used in the computation of basic and diluted earnings per share was as follows:

	For the Three Months		For the Nine Months
	Ended September 30,		Ended September 30,
(In thousands)	2016	2015	2016	2015
Basic	122,562	123,163	122,652	124,294
Diluted	128,556	128,947	128,501	130,563

(3) Recent Accounting Pronouncements

In February 2015, the Financial Accounting Standards Board ("FASB") issued ASU 2015-02, Consolidation. ASU 2015-02 makes targeted amendments to the current consolidation accounting guidance, in response to accounting complexity concerns. The guidance simplifies consolidation accounting by reducing the number of approaches to consolidation. The Company adopted this updated guidance on January 1, 2016. This adoption did not have a material effect on the Company's financial condition or results of operations, but did result in additional disclosures.

In May 2015, the FASB issued ASU 2015-09, Disclosures about Short-Duration Contracts.   ASU 2015-09 requires companies that issue short duration insurance contracts to disclose additional information, including: (i) incurred and paid claims development tables; (ii) frequency and severity of claims; and (iii) information about material changes in judgments made in calculating the liability for unpaid claim adjustment expenses, including reasons for the change and the effects on the financial statements. ASU 2015-09 is effective for annual periods beginning after December 15, 2015, and interim periods within annual periods beginning after December 15, 2016. The amendments in ASU 2015-09 should be applied retrospectively by providing comparative disclosures for each period presented, except for those requirements that apply only to the current period. As the requirements are disclosure only, the adoption of this guidance will not impact our financial condition or results of operations.

In January 2016, the FASB issued ASU 2016-01, Financial Instruments. ASU 2016-01 which amends the accounting guidance for financial instruments to require all equity investments to be measured at fair value with changes in the fair value recognized

6

through net income (other than those accounted for under equity method of accounting or those that result in consolidation of the investee). The updated guidance is effective for public business entities for annual reporting periods beginning after December 15, 2017 and interim periods within those years. The adoption of this guidance is not expected to have a material effect on the Company’s financial condition upon adoption, but will impact results of operations after adoption of this guidance as unrealized gains and losses on equity securities will no longer be reported in accumulated other comprehensive income (AOCI), but will instead be reported in net income.

In February 2016, the FASB issued ASU 2016-02, Leases, which amends the accounting and disclosure guidance for leases.  This guidance retains the two classifications of a lease, as either an operating or finance lease, both of which will require lessees to recognize a right-of-use asset and a lease liability for leases with terms of more than 12 months. The right-of-use asset and the lease liability will be determined based upon the present value of cash flows. Finance leases will reflect the financial arrangement by recognizing interest expense on the lease liability separately from the amortization expense of the right-of-use asset. Operating leases will recognize lease expense (with no separate recognition of interest expense) on a straight-line basis over the term of the lease. The accounting by lessors is not significantly changed by the updated guidance.  The updated guidance is effective for reporting periods beginning after December 15, 2018, and will require that the earliest comparative period presented include the measurement and recognition of existing leases with an adjustment to equity as if the updated guidance had always been applied. The Company is currently evaluating the impact that the adoption of this guidance will have on its results of operations, financial position and liquidity.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses, which amends the accounting guidance for credit losses on financial instruments. The updated guidance amends the current other-than-temporary impairment model for available-for-sale debt securities by requiring the recognition of impairments relating to credit losses through an allowance account and limits the amount of credit loss to the difference between a security’s amortized cost basis and its fair value. This guidance also applies a new current expected credit loss model for determining credit-related impairments for financial instruments measured at amortized cost.  The updated guidance is effective for reporting periods beginning after December 15, 2019. The Company will not be able to determine the impact the adoption of this guidance will have on its results of operations, financial position or liquidity until the year the guidance becomes effective.

All other recently issued but not yet effective accounting and reporting standards are either not applicable to the Company or are not expected to have a material impact on the Company.

(4) Acquisitions/Disposition

In February 2016, the Company acquired an 85% ownership interest for $42.3 million in a company engaged in the distribution of promotional merchandise. The fair value of the assets acquired and liabilities assumed have been estimated based on a preliminary valuation. The fair values of the assets and liabilities will be adjusted, as needed, following completion of the final valuation.

In July 2016, the Company acquired a specialty property and casualty insurance company for $15.5 million.

The following table summarizes the initial estimated fair value of net assets acquired and liabilities assumed for the business combinations completed in 2016:

(In thousands)	2016
Investments	$	6,764
Cash and cash equivalents	4,266
Real estate, furniture and equipment	701
Goodwill and other intangibles assets	45,782
Premiums and service fees receivable	3,845
Other assets	5,213
Total assets acquired	66,571
Other liabilities assumed	(4,931		)
Noncontrolling interest	(3,850		)
Net assets acquired	$	57,790

In July 2016, the Company sold Aero Precision Industries, an aviation-related business, for $253.1 million. The business had a net carrying value of $118.2 million.

7

(5) Consolidated Statement of Comprehensive Income (Loss)

The following table presents the components of the changes in accumulated other comprehensive income (loss) ("AOCI"):

(In thousands)	Unrealized Investment Gains (Losses)				Currency Translation Adjustments			Accumulated Other Comprehensive Income (Loss)
As of and for the nine months ended September 30, 2016:
Changes in AOCI
Beginning of period	$	180,695			$	(247,393	)	$	(66,698	)
Other comprehensive income (loss) before reclassifications	170,824				(77,389		)	93,435
Amounts reclassified from AOCI	(36,611		)		—			(36,611		)
Other comprehensive income (loss)	134,213				(77,389		)	56,824
Unrealized investment gain related to non-controlling interest	66				—			66
End of period	$	314,974			$	(324,782	)	$	(9,808	)
Amounts reclassified from AOCI
Pre-tax	$	(56,325	)	(1)	$	—		$	(56,325	)
Tax effect	19,714			(2)	—			19,714
After-tax amounts reclassified	$	(36,611	)		$	—		$	(36,611	)
Other comprehensive income (loss)
Pre-tax	$	198,808			$	(77,389	)	$	121,419
Tax effect	(64,595		)		—			(64,595		)
Other comprehensive income (loss)	$	134,213			$	(77,389	)	$	56,824
As of and for the three months ended September 30, 2016:
Changes in AOCI
Beginning of period	$	362,593			$	(305,312	)	$	57,281
Other comprehensive income (loss) before reclassifications	(20,968		)		(19,470		)	(40,438		)
Amounts reclassified from AOCI	(26,708		)		—			(26,708		)
Other comprehensive income (loss)	(47,676		)		(19,470		)	(67,146		)
Unrealized investment gain related to non-controlling interest	57				—			57
End of period	$	314,974			$	(324,782	)	$	(9,808	)
Amounts reclassified from AOCI
Pre-tax	$	(41,090	)	(1)	$	—		$	(41,090	)
Tax effect	14,382			(2)	—			14,382
After-tax amounts reclassified	$	(26,708	)		$	—		$	(26,708	)
Other comprehensive income (loss)
Pre-tax	$	(72,188	)		$	(19,470	)	$	(91,658	)
Tax effect	24,512				—			24,512
Other comprehensive income (loss)	$	(47,676	)		$	(19,470	)	$	(67,146	)

8

(In thousands)	Unrealized Investment Gains (Losses)				Currency Translation Adjustments			Accumulated Other Comprehensive Income (Loss)
As of and for the nine months ended September 30, 2015:
Changes in AOCI
Beginning of period	$	306,199			$	(122,649	)	$	183,550
Other comprehensive income (loss) before reclassifications	(69,078		)		(76,713		)	(145,791		)
Amounts reclassified from AOCI	(9,754		)		—			(9,754		)
Other comprehensive income (loss)	(78,832		)		(76,713		)	(155,545		)
Unrealized investment gain related to non-controlling interest	106				—			106
End of period	$	227,473			$	(199,362	)	$	28,111
Amounts reclassified from AOCI
Pre-tax	$	(15,006	)	(1)	$	—		$	(15,006	)
Tax effect	5,252			(2)	—			5,252
After-tax amounts reclassified	$	(9,754	)		$	—		$	(9,754	)
Other comprehensive income (loss)
Pre-tax	$	(135,186	)		$	(76,713	)	$	(211,899	)
Tax effect	56,354							56,354
Other comprehensive income (loss)	$	(78,832	)		$	(76,713	)	$	(155,545	)
As of and for the three months ended September 30, 2015:
Changes in AOCI
Beginning of period	$	222,882			$	(136,827	)	$	86,055
Other comprehensive income (loss) before reclassifications	3,943				(62,535		)	(58,592		)
Amounts reclassified from AOCI	554				—			554
Other comprehensive income (loss)	4,497				(62,535		)	(58,038		)
Unrealized investment gain related to non-controlling interest	94				—			94
End of period	$	227,473			$	(199,362	)	$	28,111
Amounts reclassified from AOCI
Pre-tax	$	852		(1)	$	—		$	852
Tax effect	(298		)	(2)	—			(298		)
After-tax amounts reclassified	$	554			$	—		$	554
Other comprehensive income (loss)
Pre-tax	$	(7,731	)		$	(62,535	)	$	(70,266	)
Tax effect	12,228				—			12,228
Other comprehensive income (loss)	$	4,497			$	(62,535	)	$	(58,038	)

_______________

(1) Net investment (gains) losses in the consolidated statements of income.

(2) Income tax expense in the consolidated statements of income.

9

(6) Statements of Cash Flow

Interest payments were $124,791,000 and $124,632,000 and income taxes paid were $99,161,000 and $96,364,000 in the nine months ended September 30, 2016 and 2015, respectively.

(7) Investments in Fixed Maturity Securities

At September 30, 2016 and December 31, 2015, investments in fixed maturity securities were as follows:

(In thousands)	Amortized Cost		Gross Unrealized					Fair Value		Carrying Value
			Gains		Losses
September 30, 2016
Held to maturity:
State and municipal	$	71,608	$	17,388	$	—		$	88,996	$	71,608
Residential mortgage-backed	16,569		2,232		—			18,801		16,569
Total held to maturity	88,177		19,620		—			107,797		88,177
Available for sale:
U.S. government and government agency	530,541		25,383		(931		)	554,993		554,993
State and municipal:
Special revenue	2,707,492		124,159		(1,767		)	2,829,884		2,829,884
State general obligation	528,380		33,688		(560		)	561,508		561,508
Pre-refunded	366,360		31,900		(9		)	398,251		398,251
Corporate backed	374,355		15,424		(235		)	389,544		389,544
Local general obligation	350,349		32,193		(14		)	382,528		382,528
Total state and municipal	4,326,936		237,364		(2,585		)	4,561,715		4,561,715
Mortgage-backed securities:
Residential (1)	1,131,545		27,275		(4,859		)	1,153,961		1,153,961
Commercial	108,928		1,032		(916		)	109,044		109,044
Total mortgage-backed securities	1,240,473		28,307		(5,775		)	1,263,005		1,263,005
Asset-backed	2,265,206		15,729		(12,074		)	2,268,861		2,268,861
Corporate:
Industrial	2,168,312		111,260		(3,692		)	2,275,880		2,275,880
Financial	1,288,472		52,419		(5,384		)	1,335,507		1,335,507
Utilities	199,941		11,593		(785		)	210,749		210,749
Other	90,229		1,816		(13		)	92,032		92,032
Total corporate	3,746,954		177,088		(9,874		)	3,914,168		3,914,168
Foreign	909,765		58,477		(2,490		)	965,752		965,752
Total available for sale	13,019,875		542,348		(33,729		)	13,528,494		13,528,494
Total investments in fixed maturity securities	$	13,108,052	$	561,968	$	(33,729	)	$	13,636,291	$	13,616,671

10

(In thousands)	Amortized Cost		Gross Unrealized					Fair Value		Carrying Value
			Gains		Losses
December 31, 2015
Held to maturity:
State and municipal	$	77,129	$	16,246	$	—		$	93,375	$	77,129
Residential mortgage-backed	19,138		2,207		—			21,345		19,138
Total held to maturity	96,267		18,453		—			114,720		96,267
Available for sale:
U.S. government and government agency	645,092		27,660		(2,333		)	670,419		670,419
State and municipal:
Special revenue	2,510,816		102,909		(3,737		)	2,609,988		2,609,988
State general obligation	583,456		28,068		(2,070		)	609,454		609,454
Pre-refunded	439,772		32,056		(31		)	471,797		471,797
Corporate backed	388,904		14,039		(402		)	402,541		402,541
Local general obligation	342,158		24,270		(29		)	366,399		366,399
Total state and municipal	4,265,106		201,342		(6,269		)	4,460,179		4,460,179
Mortgage-backed securities:
Residential (1)	1,126,382		18,935		(11,180		)	1,134,137		1,134,137
Commercial	64,975		875		(128		)	65,722		65,722
Total mortgage-backed securities	1,191,357		19,810		(11,308		)	1,199,859		1,199,859
Asset-backed	1,706,694		12,892		(14,414		)	1,705,172		1,705,172
Corporate:
Industrial	1,976,393		75,168		(30,027		)	2,021,534		2,021,534
Financial	1,153,096		31,744		(11,819		)	1,173,021		1,173,021
Utilities	192,857		8,321		(2,527		)	198,651		198,651
Other	81,607		245		(20		)	81,832		81,832
Total corporate	3,403,953		115,478		(44,393		)	3,475,038		3,475,038
Foreign	799,839		50,310		(12,689		)	837,460		837,460
Total available for sale	12,012,041		427,492		(91,406		)	12,348,127		12,348,127
Total investments in fixed maturity securities	$	12,108,308	$	445,945	$	(91,406	)	$	12,462,847	$	12,444,394

____________

(1) Gross unrealized losses for residential mortgage-backed securities include $857,252 and $1,269,491 as of September 30, 2016 and December 31, 2015, respectively, related to the non-credit portion of other-than-temporary impairments (“OTTI”) recognized in accumulated other comprehensive income.

The amortized cost and fair value of fixed maturity securities at September 30, 2016, by contractual maturity, are shown below. Actual maturities may differ from contractual maturities because certain issuers may have the right to call or prepay obligations.

(In thousands)	Amortized Cost		Fair Value
Due in one year or less	$	1,032,042	$	1,054,113
Due after one year through five years	5,068,197		5,246,081
Due after five years through ten years	3,287,833		3,500,463
Due after ten years	2,462,938		2,553,828
Mortgage-backed securities	1,257,042		1,281,806
Total	$	13,108,052	$	13,636,291

At September 30, 2016 and 2015, there were no investments that exceeded 10% of common stockholders' equity, other than investments in United States government and government agency securities.

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(8) Investments in Equity Securities Available for Sale

At September 30, 2016 and December 31, 2015, investments in equity securities were as follows:

(In thousands)	Cost		Gross Unrealized					Fair Value		Carrying Value
			Gains		Losses
September 30, 2016
Common stocks	$	37,897	$	215	$	(2,441	)	$	35,671	$	35,671
Preferred stocks	125,759		6,573		(9,028		)	123,304		123,304
Total	$	163,656	$	6,788	$	(11,469	)	$	158,975	$	158,975
December 31, 2015
Common stocks	$	56,462	$	—	$	(19,189	)	$	37,273	$	37,273
Preferred stocks	108,730		8,216		(3,353		)	113,593		113,593
Total	$	165,192	$	8,216	$	(22,542	)	$	150,866	$	150,866

(9) Arbitrage Trading Account

At September 30, 2016 and December 31, 2015, the fair and carrying values of the arbitrage trading account were $603 million and $377 million, respectively. The primary focus of the trading account is merger arbitrage. Merger arbitrage is the business of investing in the securities of publicly held companies which are the targets in announced tender offers and mergers. Arbitrage investing differs from other types of investing in its focus on transactions and events believed likely to bring about a change in value over a relatively short time period (usually four months or less).

The Company uses put options, call options and swap contracts in order to mitigate the impact of potential changes in market conditions on the merger arbitrage trading account. These options and contracts are reported at fair value. As of September 30, 2016, the fair value of long option contracts outstanding was $1.2 million (notional amount of $53.9 million) and the fair value of short option contracts outstanding was $0.7 million (notional amount of $103.6 million). Other than with respect to the use of these trading account securities, the Company does not make use of derivatives.

(10) Net Investment Income

Net investment income consists of the following:

	For the Three Months						For the Nine Months
	Ended September 30,						Ended September 30,
(In thousands)	2016			2015			2016			2015
Investment income earned on:
Fixed maturity securities, including cash and cash equivalents and loans receivable	$	114,271		$	104,936		$	331,448		$	318,095
Investment funds	25,293			22,926			60,385			50,838
Arbitrage trading account	6,441			2,608			12,883			11,470
Equity securities available for sale	1,069			1,109			3,217			3,513
Real estate	585			4,389			4,552			9,270
Gross investment income	147,659			135,968			412,485			393,186
Investment expense	(1,991		)	(2,754		)	(7,635		)	(8,150		)
Net investment income	$	145,668		$	133,214		$	404,850		$	385,036

(11) Investment Funds

The Company evaluates whether it is an investor in a variable interest entity (VIE).  Such entities do not have sufficient equity at risk to finance their activities without additional subordinated financial support, or the equity investors, as a group, do not have the characteristics of a controlling financial interest (primary beneficiary).  The Company determines whether it is the primary beneficiary of an entity subject to consolidation based on a qualitative assessment of the VIE's capital structure,

12

contractual terms, nature of the VIE's operations and purpose, and the Company's relative exposure to the related risks of the VIE on the date it becomes initially involved in the VIE and on an ongoing basis.  The Company is not the primary beneficiary in any of its investment funds, and accordingly, carries its interests in investments funds under the equity method of accounting.

The Company’s maximum exposure to loss with respect to these investments is limited to the carrying amount reported on the Company’s consolidated balance sheet and any unfunded commitment.

Investment funds consist of the following:

	Carrying Value as of				Income (Loss) from Investment Funds
	September 30,		December 31,		For the Nine Months Ended September 30,
(In thousands)	2016		2015		2016		2015
Real estate	$	646,102	$	580,830	$	33,028	$	51,467
Energy	80,900		93,719		7,174		(25,124		)
Hedge equity	71,371		70,580		791		(3,925		)
Other funds	433,327		424,911		19,392		28,420
Total	$	1,231,700	$	1,170,040	$	60,385	$	50,838

The Company's share of the earnings or losses of investment funds is generally reported on a one-quarter lag in order to facilitate the timely completion of the Company's consolidated financial statements.

Other funds include private equity investments carried on the equity method of accounting, which includes a publicly traded common stock investment in HealthEquity, Inc. (HQY). Our ownership interest in HQY as of September 30, 2016 is approximately 21% with a fair value of $453 million and a carrying value of $53.1 million. In October 2016, the Company sold approximately 2.2 million shares in HQY and recognized a realized investment gain of approximately $65 million. Following the completion of the sale, the Company will report its investment in HQY at fair value.

12) Real Estate

Investment in real estate represents directly owned property held for investment, as follows:    

	Carrying Value
	September 30,		December 31,
(In thousands)	2016		2015
Properties in operation	$	441,795	$	226,055
Properties under development	666,687		710,312
Total	$	1,108,482	$	936,367

In 2016, properties in operation included a long-term ground lease in Washington, D.C., a hotel in Memphis, Tennessee, an office complex in New York City and office buildings in West Palm Beach and Palm Beach, Florida. Properties in operation are net of accumulated depreciation and amortization of $13,345,000 and $9,073,000 as of September 30, 2016 and December 31, 2015, respectively. Related depreciation expense was $4,117,000 and $5,991,000 for the nine months ended September 30, 2016 and 2015, respectively. Future minimum rental income expected on operating leases relating to properties in operation is $2,982,866 in 2016, $16,900,586 in 2017, $22,572,465 in 2018, $20,707,015 in 2019, $19,471,136 in 2020, $19,649,571 in 2021 and $411,667,096 thereafter.

Properties under development include an office building in London and a mixed-use project in Washington, D.C.

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(13) Loans Receivable

Loans receivable are as follows:

(In thousands)	September 30, 2016		December 31, 2015
Amortized cost (net of valuation allowance):
Real estate loans	$	96,312	$	200,499
Commercial loans	17,684		72,604
Total	$	113,996	$	273,103
Fair value:
Real estate loans	$	97,296	$	201,641
Commercial loans	19,187		74,106
Total	$	116,483	$	275,747
Valuation allowance:
Specific	$	1,025	$	—
General	2,197		2,094
Total	$	3,222	$	2,094
	For the Three Months Ended September 30,
	2016		2015
Increase in valuation allowance	$	467	$	19
	For the Nine Months Ended September 30,
	2016		2015
Increase (decrease) in valuation allowance	$	1,128	$	(81	)

Loans receivable in non-accrual status were $9.1 million and $3.1 million as of September 30, 2016 and December 31, 2015, respectively.

The Company monitors the performance of its loans receivable and assesses the ability of the borrower to pay principal and interest based upon loan structure, underlying property values, cash flow and related financial and operating performance of the property and market conditions. Loans receivable with a potential for default are further assessed using discounted cash flow analysis and comparable cost and sales methodologies, if appropriate.

The real estate loans are secured by commercial real estate primarily located in North Carolina, Ohio and New York. These loans generally earn interest at floating LIBOR-based interest rates and have maturities (inclusive of extension options) throughAugust 2025. The commercial loans are with small business owners who have secured the related financing with the assets of the business. Commercial loans generally earn interest on a fixed basis and have varying maturities not exceeding 10 years.

In evaluating the real estate loans, the Company considers their credit quality indicators, including loan to value ratios, which compare the outstanding loan amount to the estimated value of the property, the borrower’s financial condition and performance with respect to loan terms, the position in the capital structure, the overall leverage in the capital structure and other market conditions. Based on these considerations, none of the real estate loans were considered to be impaired at September 30, 2016, and accordingly, the Company determined that a specific valuation allowance was not required.

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(14) Realized and Unrealized Investment Gains (Losses)

Realized and unrealized investment gains (losses) are as follows:

	For the Three Months Ended September 30,						For the Nine Months Ended September 30,
(In thousands)	2016			2015			2016			2015
Realized investment gains (losses):
Fixed maturity securities:
Gains	$	33,798		$	1,341		$	66,972		$	8,178
Losses	(1,150		)	(2,171		)	(5,570		)	(2,810		)
Equity securities available for sale	8,441			(21		)	13,037			9,639
Investment funds	(3,788		)	70,648			(9,041		)	92,821
Real estate	687			—			5,247			—
Other (1)	137,750			(3,378		)	136,863			5,192
Net realized gains on investments sales	175,738			66,419			207,508			113,020
Other-than-temporary impairments (2)	—			(12,515		)	(18,114		)	(12,515		)
Net investment gains	175,738			53,904			189,394			100,505
Income tax expense	(61,508		)	(18,866		)	(66,288		)	(35,177		)
After-tax net realized investment gains	$	114,230		$	35,038		$	123,106		$	65,328

Change in unrealized investment gains (losses)of available for sale securities:
Fixed maturity securities	$	(45,388	)	$	2,449		$	169,933		$	(102,863	)
Previously impaired fixed maturity securities	(1,406		)	50			413			73
Equity securities available for sale	(28,517		)	(2,353		)	12,433			(15,977		)
Investment funds	3,143			(7,876		)	16,028			(16,417		)
Total change in unrealized investment gains (losses)	(72,168		)	(7,730		)	198,807			(135,184		)
Income tax benefit (expense)	24,493			12,229			(64,594		)	56,354
Noncontrolling interests	57			94			66			106
After-tax change in unrealized investment gains (losses) of available for sale securities	$	(47,618	)	$	4,593		$	134,279		$	(78,724	)

______________________

(1) Other includes a gain of $134.9 million from the sale of Aero Precision Industries, and certain related aviation services business, for the three and nine months ended September 30, 2016.

(2) Other than temporary impairments (OTTI) for the nine months ended September 30, 2016 of $18.1 million were related to equity securities available for sale. OTTI for the three and nine months ended September 30, 2015 of $12.5 million were related to equity securities available for sale and fixed maturity securities of $3.5 million and $9.0 million, respectively.

15

(15) Securities in an Unrealized Loss Position

The following tables summarize all securities in an unrealized loss position at September 30, 2016 and December 31, 2015 by the length of time those securities have been continuously in an unrealized loss position:

	Less Than 12 Months				12 Months or Greater				Total
(In thousands)	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
September 30, 2016
U.S. government and government agency	$	54,550	$	279	$	39,092	$	652	$	93,642	$	931
State and municipal	217,215		1,095		138,082		1,490		355,297		2,585
Mortgage-backed securities	251,969		1,851		105,927		3,924		357,896		5,775
Asset-backed securities	918,983		5,718		214,436		6,356		1,133,419		12,074
Corporate	337,940		2,152		98,162		7,722		436,102		9,874
Foreign	52,233		640		30,842		1,850		83,075		2,490
Fixed maturity securities	1,832,890		11,735		626,541		21,994		2,459,431		33,729
Common stocks	18,112		779		8,116		1,662		26,228		2,441
Preferred stocks	46,135		8,199		24,845		829		70,980		9,028
Equity securities available for sale	64,247		8,978		32,961		2,491		97,208		11,469
Total	$	1,897,137	$	20,713	$	659,502	$	24,485	$	2,556,639	$	45,198
December 31, 2015
U.S. government and government agency	$	101,660	$	487	$	64,500	$	1,846	$	166,160	$	2,333
State and municipal	501,952		4,404		106,681		1,865		608,633		6,269
Mortgage-backed securities	381,986		3,639		184,807		7,669		566,793		11,308
Asset-backed securities	1,091,078		7,703		190,467		6,711		1,281,545		14,414
Corporate	1,232,940		35,406		76,797		8,987		1,309,737		44,393
Foreign	169,190		8,822		19,528		3,867		188,718		12,689
Fixed maturity securities	3,478,806		60,461		642,780		30,945		4,121,586		91,406
Common stocks	18,641		18,005		7,829		1,184		26,470		19,189
Preferred stocks	—		—		22,320		3,353		22,320		3,353
Equity securities available for sale	18,641		18,005		30,149		4,537		48,790		22,542
Total	$	3,497,447	$	78,466	$	672,929	$	35,482	$	4,170,376	$	113,948

Fixed Maturity Securities – A summary of the Company’s non-investment grade fixed maturity securities that were in an unrealized loss position at September 30, 2016 is presented in the table below:

($ in thousands)	Number of Securities	Aggregate Fair Value		Gross Unrealized Loss
Corporate	10	$	27,531	$	3,045
Mortgage-backed securities	11	23,921		1,229
Foreign government	4	23,001		1,101
Asset-backed securities	5	8,418		405
State and municipal	1	7,007		25
Total	31	$	89,878	$	5,805

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For OTTI of fixed maturity securities that management does not intend to sell or, to be required to sell, the portion of the decline in value that is considered to be due to credit factors is recognized in earnings, and the portion of the decline in value that is considered to be due to non-credit factors is recognized in other comprehensive income.

The Company has evaluated its fixed maturity securities in an unrealized loss position and believes the unrealized losses are due primarily to temporary market and sector-related factors rather than to issuer-specific factors. None of these securities are delinquent or in default under financial covenants. Based on its assessment of these issuers, the Company expects them to continue to meet their contractual payment obligations as they become due and does not consider any of these securities to be OTTI.

Preferred Stocks – At September 30, 2016, there were three preferred stocks in an unrealized loss position, with an aggregate fair value of $71 million and a gross unrealized loss of $9 million. Based upon management’s view of the underlying value of these securities, the Company does not consider these equity securities to be OTTI.

Common Stocks – At September 30, 2016, there were threecommon stocks in an unrealized loss position, with an aggregate fair value of $26 million and a gross unrealized loss of $2 million. Based on management's view of the underlying securities, the Company does not consider these equity securities to be OTTI.

Loans Receivable – The Company monitors the performance of its loans receivable, including current market conditions for each loan and the ability to collect principal and interest. For loans where the Company determines it is probable that the contractual terms will not be met, an analysis is performed and a valuation reserve is established, if necessary, with a charge to earnings. Loans receivable are reported net of a valuation reserve of $3 million and $2 million at September 30, 2016 and December 31, 2015, respectively.

(16)Fair Value Measurements

The Company’s fixed maturity and equity securities classified as available for sale and its trading account securities are carried at fair value. Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” The Company utilizes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels, as follows:

Level 1 - Quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.  

Level 2 - Quoted prices for similar assets or valuations based on inputs that are observable.

Level 3 - Estimates of fair value based on internal pricing methodologies using unobservable inputs. Unobservable inputs are only used to measure fair value to the extent that observable inputs are not available.

Substantially, all of the Company’s fixed maturity securities were priced by independent pricing services. The prices provided by the independent pricing services are estimated based on observable market data in active markets utilizing pricing models and processes, which may include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, sector groupings, matrix pricing and reference data. The pricing services may prioritize inputs differently on any given day for any security based on market conditions, and not all inputs are available for each security evaluation on any given day. The pricing services used by the Company have indicated that they will only produce an estimate of fair value if objectively verifiable information is available. The determination of whether markets are active or inactive is based upon the volume and level of activity for a particular asset class. The Company reviews the prices provided by pricing services for reasonableness and periodically performs independent price tests of a sample of securities to ensure proper valuation.

If prices from independent pricing services are not available for fixed maturity securities, the Company estimates the fair value. For Level 2 securities, the Company utilizes pricing models and processes which may include benchmark yields, sector groupings, matrix pricing, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, bids, offers and reference data. Where broker quotes are used, the Company generally requests two or more quotes and sets a price within the range of quotes received based on its assessment of the credibility of the quote and its own evaluation of the security. The Company generally does not adjust quotes received from brokers. For securities traded only in private negotiations, the Company determines fair value based primarily on the cost of such securities, which is adjusted to reflect prices of recent placements of securities of the same issuer, financial projections, credit quality and business developments of the issuer and other relevant information.

For Level 3 securities, the Company generally uses a discounted cash flow model to estimate the fair value of fixed maturity securities. The cash flow models are based upon assumptions as to prevailing credit spreads, interest rate and interest rate volatility,

17

time to maturity and subordination levels. Projected cash flows are discounted at rates that are adjusted to reflect illiquidity, where appropriate.

The following tables present the assets and liabilities measured at fair value on a recurring basis as of September 30, 2016 and December 31, 2015 by level:

(In thousands)	Total		Level 1		Level 2		Level 3
September 30, 2016
Assets:
Fixed maturity securities available for sale:
U.S. government and government agency	$	554,993	$	—	$	554,993	$	—
State and municipal	4,561,715		—		4,561,715		—
Mortgage-backed securities	1,263,005		—		1,263,005		—
Asset-backed securities	2,268,861		—		2,268,676		185
Corporate	3,914,168		—		3,914,168		—
Foreign government	965,752		—		965,752		—
Total fixed maturity securities available for sale	13,528,494		—		13,528,309		185
Equity securities available for sale:
Common stocks	35,671		27,555		—		8,116
Preferred stocks	123,304		—		119,630		3,674
Total equity securities available for sale	158,975		27,555		119,630		11,790
Arbitrage trading account	602,965		320,280		282,685		—
Total	$	14,290,434	$	347,835	$	13,930,624	$	11,975
Liabilities:
Trading account securities sold but not yet purchased	$	60,959	$	60,947	$	12	$	—
December 31, 2015
Assets:
Fixed maturity securities available for sale:
U.S. government and government agency	$	670,419	$	—	$	670,419	$	—
State and municipal	4,460,179		—		4,460,179		—
Mortgage-backed securities	1,199,859		—		1,199,859		—
Asset-backed securities	1,705,172		—		1,704,973		199
Corporate	3,475,038		—		3,474,884		154
Foreign government	837,460		—		837,460		—
Total fixed maturity securities available for sale	12,348,127		—		12,347,774		353
Equity securities available for sale:
Common stocks	37,273		29,444		—		7,829
Preferred stocks	113,593		—		109,969		3,624
Total equity securities available for sale	150,866		29,444		109,969		11,453
Arbitrage trading account	376,697		256,914		119,607		176
Total	$	12,875,690	$	286,358	$	12,577,350	$	11,982
Liabilities:
Trading account securities sold but not yet purchased	$	37,035	$	35,559	$	1,476	$	—

There were no significant transfers between Levels 1 and 2 during the nine months ended September 30, 2016 or during the year ended December 31, 2015.

18

The following tables summarize changes in Level 3 assets and liabilities for the nine months ended September 30, 2016 and for the year ended December 31, 2015:

	Gains (Losses) Included in:
(In thousands)	Beginning Balance		Earnings (Losses)			Other Comprehensive Income (Loss)			Impairments			Purchases		(Sales)			Paydowns / Maturities			Transfers			Ending Balance
																				In / (Out)
Nine months ended September 30, 2016:
Assets:
Fixed maturities securities available for sale:
Asset-backed securities	$	199	$	3		$	13		$	—		$	—	$	—		$	(30	)	$	—		$	185
Corporate	154		177			—			—			—		(331		)	—			—			—
Total	353		180			13			—			—		(331		)	(30		)	—			185
Equity securities available for sale:
Common stocks	7,829		—			(478		)	—			765		—			—			—			8,116
Preferred stocks	3,624		50			—			—			—		—			—			—			3,674
Total	11,453		50			(478		)	—			765		—			—			—			11,790
Arbitrage trading account	176		(176		)	—			—			—		—			—			—			—
Total	$	11,982	$	54		$	(465	)	$	—		$	765	$	(331	)	$	(30	)	$	—		$	11,975
Year ended December 31, 2015:
Assets:
Fixed maturities securities available for sale:
Asset-backed securities	$	20,611	$	19		$	191		$	—		$	—	$	—		$	(1,820	)	$	(18,802	)	$	199
Corporate	154		—			—			—			—		—			—			—			154
Total	20,765		19			191			—			—		—			(1,820		)	(18,802		)	353
Equity securities available for sale:
Common stocks	10,741		—			(273		)	(2,331		)	—		(308		)	—			—			7,829
Preferred stocks	3,713		(89		)	—			—			—		—			—			—			3,624
Total	14,454		(89		)	(273		)	(2,331		)	—		(308		)	—			—			11,453
Arbitrage trading account	720		(799		)	—			—			72,640		(71,921		)	—			(464		)	176
Total	$	35,939	$	(869	)	$	(82	)	$	(2,331	)	$	72,640	$	(72,229	)	$	(1,820	)	$	(19,266	)	$	11,982

During the nine months ended September 30, 2016, there were no transfers out of Level 3. During the year ended December 31, 2015, five securities were transferred out of Level 3 as an observable price became available.

19

(17) Fair Value of Financial Instruments

The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments:

	September 30, 2016				December 31, 2015
(In thousands)	Carrying Value		Fair Value		Carrying Value		Fair Value
Assets:
Fixed maturity securities	$	13,616,671	$	13,636,291	$	12,444,394	$	12,462,847
Equity securities available for sale	158,975		158,975		150,866		150,866
Arbitrage trading account	602,965		602,965		376,697		376,697
Loans receivable	113,996		116,483		273,103		275,747
Cash and cash equivalents	873,064		873,064		763,631		763,631
Trading account receivables from brokers and clearing organizations	185,548		185,548		383,115		383,115
Due from broker	—		—		1,713		1,713
Liabilities:
Due to broker	101,405		101,405		—		—
Trading account securities sold but not yet purchased	60,959		60,959		37,035		37,035
Subordinated debentures	727,390		779,056		340,320		355,880
Senior notes and other debt	1,762,487		1,997,430		1,844,621		2,029,572

The estimated fair values of the Company’s fixed maturity securities, equity securities available for sale and arbitrage trading account securities are based on various valuation techniques that rely on fair value measurements as described in Note 16 above. The fair value of loans receivable are estimated by using current institutional purchaser yield requirements for loans with similar credit characteristics, which is considered a Level 2 input. The fair value of the senior notes and other debt and the subordinated debentures is based on spreads for similar securities, which is considered a Level 2 input.

(18) Reinsurance

The following is a summary of reinsurance financial information:

	For the Three Months						For the Nine Months
	Ended September 30,						Ended September 30,
(In thousands)	2016			2015			2016			2015
Written premiums:
Direct	$	1,643,870		$	1,601,344		$	5,061,646		$	4,852,584
Assumed	224,979			221,237			702,265			633,200
Ceded	(261,484		)	(251,544		)	(850,255		)	(795,420		)
Total net premiums written	$	1,607,365		$	1,571,037		$	4,913,656		$	4,690,364
Earned premiums:
Direct	$	1,647,033		$	1,575,624		$	4,824,768		$	4,646,343
Assumed	216,758			217,668			635,443			632,362
Ceded	(277,847		)	(261,734		)	(787,139		)	(782,093		)
Total net premiums earned	$	1,585,944		$	1,531,558		$	4,673,072		$	4,496,612
Ceded losses and loss expenses incurred	$	213,065		$	123,765		$	507,258		$	374,084
Ceded commissions earned	$	47,315		$	45,946		$	143,809		$	129,766

The Company reinsures a portion of its insurance exposures in order to reduce its net liability on individual risks and catastrophe losses. The Company also cedes premiums to state assigned risk plans and captive insurance companies. Estimated amounts due from reinsurers are reported net of reserves for uncollectible reinsurance of $1 million as of September 30, 2016 and December 31, 2015.

20

(19) Restricted Stock Units

Pursuant to its stock incentive plan, the Company may issue restricted stock units (RSUs) to employees of the Company and its subsidiaries. The RSUs generally vest three to five years from the award date and are subject to other vesting and forfeiture provisions contained in the award agreement. RSUs are expensed pro-ratably over the vesting period. RSU expenses were $25 million and $23 million for the nine months ended September 30, 2016 and 2015, respectively. A summary of RSUs issued in the nine months ended September 30, 2016 and 2015 follows:

($ in thousands)	Units	Fair Value
Nine months ended September 30,
2016	990,487	$	57,959
2015	971,457	$	54,439

(20) Litigation and Contingent Liabilities

In the ordinary course of business, the Company is subject to disputes, litigation and arbitration arising from its insurance and reinsurance businesses. These matters are generally related to insurance and reinsurance claims and are considered in the establishment of loss and loss expense reserves. In addition, the Company may also become involved in legal actions which seek extra-contractual damages, punitive damages or penalties, including claims alleging bad faith in handling of insurance claims. The Company expects its ultimate liability with respect to such matters will not be material to its financial condition. However, adverse outcomes on such matters are possible, from time to time, and could be material to the Company’s results of operations in any particular financial reporting period.

(21) Business Segments

The Company’s reportable segments include the following two business segments:

• Insurance - primarily commercial insurance business, including excess and surplus lines and admitted lines in the United States, United Kingdom, Continental Europe, South America, Canada, Scandinavia, Asia and Australia; and

• Reinsurance - reinsurance business on a facultative and treaty basis, primarily in the United States, United Kingdom, Continental Europe, Australia, the Asia-Pacific Region, and South Africa.

Commencing with the first quarter of 2016, the Company changed the aggregation of its business segments. Insurance-Domestic operating units and Insurance-International operating units, previously reported separately, have been aggregated into the Insurance segment. The segment disclosures for prior periods have been revised to be consistent with the new reportable business segment presentation.

The accounting policies of the segments are the same as those described in the summary of significant accounting policies. Income tax expense and benefits are calculated based upon the Company's overall effective tax rate.

21

Summary financial information about the Company's reporting segments is presented in the following tables. Income (loss) before income taxes by segment includes allocated investment income. Identifiable assets by segment are those assets used in or allocated to the operation of each segment.

	Revenues
(In thousands)	Earned Premiums		Investment Income		Other		Total		Pre-Tax Income (Loss)			Net Income (Loss) to Common Stockholders
Three months ended September 30, 2016
Insurance	$	1,431,664	$	117,388	$	22,819	$	1,571,871	$	215,649		$	144,310
Reinsurance	154,280		21,478		—		175,758		22,171			15,167
Corporate, other and eliminations (1)	—		6,802		89,560		96,362		(81,941		)	(53,055		)
Net investment gains	—		—		175,736		175,736		175,736			114,228
Total	$	1,585,944	$	145,668	$	288,115	$	2,019,727	$	331,615		$	220,650
Three months ended September 30, 2015
Insurance	$	1,379,501	$	106,989	$	23,021	$	1,509,511	$	204,109		$	139,446
Reinsurance	152,057		19,468		—		171,525		22,413			15,807
Corporate, other and eliminations (1)	—		6,757		119,260		126,017		(51,506		)	(37,684		)
Net investment gains	—		—		53,904		53,904		53,904			35,038
Total	$	1,531,558	$	133,214	$	196,185	$	1,860,957	$	228,920		$	152,607
Nine months ended September 30, 2016:
Insurance	$	4,206,887	322,779		$	77,215	$	4,606,881	$	604,825		$	407,346
Reinsurance	466,185		59,244		—		525,429		61,041			42,285
Corporate, other and eliminations (1)	—		22,827		338,009		360,836		(190,655		)	(123,610		)
Net investment gains	—		—		189,394		189,394		189,394			123,106
Total	$	4,673,072	$	404,850	$	604,618	$	5,682,540	$	664,605		$	449,127
Nine months ended September 30, 2015:
Insurance	$	4,042,159	$	309,337	$	72,981	$	4,424,477	$	575,748		$	395,581
Reinsurance	454,453		54,575		—		509,028		69,797			49,134
Corporate, other and eliminations (1)	—		21,124		340,267		361,391		(170,226		)	(116,094		)
Net investment gains	—		—		100,505		100,505		100,505			65,328
Total	$	4,496,612	$	385,036	$	513,753	$	5,395,401	$	575,824		$	393,949

________

(1) Corporate, other and eliminations represent corporate revenues and expenses that are not allocated to business segments.

Identifiable Assets

(In thousands)	September 30, 2016		December 31, 2015
Insurance	$	18,972,237	$	18,063,730
Reinsurance	2,585,307		2,441,340
Corporate, other and eliminations	1,788,112		1,219,086
Consolidated	$	23,345,656	$	21,724,156

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Net premiums earned by major line of business are as follows:

	For the Three Months				For the Nine Months
	Ended September 30,				Ended September 30,
(In thousands)	2016		2015		2016		2015
Insurance:
Other liability	$	465,068	$	418,133	$	1,331,143	$	1,216,411
Workers’ compensation	355,604		347,745		1,047,412		1,010,279
Short-tail lines (1)	317,498		327,357		977,138		973,606
Commercial automobile	164,540		170,660		481,249		506,229
Professional liability	128,954		115,606		369,945		335,634
Total Insurance	1,431,664		1,379,501		4,206,887		4,042,159
Reinsurance:
Casualty	93,757		103,198		290,373		314,462
Property	60,523		48,859		175,812		139,991
Total Reinsurance	154,280		152,057		466,185		454,453
Total	$	1,585,944	$	1,531,558	$	4,673,072	$	4,496,612

______________

(1) Short-tail lines include commercial multi-peril (non-liability), inland marine, accident and health, fidelity and surety, boiler and machinery and other lines.

23

SAFE HARBOR STATEMENT

This is a “Safe Harbor” Statement under the Private Securities Litigation Reform Act of 1995. Any forward-looking statements contained herein, including statements related to our outlook for the industry and for our performance for the year 2016 and beyond, are based upon the Company’s historical performance and on current plans, estimates and expectations. The inclusion of this forward-looking information should not be regarded as a representation by us or any other person that the future plans, estimates or expectations contemplated by us will be achieved. They are subject to various risks and uncertainties, including but not limited to: the cyclical nature of the property casualty industry; the impact of significant competition, including new alternative entrants to the industry; the long-tail and potentially volatile nature of the insurance and reinsurance business; product demand and pricing; claims development and the process of estimating reserves; investment risks, including those of our portfolio of fixed maturity securities and investments in equity securities, including investments in financial institutions, municipal bonds, mortgage-backed securities, loans receivable, investment funds, including real estate, merger arbitrage, energy related and private equity investments; the effects of emerging claim and coverage issues; the uncertain nature of damage theories and loss amounts; natural and man-made catastrophic losses, including as a result of terrorist activities; general economic and market activities, including inflation, interest rates, and volatility in the credit and capital markets; the impact of the conditions in the financial markets and the global economy, and the potential effect of legislative, regulatory, accounting or other initiatives taken in response, on our results and financial condition; foreign currency and political risks (including those associated with the United Kingdom's expected withdrawal from the European Union, or "Brexit") relating to our international operations; our ability to attract and retain key personnel and qualified employees; continued availability of capital and financing; the success of our new ventures or acquisitions and the availability of other opportunities; the availability of reinsurance; our retention under the Terrorism Risk Insurance Program Reauthorization Act of 2015; the ability of our reinsurers to pay reinsurance recoverables owed to us; other legislative and regulatory developments, including those related to business practices in the insurance industry; credit risk related to our policyholders, independent agents and brokers; changes in the ratings assigned to us or our insurance company subsidiaries by rating agencies; the availability of dividends from our insurance company subsidiaries; potential difficulties with technology and/or data security; the effectiveness of our controls to ensure compliance with guidelines, policies and legal and regulatory standards; and other risks detailed from time to time in the Company’s filings with the Securities and Exchange Commission. These risks and uncertainties could cause our actual results for the year 2016 and beyond to differ materially from those expressed in any forward-looking statement we make. Any projections of growth in our revenues would not necessarily result in commensurate levels of earnings. Our future financial performance is dependent upon factors discussed in our Annual Report on Form 10-K, elsewhere in this Form 10-Q and our other SEC filings. Forward-looking statements speak only as of the date on which they are made. Except to the extent required by applicable laws, the Company does not undertake any obligation to update or revise any forward-looking statement, whether as a result of new information, future developments or otherwise.

24

Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations

Overview

W. R. Berkley Corporation is an insurance holding company that is among the largest commercial lines writers in the United States and operates in two business segments: Insurance and Reinsurance. Our decentralized structure provides us with the flexibility to respond quickly and efficiently to local or specific market conditions and to pursue specialty business niches. It also allows us to be closer to our customers in order to better understand their individual needs and risk characteristics. While providing our business units with certain operating autonomy, our structure allows us to capitalize on the benefits of economies of scale through centralized capital, investment, reinsurance, enterprise risk management, and actuarial, financial and corporate legal staff support. The Company’s primary sources of revenues and earnings are its insurance operations and its investments.

An important part of our strategy is to form new operating units to capitalize on various business opportunities. Over the years, the Company has formed numerous operating units that are focused on important parts of the economy in the U.S., including high net worth personal lines, healthcare, energy and agriculture, and on growing international markets, including Scandinavia, Australia, the Asia-Pacific region, South America and South Africa.

The profitability of the Company’s insurance business is affected primarily by the adequacy of premium rates. The ultimate adequacy of premium rates is not known with certainty at the time an insurance policy is issued because premiums are determined before claims are reported. The ultimate adequacy of premium rates is affected mainly by the severity and frequency of claims, which are influenced by many factors, including natural and other disasters, regulatory measures and court decisions that define and change the extent of coverage and the effects of economic inflation on the amount of compensation for injuries or losses. General insurance prices are also influenced by available insurance capacity, i.e., the level of statutory capital and surplus employed in the industry, and the industry’s willingness to deploy that capital.

Although insurance prices have generally increased for most lines of business since 2011, the rate of increase has declined in more recent years. Loss costs have also increased over that period of time. With the low level of interest rates available, current price levels for certain lines of business remain below the prices required for the Company to achieve its long-term return objectives. Part of the Company's strategy is to selectively reduce its business in areas where it believes returns are not adequate. Price changes are reflected in the Company’s results over time as premiums are earned.

The Company’s profitability is also affected by its investment income and investment gains. The Company’s invested assets are invested principally in fixed maturity securities. The return on fixed maturity securities is affected primarily by general interest rates, as well as the credit quality and duration of the securities. Returns available on fixed maturity investments are at historically low levels. The Company's investment income has been negatively impacted by the low fixed maturity investment returns, and will be further impacted if investment returns remain at this level.

The Company invests in equity securities, merger arbitrage securities, investment funds (including energy related funds), private equity, loans and real estate related assets. The Company's investments in investment funds and its other alternative investments have experienced, and the Company expects to continue to experience, greater fluctuations in investment income.

Given the persistently low rate environment, investing for total return including realized gains is an important part of our investment strategy. These gains cause variability in the Company's quarterly results, but have enhanced overall return. In July 2016, the Company sold a wholly-owned investment, Aero Precision Industries, and certain related aviation services businesses and recognized a realized investment gain of $134.9 million. In October 2016, the Company sold approximately 2.2 million shares in HealthEquity, Inc. (HQY) and recognized a realized investment gain of approximately $65 million. Following the completion of the sale, the Company will report its investment in HQY at fair value.

Commencing with the first quarter of 2016, the Company changed the aggregation of its business segments. Operating units in the Insurance-Domestic segment and Insurance-International segment, were combined into the Insurance segment. The segment disclosures for prior periods have been revised to be consistent with the new reportable business segment presentation.

25

Critical Accounting Estimates

The following presents a discussion of accounting policies and estimates relating to reserves for losses and loss expenses, assumed premiums and other-than-temporary impairments of investments. Management believes these policies and estimates are the most critical to its operations and require the most difficult, subjective and complex judgments.

Reserves for Losses and Loss Expenses.To recognize liabilities for unpaid losses, either known or unknown, insurers establish reserves, which is a balance sheet account representing estimates of future amounts needed to pay claims and related expenses with respect to insured events which have occurred. Estimates and assumptions relating to reserves for losses and loss expenses are based on complex and subjective judgments, often including the interplay of specific uncertainties with related accounting and actuarial measurements. Such estimates are also susceptible to change as significant periods of time may elapse between the occurrence of an insured loss, the report of the loss to the insurer, the ultimate determination of the cost of the loss and the insurer’s payment of that loss.

In general, when a claim is reported, claims personnel establish a “case reserve” for the estimated amount of the ultimate payment based upon known information about the claim at that time. The estimate represents an informed judgment based on general reserving practices and reflects the experience and knowledge of the claims personnel regarding the nature and value of the specific type of claim. Reserves are also established on an aggregate basis to provide for losses incurred but not reported (“IBNR”) to the insurer, potential inadequacy of case reserves and the estimated expenses of settling claims, including legal and other fees and general expenses of administrating the claims adjustment process. Reserves are established based upon the then current legal interpretation of coverage provided.

In examining reserve adequacy, several factors are considered in estimating the ultimate economic value of losses. These factors include, among other things, historical data, legal developments, changes in social attitudes and economic conditions, including the effects of inflation. The actuarial process relies on the basic assumption that past experience, adjusted judgmentally for the effects of current developments and anticipated trends, is an appropriate basis for predicting future outcomes. Reserve amounts are based on management’s informed estimates and judgments using currently available data. As additional experience and other data become available and are reviewed, these estimates and judgments may be revised. This may result in reserve increases or decreases that would be reflected in our results in periods in which such estimates and assumptions are changed.

Reserves do not represent an exact calculation of liability. Rather, reserves represent an estimate of what management expects the ultimate settlement and claim administration will cost. While the methods for establishing reserves are well tested over time, some of the major assumptions about anticipated loss emergence patterns are subject to uncertainty. These estimates, which generally involve actuarial projections, are based on management’s assessment of facts and circumstances then known, as well as estimates of trends in claims severity and frequency, judicial theories of liability and other factors, including the actions of third parties which are beyond the Company’s control. These variables are affected by external and internal events, such as inflation and economic volatility, judicial and litigation trends, reinsurance coverage, legislative changes and claim handling and reserving practices, which make it more difficult to accurately predict claim costs. The inherent uncertainties of estimating reserves are greater for certain types of liabilities where long periods of time elapse before a definitive determination of liability is made. Because setting reserves is inherently uncertain, the Company cannot provide assurance that its current reserves will prove adequate in light of subsequent events.

Loss reserves included in the Company’s financial statements represent management’s best estimates based upon an actuarially derived point estimate and other considerations. The Company uses a variety of actuarial techniques and methods to derive an actuarial point estimate for each operating unit. These methods include paid loss development, incurred loss development, paid and incurred Bornhuetter-Ferguson methods and frequency and severity methods. In circumstances where one actuarial method is considered more credible than the others, that method is used to set the point estimate. For example, the paid loss and incurred loss development methods rely on historical paid and incurred loss data. For new lines of business, where there is insufficient history of paid and incurred claims data, or in circumstances where there have been significant changes in claim practices, the paid and incurred loss development methods would be less credible than other actuarial methods. The actuarial point estimate may also be based on a judgmental weighting of estimates produced from each of the methods considered. Industry loss experience is used to supplement the Company’s own data in selecting “tail factors” and in areas where the Company’s own data is limited. The actuarial data is analyzed by line of business, coverage and accident or policy year, as appropriate, for each operating unit.

The establishment of the actuarially derived loss reserve point estimate also includes consideration of qualitative factors that may affect the ultimate losses. These qualitative considerations include, among others, the impact of re-underwriting initiatives, changes in the mix of business, changes in distribution sources and changes in policy terms and conditions. Examples of changes in terms and conditions that can have a significant impact on reserve levels are the use of aggregate policy limits, the expansion of coverage exclusions, whether or not defense costs are within policy limits, and changes in deductibles and attachment points.

26

The key assumptions used to arrive at the best estimate of loss reserves are the expected loss ratios, rate of loss cost inflation, and reported and paid loss emergence patterns. Expected loss ratios represent management’s expectation of losses at the time the business is written, before any actual claims experience has emerged. This expectation is a significant determinant of the estimate of loss reserves for recently written business where there is little paid or incurred loss data to consider. Expected loss ratios are generally derived from historical loss ratios adjusted for the impact of rate changes, loss cost trends and known changes in the type of risks underwritten. Expected loss ratios are estimated for each key line of business within each operating unit. Expected loss cost inflation is particularly important for the long-tail lines, such as excess casualty, and claims with a high medical component, such as workers’ compensation. Reported and paid loss emergence patterns are used to project current reported or paid loss amounts to their ultimate settlement value. Loss development factors are based on the historical emergence patterns of paid and incurred losses, and are derived from the Company’s own experience and industry data. The paid loss emergence pattern is also significant to excess and assumed workers’ compensation reserves because those reserves are discounted to their estimated present value based upon such estimated payout patterns. Management believes the estimates and assumptions it makes in the reserving process provide the best estimate of the ultimate cost of settling claims and related expenses with respect to insured events which have occurred; however, different assumptions and variables could lead to significantly different reserve estimates.

Loss frequency and severity are measures of loss activity that are considered in determining the key assumptions described in our discussion of loss and loss expense reserves, including expected loss ratios, rate of loss cost inflation and reported and paid loss emergence patterns. Loss frequency is a measure of the number of claims per unit of insured exposure, and loss severity is a measure of the average size of claims. Factors affecting loss frequency include the effectiveness of loss controls and safety programs and changes in economic activity or weather patterns. Factors affecting loss severity include changes in policy limits, retentions, rate of inflation and judicial interpretations.

Another factor affecting estimates of loss frequency and severity is the loss reporting lag, which is the period of time between the occurrence of a loss and the date the loss is reported to the Company. The length of the loss reporting lag affects our ability to accurately predict loss frequency (loss frequencies are more predictable for lines with short reporting lags) as well as the amount of reserves needed for incurred but not reported losses (less IBNR is required for lines with short reporting lags). As a result, loss reserves for lines with short reporting lags are likely to have less variation from initial loss estimates. For lines with short reporting lags, which include commercial automobile, primary workers’ compensation, other liability (claims-made) and property business, the key assumption is the loss emergence pattern used to project ultimate loss estimates from known losses paid or reported to date. For lines of business with long reporting lags, which include other liability (occurrence), products liability, excess workers’ compensation and liability reinsurance, the key assumption is the expected loss ratio since there is often little paid or incurred loss data to consider. Historically, the Company has experienced less variation from its initial loss estimates for lines of businesses with short reporting lags than for lines of business with long reporting lags.

The key assumptions used in calculating the most recent estimate of the loss reserves are reviewed each quarter and adjusted, to the extent necessary, to reflect the latest reported loss data, current trends and other factors observed. If the actual level of loss frequency and severity are higher or lower than expected, the ultimate losses will be different than management’s estimate. The following table reflects the impact of changes (which could be favorable or unfavorable) in frequency and severity, relative to our assumptions, on our loss estimate for claims occurring in 2015:

(In thousands)	Frequency (+/-)
Severity (+/-)	1%		5%		10%
1%	$	73,437	$	221,040	$	405,545
5%	221,040		374,490		566,302
10%	405,545		566,302		767,248

Our net reserves for losses and loss expenses of approximately $9.5 billion as of September 30, 2016 relate to multiple accident years. Therefore, the impact of changes in frequency or severity for more than one accident year could be higher or lower than the amounts reflected above. The impact of such changes would likely be manifested gradually over the course of many years, as the magnitude of the changes became evident.

Approximately $1.4 billion, or 15%, of the Company’s net loss reserves as of September 30, 2016 relate to the Reinsurance segment. There is a higher degree of uncertainty and greater variability regarding estimates of assumed loss reserves because those estimates are based, in part, upon information received from ceding companies. If information received from ceding companies is not timely or correct, the Company’s estimate of ultimate losses may not be accurate. Furthermore, due to delayed reporting of claim information by ceding companies, the claim settlement tail for assumed reinsurance is extended. Management considers the impact of delayed reporting in its selection of assumed loss development factors.

27

Information received from ceding companies is used to set initial expected loss ratios, to establish case reserves and to estimate reserves for incurred but not reported losses on assumed reinsurance business. This information, which is generally provided through reinsurance intermediaries, is gathered through the underwriting process and from periodic claim reports and other correspondence with ceding companies. The Company performs underwriting and claim audits of selected ceding companies to determine the accuracy and completeness of information provided to the Company. The information received from the ceding companies is supplemented by the Company’s own loss development experience with similar lines of business as well as industry loss trends and loss development benchmarks.

Following is a summary of the Company’s reserves for losses and loss expenses by business segment:

(In thousands)	September 30, 2016		December 31, 2015
Insurance	$	8,143,250	$	7,876,193
Reinsurance	1,403,626		1,368,679
Net reserves for losses and loss expenses	9,546,876		9,244,872
Ceded reserves for losses and loss expenses	1,550,954		1,424,278
Gross reserves for losses and loss expenses	$	11,097,830	$	10,669,150

Following is a summary of the Company’s net reserves for losses and loss expenses by major line of business:

(In thousands)	Reported Case Reserves		Incurred But Not Reported		Total
September 30, 2016
Other liability	$	1,187,601	$	2,054,841	$	3,242,442
Workers’ compensation (1)	1,593,772		1,330,303		2,924,075
Professional liability	256,005		474,940		730,945
Short-tail lines (2)	339,852		291,692		631,544
Commercial automobile	359,455		254,789		614,244
Total Insurance	3,736,685		4,406,565		8,143,250
Reinsurance (1)	686,218		717,408		1,403,626
Total	$	4,422,903	$	5,123,973	$	9,546,876
December 31, 2015
Other liability	$	1,079,641	$	1,947,637	$	3,027,278
Workers’ compensation (1)	1,655,726		1,263,508		2,919,234
Professional liability	256,783		478,796		735,579
Short-tail lines (2)	317,375		282,448		599,823
Commercial automobile	352,208		242,071		594,279
Total Insurance	3,661,733		4,214,460		7,876,193
Reinsurance (1)	631,666		737,013		1,368,679
Total	$	4,293,399	$	4,951,473	$	9,244,872

___________

(1) Reserves for workers’ compensation and reinsurance are net of an aggregate net discount of $652 million and $699 million as of September 30, 2016 and December 31, 2015, respectively.

(2) Short-tail lines include commercial multi-peril (non-liability), inland marine, accident and health, fidelity and surety, boiler and machinery and other lines.

The Company evaluates reserves for losses and loss adjustment expenses on a quarterly basis. Changes in estimates of prior year losses are reported when such changes are made. The changes in prior year loss reserve estimates are generally the result of ongoing analysis of recent loss development trends. Original estimates are increased or decreased as additional information becomes known regarding individual claims and aggregate claim trends.

Certain of the Company's insurance and reinsurance contracts are retrospectively rated, whereby the Company collects more or less premiums based on the level of loss activity. For those contracts, changes in loss and loss adjustment expenses for prior years may be fully or partially offset by additional or return premiums.

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Net prior year development (i.e. the sum of prior year reserve changes and prior year earned premiums changes) for the nine months ended September 30, 2016 and 2015 are as follows:

(In thousands)	2016		2015
Net decrease in prior year loss reserves	$	23,518	$	39,095
Increase in prior year earned premiums	18,039		9,733
Net favorable prior year development	$	41,557	$	48,828

In 2016, favorable prior year development (net of additional and return premiums) of $42 million included $38 million for the Insurance segment and $4 million for the Reinsurance segment. The favorable development for the Insurance segment was primarily attributable to workers' compensation business, partially offset by adverse development for commercial auto liability and medical and other professional liability. The favorable development for workers' compensation stems from accident years 2003 through 2015, but is concentrated in accident years 2014 and 2015; it reflects claims frequency trends (i.e., number of reported claims per unit of exposure) that continue to be better than we expected. The unfavorable development for commercial auto liability was driven by higher large loss activity than expected in accident years 2014 and 2015, and the unfavorable development for medical professional liability was primarily in accident years prior to 2013 and stemmed from a class of medical professional liability business that we discontinued writing in 2013.

In 2015, favorable prior year development (net of additional and return premiums) was $49 million, and included $41 million for the Insurance segment and $8 million for the Reinsurance segment. The favorable development for the Insurance segment was primarily attributable to excess and surplus lines casualty business from accident years 2009 through 2014, partially offset by adverse development in commercial auto liability from accident years 2011 through 2014. The favorable development for excess and surplus lines reflects the continuation of favorable claim frequency trends (i.e., number of reported claims per unit of exposure), while the unfavorable development for commercial auto liability is driven by higher large loss activity.

Reserve Discount. The Company discounts its liabilities for certain workers’ compensation reserves. The amount of workers’ compensation reserves that were discounted was $1,930 million and $2,308 million at September 30, 2016 and December 31, 2015, respectively. The aggregate net discount for those reserves, after reflecting the effects of ceded reinsurance, was $652 million and $699 million at September 30, 2016 and December 31, 2015, respectively. At September 30, 2016, discount rates by year ranged from 1.8% to 6.5%, with a weighted average discount rate of 3.9%.

         Substantially all of the workers’ compensation discount (97% at September 30, 2016) relates to excess workers’ compensation reserves. In order to properly match loss expenses with income earned on investment securities supporting the liabilities, reserves for excess workers’ compensation business are discounted using risk-free discount rates determined by reference to the U.S. Treasury yield curve. These rates are determined annually based on the weighted average rate for the period. Once established, no adjustments are made to the discount rate for that period, and any increases or decreases in loss reserves in subsequent years are discounted at the same rate, without regard to when any such adjustments are recognized. The expected loss and loss expense payout patterns subject to discounting are derived from the Company’s loss payout experience.  

    The Company also discounts reserves for certain other long-duration workers’ compensation reserves (representing approximately 3% of total discounted reserves at September 30, 2016), including reserves for quota share reinsurance and reserves related to losses regarding occupational lung disease. These reserves are discounted at statutory rates permitted by the Department of Insurance of the State of Delaware.

Assumed Reinsurance Premiums. The Company estimates the amount of assumed reinsurance premiums that it will receive under treaty reinsurance agreements at the inception of the contracts. These premium estimates are revised as the actual amount of assumed premiums is reported to the Company by the ceding companies. As estimates of assumed premiums are made or revised, the related amount of earned premiums, commissions and incurred losses associated with those premiums are recorded. Estimated assumed premiums receivable were approximately $68 million at September 30, 2016 and $62 million at December 31, 2015. The assumed premium estimates are based upon terms set forth in reinsurance agreements, information received from ceding companies during the underwriting and negotiation of agreements, reports received from ceding companies and discussions and correspondence with reinsurance intermediaries. The Company also considers its own view of market conditions, economic trends and experience with similar lines of business. These premium estimates represent management’s best estimate of the ultimate amount of premiums to be received under its assumed reinsurance agreements.

Other-Than-Temporary Impairments (OTTI) of Investments. The cost of securities is adjusted where appropriate to include a provision for decline in value which is considered to be other-than-temporary. An other-than-temporary decline is

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considered to occur in investments where there has been a sustained reduction in fair value and where the Company does not expect the fair value to recover prior to the time of sale or maturity. Since equity securities do not have a contractual cash flow or maturity, the Company considers whether the price of an equity security is expected to recover within a reasonable period of time.

The Company classifies its fixed maturity securities and preferred stocks by credit rating, primarily based on ratings assigned by credit rating agencies. For purposes of classifying securities with different ratings, the Company uses the lower rating if two ratings were assigned and the middle rating if three ratings were assigned, unless the Company’s own analysis indicates that the lower rating is more appropriate. Securities that are not rated by a rating agency are evaluated and classified by the Company on a case-by-case basis.

Fixed Maturity Securities – For securities that we intend to sell or, more likely than not, would be required to sell, a decline in value below amortized cost is considered to be OTTI. The amount of OTTI is equal to the difference between amortized cost and fair value at the balance sheet date. For securities that we do not intend to sell or expect to be required to sell, a decline in value below amortized cost is considered to be an OTTI if we do not expect to recover the entire amortized cost basis of a security (i.e., the present value of cash flows expected to be collected is less than the amortized cost basis of the security).

The portion of the decline in value considered to be a credit loss (i.e., the difference between the present value of cash flows expected to be collected and the amortized cost basis of the security) is recognized in earnings. The portion of the decline in value not considered to be a credit loss (i.e., the difference in the present value of cash flows expected to be collected and the fair value of the security) is recognized in other comprehensive income.

Impairment assessments for structured securities, including mortgage-backed securities and asset-backed securities, collateralized debt obligations and corporate debt, are generally evaluated based on the performance of the underlying collateral under various economic and default scenarios that may involve subjective judgments and estimates by management. Modeling these securities involves various factors, such as projected default rates, the nature and realizable value of the collateral, if any, the ability of the issuer to make scheduled payments, historical performance and other relevant economic and performance factors. If an OTTI determination is made, a discounted cash flow analysis is used to ascertain the amount of the credit impairment.

The following table provides a summary of fixed maturity securities in an unrealized loss position as of September 30, 2016:

($ in thousands)	Number of Securities	Aggregate Fair Value		Gross Unrealized Loss
Unrealized loss less than 20% of amortized cost	351	$	2,442,037	$	28,610
Unrealized loss of 20% or greater of amortized cost:
Less than twelve months	1	185		143
Twelve months and longer	4	17,209		4,976
Total	356	$	2,459,431	$	33,729

A summary of the Company’s non-investment grade fixed maturity securities that were in an unrealized loss position at September 30, 2016 is presented in the table below:

($ in thousands)	Number of Securities	Aggregate Fair Value		Gross Unrealized Loss
Corporate	10	$	27,531	$	3,045
Mortgage-backed securities	11	23,921		1,229
Foreign government	4	23,001		1,101
Asset-backed securities	5	8,418		405
State and municipal	1	7,007		25
Total	31	$	89,878	$	5,805

The Company has evaluated its fixed maturity securities in an unrealized loss position and believes the unrealized loss is due primarily to temporary market and sector-related factors rather than to issuer-specific factors. None of these securities are delinquent or in default under financial covenants. Based on its assessment of these issuers, the Company expects them to continue to meet their contractual payment obligations as they become due and does not consider any of these securities to be

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OTTI. There were no OTTI of fixed maturity securities for the three or nine months ended September 30, 2016. For the three and nine months ended September 30, 2015, OTTI for fixed maturity securities recognized in earnings was $9 million, all of which was considered due to credit factors.

Preferred Stocks– At September 30, 2016, there were three preferred stocks in an unrealized loss position, with an aggregate fair value of $71 million and a gross unrealized loss of $9 million. Based on management's view of the underlying value of these securities, the Company does not consider these equity securities to be OTTI. There were no OTTI of preferred stock for the three and nine months ended September 30, 2016 and 2015.

Common Stocks – At September 30, 2016, there were three common stocks in an unrealized loss position, with an aggregate fair value of $26 million and a gross unrealized loss of $2 million. Based upon management’s view of the underlying value of these securities, the Company does not consider these equity securities to be OTTI. For the nine months ended September 30, 2016, the Company reported OTTI for common stocks of $18.1 million. There was no OTTI of common stocks for the three months ended September 30, 2016. For the three and nine months ended September 30, 2015, OTTI for common stocks was $3.5 million.

Loans Receivable – The Company monitors the performance of its loans receivable, including current market conditions for each loan and the ability to collect principal and interest. For loans where the Company determines it is probable that the contractual terms will not be met, an analysis is performed and a valuation reserve is established, if necessary, with a charge to earnings. Loans receivable are reported net of a valuation reserve of $3 million and $2 million at September 30, 2016 and December 31, 2015, respectively.

The Company monitors the performance of its loans receivable and assesses the ability of each borrower to pay principal and interest based upon loan structure, underlying property values, cash flow and related financial and operating performance of the property and market conditions. Loans receivable with a potential for default are further assessed using discounted cash flow analysis and comparable cost and sales methodologies, if appropriate.

Fair Value Measurements.The Company’s fixed maturity and equity securities available for sale and its trading account securities are carried at fair value. Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” The Company utilizes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for similar assets in active markets. Level 3 inputs are unobservable inputs for the asset or liability. Unobservable inputs may only be used to measure fair value to the extent that observable inputs are not available. The fair value of the vast majority of the Company’s portfolio is based on observable data (other than quoted prices) and, accordingly, is classified as Level 2.

In classifying particular financial securities in the fair value hierarchy, the Company uses its judgment to determine whether the market for a security is active and whether significant pricing inputs are observable. The Company determines the existence of an active market by assessing whether transactions occur with sufficient frequency and volume to provide reliable pricing information. The Company determines whether inputs are observable based on the use of such information by pricing services and external investment managers, the uninterrupted availability of such inputs, the need to make significant adjustments to such inputs and the volatility of such inputs over time. If the market for a security is determined to be inactive or if significant inputs used to price a security are determined to be unobservable, the security is categorized in Level 3 of the fair value hierarchy.

Because many fixed maturity securities do not trade on a daily basis, the Company utilizes pricing models and processes which may include benchmark curves, benchmarking of like securities, sector groupings and matrix pricing. Market inputs used to evaluate securities include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data. Quoted prices are often unavailable for recently issued securities that are infrequently traded or securities that are only traded in private transactions. For publicly traded securities for which quoted prices are unavailable, the Company determines fair value based on independent broker quotations and other observable market data. For securities traded only in private negotiations, the Company determines fair value based primarily on the cost of such securities, which is adjusted to reflect prices of recent placements of securities of the same issuer, financial data, projections and business developments of the issuer and other relevant information.

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The following is a summary of pricing sources for the Company's fixed maturity securities available for sale as of September 30, 2016:

($ in thousands)	Carrying Value		Percent of Total
Pricing source:
Independent pricing services	$	13,277,130	98.1	%
Syndicate manager	54,247		0.4
Directly by the Company based on:
Observable data	196,932		1.5
Cash flow model	185		—
Total	$	13,528,494	100.0	%

Independent pricing services – Substantially all of the Company’s fixed maturity securities available for sale were priced by independent pricing services (generally one U.S. pricing service plus additional pricing services with respect to a limited number of foreign securities held by the Company). The prices provided by the independent pricing services are generally based on observable market data in active markets (e.g., broker quotes and prices observed for comparable securities). The determination of whether markets are active or inactive is based upon the volume and level of activity for a particular asset class. The Company reviews the prices provided by pricing services for reasonableness based upon current trading levels for similar securities. If the prices appear unusual to the Company, they are re-examined and the value is either confirmed or revised. In addition, the Company periodically performs independent price tests of a sample of securities to ensure proper valuation and to verify our understanding of how securities are priced. As of September 30, 2016, the Company did not make any adjustments to the prices provided by the pricing services. Based upon the Company’s review of the methodologies used by the independent pricing services, these securities were classified as Level 2.

Syndicate manager – The Company has a 15% participation in a Lloyd’s syndicate, and the Company’s share of the securities owned by the syndicate is priced by the syndicate’s manager. The majority of the securities are liquid, short duration fixed maturity securities. The Company reviews the syndicate manager’s pricing methodology and audited financial statements and holds discussions with the syndicate manager as necessary to confirm its understanding and agreement with security prices. Based upon the Company’s review of the methodologies used by the syndicate manager, these securities were classified as Level 2.

Observable data – If independent pricing is not available, the Company prices the securities directly. Prices are based on observable market data where available, including current trading levels for similar securities and non-binding quotations from brokers. The Company generally requests two or more quotes. If more than one quote is received, the Company sets a price within the range of quotes received based on its assessment of the credibility of the quote and its own evaluation of the security. The Company generally does not adjust quotes obtained from brokers. Since these securities were priced based on observable data, they were classified as Level 2.

Cash flow model – If the above methodologies are not available, the Company prices securities using a discounted cash flow model based upon assumptions as to prevailing credit spreads, interest rates and interest rate volatility, time to maturity and subordination levels. Discount rates are adjusted to reflect illiquidity where appropriate. These securities were classified as Level 3.

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Results of Operations for the Nine Months Ended September 30,2016 and 2015

Business Segment Results

Following is a summary of gross and net premiums written, net premiums earned, loss ratios (losses and loss expenses incurred expressed as a percentage of premiums earned), expense ratios (underwriting expenses expressed as a percentage of premiums earned) and United States Generally Accepted Accounting Principles (“GAAP”) combined ratios (sum of loss ratio and expense ratio) for each of our business segments for the nine months ended September 30, 2016 and 2015. The GAAP combined ratio represents a measure of underwriting profitability, excluding investment income. A GAAP combined ratio in excess of 100 indicates an underwriting loss; a number below 100 indicates an underwriting profit.

($ in thousands)	2016			2015
Insurance:
Gross premiums written	$	5,212,415		$	5,002,603
Net premiums written	4,410,254			4,238,544
Net premiums earned	4,206,887			4,042,159
Loss ratio	61.1		%	61.0		%
Expense ratio	32.4		%	32.6		%
GAAP combined ratio	93.5		%	93.6		%
Reinsurance:
Gross premiums written	$	551,496		$	483,181
Net premiums written	503,402			451,820
Net premiums earned	466,185			454,453
Loss ratio	60.7		%	58.9		%
Expense ratio	39.0		%	37.8		%
GAAP combined ratio	99.7		%	96.7		%
Consolidated:
Gross premiums written	$	5,763,911		$	5,485,784
Net premiums written	4,913,656			4,690,364
Net premiums earned	4,673,072			4,496,612
Loss ratio	61.0		%	60.8		%
Expense ratio	33.1		%	33.2		%
GAAP combined ratio	94.1		%	94.0		%

Net Income to Common Stockholders. The following table presents the Company’s net income to common stockholders and net income per diluted share for the nine months ended September 30, 2016 and 2015:

(In thousands, except per share data)	2016		2015
Net income to common stockholders	$	449,127	$	393,949
Weighted average diluted shares	128,501		130,563
Net income per diluted share	$	3.50	$	3.02

The Company reported net income of $449 million in 2016 compared to $394 million in 2015. The 14% increase in net income was primarily due to an increase in after-tax net investment gains of $58 million (inclusive of OTTI), an increase in after-tax net investment income of $13 million and an increase in after-tax net foreign currency gains of $5 million, partially offset by an after-tax decrease in insurance service income of $6 million and an after-tax increase in other expenses of $11 million. The number of weighted average diluted shares decreased as a result of the Company’s repurchases of its common stock in 2016 and in 2015.

Premiums. Gross premiums written were $5,764 million in 2016, an increase of 5% from $5,486 million in 2015. The growth was largely due to an increase in new business in the Insurance segment of 11%. Approximately 77% of policies expiring in 2016 were renewed, compared with a 78% renewal retention rate for policies expiring in 2015.

Average renewal premium rates for insurance and facultative reinsurance increased 0.2% in 2016 when adjusted for change in exposures.

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A summary of gross premiums written in 2016 compared with 2015 by line of business within each business segment follows:

• Insurance - gross premiums increased 4% to $5,212 million in 2016 from $5,003 million in 2015. Gross premiums increased $182 million (13%) for other liability, $28 million (2%) for workers' compensation and $45 million (10%) for professional liability, and decreased $33 million (3%) for short-tail lines and $13 million (3%) for commercial auto.

• Reinsurance - gross premiums increased 14% to $552 million in 2016 from $483 million in 2015. Gross premiums increased $68 million (42%) for property lines and $1 million (less than 1%) for casualty lines. The increase in property premiums was primarily due to growth in structured property reinsurance.

Net premiums written were $4,914 million in 2016, an increase of 5% from $4,690 million in 2015. Ceded reinsurance premiums as a percentage of gross written premiums were 14% in both 2016 and in 2015.

Premiums earned increased 4% to $4,673 million in 2016 from $4,497 million in 2015. Insurance premiums (including the impact of rate changes) are generally earned evenly over the policy term, and accordingly, recent rate increases will be earned over the upcoming quarters. Premiums earned in 2016 are related to business written during both 2016 and 2015. Audit premiums were $116 million in 2016 compared with $112 million in 2015.

Net Investment Income. Following is a summary of net investment income for the nine months ended September 30, 2016 and 2015:

	Amount						Average Annualized Yield
($ In thousands)	2016			2015			2016		2015
Fixed maturity securities, including cash and cash equivalents and loans receivable	$	331,448		$	318,095		3.3	%	3.3	%
Investment funds	60,385			50,838			6.6		5.6
Arbitrage trading account	12,883			11,470			4.4		2.7
Real estate	4,552			9,270			0.6		1.6
Equity securities available for sale	3,217			3,513			2.2		2.8
Gross investment income	412,485			393,186			3.3		3.3
Investment expenses	(7,635		)	(8,150		)
Total	$	404,850		$	385,036		3.3	%	3.2	%

Net investment income increased 5% to $405 million in 2016 from $385 million in 2015 due primarily to a $13 millionincrease in income from fixed maturity securities and a $10 million increase in investment funds, partially offset by a decrease in income from real estate of $5 million. The increase in investment income from investment funds (reported on a one-quarter lag) was primarily due to improvement in the performance for energy funds, partially offset by a decrease in real estate funds. Average invested assets, at cost (including cash and cash equivalents), were $17.0 billion in 2016 and $15.9 billion in 2015.

Insurance Service Fees. The Company earns fees from an insurance distribution business and as a servicing carrier of workers' compensation assigned risk plans for certain states. Service fees increased to $109 million in 2016 from $108 million in 2015.

Net Realized Gains on Investment Sales. The Company buys and sells securities on a regular basis in order to maximize its total return on investments. Decisions to sell securities are based on management’s view of the underlying fundamentals of specific securities as well as management’s expectations regarding interest rates, credit spreads, currency values and general economic conditions. Net realized gains on investment sales were $208 million in 2016 compared with $113 million in 2015. The increase primarily relates to the sale of Aero Precision Industries.

Other-Than-Temporary Impairments. Other-than-temporary impairments of $18.1 million in 2016 were related to common stocks. Other-than-temporary impairments of $12.5 million in 2015 were related to fixed maturity securities ($9.0 million) and common stock ($3.5 million).

Revenues from Non-Insurance Businesses. Revenues from non-insurance businesses were derived from a business engaged in the distribution of promotional merchandise and aviation-related businesses that provide services to aviation markets, including (i) the distribution, manufacturing, repair and overhaul of aircraft parts and components, (ii) the sale of new

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and used aircraft, and (iii) avionics, fuel, maintenance, storage and charter services. Revenues from non-insurance businesses were $306 million in 2016 and $305 million in 2015.

Losses and Loss Expenses. Losses and loss expenses increased to $2,852 million in 2016 from $2,733 million in 2015. The consolidated loss ratio was 61.0% in 2016 and 60.8% in 2015. Catastrophe losses, net of reinsurance recoveries and reinstatement premiums, were $68 million in 2016 and $46 million in 2015. Favorable prior year reserve development (net of premium offsets) was $42 million in 2016 and $49 million in 2015. The loss ratio excluding catastrophe losses and prior year reserve development decreased 0.5 points to 60.4% in 2016 from 60.9% in 2015.

A summary of loss ratios in 2016 compared with 2015 by business segment follows:

• Insurance - The loss ratio was 61.1% in 2016 and 61.0% in 2015. Catastrophe losses were $58 million in 2016 compared with $43 million in 2015. Favorable prior year reserve development was $38 million in 2016 and $41 million in 2015. The loss ratio excluding catastrophe losses and prior year reserve development decreased 0.3 points to 60.6% in 2016 from 60.9% in 2015.

• Reinsurance - The loss ratio of 60.7% in 2016 was 1.8 points higher than the loss ratio of 58.9% in 2015. Catastrophe losses were $10 million in 2016 compared with $3 million in 2015. Favorable prior year reserve development was $4 million in 2016 compared with $8 million in 2015. The loss ratio excluding catastrophe losses and prior year reserve development decreased 0.6 points to 59.4% in 2016 from 60.0% in 2015.

Other Operating Costs and Expenses. Following is a summary of other operating costs and expenses:

(In thousands)	2016			2015
Underwriting expenses	$	1,544,792		$	1,491,109
Service expenses	103,868			93,314
Net foreign currency gains	(11,547		)	(3,234		)
Other costs and expenses	133,337			116,980
Total	$	1,770,450		$	1,698,169

Underwriting expenses are comprised of commissions paid to agents and brokers, premium taxes and other assessments and internal underwriting costs. Underwriting expenses increased 4% compared with an increase in net premiums earned of 4%. The expense ratio (underwriting expenses expressed as a percentage of premiums earned) was 33.2% for the nine months ended September 30, 2016 and 2015.

Service expenses, which represent the costs associated with the fee-based businesses, increased to $104 million in 2016 from $93 million in 2015.

Net foreign currency gains result from transactions denominated in a currency other than a company's operating functional currency. Net foreign currency gains were $12 million in 2016 compared to $3 million in 2015.

Other costs and expenses represent general and administrative expenses of the parent company and other expenses not allocated to business segments, including the cost of certain long-term incentive plans and new business ventures. Other costs and expenses increased to $133 million in 2016 from $117 million in 2015.

Expenses from Non-Insurance Businesses. Expenses from non-insurance businesses represent costs associated with a business engaged in the distribution of promotional merchandise and aviation-related businesses that include (i) cost of goods sold related to aircraft and products sold and services provided, and (ii) general and administrative expenses. Expenses from non-insurance businesses were $291 million in 2016 compared to $289 million in 2015.

Interest Expense. Interest expense was $104 million in 2016 compared with $99 million in 2015. During 2016, the Company repaid $83 million of debt on various issuances, mainly in connection with the sale of Aero Precision Industries. The Company repaid $200 million of 5% senior notes at maturity on May 15, 2015. In February 2016, the Company issued $110 million of 5.9% subordinated debentures maturing in 2056, and in May 2016, the Company issued $290 million of 5.75% subordinated debentures maturing in 2056.

Income Taxes. The effective income tax rate was 32% in both 2016 and 2015. The effective income tax rate differs from the federal income tax rate of 35% primarily because of tax-exempt investment income.

The Company has not provided U.S. deferred income taxes on the undistributed earnings of approximately $69 million of its non-U.S. subsidiaries since these earnings are intended to be permanently reinvested in the non-U.S. subsidiaries. However,

35

in the future, if such earnings were distributed to the Company, taxes of approximately $8 million, assuming all tax credits are realized, would be payable on such undistributed earnings and would be reflected in the tax provision for the year in which these earnings are no longer intended to be permanently reinvested in the foreign subsidiary.

Results of Operations for the Three Months Ended September 30,2016 and 2015

Business Segment Results

Following is a summary of gross and net premiums written, net premiums earned, loss ratios (losses and loss expenses incurred expressed as a percentage of premiums earned), expense ratios (underwriting expenses expressed as a percentage of premiums earned) and United States Generally Accepted Accounting Principles (“GAAP”) combined ratios (sum of loss ratio and expense ratio) for each of our business segments for the three months ended September 30, 2016 and 2015. The GAAP combined ratio represents a measure of underwriting profitability, excluding investment income. A GAAP combined ratio in excess of 100 indicates an underwriting loss; a number below 100 indicates an underwriting profit.

($ in thousands)	2016			2015
Insurance:
Gross premiums written	$	1,696,071		$	1,651,246
Net premiums written	1,449,767			1,412,327
Net premiums earned	1,431,664			1,379,501
Loss ratio	60.9		%	60.6		%
Expense ratio	32.4		%	32.6		%
GAAP combined ratio	93.3		%	93.2		%
Reinsurance:
Gross premiums written	$	172,778		$	171,335
Net premiums written	157,598			158,710
Net premiums earned	154,280			152,057
Loss ratio	61.1		%	59.1		%
Expense ratio	38.5		%	39.0		%
GAAP combined ratio	99.6		%	98.1		%
Consolidated:
Gross premiums written	$	1,868,849		$	1,822,581
Net premiums written	1,607,365			1,571,037
Net premiums earned	1,585,944			1,531,558
Loss ratio	60.9		%	60.5		%
Expense ratio	33.0		%	33.2		%
GAAP combined ratio	93.9		%	93.7		%

Net Income to Common Stockholders. The following table presents the Company’s net income to common stockholders and net income per diluted share for the three months ended September 30, 2016 and 2015:

(In thousands, except per share data)	2016		2015
Net income to common stockholders	$	220,650	$	152,607
Weighted average diluted shares	128,556		128,947
Net income per diluted share	$	1.72	$	1.18

The Company reported net income of $221 million in 2016 compared to $153 million in 2015. The 45% increase in net income was primarily due to an increase in after-tax net investment gains of $79 million and an increase in after-tax net investment income of $8 million, partially offset by a decrease in after-tax income from non-insurance businesses of $3 million, a decrease in after-tax service fee income of $4 million, an after-tax increase in interest expense of $4 million and an after-tax increase in other expenses of $8 million. The number of weighted average diluted shares decreased as a result of the Company’s repurchases of its common stock in 2016 and 2015.

Premiums. Gross premiums written were $1,869 million in 2016, an increase of 3% from $1,823 million in 2015. The growth was largely due to an increase in new business in the Insurance segment of 9%. Approximately 77% of policies expiring in 2016 were renewed, compared with a 78% renewal retention rate for policies expiring in 2015.

Average renewal premium rates for insurance and facultative reinsurance decreased 0.2% in 2016 when adjusted for change in exposures.

36

A summary of gross premiums written in 2016 compared with 2015 by line of business within each business segment follows:

• Insurance - gross premiums increased 3% to $1,696 million in 2016 from $1,651 million in 2015. Gross premiums increased $61 million (12%) for other liability and $16 million (10%) for professional liability, and decreased $10 million (2%) for workers' compensation, $17 million (4%) for short tail lines, and $5 million (3%) for commercial auto.

• Reinsurance - gross premiums increased 1% to $173 million in 2016 from $171 million in 2015. Gross premiums increased $14 million (24%) for property lines and decreased $12 million (11%) for casualty lines. The increase in property premiums was primarily due to growth in structured property reinsurance.

Net premiums written were $1,607 million in 2016, an increase of 2% from $1,571 million in 2015. Ceded reinsurance premiums as a percentage of gross written premiums were 14% in both 2016 and 2015.

Premiums earned increased 4% to $1,586 million in 2016 from $1,532 million in 2015. Insurance premiums (including the impact of rate changes) are generally earned evenly over the policy term. Premiums earned in 2016 are related to business written during both 2016 and 2015. Audit premiums were $35 million in 2016 compared with $39 million in 2015.

Net Investment Income. Following is a summary of net investment income for the three months ended September 30, 2016 and 2015:

	Amount						Average Annualized Yield
($ In thousands)	2016			2015			2016		2015
Fixed maturity securities, including cash and cash equivalents and loans receivable	$	114,271		$	104,936		3.3	%	3.2	%
Investment funds	25,293			22,926			8.1		7.9
Arbitrage trading account	6,441			2,608			5.6		2.1
Real estate	585			4,389			0.2		2.1
Equity securities available for sale	1,069			1,109			2.0		2.6
Gross investment income	147,659			135,968			3.5		3.4
Investment expenses	(1,991		)	(2,754		)
Total	$	145,668		$	133,214		3.4	%	3.3	%

Net investment income increased 9% to $146 million in 2016 from $133 million in 2015 due primarily to a $9 million increase from fixed maturity securities, a $4 million increase in income from the arbitrage trading account and a $2 million increase from investment funds, partially offset by a decrease in real estate of $4 million. Average invested assets, at cost (including cash and cash equivalents), were $17.0 billion in 2016 and $15.9 billion in 2015.

Insurance Service Fees. The Company earns fees from an insurance distribution business and as a servicing carrier of workers' compensation assigned risk plans for certain states. Service fees decreased to $32 million in 2016 from $35 million in 2015.

Net Realized Gains on Investment Sales. The Company buys and sells securities on a regular basis in order to maximize its total return on investments. Decisions to sell securities are based on management’s view of the underlying fundamentals of specific securities as well as management’s expectations regarding interest rates, credit spreads, currency values and general economic conditions. Net realized gains on investment sales were $176 million in 2016 compared with $66 million in 2015, with the increase mainly relating to the sale of Aero Precision Industries.

Other-Than-Temporary Impairments. There were no other-than-temporary impairments during the three months ended September 30, 2016. Other-than-temporary impairments of $12.5 million during the three months ended September 30, 2015 were related to fixed maturity securities ($9.0 million) and common stock ($3.5 million).

Revenues from Non-Insurance Businesses. Revenues from non-insurance businesses were derived from a business engaged in the distribution of promotional merchandise and aviation-related businesses that provide services to aviation markets, including (i) the distribution, manufacturing, repair and overhaul of aircraft parts and components, (ii) the sale of new and used aircraft, and (iii) avionics, fuel, maintenance, storage and charter services. Revenues from non-insurance businesses were $80 million in 2016 and $107 million in 2015. The decrease was primarily related to the sale of Aero Precision Industries during the quarter.

37

Losses and Loss Expenses. Losses and loss expenses increased to $966 million in 2016 from $926 million in 2015. The consolidated loss ratio was 60.9% in 2016 and 60.5% in 2015. Catastrophe losses, net of reinsurance recoveries and reinstatement premiums, were $12 million in 2016 and $7 million in 2015. Favorable prior year reserve development (net of premium offsets) was $13 million in 2016 and $15 million 2015. The loss ratio, excluding catastrophe losses and prior year reserve development, decreased 0.1 points to 60.9% in 2016 from 61.0% in 2015.

A summary of loss ratios in 2016 compared with 2015 by business segment follows:

• Insurance - The loss ratio of 60.9% in 2016 was 0.3 points higher than the loss ratio of 60.6% in 2015. Catastrophe losses were $9 million in 2016 compared with $7 million in 2015. Favorable prior year reserve development was $13 million in 2016 and $10 million in 2015. The loss ratio, excluding catastrophe losses and prior year reserve development, increased 0.4 points to 61.2% in 2016 from 60.8% in 2015.

• Reinsurance - The loss ratio of 61.1% in 2016 was 2.0 points higher than the loss ratio of 59.1% in 2015. Catastrophe losses were $3 million in 2016 compared with $1 million in 2015. Favorable prior year reserve development was $0 in 2016 compared with $5 million in 2015. The loss ratio, excluding catastrophe losses and prior year reserve development, decreased 2.8 points to 59.0% in 2016 from 61.8% in 2015.

Other Operating Costs and Expenses. Following is a summary of other operating costs and expenses:

(In thousands)	2016			2015
Underwriting expenses	$	523,254		$	508,815
Service expenses	32,441			29,856
Net foreign currency gains	(2,193		)	(5,743		)
Other costs and expenses	52,846			40,613
Total	$	606,348		$	573,541

Underwriting expenses are comprised of commissions paid to agents and brokers, premium taxes and other assessments and internal underwriting costs. Underwriting expenses increased 3% compared with an increase in net premiums earned of 4%. The expense ratio (underwriting expenses expressed as a percentage of premiums earned) decreased to 33.0% from 33.2% in 2015.

Service expenses, which represent the costs associated with the fee-based businesses, increased to $32 million in 2016 from $30 million in 2015.

Net foreign currency gains result from transactions denominated in a currency other than a company's operating functional currency. Net foreign currency gains were $2 million in 2016 compared to $6 million in 2015.

Other costs and expenses represent general and administrative expenses of the parent company and other expenses not allocated to business segments, including the cost of certain long-term incentive plans and new business ventures. Other costs and expenses increased to $53 million in 2016 from $41 million in 2015.

Expenses from Non-Insurance Businesses. Expenses from non-insurance businesses represent costs associated with a business engaged in the distribution of promotional merchandise and aviation-related businesses that include (i) cost of goods sold related to aircraft and products sold and services provided, and (ii) general and administrative expenses. Expenses from non-insurance businesses were $79 million in 2016 compared to $101 million in 2015, with the decrease primarily related to the sale of Aero Precision Industries during the quarter.

Interest Expense. Interest expense was $37 million in 2016 compared with $32 million in 2015. During 2016, the Company repaid $83 million of debt on various issuances, mainly in connection with the sale of Aero Precision Industries. The Company repaid $200 million of 5.60% senior notes at maturity on May 15, 2015. In February 2016, the Company issued $110 million of 5.9% subordinated debentures maturing in 2056, and in May 2016, the Company issued $290 million of 5.75% subordinated debentures maturing in 2056.

Income Taxes. The effective income tax rate was 33% in both 2016 and 2015. The effective income tax rate differs from the federal income tax rate of 35% primarily because of tax-exempt investment income.

The Company has not provided U.S. deferred income taxes on the undistributed earnings of approximately $69 million of its non-U.S. subsidiaries since these earnings are intended to be permanently reinvested in the non-U.S. subsidiaries. However, in the future, if such earnings were distributed to the Company, taxes of approximately $8 million, assuming all tax credits are realized, would be payable on such undistributed earnings and would be reflected in the tax provision for the year in which these earnings are no longer intended to be permanently reinvested in the foreign subsidiary.

38

Investments

As part of its investment strategy, the Company establishes a level of cash and highly liquid short-term and intermediate-term securities that, combined with expected cash flow, it believes is adequate to meet its payment obligations. Due to the historically low fixed maturity investment returns, the Company invests in equity securities, merger arbitrage securities, investment funds, private equity, loans and real estate related assets. The Company's investments in investment funds and its other alternative investments have experienced, and the Company expects to continue to experience, greater fluctuations in investment income.

The Company also attempts to maintain an appropriate relationship between the average duration of the investment portfolio and the approximate duration of its liabilities (i.e., policy claims and debt obligations). The average duration of the fixed maturity portfolio, including cash and cash equivalents, was 3.0 years at September 30, 2016, down 0.3 from 3.3 years at December 31, 2015. The Company’s fixed maturity investment portfolio and investment-related assets as of September 30, 2016 were as follows:

($ in thousands)	Carrying Value		Percent of Total
Fixed maturity securities:
U.S. government and government agencies	$	554,993	3.1	%
State and municipal:
Special revenue	2,853,455		16.1
State general obligation	595,227		3.4
Pre-refunded (1)	399,021		2.3
Local general obligation	396,076		2.2
Corporate backed	389,544		2.2
Total state and municipal	4,633,323		26.2
Mortgage-backed securities:
Agency	905,958		5.1
Residential-Prime	225,754		1.3
Commercial	109,044		0.6
Residential-Alt A	38,818		0.2
Total mortgage-backed securities	1,279,574		7.2
Asset-backed securities	2,268,861		12.8
Corporate:
Industrial	2,275,880		12.9
Financial	1,335,507		7.5
Utilities	210,749		1.2
Other	92,032		0.5
Total corporate	3,914,168		22.1
Foreign government and foreign government agencies	965,752		5.5
Total fixed maturity securities	13,616,671		76.9
Equity securities available for sale:
Preferred stocks	123,304		0.7
Common stocks	35,671		0.2
Total equity securities available for sale	158,975		0.9
Investment funds	1,231,700		7.0
Real estate	1,108,482		6.3
Cash and cash equivalents	873,064		4.9
Arbitrage trading account	602,965		3.4
Loans receivable	113,996		0.6
Total investments	$	17,705,853	100.0	%

________________________

(1) Pre-refunded securities are securities for which an escrow account has been established to fund the remaining payments of principal and interest through maturity. Such escrow accounts are funded almost exclusively with U.S. Treasury and U.S. government agency securities.

Fixed Maturity Securities. The Company’s investment policy with respect to fixed maturity securities is generally to purchase instruments with the expectation of holding them to their maturity. However, management of the available for sale

39

portfolio is considered necessary to maintain an approximate matching of assets and liabilities as well as to adjust the portfolio as a result of changes in financial market conditions and tax considerations.

The Company’s philosophy related to holding or selling fixed maturity securities is based on its objective of maximizing total return. The key factors that management considers in its investment decisions as to whether to hold or sell fixed maturity securities are its view of the underlying fundamentals of specific securities as well as its expectations regarding interest rates, credit spreads and currency values. In a period in which management expects interest rates to rise, the Company may sell longer duration securities in order to mitigate the impact of an interest rate rise on the fair value of the portfolio. Similarly, in a period in which management expects credit spreads to widen, the Company may sell lower quality securities, and in a period in which management expects certain foreign currencies to decline in value, the Company may sell securities denominated in those foreign currencies. The sale of fixed maturity securities in order to achieve the objective of maximizing total return may result in realized gains; however, there is no reason to expect these gains to continue in future periods.

At September 30, 2016, investments in foreign government fixed maturity securities (which are generally held by the Company's foreign operations) were as follows:

(In thousands)	Carrying Value
Argentina	$	257,991
Australia	244,658
Canada	167,794
United Kingdom	129,265
Germany	43,069
Brazil	39,459
Norway	34,369
Supranational (1)	33,061
Colombia	6,040
Uruguay	5,158
Singapore	4,888
Total	$	965,752

________

(1) Supranational represents investments in the North American Development Bank, European Investment Bank and International Bank for Reconstruction and Development.

Equity Securities. Equity securities primarily represent investments in high-dividend yielding common and preferred stocks issued by large market capitalization companies.

Investment Funds. At September 30, 2016, the carrying value of investment funds was $1,232 million, including investments in real estate funds of $646 million, energy funds of $81 million, hedge equity funds of $71 million, and other funds of $434 million. Investment funds are generally reported on a one-quarter lag.

Real Estate. Real estate is directly owned property held for investment. At September 30, 2016, real estate properties in operation included a long-term ground lease in Washington D.C, a hotel in Memphis, Tennessee, an office complex in New York City and office buildings in West Palm Beach and Palm Beach, Florida. In addition, there are two properties under development: an office building in London and a mixed-use project in Washington D.C. The Company expects to fund further development costs for these projects with a combination of its own funds and external financing.

Arbitrage Trading Account. The arbitrage trading account is comprised of direct investments in arbitrage securities. Merger arbitrage is the business of investing in the securities of publicly held companies that are the targets in announced tender offers and mergers.

Loans Receivable. Loans receivable, which are carried at amortized cost, had an aggregate cost of $114 million and an aggregate fair value of $117 million at September 30, 2016. The amortized cost of loans receivable is net of a valuation allowance of $3 million as of September 30, 2016. Loans receivable include real estate loans of $96 million that are secured by commercial real estate located primarily in North Carolina, Ohio and New York. Real estate loans receivable generally earn interest at floating LIBOR-based interest rates and have maturities (inclusive of extension options) through August 2025. Loans receivable include commercial loans of $18 million that are secured by business assets and have fixed interest rates with varying maturities not exceeding 10 years.

40

Market Risk. The fair value of the Company’s investments is subject to risks of fluctuations in credit quality and interest rates. The Company uses various models and stress test scenarios to monitor and manage interest rate risk. The Company attempts to manage its interest rate risk by maintaining an appropriate relationship between the effective duration of the investment portfolio and the approximate duration of its liabilities (i.e., policy claims and debt obligations). The effective duration for the fixed maturity portfolio (including cash and cash equivalents) was 3.0 years at September 30, 2016, down 0.3from 3.3 years at December 31, 2015.

In addition, the fair value of the Company’s international investments is subject to currency risk. The Company attempts to manage its currency risk by matching its foreign currency assets and liabilities where considered appropriate.

41

Liquidity and Capital Resources

Cash Flow. Cash flow provided from operating activities increased to $727 million in the first nine months of 2016 from $620 million in the comparable period in 2015.

The Company's insurance subsidiaries' principal sources of cash are premiums, investment income, service fees and proceeds from sales and maturities of portfolio investments. The principal uses of cash are payments for claims, taxes, operating expenses and dividends. The Company expects its insurance subsidiaries to fund the payment of losses with cash received from premiums, investment income and fees. The Company targets an average duration for its investment portfolio that is within one year of the average duration of its liabilities so that portions of its investment portfolio mature throughout the claim cycle and are available for the payment of claims if necessary. In the event operating cash flow and proceeds from maturities and prepayments of fixed income securities are not sufficient to fund claim payments and other cash requirements, the remainder of the Company's cash and investments is available to pay claims and other obligations as they become due. The Company's investment portfolio is highly liquid, with approximately 82% invested in cash, cash equivalents and marketable fixed maturity securities as of September 30, 2016. If the sale of fixed maturity securities were to become necessary, a realized gain or loss equal to the difference between the cost and sales price of securities sold would be recognized.

Debt. At September 30, 2016, the Company had senior notes, subordinated debentures and other debt outstanding with a carrying value of $2,490 million and a face amount of $2,525 million. The maturities of the outstanding debt are $8 million in 2017, $441 million in 2019, $300 million in 2020, $427 million in 2022, $250 million in 2037, $350 million in 2044, $350 million in 2053 and $400 million in 2056.

In February 2016, the Company issued $110 million aggregate principal amount of its 5.9% subordinated debentures due 2056, and in May 2016, the Company issued $290 million aggregate principal amount of its 5.75% subordinated debentures due 2056. During 2016, the Company repaid $83 million of debt on various issuances, mainly in connection with the sale of Areo Precision Industries. In May 2015, the Company repaid $200 million of 5.60% senior notes at maturity and $71 million of mortgage loans.

Equity. At September 30, 2016, total common stockholders’ equity was $4.9 billion, common shares outstanding were approximately 122 million and stockholders’ equity per outstanding share was $40.48. During the nine months ended September 30, 2016, the Company repurchased 1,821,340 shares of its common stock for $99.3 million.

Total Capital.Total capitalization (equity, debt and subordinated debentures) was $7 billion at September 30, 2016. The percentage of the Company’s capital attributable to debt and subordinated debentures was 34% at September 30, 2016 and 32% at December 31, 2015.

Item 3.Quantitative and Qualitative Disclosure About Market Risk

Reference is made to the information under “Investments - Market Risk” under the caption “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in this Form 10-Q.

Item 4.Controls and Procedures

Disclosure Controls and Procedures. The Company’s management, including its Chief Executive Officer and Chief Financial Officer, has conducted an evaluation of the effectiveness of the Company’s disclosure controls and procedures pursuant to Securities Exchange Act Rule 13a-14 as of the end of the period covered by this quarterly report. Based on that evaluation, the Chief Executive Officer and Chief Financial Officer concluded that the Company has in place effective controls and procedures designed to ensure that information required to be disclosed by the Company in the reports it files or submits under the Securities Exchange Act of 1934, as amended, and the rules thereunder, is recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s rules and forms.

Changes in Internal Control over Financial Reporting. During the quarter ended September 30, 2016, there were no changes in the Company’s internal control over financial reporting that have materially affected, or are reasonably likely to materially affect, the Company’s internal control over financial reporting.

PART II — OTHER INFORMATION

Item 1.Legal Proceedings

Please see Note 20 to the notes to the interim consolidated financial statements.

42

Item 1A.Risk Factors

There have been no material changes from the risk factors previously disclosed in the Company’s annual report on Form 10-K for the fiscal year ended December 31, 2015, as updated by its quarterly report on Form 10-Q for the quarterly period ended June 30, 2016.

Item 2.Unregistered Sales of Equity Securities and Use of Proceeds

Set forth below is a summary of the shares repurchased by the Company during the three months ended September 30, 2016 and the number of shares remaining authorized for purchase by the Company:

	Total number of shares purchased	Average price paid per share		Total number of shares purchased as part of publicly announced plans or programs	Maximum number of shares that may yet be purchased under the plans or programs
July 2016	—	—		—	8,512,923
August 2016	110,789	$	57.936	110,789	8,402,134
September 2016	976,496	$	57.376	976,496	7,425,638

Item 6.Exhibits

Number
(31.1)	Certification of the Chief Executive Officer pursuant to Rule 13a-14(a)/ 15d-14(a).
(31.2)	Certification of the Chief Financial Officer pursuant to Rule 13a-14(a)/ 15d-14(a).
(32.1)	Certification of the Chief Executive Officer and Chief Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

43

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this Report to be signed on its behalf by the undersigned thereunto duly authorized.

		W. R. BERKLEY CORPORATION
Date:	November 7, 2016	/s/ W. Robert Berkley, Jr.
		W. Robert Berkley, Jr.
		President and Chief Executive Officer
Date:	November 7, 2016	/s/ Richard M. Baio
		Richard M. Baio
		Senior Vice President - Chief Financial Officer and Treasurer

44

EX-31.1

Exhibit 31.1

CERTIFICATIONS

I, W. Robert Berkley, Jr., President and Chief Executive Officer of W. R. Berkley Corporation (the “registrant”), certify that:

1. I have reviewed this quarterly report on Form 10-Q of the registrant;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: November 7, 2016

/s/ W. Robert Berkley, Jr.

W. Robert Berkley, Jr.

President and

Chief Executive Officer 

EX-31.2

Exhibit 31.2

CERTIFICATIONS

I, Richard M. Baio, Senior Vice President - Chief Financial Officer and Treasurer of W. R. Berkley Corporation (the “registrant”), certify that:

1. I have reviewed this quarterly report on Form 10-Q of the registrant;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: November 7, 2016

/s/ Richard M. Baio

Richard M. Baio

Senior Vice President — Chief Financial Officer and Treasurer

EX-32.1

Exhibit 32.1

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of W. R. Berkley Corporation (the “Company”) on Form 10-Q for the period ended September 30, 2016 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), we, W. Robert Berkley, Jr., President and Chief Executive Officer of the Company, and Richard M. Baio, Senior Vice President - Chief Financial Officer and Treasurer of the Company, certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ W. Robert Berkley, Jr.

W. Robert Berkley, Jr.

President and Chief Executive Officer

/s/ Richard M. Baio

Richard M. Baio

Senior Vice President — Chief Financial Officer and Treasurer

November 7, 2016

A signed original of this written statement required by Section 906 has been provided to W. R. Berkley Corporation (the “Company”) and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.

XML

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Nov. 02, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	BERKLEY W R CORP
Entity Central Index Key	0000011544
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		121,371,880

XML

Consolidated Balance Sheet Consolidated Balance Sheet - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Assets [Abstract]
Fixed maturity securities	$ 13,616,671	$ 12,444,394
Loans receivable	158,975	150,866
Equity securities available for sale	602,965	376,697
Investment funds	1,231,700	1,170,040
Loans receivable	113,996	273,103
Real estate	1,108,482	936,367
Total investments	16,832,789	15,351,467
Cash and cash equivalents	873,064	763,631
Premiums and fees receivable	1,742,210	1,669,186
Due from reinsurers	1,692,779	1,532,829
Prepaid reinsurance premiums	429,850	394,387
Trading account receivables from brokers and clearing organizations	185,548	383,115
Deferred policy acquisition costs	564,663	513,128
Property, furniture and equipment	348,169	348,224
Federal and foreign income taxes	0	48,952
Goodwill	134,146	153,291
Accrued investment income	133,720	123,164
Other assets	408,718	442,782
Total assets	23,345,656	21,724,156
Liabilities:
Reserves for losses and loss expenses	11,097,830	10,669,150
Unearned premiums	3,408,640	3,137,133
Due to reinsurers	261,622	224,752
Trading account securities sold but not yet purchased	60,959	37,035
Deferred Tax Liabilities, Net, Current	96,885	0
Other liabilities	968,019	837,937
Subordinated debentures	727,390	340,320
Senior notes and other debt	1,762,487	1,844,621
Total liabilities	18,383,832	17,090,948
Equity:
Authorized 5,000,000 shares; issued and outstanding - none
Authorized 500,000,000 shares, issued and outstanding, net of treasury shares, 121,684,506 and 123,307,837 shares, respectively	47,024	47,024
Additional paid-in capital	1,027,465	1,005,455
Retained earnings	6,519,536	6,178,070
Accumulated other comprehensive loss	(9,808)	(66,698)
Treasury stock, at cost,113,433,412 and 111,810,081 shares, respectively	2,658,452	2,563,605
Total stockholders’ equity	4,925,765	4,600,246
Noncontrolling interests	36,059	32,962
Total equity	4,961,824	4,633,208
Total liabilities and equity	$ 23,345,656	$ 21,724,156

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Consolidated Balance Sheet Consolidated Balance Sheet (Parenthetical) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Preferred stock, par value $.10 per share:	$ 0.1	$ 0.1
Preferred shares authorized	5,000,000	5,000,000
Preferred shares issued	0	0
Preferred shares outstanding	0	0
Common stock, par value $.20 per share:	$ 0.2	$ 0.2
Common shares authorized	500,000,000	500,000,000
Common shares issued	122,641,527	123,307,837
Common shares outstanding	122,641,527	123,307,837
Treasury stock issued at cost	112,476,391	111,810,081

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Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
REVENUES:
Net premiums written	$ 1,607,365	$ 1,571,037	$ 4,913,656	$ 4,690,364
Change in net unearned premiums	(21,421)	(39,479)	(240,584)	(193,752)
Net premiums earned	1,585,944	1,531,558	4,673,072	4,496,612
Net investment income	145,668	133,214	404,850	385,036
Insurance service fees	32,135	35,192	109,437	107,652
Net realized investment gains	175,738	66,419	207,508	113,020
Marketable Securities, Realized Loss, Other than Temporary Impairments, Amount	0	12,515	(18,114)	12,515
Revenues from non-insurance businesses	80,242	107,059	305,787	305,261
Other income	0	30	0	335
Total revenues	2,019,727	1,860,957	5,682,540	5,395,401
OPERATING COSTS AND EXPENSES:
Losses and loss expenses	965,856	926,355	2,852,339	2,733,298
Other operating costs and expenses	606,348	573,541	1,770,450	1,698,169
Expenses from non-insurance businesses	78,865	100,500	291,127	288,900
Interest expense	37,043	31,641	104,019	99,210
Total operating costs and expenses	1,688,112	1,632,037	5,017,935	4,819,577
Income before income taxes	331,615	228,920	664,605	575,824
Income tax expense	(110,952)	(76,184)	(214,789)	(181,595)
Net income before noncontrolling interests	220,663	152,736	449,816	394,229
Noncontrolling interests	(13)	(129)	(689)	(280)
Net income to common stockholders	$ 220,650	$ 152,607	$ 449,127	$ 393,949
NET INCOME PER SHARE:
Basic	$ 1.80	$ 1.24	$ 3.66	$ 3.17
Diluted	$ 1.72	$ 1.18	$ 3.50	$ 3.02

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Consolidated Statements of Comprehensive Income Statement - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net income before noncontrolling interests	$ 220,663	$ 152,736	$ 449,816	$ 394,229
Other comprehensive income (loss):
Change in unrealized currency translation adjustments	(19,470)	(62,535)	(77,389)	(76,713)
Change in unrealized investment gains, net of taxes	(47,676)	4,497	134,213	(78,832)
Other comprehensive income (loss)	(67,146)	(58,038)	56,824	(155,545)
Comprehensive income	153,517	94,698	506,640	238,684
Noncontrolling interest	44	(35)	(623)	(174)
Comprehensive income to common stockholders	$ 153,561	$ 94,663	$ 506,017	$ 238,510

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Consolidated Statements of Stockholders' Equity Statement - USD ($) $ in Thousands	Total	Common stocks	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	Accumulated Translation Adjustment [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]
Beginning and end of period at Dec. 31, 2014		$ 47,024	$ 991,512	$ 5,732,410	$ 306,199	$ (122,649)		$ (2,364,551)	$ 34,189
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued including tax benefit			(25,394)
Restricted stock units expensed			23,429
Net income before noncontrolling interests	$ 394,229			393,949					280
Dividends				(43,239)
Change in unrealized investment gains, net of taxes	(78,832)				(78,773)
Unrealized gains on other-than-temporarily impaired securities					47
Change in unrealized currency translation adjustments	(76,713)					(76,713)
Stock exercised/vested								23,667
Stock repurchased								(223,652)
Contributions (distributions)									(992)
Other comprehensive income (loss)	(155,545)					(76,713)	$ (155,545)		(106)
End of period at Sep. 30, 2015			989,547	6,083,120	227,473	(199,362)	28,111	(2,564,536)	33,371
Beginning and end of period at Dec. 31, 2015	4,633,208	$ 47,024	1,005,455	6,178,070	180,695	(247,393)		(2,563,605)	32,962
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued including tax benefit			(3,421)
Restricted stock units expensed			25,431
Net income before noncontrolling interests	449,816			449,127					689
Dividends				(107,661)
Change in unrealized investment gains, net of taxes	134,213				133,866
Unrealized gains on other-than-temporarily impaired securities					413
Change in unrealized currency translation adjustments	(77,389)					(77,389)
Stock exercised/vested								5,023
Stock repurchased								(99,870)
Contributions (distributions)									2,474
Other comprehensive income (loss)	56,824					(77,389)	56,824		(66)
End of period at Sep. 30, 2016	$ 4,961,824		$ 1,027,465	$ 6,519,536	$ 314,974	$ (324,782)	$ (9,808)	$ (2,658,452)	$ 36,059

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Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
CASH FROM (USED IN) OPERATING ACTIVITIES:
Net income to common stockholders	$ 449,127	$ 393,949
Adjustments to reconcile net income to net cash from operating activities:
Net investment gains	(189,394)	(100,505)
Depreciation and amortization	69,153	65,384
Noncontrolling interests	689	280
Investment funds	(60,387)	(50,838)
Stock incentive plans	27,033	24,052
Change in:
Arbitrage trading account	(4,777)	(4,157)
Premiums and fees receivable	(92,372)	(99,541)
Reinsurance accounts	(154,939)	(62,272)
Deferred policy acquisition costs	(51,795)	(40,216)
Income taxes	89,007	80,587
Reserves for losses and loss expenses	440,486	362,854
Unearned premiums	269,287	198,534
Other	(64,608)	(147,776)
Net cash from operating activities	726,510	620,335
CASH FROM (USED IN) INVESTING ACTIVITIES:
Proceeds from sale of fixed maturity securities	1,074,630	765,764
Proceeds from sale of equity securities	123,187	23,778
Distributions from investment funds	5,630	198,489
Proceeds from maturities and prepayments of fixed maturity securities	2,189,365	2,727,635
Purchase of fixed maturity securities	(4,280,457)	(3,387,648)
Purchase of equity securities	(127,303)	(37,754)
Real estate purchased	(207,829)	(150,940)
Change in loans receivable	159,128	35,739
Net additions to property, furniture and equipment	(37,895)	(40,262)
Change in balances due to security brokers	102,981	43,429
Proceeds from Divestiture of Businesses, Net of Cash Divested	250,216	0
Payment for business purchased net of cash aquired	(53,524)	(7,156)
Net cash from (used in) investing activities	(801,871)	171,074
CASH FROM (USED IN) FINANCING ACTIVITIES:
Repayment of senior notes and other debt	(70,567)	(279,204)
Proceeds from Issuance of Debt	386,848	1,891
Cash dividends to common stockholders	(30,654)	(43,239)
Purchase of common treasury shares	(99,870)	(223,652)
Other, net	(1,376)	(3,345)
Net cash from (used in) financing activities	184,381	(547,549)
Net impact on cash due to change in foreign exchange rates	413	(38,367)
Net change in cash and cash equivalents	109,433	205,493
Cash and cash equivalents at beginning of year	763,631	674,441
Cash and cash equivalents at end of period	$ 873,064	$ 879,934

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General General

9 Months Ended

Sep. 30, 2016

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]

General

The unaudited consolidated financial statements, which include the accounts of W. R. Berkley Corporation and its subsidiaries (the “Company”) have been prepared on the basis of U.S. generally accepted accounting principles (“GAAP”) for interim financial information. Accordingly, they do not include all the information and notes required by GAAP for annual financial statements. The unaudited consolidated financial statements reflect all adjustments, consisting only of normal recurring items, which are necessary to present fairly the Company’s financial position and results of operations on a basis consistent with the prior audited consolidated financial statements. Operating results for interim periods are not necessarily indicative of the results that may be expected for the year. All significant intercompany accounts and transactions have been eliminated. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the revenues and expenses reflected during the reporting period. For further information related to a description of areas of judgment and estimates and other information necessary to understand the Company’s financial position and results of operations, refer to the audited consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015. Reclassifications have been made in the 2015 financial statements as originally reported to conform to the presentation of the 2016 financial statements.

The income tax provision has been computed based on the Company’s estimated annual effective tax rate. The effective tax rate for the quarter differs from the federal income tax rate of 35% principally because of tax-exempt investment income.

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Per Share Data Per Share Data

9 Months Ended

Sep. 30, 2016

Earnings Per Share [Abstract]

Earnings Per Share

Per Share Data

The Company presents both basic and diluted net income per share (“EPS”) amounts. Basic EPS is calculated by dividing net income by the weighted average number of common shares outstanding during the period. Diluted EPS is based upon the weighted average number of common and common equivalent shares outstanding during the period and is calculated using the treasury stock method for stock incentive plans. Common equivalent shares are excluded from the computation in periods in which they have an anti-dilutive effect. Stock options for which the exercise price exceeds the average market price over the period have an anti-dilutive effect on EPS and, accordingly, are excluded from the calculation.

The weighted average number of common shares used in the computation of basic and diluted earnings per share was as follows:

	For the Three Months		For the Nine Months
	Ended September 30,		Ended September 30,
(In thousands)	2016	2015	2016	2015
Basic	122,562	123,163	122,652	124,294
Diluted	128,556	128,947	128,501	130,563

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Recent Accounting Pronouncements Recent Accounting Pronouncements

9 Months Ended

Sep. 30, 2016

Accounting Policies [Abstract]

Recent Accounting Pronouncements

Recent Accounting Pronouncements

In February 2015, the Financial Accounting Standards Board ("FASB") issued ASU 2015-02, Consolidation. ASU 2015-02 makes targeted amendments to the current consolidation accounting guidance, in response to accounting complexity concerns. The guidance simplifies consolidation accounting by reducing the number of approaches to consolidation. The Company adopted this updated guidance on January 1, 2016. This adoption did not have a material effect on the Company's financial condition or results of operations, but did result in additional disclosures.

In May 2015, the FASB issued ASU 2015-09, Disclosures about Short-Duration Contracts.   ASU 2015-09 requires companies that issue short duration insurance contracts to disclose additional information, including: (i) incurred and paid claims development tables; (ii) frequency and severity of claims; and (iii) information about material changes in judgments made in calculating the liability for unpaid claim adjustment expenses, including reasons for the change and the effects on the financial statements. ASU 2015-09 is effective for annual periods beginning after December 15, 2015, and interim periods within annual periods beginning after December 15, 2016. The amendments in ASU 2015-09 should be applied retrospectively by providing comparative disclosures for each period presented, except for those requirements that apply only to the current period. As the requirements are disclosure only, the adoption of this guidance will not impact our financial condition or results of operations.

In January 2016, the FASB issued ASU 2016-01, Financial Instruments. ASU 2016-01 which amends the accounting guidance for financial instruments to require all equity investments to be measured at fair value with changes in the fair value recognized through net income (other than those accounted for under equity method of accounting or those that result in consolidation of the investee). The updated guidance is effective for public business entities for annual reporting periods beginning after December 15, 2017 and interim periods within those years. The adoption of this guidance is not expected to have a material effect on the Company’s financial condition upon adoption, but will impact results of operations after adoption of this guidance as unrealized gains and losses on equity securities will no longer be reported in accumulated other comprehensive income (AOCI), but will instead be reported in net income.

In February 2016, the FASB issued ASU 2016-02, Leases, which amends the accounting and disclosure guidance for leases.  This guidance retains the two classifications of a lease, as either an operating or finance lease, both of which will require lessees to recognize a right-of-use asset and a lease liability for leases with terms of more than 12 months. The right-of-use asset and the lease liability will be determined based upon the present value of cash flows. Finance leases will reflect the financial arrangement by recognizing interest expense on the lease liability separately from the amortization expense of the right-of-use asset. Operating leases will recognize lease expense (with no separate recognition of interest expense) on a straight-line basis over the term of the lease. The accounting by lessors is not significantly changed by the updated guidance.  The updated guidance is effective for reporting periods beginning after December 15, 2018, and will require that the earliest comparative period presented include the measurement and recognition of existing leases with an adjustment to equity as if the updated guidance had always been applied. The Company is currently evaluating the impact that the adoption of this guidance will have on its results of operations, financial position and liquidity.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses, which amends the accounting guidance for credit losses on financial instruments. The updated guidance amends the current other-than-temporary impairment model for available-for-sale debt securities by requiring the recognition of impairments relating to credit losses through an allowance account and limits the amount of credit loss to the difference between a security’s amortized cost basis and its fair value. This guidance also applies a new current expected credit loss model for determining credit-related impairments for financial instruments measured at amortized cost.  The updated guidance is effective for reporting periods beginning after December 15, 2019. The Company will not be able to determine the impact the adoption of this guidance will have on its results of operations, financial position or liquidity until the year the guidance becomes effective.

All other recently issued but not yet effective accounting and reporting standards are either not applicable to the Company or are not expected to have a material impact on the Company.

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Acquistions Acquisitions

9 Months Ended

Sep. 30, 2016

Business Combinations [Abstract]

Business Combination Disclosure

Acquisitions/Disposition

In February 2016, the Company acquired an 85% ownership interest for $42.3 million in a company engaged in the distribution of promotional merchandise. The fair value of the assets acquired and liabilities assumed have been estimated based on a preliminary valuation. The fair values of the assets and liabilities will be adjusted, as needed, following completion of the final valuation.

In July 2016, the Company acquired a specialty property and casualty insurance company for $15.5 million.

The following table summarizes the initial estimated fair value of net assets acquired and liabilities assumed for the business combinations completed in 2016:

(In thousands)	2016
Investments	$	6,764
Cash and cash equivalents	4,266
Real estate, furniture and equipment	701
Goodwill and other intangibles assets	45,782
Premiums and service fees receivable	3,845
Other assets	5,213
Total assets acquired	66,571
Other liabilities assumed	(4,931		)
Noncontrolling interest	(3,850		)
Net assets acquired	$	57,790

In July 2016, the Company sold Aero Precision Industries, an aviation-related business, for $253.1 million. The business had a net carrying value of $118.2 million.

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Statements of Comprehensive Income (Loss) Statements of Comprehensive Income (Loss) (Notes)

9 Months Ended

Sep. 30, 2016

Equity [Abstract]

Comprehensive Income (Loss)

____

(1) Net investment (gains) losses in the consolidated statements of income.

(2) Income tax expense in the consolidated statements of income.

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Statements of Cash Flow Statements of Cash Flow

9 Months Ended

Sep. 30, 2016

Supplemental Cash Flow Elements [Abstract]

Cash Flow, Supplemental Disclosures

Statements of Cash Flow

Interest payments were $124,791,000 and $124,632,000 and income taxes paid were $99,161,000 and $96,364,000 in the nine months ended September 30, 2016 and 2015, respectively.

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Investments In Fixed Maturity Securities

9 Months Ended

Sep. 30, 2016

Debt Securities [Member]

Schedule of Marketable Securities [Line Items]

Investments In Fixed Maturity Securities

Investments in Fixed Maturity Securities

At September 30, 2016 and December 31, 2015, investments in fixed maturity securities were as follows:

(In thousands)	Amortized Cost		Gross Unrealized					Fair Value		Carrying Value
			Gains		Losses
September 30, 2016
Held to maturity:
State and municipal	$	71,608	$	17,388	$	—		$	88,996	$	71,608
Residential mortgage-backed	16,569		2,232		—			18,801		16,569
Total held to maturity	88,177		19,620		—			107,797		88,177
Available for sale:
U.S. government and government agency	530,541		25,383		(931		)	554,993		554,993
State and municipal:
Special revenue	2,707,492		124,159		(1,767		)	2,829,884		2,829,884
State general obligation	528,380		33,688		(560		)	561,508		561,508
Pre-refunded	366,360		31,900		(9		)	398,251		398,251
Corporate backed	374,355		15,424		(235		)	389,544		389,544
Local general obligation	350,349		32,193		(14		)	382,528		382,528
Total state and municipal	4,326,936		237,364		(2,585		)	4,561,715		4,561,715
Mortgage-backed securities:
Residential (1)	1,131,545		27,275		(4,859		)	1,153,961		1,153,961
Commercial	108,928		1,032		(916		)	109,044		109,044
Total mortgage-backed securities	1,240,473		28,307		(5,775		)	1,263,005		1,263,005
Asset-backed	2,265,206		15,729		(12,074		)	2,268,861		2,268,861
Corporate:
Industrial	2,168,312		111,260		(3,692		)	2,275,880		2,275,880
Financial	1,288,472		52,419		(5,384		)	1,335,507		1,335,507
Utilities	199,941		11,593		(785		)	210,749		210,749
Other	90,229		1,816		(13		)	92,032		92,032
Total corporate	3,746,954		177,088		(9,874		)	3,914,168		3,914,168
Foreign	909,765		58,477		(2,490		)	965,752		965,752
Total available for sale	13,019,875		542,348		(33,729		)	13,528,494		13,528,494
Total investments in fixed maturity securities	$	13,108,052	$	561,968	$	(33,729	)	$	13,636,291	$	13,616,671

(In thousands)	Amortized Cost		Gross Unrealized					Fair Value		Carrying Value
			Gains		Losses
December 31, 2015
Held to maturity:
State and municipal	$	77,129	$	16,246	$	—		$	93,375	$	77,129
Residential mortgage-backed	19,138		2,207		—			21,345		19,138
Total held to maturity	96,267		18,453		—			114,720		96,267
Available for sale:
U.S. government and government agency	645,092		27,660		(2,333		)	670,419		670,419
State and municipal:
Special revenue	2,510,816		102,909		(3,737		)	2,609,988		2,609,988
State general obligation	583,456		28,068		(2,070		)	609,454		609,454
Pre-refunded	439,772		32,056		(31		)	471,797		471,797
Corporate backed	388,904		14,039		(402		)	402,541		402,541
Local general obligation	342,158		24,270		(29		)	366,399		366,399
Total state and municipal	4,265,106		201,342		(6,269		)	4,460,179		4,460,179
Mortgage-backed securities:
Residential (1)	1,126,382		18,935		(11,180		)	1,134,137		1,134,137
Commercial	64,975		875		(128		)	65,722		65,722
Total mortgage-backed securities	1,191,357		19,810		(11,308		)	1,199,859		1,199,859
Asset-backed	1,706,694		12,892		(14,414		)	1,705,172		1,705,172
Corporate:
Industrial	1,976,393		75,168		(30,027		)	2,021,534		2,021,534
Financial	1,153,096		31,744		(11,819		)	1,173,021		1,173,021
Utilities	192,857		8,321		(2,527		)	198,651		198,651
Other	81,607		245		(20		)	81,832		81,832
Total corporate	3,403,953		115,478		(44,393		)	3,475,038		3,475,038
Foreign	799,839		50,310		(12,689		)	837,460		837,460
Total available for sale	12,012,041		427,492		(91,406		)	12,348,127		12,348,127
Total investments in fixed maturity securities	$	12,108,308	$	445,945	$	(91,406	)	$	12,462,847	$	12,444,394

____________

(1) Gross unrealized losses for residential mortgage-backed securities include $857,252 and $1,269,491 as of September 30, 2016 and December 31, 2015, respectively, related to the non-credit portion of other-than-temporary impairments (“OTTI”) recognized in accumulated other comprehensive income.

The amortized cost and fair value of fixed maturity securities at September 30, 2016, by contractual maturity, are shown below. Actual maturities may differ from contractual maturities because certain issuers may have the right to call or prepay obligations.

(In thousands)	Amortized Cost		Fair Value
Due in one year or less	$	1,032,042	$	1,054,113
Due after one year through five years	5,068,197		5,246,081
Due after five years through ten years	3,287,833		3,500,463
Due after ten years	2,462,938		2,553,828
Mortgage-backed securities	1,257,042		1,281,806
Total	$	13,108,052	$	13,636,291

At September 30, 2016 and 2015, there were no investments that exceeded 10% of common stockholders' equity, other than investments in United States government and government agency securities.

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Investments in Equity Securities

9 Months Ended

Sep. 30, 2016

Equity securities available for sale

Schedule of Available-for-sale Securities [Line Items]

Investments in Equity Securities

Investments in Equity Securities Available for Sale

At September 30, 2016 and December 31, 2015, investments in equity securities were as follows:

(In thousands)	Cost		Gross Unrealized					Fair Value		Carrying Value
			Gains		Losses
September 30, 2016
Common stocks	$	37,897	$	215	$	(2,441	)	$	35,671	$	35,671
Preferred stocks	125,759		6,573		(9,028		)	123,304		123,304
Total	$	163,656	$	6,788	$	(11,469	)	$	158,975	$	158,975
December 31, 2015
Common stocks	$	56,462	$	—	$	(19,189	)	$	37,273	$	37,273
Preferred stocks	108,730		8,216		(3,353		)	113,593		113,593
Total	$	165,192	$	8,216	$	(22,542	)	$	150,866	$	150,866

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Arbitrage Trading Account Arbitrage Trading Account (Notes)

9 Months Ended

Sep. 30, 2016

Schedule of Investments [Abstract]

Arbitrage Trading Account and Arbitrage Funds [Text Block]

Arbitrage Trading Account

At September 30, 2016 and December 31, 2015, the fair and carrying values of the arbitrage trading account were $603 million and $377 million, respectively. The primary focus of the trading account is merger arbitrage. Merger arbitrage is the business of investing in the securities of publicly held companies which are the targets in announced tender offers and mergers. Arbitrage investing differs from other types of investing in its focus on transactions and events believed likely to bring about a change in value over a relatively short time period (usually four months or less).

The Company uses put options, call options and swap contracts in order to mitigate the impact of potential changes in market conditions on the merger arbitrage trading account. These options and contracts are reported at fair value. As of September 30, 2016, the fair value of long option contracts outstanding was $1.2 million (notional amount of $53.9 million) and the fair value of short option contracts outstanding was $0.7 million (notional amount of $103.6 million). Other than with respect to the use of these trading account securities, the Company does not make use of derivatives.

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Net Investment Income Net Investment Income

9 Months Ended

Sep. 30, 2016

Income Statement [Abstract]

Net Investment Income

Net Investment Income

Net investment income consists of the following:

	For the Three Months						For the Nine Months
	Ended September 30,						Ended September 30,
(In thousands)	2016			2015			2016			2015
Investment income earned on:
Fixed maturity securities, including cash and cash equivalents and loans receivable	$	114,271		$	104,936		$	331,448		$	318,095
Investment funds	25,293			22,926			60,385			50,838
Arbitrage trading account	6,441			2,608			12,883			11,470
Equity securities available for sale	1,069			1,109			3,217			3,513
Real estate	585			4,389			4,552			9,270
Gross investment income	147,659			135,968			412,485			393,186
Investment expense	(1,991		)	(2,754		)	(7,635		)	(8,150		)
Net investment income	$	145,668		$	133,214		$	404,850		$	385,036

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Investment Funds Investment Funds

9 Months Ended

Sep. 30, 2016

Equity Method Investments and Joint Ventures [Abstract]

Net Investment Income

Investment Funds

The Company evaluates whether it is an investor in a variable interest entity (VIE).  Such entities do not have sufficient equity at risk to finance their activities without additional subordinated financial support, or the equity investors, as a group, do not have the characteristics of a controlling financial interest (primary beneficiary).  The Company determines whether it is the primary beneficiary of an entity subject to consolidation based on a qualitative assessment of the VIE's capital structure, contractual terms, nature of the VIE's operations and purpose, and the Company's relative exposure to the related risks of the VIE on the date it becomes initially involved in the VIE and on an ongoing basis.  The Company is not the primary beneficiary in any of its investment funds, and accordingly, carries its interests in investments funds under the equity method of accounting.

The Company’s maximum exposure to loss with respect to these investments is limited to the carrying amount reported on the Company’s consolidated balance sheet and any unfunded commitment.

Investment funds consist of the following:

	Carrying Value as of				Income (Loss) from Investment Funds
	September 30,		December 31,		For the Nine Months Ended September 30,
(In thousands)	2016		2015		2016		2015
Real estate	$	646,102	$	580,830	$	33,028	$	51,467
Energy	80,900		93,719		7,174		(25,124		)
Hedge equity	71,371		70,580		791		(3,925		)
Other funds	433,327		424,911		19,392		28,420
Total	$	1,231,700	$	1,170,040	$	60,385	$	50,838

The Company's share of the earnings or losses of investment funds is generally reported on a one-quarter lag in order to facilitate the timely completion of the Company's consolidated financial statements.

Other funds include private equity investments carried on the equity method of accounting, which includes a publicly traded common stock investment in HealthEquity, Inc. (HQY). Our ownership interest in HQY as of September 30, 2016 is approximately 21% with a fair value of $453 million and a carrying value of $53.1 million. In October 2016, the Company sold approximately 2.2 million shares in HQY and recognized a realized investment gain of approximately $65 million. Following the completion of the sale, the Company will report its investment in HQY at fair value.

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Real Estate Real Estate

9 Months Ended

Sep. 30, 2016

Real Estate [Abstract]

Real Estate

Real Estate

Investment in real estate represents directly owned property held for investment, as follows:    

	Carrying Value
	September 30,		December 31,
(In thousands)	2016		2015
Properties in operation	$	441,795	$	226,055
Properties under development	666,687		710,312
Total	$	1,108,482	$	936,367

In 2016, properties in operation included a long-term ground lease in Washington, D.C., a hotel in Memphis, Tennessee, an office complex in New York City and office buildings in West Palm Beach and Palm Beach, Florida. Properties in operation are net of accumulated depreciation and amortization of $13,345,000 and $9,073,000 as of September 30, 2016 and December 31, 2015, respectively. Related depreciation expense was $4,117,000 and $5,991,000 for the nine months ended September 30, 2016 and 2015, respectively. Future minimum rental income expected on operating leases relating to properties in operation is $2,982,866 in 2016, $16,900,586 in 2017, $22,572,465 in 2018, $20,707,015 in 2019, $19,471,136 in 2020, $19,649,571 in 2021 and $411,667,096 thereafter.

Properties under development include an office building in London and a mixed-use project in Washington, D.C.

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Loans Receivable Loans Receivable

9 Months Ended

Sep. 30, 2016

Receivables [Abstract]

Loans Receivable

Loans Receivable

Loans receivable are as follows:

(In thousands)	September 30, 2016		December 31, 2015
Amortized cost (net of valuation allowance):
Real estate loans	$	96,312	$	200,499
Commercial loans	17,684		72,604
Total	$	113,996	$	273,103
Fair value:
Real estate loans	$	97,296	$	201,641
Commercial loans	19,187		74,106
Total	$	116,483	$	275,747
Valuation allowance:
Specific	$	1,025	$	—
General	2,197		2,094
Total	$	3,222	$	2,094
	For the Three Months Ended September 30,
	2016		2015
Increase in valuation allowance	$	467	$	19
	For the Nine Months Ended September 30,
	2016		2015
Increase (decrease) in valuation allowance	$	1,128	$	(81	)

Loans receivable in non-accrual status were $9.1 million and $3.1 million as of September 30, 2016 and December 31, 2015, respectively.

The Company monitors the performance of its loans receivable and assesses the ability of the borrower to pay principal and interest based upon loan structure, underlying property values, cash flow and related financial and operating performance of the property and market conditions. Loans receivable with a potential for default are further assessed using discounted cash flow analysis and comparable cost and sales methodologies, if appropriate.

The real estate loans are secured by commercial real estate primarily located in North Carolina, Ohio and New York. These loans generally earn interest at floating LIBOR-based interest rates and have maturities (inclusive of extension options) throughAugust 2025. The commercial loans are with small business owners who have secured the related financing with the assets of the business. Commercial loans generally earn interest on a fixed basis and have varying maturities not exceeding 10 years.

In evaluating the real estate loans, the Company considers their credit quality indicators, including loan to value ratios, which compare the outstanding loan amount to the estimated value of the property, the borrower’s financial condition and performance with respect to loan terms, the position in the capital structure, the overall leverage in the capital structure and other market conditions. Based on these considerations, none of the real estate loans were considered to be impaired at September 30, 2016, and accordingly, the Company determined that a specific valuation allowance was not required.

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Realized And Unrealized Investment Gains (Losses)

9 Months Ended

Sep. 30, 2016

Realized and Unrealized Investment Gains (Losses) [Abstract]

Realized and Unrealized Investment Gains (Losses)

Realized and Unrealized Investment Gains (Losses)

Realized and unrealized investment gains (losses) are as follows:

	For the Three Months Ended September 30,						For the Nine Months Ended September 30,
(In thousands)	2016			2015			2016			2015
Realized investment gains (losses):
Fixed maturity securities:
Gains	$	33,798		$	1,341		$	66,972		$	8,178
Losses	(1,150		)	(2,171		)	(5,570		)	(2,810		)
Equity securities available for sale	8,441			(21		)	13,037			9,639
Investment funds	(3,788		)	70,648			(9,041		)	92,821
Real estate	687			—			5,247			—
Other (1)	137,750			(3,378		)	136,863			5,192
Net realized gains on investments sales	175,738			66,419			207,508			113,020
Other-than-temporary impairments (2)	—			(12,515		)	(18,114		)	(12,515		)
Net investment gains	175,738			53,904			189,394			100,505
Income tax expense	(61,508		)	(18,866		)	(66,288		)	(35,177		)
After-tax net realized investment gains	$	114,230		$	35,038		$	123,106		$	65,328

Change in unrealized investment gains (losses)of available for sale securities:
Fixed maturity securities	$	(45,388	)	$	2,449		$	169,933		$	(102,863	)
Previously impaired fixed maturity securities	(1,406		)	50			413			73
Equity securities available for sale	(28,517		)	(2,353		)	12,433			(15,977		)
Investment funds	3,143			(7,876		)	16,028			(16,417		)
Total change in unrealized investment gains (losses)	(72,168		)	(7,730		)	198,807			(135,184		)
Income tax benefit (expense)	24,493			12,229			(64,594		)	56,354
Noncontrolling interests	57			94			66			106
After-tax change in unrealized investment gains (losses) of available for sale securities	$	(47,618	)	$	4,593		$	134,279		$	(78,724	)

______________________

(1) Other includes a gain of $134.9 million from the sale of Aero Precision Industries, and certain related aviation services business, for the three and nine months ended September 30, 2016.

(2) Other than temporary impairments (OTTI) for the nine months ended September 30, 2016 of $18.1 million were related to equity securities available for sale. OTTI for the three and nine months ended September 30, 2015 of $12.5 million were related to equity securities available for sale and fixed maturity securities of $3.5 million and $9.0 million, respectively.

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Securities In An Unrealized Loss Position

9 Months Ended

Sep. 30, 2016

Investments [Abstract]

Securities in Unrealized Loss Position

Securities in an Unrealized Loss Position

The following tables summarize all securities in an unrealized loss position at September 30, 2016 and December 31, 2015 by the length of time those securities have been continuously in an unrealized loss position:

	Less Than 12 Months				12 Months or Greater				Total
(In thousands)	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
September 30, 2016
U.S. government and government agency	$	54,550	$	279	$	39,092	$	652	$	93,642	$	931
State and municipal	217,215		1,095		138,082		1,490		355,297		2,585
Mortgage-backed securities	251,969		1,851		105,927		3,924		357,896		5,775
Asset-backed securities	918,983		5,718		214,436		6,356		1,133,419		12,074
Corporate	337,940		2,152		98,162		7,722		436,102		9,874
Foreign	52,233		640		30,842		1,850		83,075		2,490
Fixed maturity securities	1,832,890		11,735		626,541		21,994		2,459,431		33,729
Common stocks	18,112		779		8,116		1,662		26,228		2,441
Preferred stocks	46,135		8,199		24,845		829		70,980		9,028
Equity securities available for sale	64,247		8,978		32,961		2,491		97,208		11,469
Total	$	1,897,137	$	20,713	$	659,502	$	24,485	$	2,556,639	$	45,198
December 31, 2015
U.S. government and government agency	$	101,660	$	487	$	64,500	$	1,846	$	166,160	$	2,333
State and municipal	501,952		4,404		106,681		1,865		608,633		6,269
Mortgage-backed securities	381,986		3,639		184,807		7,669		566,793		11,308
Asset-backed securities	1,091,078		7,703		190,467		6,711		1,281,545		14,414
Corporate	1,232,940		35,406		76,797		8,987		1,309,737		44,393
Foreign	169,190		8,822		19,528		3,867		188,718		12,689
Fixed maturity securities	3,478,806		60,461		642,780		30,945		4,121,586		91,406
Common stocks	18,641		18,005		7,829		1,184		26,470		19,189
Preferred stocks	—		—		22,320		3,353		22,320		3,353
Equity securities available for sale	18,641		18,005		30,149		4,537		48,790		22,542
Total	$	3,497,447	$	78,466	$	672,929	$	35,482	$	4,170,376	$	113,948

Fixed Maturity Securities – A summary of the Company’s non-investment grade fixed maturity securities that were in an unrealized loss position at September 30, 2016 is presented in the table below:

($ in thousands)	Number of Securities	Aggregate Fair Value		Gross Unrealized Loss
Corporate	10	$	27,531	$	3,045
Mortgage-backed securities	11	23,921		1,229
Foreign government	4	23,001		1,101
Asset-backed securities	5	8,418		405
State and municipal	1	7,007		25
Total	31	$	89,878	$	5,805

For OTTI of fixed maturity securities that management does not intend to sell or, to be required to sell, the portion of the decline in value that is considered to be due to credit factors is recognized in earnings, and the portion of the decline in value that is considered to be due to non-credit factors is recognized in other comprehensive income.

The Company has evaluated its fixed maturity securities in an unrealized loss position and believes the unrealized losses are due primarily to temporary market and sector-related factors rather than to issuer-specific factors. None of these securities are delinquent or in default under financial covenants. Based on its assessment of these issuers, the Company expects them to continue to meet their contractual payment obligations as they become due and does not consider any of these securities to be OTTI.

Preferred Stocks – At September 30, 2016, there were three preferred stocks in an unrealized loss position, with an aggregate fair value of $71 million and a gross unrealized loss of $9 million. Based upon management’s view of the underlying value of these securities, the Company does not consider these equity securities to be OTTI.

Common Stocks – At September 30, 2016, there were threecommon stocks in an unrealized loss position, with an aggregate fair value of $26 million and a gross unrealized loss of $2 million. Based on management's view of the underlying securities, the Company does not consider these equity securities to be OTTI.

Loans Receivable – The Company monitors the performance of its loans receivable, including current market conditions for each loan and the ability to collect principal and interest. For loans where the Company determines it is probable that the contractual terms will not be met, an analysis is performed and a valuation reserve is established, if necessary, with a charge to earnings. Loans receivable are reported net of a valuation reserve of $3 million and $2 million at September 30, 2016 and December 31, 2015, respectively.

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Fair Value Measurements Fair Value Measurements

9 Months Ended

Sep. 30, 2016

Fair Value Disclosures [Abstract]

Fair Value Disclosures

Fair Value Measurements

The Company’s fixed maturity and equity securities classified as available for sale and its trading account securities are carried at fair value. Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” The Company utilizes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels, as follows:

Level 1 - Quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.  

Level 2 - Quoted prices for similar assets or valuations based on inputs that are observable.

Level 3 - Estimates of fair value based on internal pricing methodologies using unobservable inputs. Unobservable inputs are only used to measure fair value to the extent that observable inputs are not available.

Substantially, all of the Company’s fixed maturity securities were priced by independent pricing services. The prices provided by the independent pricing services are estimated based on observable market data in active markets utilizing pricing models and processes, which may include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, sector groupings, matrix pricing and reference data. The pricing services may prioritize inputs differently on any given day for any security based on market conditions, and not all inputs are available for each security evaluation on any given day. The pricing services used by the Company have indicated that they will only produce an estimate of fair value if objectively verifiable information is available. The determination of whether markets are active or inactive is based upon the volume and level of activity for a particular asset class. The Company reviews the prices provided by pricing services for reasonableness and periodically performs independent price tests of a sample of securities to ensure proper valuation.

If prices from independent pricing services are not available for fixed maturity securities, the Company estimates the fair value. For Level 2 securities, the Company utilizes pricing models and processes which may include benchmark yields, sector groupings, matrix pricing, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, bids, offers and reference data. Where broker quotes are used, the Company generally requests two or more quotes and sets a price within the range of quotes received based on its assessment of the credibility of the quote and its own evaluation of the security. The Company generally does not adjust quotes received from brokers. For securities traded only in private negotiations, the Company determines fair value based primarily on the cost of such securities, which is adjusted to reflect prices of recent placements of securities of the same issuer, financial projections, credit quality and business developments of the issuer and other relevant information.

For Level 3 securities, the Company generally uses a discounted cash flow model to estimate the fair value of fixed maturity securities. The cash flow models are based upon assumptions as to prevailing credit spreads, interest rate and interest rate volatility, time to maturity and subordination levels. Projected cash flows are discounted at rates that are adjusted to reflect illiquidity, where appropriate.

The following tables present the assets and liabilities measured at fair value on a recurring basis as of September 30, 2016 and December 31, 2015 by level:

(In thousands)	Total		Level 1		Level 2		Level 3
September 30, 2016
Assets:
Fixed maturity securities available for sale:
U.S. government and government agency	$	554,993	$	—	$	554,993	$	—
State and municipal	4,561,715		—		4,561,715		—
Mortgage-backed securities	1,263,005		—		1,263,005		—
Asset-backed securities	2,268,861		—		2,268,676		185
Corporate	3,914,168		—		3,914,168		—
Foreign government	965,752		—		965,752		—
Total fixed maturity securities available for sale	13,528,494		—		13,528,309		185
Equity securities available for sale:
Common stocks	35,671		27,555		—		8,116
Preferred stocks	123,304		—		119,630		3,674
Total equity securities available for sale	158,975		27,555		119,630		11,790
Arbitrage trading account	602,965		320,280		282,685		—
Total	$	14,290,434	$	347,835	$	13,930,624	$	11,975
Liabilities:
Trading account securities sold but not yet purchased	$	60,959	$	60,947	$	12	$	—
December 31, 2015
Assets:
Fixed maturity securities available for sale:
U.S. government and government agency	$	670,419	$	—	$	670,419	$	—
State and municipal	4,460,179		—		4,460,179		—
Mortgage-backed securities	1,199,859		—		1,199,859		—
Asset-backed securities	1,705,172		—		1,704,973		199
Corporate	3,475,038		—		3,474,884		154
Foreign government	837,460		—		837,460		—
Total fixed maturity securities available for sale	12,348,127		—		12,347,774		353
Equity securities available for sale:
Common stocks	37,273		29,444		—		7,829
Preferred stocks	113,593		—		109,969		3,624
Total equity securities available for sale	150,866		29,444		109,969		11,453
Arbitrage trading account	376,697		256,914		119,607		176
Total	$	12,875,690	$	286,358	$	12,577,350	$	11,982
Liabilities:
Trading account securities sold but not yet purchased	$	37,035	$	35,559	$	1,476	$	—

There were no significant transfers between Levels 1 and 2 during the nine months ended September 30, 2016 or during the year ended December 31, 2015.

The following tables summarize changes in Level 3 assets and liabilities for the nine months ended September 30, 2016 and for the year ended December 31, 2015:

	Gains (Losses) Included in:
(In thousands)	Beginning Balance		Earnings (Losses)			Other Comprehensive Income (Loss)			Impairments			Purchases		(Sales)			Paydowns / Maturities			Transfers			Ending Balance
																				In / (Out)
Nine months ended September 30, 2016:
Assets:
Fixed maturities securities available for sale:
Asset-backed securities	$	199	$	3		$	13		$	—		$	—	$	—		$	(30	)	$	—		$	185
Corporate	154		177			—			—			—		(331		)	—			—			—
Total	353		180			13			—			—		(331		)	(30		)	—			185
Equity securities available for sale:
Common stocks	7,829		—			(478		)	—			765		—			—			—			8,116
Preferred stocks	3,624		50			—			—			—		—			—			—			3,674
Total	11,453		50			(478		)	—			765		—			—			—			11,790
Arbitrage trading account	176		(176		)	—			—			—		—			—			—			—
Total	$	11,982	$	54		$	(465	)	$	—		$	765	$	(331	)	$	(30	)	$	—		$	11,975
Year ended December 31, 2015:
Assets:
Fixed maturities securities available for sale:
Asset-backed securities	$	20,611	$	19		$	191		$	—		$	—	$	—		$	(1,820	)	$	(18,802	)	$	199
Corporate	154		—			—			—			—		—			—			—			154
Total	20,765		19			191			—			—		—			(1,820		)	(18,802		)	353
Equity securities available for sale:
Common stocks	10,741		—			(273		)	(2,331		)	—		(308		)	—			—			7,829
Preferred stocks	3,713		(89		)	—			—			—		—			—			—			3,624
Total	14,454		(89		)	(273		)	(2,331		)	—		(308		)	—			—			11,453
Arbitrage trading account	720		(799		)	—			—			72,640		(71,921		)	—			(464		)	176
Total	$	35,939	$	(869	)	$	(82	)	$	(2,331	)	$	72,640	$	(72,229	)	$	(1,820	)	$	(19,266	)	$	11,982

During the nine months ended September 30, 2016, there were no transfers out of Level 3. During the year ended December 31, 2015, five securities were transferred out of Level 3 as an observable price became available.

Fair Value of Financial Instruments

The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments:

	September 30, 2016				December 31, 2015
(In thousands)	Carrying Value		Fair Value		Carrying Value		Fair Value
Assets:
Fixed maturity securities	$	13,616,671	$	13,636,291	$	12,444,394	$	12,462,847
Equity securities available for sale	158,975		158,975		150,866		150,866
Arbitrage trading account	602,965		602,965		376,697		376,697
Loans receivable	113,996		116,483		273,103		275,747
Cash and cash equivalents	873,064		873,064		763,631		763,631
Trading account receivables from brokers and clearing organizations	185,548		185,548		383,115		383,115
Due from broker	—		—		1,713		1,713
Liabilities:
Due to broker	101,405		101,405		—		—
Trading account securities sold but not yet purchased	60,959		60,959		37,035		37,035
Subordinated debentures	727,390		779,056		340,320		355,880
Senior notes and other debt	1,762,487		1,997,430		1,844,621		2,029,572

The estimated fair values of the Company’s fixed maturity securities, equity securities available for sale and arbitrage trading account securities are based on various valuation techniques that rely on fair value measurements as described in Note 16 above. The fair value of loans receivable are estimated by using current institutional purchaser yield requirements for loans with similar credit characteristics, which is considered a Level 2 input. The fair value of the senior notes and other debt and the subordinated debentures is based on spreads for similar securities, which is considered a Level 2 input.

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Reinsurance Reinsurance

9 Months Ended

Sep. 30, 2016

Insurance [Abstract]

Reinsurance [Text Block]

Reinsurance

The following is a summary of reinsurance financial information:

	For the Three Months						For the Nine Months
	Ended September 30,						Ended September 30,
(In thousands)	2016			2015			2016			2015
Written premiums:
Direct	$	1,643,870		$	1,601,344		$	5,061,646		$	4,852,584
Assumed	224,979			221,237			702,265			633,200
Ceded	(261,484		)	(251,544		)	(850,255		)	(795,420		)
Total net premiums written	$	1,607,365		$	1,571,037		$	4,913,656		$	4,690,364
Earned premiums:
Direct	$	1,647,033		$	1,575,624		$	4,824,768		$	4,646,343
Assumed	216,758			217,668			635,443			632,362
Ceded	(277,847		)	(261,734		)	(787,139		)	(782,093		)
Total net premiums earned	$	1,585,944		$	1,531,558		$	4,673,072		$	4,496,612
Ceded losses and loss expenses incurred	$	213,065		$	123,765		$	507,258		$	374,084
Ceded commissions earned	$	47,315		$	45,946		$	143,809		$	129,766

The Company reinsures a portion of its insurance exposures in order to reduce its net liability on individual risks and catastrophe losses. The Company also cedes premiums to state assigned risk plans and captive insurance companies. Estimated amounts due from reinsurers are reported net of reserves for uncollectible reinsurance of $1 million as of September 30, 2016 and December 31, 2015.

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Fair Value Of Financial Instruments Fair Value of Financial Instruments (Notes)

9 Months Ended

Sep. 30, 2016

Fair Value Disclosures [Abstract]

Fair Value Disclosures

Fair Value Measurements

The Company’s fixed maturity and equity securities classified as available for sale and its trading account securities are carried at fair value. Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” The Company utilizes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels, as follows:

Level 1 - Quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.  

Level 2 - Quoted prices for similar assets or valuations based on inputs that are observable.

Level 3 - Estimates of fair value based on internal pricing methodologies using unobservable inputs. Unobservable inputs are only used to measure fair value to the extent that observable inputs are not available.

Substantially, all of the Company’s fixed maturity securities were priced by independent pricing services. The prices provided by the independent pricing services are estimated based on observable market data in active markets utilizing pricing models and processes, which may include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, sector groupings, matrix pricing and reference data. The pricing services may prioritize inputs differently on any given day for any security based on market conditions, and not all inputs are available for each security evaluation on any given day. The pricing services used by the Company have indicated that they will only produce an estimate of fair value if objectively verifiable information is available. The determination of whether markets are active or inactive is based upon the volume and level of activity for a particular asset class. The Company reviews the prices provided by pricing services for reasonableness and periodically performs independent price tests of a sample of securities to ensure proper valuation.

If prices from independent pricing services are not available for fixed maturity securities, the Company estimates the fair value. For Level 2 securities, the Company utilizes pricing models and processes which may include benchmark yields, sector groupings, matrix pricing, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, bids, offers and reference data. Where broker quotes are used, the Company generally requests two or more quotes and sets a price within the range of quotes received based on its assessment of the credibility of the quote and its own evaluation of the security. The Company generally does not adjust quotes received from brokers. For securities traded only in private negotiations, the Company determines fair value based primarily on the cost of such securities, which is adjusted to reflect prices of recent placements of securities of the same issuer, financial projections, credit quality and business developments of the issuer and other relevant information.

For Level 3 securities, the Company generally uses a discounted cash flow model to estimate the fair value of fixed maturity securities. The cash flow models are based upon assumptions as to prevailing credit spreads, interest rate and interest rate volatility, time to maturity and subordination levels. Projected cash flows are discounted at rates that are adjusted to reflect illiquidity, where appropriate.

The following tables present the assets and liabilities measured at fair value on a recurring basis as of September 30, 2016 and December 31, 2015 by level:

(In thousands)	Total		Level 1		Level 2		Level 3
September 30, 2016
Assets:
Fixed maturity securities available for sale:
U.S. government and government agency	$	554,993	$	—	$	554,993	$	—
State and municipal	4,561,715		—		4,561,715		—
Mortgage-backed securities	1,263,005		—		1,263,005		—
Asset-backed securities	2,268,861		—		2,268,676		185
Corporate	3,914,168		—		3,914,168		—
Foreign government	965,752		—		965,752		—
Total fixed maturity securities available for sale	13,528,494		—		13,528,309		185
Equity securities available for sale:
Common stocks	35,671		27,555		—		8,116
Preferred stocks	123,304		—		119,630		3,674
Total equity securities available for sale	158,975		27,555		119,630		11,790
Arbitrage trading account	602,965		320,280		282,685		—
Total	$	14,290,434	$	347,835	$	13,930,624	$	11,975
Liabilities:
Trading account securities sold but not yet purchased	$	60,959	$	60,947	$	12	$	—
December 31, 2015
Assets:
Fixed maturity securities available for sale:
U.S. government and government agency	$	670,419	$	—	$	670,419	$	—
State and municipal	4,460,179		—		4,460,179		—
Mortgage-backed securities	1,199,859		—		1,199,859		—
Asset-backed securities	1,705,172		—		1,704,973		199
Corporate	3,475,038		—		3,474,884		154
Foreign government	837,460		—		837,460		—
Total fixed maturity securities available for sale	12,348,127		—		12,347,774		353
Equity securities available for sale:
Common stocks	37,273		29,444		—		7,829
Preferred stocks	113,593		—		109,969		3,624
Total equity securities available for sale	150,866		29,444		109,969		11,453
Arbitrage trading account	376,697		256,914		119,607		176
Total	$	12,875,690	$	286,358	$	12,577,350	$	11,982
Liabilities:
Trading account securities sold but not yet purchased	$	37,035	$	35,559	$	1,476	$	—

There were no significant transfers between Levels 1 and 2 during the nine months ended September 30, 2016 or during the year ended December 31, 2015.

The following tables summarize changes in Level 3 assets and liabilities for the nine months ended September 30, 2016 and for the year ended December 31, 2015:

	Gains (Losses) Included in:
(In thousands)	Beginning Balance		Earnings (Losses)			Other Comprehensive Income (Loss)			Impairments			Purchases		(Sales)			Paydowns / Maturities			Transfers			Ending Balance
																				In / (Out)
Nine months ended September 30, 2016:
Assets:
Fixed maturities securities available for sale:
Asset-backed securities	$	199	$	3		$	13		$	—		$	—	$	—		$	(30	)	$	—		$	185
Corporate	154		177			—			—			—		(331		)	—			—			—
Total	353		180			13			—			—		(331		)	(30		)	—			185
Equity securities available for sale:
Common stocks	7,829		—			(478		)	—			765		—			—			—			8,116
Preferred stocks	3,624		50			—			—			—		—			—			—			3,674
Total	11,453		50			(478		)	—			765		—			—			—			11,790
Arbitrage trading account	176		(176		)	—			—			—		—			—			—			—
Total	$	11,982	$	54		$	(465	)	$	—		$	765	$	(331	)	$	(30	)	$	—		$	11,975
Year ended December 31, 2015:
Assets:
Fixed maturities securities available for sale:
Asset-backed securities	$	20,611	$	19		$	191		$	—		$	—	$	—		$	(1,820	)	$	(18,802	)	$	199
Corporate	154		—			—			—			—		—			—			—			154
Total	20,765		19			191			—			—		—			(1,820		)	(18,802		)	353
Equity securities available for sale:
Common stocks	10,741		—			(273		)	(2,331		)	—		(308		)	—			—			7,829
Preferred stocks	3,713		(89		)	—			—			—		—			—			—			3,624
Total	14,454		(89		)	(273		)	(2,331		)	—		(308		)	—			—			11,453
Arbitrage trading account	720		(799		)	—			—			72,640		(71,921		)	—			(464		)	176
Total	$	35,939	$	(869	)	$	(82	)	$	(2,331	)	$	72,640	$	(72,229	)	$	(1,820	)	$	(19,266	)	$	11,982

During the nine months ended September 30, 2016, there were no transfers out of Level 3. During the year ended December 31, 2015, five securities were transferred out of Level 3 as an observable price became available.

Fair Value of Financial Instruments

The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments:

	September 30, 2016				December 31, 2015
(In thousands)	Carrying Value		Fair Value		Carrying Value		Fair Value
Assets:
Fixed maturity securities	$	13,616,671	$	13,636,291	$	12,444,394	$	12,462,847
Equity securities available for sale	158,975		158,975		150,866		150,866
Arbitrage trading account	602,965		602,965		376,697		376,697
Loans receivable	113,996		116,483		273,103		275,747
Cash and cash equivalents	873,064		873,064		763,631		763,631
Trading account receivables from brokers and clearing organizations	185,548		185,548		383,115		383,115
Due from broker	—		—		1,713		1,713
Liabilities:
Due to broker	101,405		101,405		—		—
Trading account securities sold but not yet purchased	60,959		60,959		37,035		37,035
Subordinated debentures	727,390		779,056		340,320		355,880
Senior notes and other debt	1,762,487		1,997,430		1,844,621		2,029,572

The estimated fair values of the Company’s fixed maturity securities, equity securities available for sale and arbitrage trading account securities are based on various valuation techniques that rely on fair value measurements as described in Note 16 above. The fair value of loans receivable are estimated by using current institutional purchaser yield requirements for loans with similar credit characteristics, which is considered a Level 2 input. The fair value of the senior notes and other debt and the subordinated debentures is based on spreads for similar securities, which is considered a Level 2 input.

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Restricted Stock Units Restricted Stock Units (Notes)

9 Months Ended

Sep. 30, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Restricted Stock Units

Restricted Stock Units

Pursuant to its stock incentive plan, the Company may issue restricted stock units (RSUs) to employees of the Company and its subsidiaries. The RSUs generally vest three to five years from the award date and are subject to other vesting and forfeiture provisions contained in the award agreement. RSUs are expensed pro-ratably over the vesting period. RSU expenses were $25 million and $23 million for the nine months ended September 30, 2016 and 2015, respectively. A summary of RSUs issued in the nine months ended September 30, 2016 and 2015 follows:

($ in thousands)	Units	Fair Value
Nine months ended September 30,
2016	990,487	$	57,959
2015	971,457	$	54,439

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Litigation and Contingent Liabilities Litigation and Contingent Liabilities

9 Months Ended

Sep. 30, 2016

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies Disclosure [Text Block]

Litigation and Contingent Liabilities

In the ordinary course of business, the Company is subject to disputes, litigation and arbitration arising from its insurance and reinsurance businesses. These matters are generally related to insurance and reinsurance claims and are considered in the establishment of loss and loss expense reserves. In addition, the Company may also become involved in legal actions which seek extra-contractual damages, punitive damages or penalties, including claims alleging bad faith in handling of insurance claims. The Company expects its ultimate liability with respect to such matters will not be material to its financial condition. However, adverse outcomes on such matters are possible, from time to time, and could be material to the Company’s results of operations in any particular financial reporting period.

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Industry Segments

9 Months Ended

Sep. 30, 2016

Segment Reporting [Abstract]

Industry Segments

The Company’s reportable segments include the following two business segments:

• Insurance - primarily commercial insurance business, including excess and surplus lines and admitted lines in the United States, United Kingdom, Continental Europe, South America, Canada, Scandinavia, Asia and Australia; and

• Reinsurance - reinsurance business on a facultative and treaty basis, primarily in the United States, United Kingdom, Continental Europe, Australia, the Asia-Pacific Region, and South Africa.

Commencing with the first quarter of 2016, the Company changed the aggregation of its business segments. Insurance-Domestic operating units and Insurance-International operating units, previously reported separately, have been aggregated into the Insurance segment. The segment disclosures for prior periods have been revised to be consistent with the new reportable business segment presentation.

The accounting policies of the segments are the same as those described in the summary of significant accounting policies. Income tax expense and benefits are calculated based upon the Company's overall effective tax rate.

Summary financial information about the Company's reporting segments is presented in the following tables. Income (loss) before income taxes by segment includes allocated investment income. Identifiable assets by segment are those assets used in or allocated to the operation of each segment.

	Revenues
(In thousands)	Earned Premiums		Investment Income		Other		Total		Pre-Tax Income (Loss)			Net Income (Loss) to Common Stockholders
Three months ended September 30, 2016
Insurance	$	1,431,664	$	117,388	$	22,819	$	1,571,871	$	215,649		$	144,310
Reinsurance	154,280		21,478		—		175,758		22,171			15,167
Corporate, other and eliminations (1)	—		6,802		89,560		96,362		(81,941		)	(53,055		)
Net investment gains	—		—		175,736		175,736		175,736			114,228
Total	$	1,585,944	$	145,668	$	288,115	$	2,019,727	$	331,615		$	220,650
Three months ended September 30, 2015
Insurance	$	1,379,501	$	106,989	$	23,021	$	1,509,511	$	204,109		$	139,446
Reinsurance	152,057		19,468		—		171,525		22,413			15,807
Corporate, other and eliminations (1)	—		6,757		119,260		126,017		(51,506		)	(37,684		)
Net investment gains	—		—		53,904		53,904		53,904			35,038
Total	$	1,531,558	$	133,214	$	196,185	$	1,860,957	$	228,920		$	152,607
Nine months ended September 30, 2016:
Insurance	$	4,206,887	322,779		$	77,215	$	4,606,881	$	604,825		$	407,346
Reinsurance	466,185		59,244		—		525,429		61,041			42,285
Corporate, other and eliminations (1)	—		22,827		338,009		360,836		(190,655		)	(123,610		)
Net investment gains	—		—		189,394		189,394		189,394			123,106
Total	$	4,673,072	$	404,850	$	604,618	$	5,682,540	$	664,605		$	449,127
Nine months ended September 30, 2015:
Insurance	$	4,042,159	$	309,337	$	72,981	$	4,424,477	$	575,748		$	395,581
Reinsurance	454,453		54,575		—		509,028		69,797			49,134
Corporate, other and eliminations (1)	—		21,124		340,267		361,391		(170,226		)	(116,094		)
Net investment gains	—		—		100,505		100,505		100,505			65,328
Total	$	4,496,612	$	385,036	$	513,753	$	5,395,401	$	575,824		$	393,949

________

(1) Corporate, other and eliminations represent corporate revenues and expenses that are not allocated to business segments.

Identifiable Assets

(In thousands)	September 30, 2016		December 31, 2015
Insurance	$	18,972,237	$	18,063,730
Reinsurance	2,585,307		2,441,340
Corporate, other and eliminations	1,788,112		1,219,086
Consolidated	$	23,345,656	$	21,724,156

Net premiums earned by major line of business are as follows:

	For the Three Months				For the Nine Months
	Ended September 30,				Ended September 30,
(In thousands)	2016		2015		2016		2015
Insurance:
Other liability	$	465,068	$	418,133	$	1,331,143	$	1,216,411
Workers’ compensation	355,604		347,745		1,047,412		1,010,279
Short-tail lines (1)	317,498		327,357		977,138		973,606
Commercial automobile	164,540		170,660		481,249		506,229
Professional liability	128,954		115,606		369,945		335,634
Total Insurance	1,431,664		1,379,501		4,206,887		4,042,159
Reinsurance:
Casualty	93,757		103,198		290,373		314,462
Property	60,523		48,859		175,812		139,991
Total Reinsurance	154,280		152,057		466,185		454,453
Total	$	1,585,944	$	1,531,558	$	4,673,072	$	4,496,612

______________

(1) Short-tail lines include commercial multi-peril (non-liability), inland marine, accident and health, fidelity and surety, boiler and machinery and other lines.

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Per Share Data (Tables)

9 Months Ended

Sep. 30, 2016

Earnings Per Share [Abstract]

Schedule of Weighted Average Number of Shares [Table Text Block]

The weighted average number of common shares used in the computation of basic and diluted earnings per share was as follows:

	For the Three Months		For the Nine Months
	Ended September 30,		Ended September 30,
(In thousands)	2016	2015	2016	2015
Basic	122,562	123,163	122,652	124,294
Diluted	128,556	128,947	128,501	130,563

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Acquistions Acquisitions (Tables)

9 Months Ended

Sep. 30, 2016

Business Acquisition [Line Items]

Summary of fair value of net assets acquired and liabilities assumed

The following table summarizes the initial estimated fair value of net assets acquired and liabilities assumed for the business combinations completed in 2016:

(In thousands)	2016
Investments	$	6,764
Cash and cash equivalents	4,266
Real estate, furniture and equipment	701
Goodwill and other intangibles assets	45,782
Premiums and service fees receivable	3,845
Other assets	5,213
Total assets acquired	66,571
Other liabilities assumed	(4,931		)
Noncontrolling interest	(3,850		)
Net assets acquired	$	57,790

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Statements of Comprehensive Income (Loss) Statements of Comprehensive Income (Loss) (Tables)

9 Months Ended

Sep. 30, 2015

Equity [Abstract]

Components of changes in accumulated other comprehensive income (loss)

(In thousands)	Unrealized Investment Gains (Losses)				Currency Translation Adjustments			Accumulated Other Comprehensive Income (Loss)
As of and for the nine months ended September 30, 2015:
Changes in AOCI
Beginning of period	$	306,199			$	(122,649	)	$	183,550
Other comprehensive income (loss) before reclassifications	(69,078		)		(76,713		)	(145,791		)
Amounts reclassified from AOCI	(9,754		)		—			(9,754		)
Other comprehensive income (loss)	(78,832		)		(76,713		)	(155,545		)
Unrealized investment gain related to non-controlling interest	106				—			106
End of period	$	227,473			$	(199,362	)	$	28,111
Amounts reclassified from AOCI
Pre-tax	$	(15,006	)	(1)	$	—		$	(15,006	)
Tax effect	5,252			(2)	—			5,252
After-tax amounts reclassified	$	(9,754	)		$	—		$	(9,754	)
Other comprehensive income (loss)
Pre-tax	$	(135,186	)		$	(76,713	)	$	(211,899	)
Tax effect	56,354							56,354
Other comprehensive income (loss)	$	(78,832	)		$	(76,713	)	$	(155,545	)
As of and for the three months ended September 30, 2015:
Changes in AOCI
Beginning of period	$	222,882			$	(136,827	)	$	86,055
Other comprehensive income (loss) before reclassifications	3,943				(62,535		)	(58,592		)
Amounts reclassified from AOCI	554				—			554
Other comprehensive income (loss)	4,497				(62,535		)	(58,038		)
Unrealized investment gain related to non-controlling interest	94				—			94
End of period	$	227,473			$	(199,362	)	$	28,111
Amounts reclassified from AOCI
Pre-tax	$	852		(1)	$	—		$	852
Tax effect	(298		)	(2)	—			(298		)
After-tax amounts reclassified	$	554			$	—		$	554
Other comprehensive income (loss)
Pre-tax	$	(7,731	)		$	(62,535	)	$	(70,266	)
Tax effect	12,228				—			12,228
Other comprehensive income (loss)	$	4,497			$	(62,535	)	$	(58,038	)

_______________

(1) Net investment (gains) losses in the consolidated statements of income.

(2) Income tax expense in the consolidated statements of income.

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Investments In Fixed Maturity Securities Investments in Fixed Maturity Securities (Tables)

9 Months Ended

Sep. 30, 2016

Schedule of Marketable Securities [Line Items]

Amortized cost and fair value of fixed maturity securities by contractual maturity

The amortized cost and fair value of fixed maturity securities at September 30, 2016, by contractual maturity, are shown below. Actual maturities may differ from contractual maturities because certain issuers may have the right to call or prepay obligations.

(In thousands)	Amortized Cost		Fair Value
Due in one year or less	$	1,032,042	$	1,054,113
Due after one year through five years	5,068,197		5,246,081
Due after five years through ten years	3,287,833		3,500,463
Due after ten years	2,462,938		2,553,828
Mortgage-backed securities	1,257,042		1,281,806
Total	$	13,108,052	$	13,636,291

Debt Securities [Member]

Schedule of Marketable Securities [Line Items]

Schedule of investments in fixed maturity securities

At September 30, 2016 and December 31, 2015, investments in fixed maturity securities were as follows:

(In thousands)	Amortized Cost		Gross Unrealized					Fair Value		Carrying Value
			Gains		Losses
September 30, 2016
Held to maturity:
State and municipal	$	71,608	$	17,388	$	—		$	88,996	$	71,608
Residential mortgage-backed	16,569		2,232		—			18,801		16,569
Total held to maturity	88,177		19,620		—			107,797		88,177
Available for sale:
U.S. government and government agency	530,541		25,383		(931		)	554,993		554,993
State and municipal:
Special revenue	2,707,492		124,159		(1,767		)	2,829,884		2,829,884
State general obligation	528,380		33,688		(560		)	561,508		561,508
Pre-refunded	366,360		31,900		(9		)	398,251		398,251
Corporate backed	374,355		15,424		(235		)	389,544		389,544
Local general obligation	350,349		32,193		(14		)	382,528		382,528
Total state and municipal	4,326,936		237,364		(2,585		)	4,561,715		4,561,715
Mortgage-backed securities:
Residential (1)	1,131,545		27,275		(4,859		)	1,153,961		1,153,961
Commercial	108,928		1,032		(916		)	109,044		109,044
Total mortgage-backed securities	1,240,473		28,307		(5,775		)	1,263,005		1,263,005
Asset-backed	2,265,206		15,729		(12,074		)	2,268,861		2,268,861
Corporate:
Industrial	2,168,312		111,260		(3,692		)	2,275,880		2,275,880
Financial	1,288,472		52,419		(5,384		)	1,335,507		1,335,507
Utilities	199,941		11,593		(785		)	210,749		210,749
Other	90,229		1,816		(13		)	92,032		92,032
Total corporate	3,746,954		177,088		(9,874		)	3,914,168		3,914,168
Foreign	909,765		58,477		(2,490		)	965,752		965,752
Total available for sale	13,019,875		542,348		(33,729		)	13,528,494		13,528,494
Total investments in fixed maturity securities	$	13,108,052	$	561,968	$	(33,729	)	$	13,636,291	$	13,616,671

(In thousands)	Amortized Cost		Gross Unrealized					Fair Value		Carrying Value
			Gains		Losses
December 31, 2015
Held to maturity:
State and municipal	$	77,129	$	16,246	$	—		$	93,375	$	77,129
Residential mortgage-backed	19,138		2,207		—			21,345		19,138
Total held to maturity	96,267		18,453		—			114,720		96,267
Available for sale:
U.S. government and government agency	645,092		27,660		(2,333		)	670,419		670,419
State and municipal:
Special revenue	2,510,816		102,909		(3,737		)	2,609,988		2,609,988
State general obligation	583,456		28,068		(2,070		)	609,454		609,454
Pre-refunded	439,772		32,056		(31		)	471,797		471,797
Corporate backed	388,904		14,039		(402		)	402,541		402,541
Local general obligation	342,158		24,270		(29		)	366,399		366,399
Total state and municipal	4,265,106		201,342		(6,269		)	4,460,179		4,460,179
Mortgage-backed securities:
Residential (1)	1,126,382		18,935		(11,180		)	1,134,137		1,134,137
Commercial	64,975		875		(128		)	65,722		65,722
Total mortgage-backed securities	1,191,357		19,810		(11,308		)	1,199,859		1,199,859
Asset-backed	1,706,694		12,892		(14,414		)	1,705,172		1,705,172
Corporate:
Industrial	1,976,393		75,168		(30,027		)	2,021,534		2,021,534
Financial	1,153,096		31,744		(11,819		)	1,173,021		1,173,021
Utilities	192,857		8,321		(2,527		)	198,651		198,651
Other	81,607		245		(20		)	81,832		81,832
Total corporate	3,403,953		115,478		(44,393		)	3,475,038		3,475,038
Foreign	799,839		50,310		(12,689		)	837,460		837,460
Total available for sale	12,012,041		427,492		(91,406		)	12,348,127		12,348,127
Total investments in fixed maturity securities	$	12,108,308	$	445,945	$	(91,406	)	$	12,462,847	$	12,444,394

____________

(1) Gross unrealized losses for residential mortgage-backed securities include $857,252 and $1,269,491 as of September 30, 2016 and December 31, 2015, respectively, related to the non-credit portion of other-than-temporary impairments (“OTTI”) recognized in accumulated other comprehensive income.

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Investments in Equity Securities Investments in Equity Securities (Tables)

9 Months Ended

Sep. 30, 2016

Equity securities available for sale

Schedule of Available-for-sale Securities [Line Items]

Schedule of Investments in Equity Securities

At September 30, 2016 and December 31, 2015, investments in equity securities were as follows:

(In thousands)	Cost		Gross Unrealized					Fair Value		Carrying Value
			Gains		Losses
September 30, 2016
Common stocks	$	37,897	$	215	$	(2,441	)	$	35,671	$	35,671
Preferred stocks	125,759		6,573		(9,028		)	123,304		123,304
Total	$	163,656	$	6,788	$	(11,469	)	$	158,975	$	158,975
December 31, 2015
Common stocks	$	56,462	$	—	$	(19,189	)	$	37,273	$	37,273
Preferred stocks	108,730		8,216		(3,353		)	113,593		113,593
Total	$	165,192	$	8,216	$	(22,542	)	$	150,866	$	150,866

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Net Investment Income (Tables)

9 Months Ended

Sep. 30, 2016

Net Investment Income [Abstract]

Schedule of Net Investment Income

Net investment income consists of the following:

	For the Three Months						For the Nine Months
	Ended September 30,						Ended September 30,
(In thousands)	2016			2015			2016			2015
Investment income earned on:
Fixed maturity securities, including cash and cash equivalents and loans receivable	$	114,271		$	104,936		$	331,448		$	318,095
Investment funds	25,293			22,926			60,385			50,838
Arbitrage trading account	6,441			2,608			12,883			11,470
Equity securities available for sale	1,069			1,109			3,217			3,513
Real estate	585			4,389			4,552			9,270
Gross investment income	147,659			135,968			412,485			393,186
Investment expense	(1,991		)	(2,754		)	(7,635		)	(8,150		)
Net investment income	$	145,668		$	133,214		$	404,850		$	385,036

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Investment Funds Investment Funds (Tables)

9 Months Ended

Sep. 30, 2016

Equity Method Investments and Joint Ventures [Abstract]

Schedule of Net Investment Funds

Investment funds consist of the following:

	Carrying Value as of				Income (Loss) from Investment Funds
	September 30,		December 31,		For the Nine Months Ended September 30,
(In thousands)	2016		2015		2016		2015
Real estate	$	646,102	$	580,830	$	33,028	$	51,467
Energy	80,900		93,719		7,174		(25,124		)
Hedge equity	71,371		70,580		791		(3,925		)
Other funds	433,327		424,911		19,392		28,420
Total	$	1,231,700	$	1,170,040	$	60,385	$	50,838

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Real Estate Real Estate (Tables)

9 Months Ended

Sep. 30, 2016

Real Estate [Abstract]

Schedule of Real Estate Investments

Investment in real estate represents directly owned property held for investment, as follows:    

	Carrying Value
	September 30,		December 31,
(In thousands)	2016		2015
Properties in operation	$	441,795	$	226,055
Properties under development	666,687		710,312
Total	$	1,108,482	$	936,367

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Loans Receivable Loans Receivable (Tables)

9 Months Ended

Sep. 30, 2016

Receivables [Abstract]

Schedule of Loans Receivable

Loans receivable are as follows:

(In thousands)	September 30, 2016		December 31, 2015
Amortized cost (net of valuation allowance):
Real estate loans	$	96,312	$	200,499
Commercial loans	17,684		72,604
Total	$	113,996	$	273,103
Fair value:
Real estate loans	$	97,296	$	201,641
Commercial loans	19,187		74,106
Total	$	116,483	$	275,747
Valuation allowance:
Specific	$	1,025	$	—
General	2,197		2,094
Total	$	3,222	$	2,094
	For the Three Months Ended September 30,
	2016		2015
Increase in valuation allowance	$	467	$	19
	For the Nine Months Ended September 30,
	2016		2015
Increase (decrease) in valuation allowance	$	1,128	$	(81	)

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Realized And Unrealized Investment Gains (Losses) (Tables)

9 Months Ended

Sep. 30, 2016

Realized and Unrealized Investment Gains (Losses) [Abstract]

Realized and Unrealized Investment Gains (Losses)

Realized and unrealized investment gains (losses) are as follows:

	For the Three Months Ended September 30,						For the Nine Months Ended September 30,
(In thousands)	2016			2015			2016			2015
Realized investment gains (losses):
Fixed maturity securities:
Gains	$	33,798		$	1,341		$	66,972		$	8,178
Losses	(1,150		)	(2,171		)	(5,570		)	(2,810		)
Equity securities available for sale	8,441			(21		)	13,037			9,639
Investment funds	(3,788		)	70,648			(9,041		)	92,821
Real estate	687			—			5,247			—
Other (1)	137,750			(3,378		)	136,863			5,192
Net realized gains on investments sales	175,738			66,419			207,508			113,020
Other-than-temporary impairments (2)	—			(12,515		)	(18,114		)	(12,515		)
Net investment gains	175,738			53,904			189,394			100,505
Income tax expense	(61,508		)	(18,866		)	(66,288		)	(35,177		)
After-tax net realized investment gains	$	114,230		$	35,038		$	123,106		$	65,328

Unrealized Gain (Loss) on Investments

Change in unrealized investment gains (losses)of available for sale securities:
Fixed maturity securities	$	(45,388	)	$	2,449		$	169,933		$	(102,863	)
Previously impaired fixed maturity securities	(1,406		)	50			413			73
Equity securities available for sale	(28,517		)	(2,353		)	12,433			(15,977		)
Investment funds	3,143			(7,876		)	16,028			(16,417		)
Total change in unrealized investment gains (losses)	(72,168		)	(7,730		)	198,807			(135,184		)
Income tax benefit (expense)	24,493			12,229			(64,594		)	56,354
Noncontrolling interests	57			94			66			106
After-tax change in unrealized investment gains (losses) of available for sale securities	$	(47,618	)	$	4,593		$	134,279		$	(78,724	)

______________________

(1) Other includes a gain of $134.9 million from the sale of Aero Precision Industries, and certain related aviation services business, for the three and nine months ended September 30, 2016.

(2) Other than temporary impairments (OTTI) for the nine months ended September 30, 2016 of $18.1 million were related to equity securities available for sale. OTTI for the three and nine months ended September 30, 2015 of $12.5 million were related to equity securities available for sale and fixed maturity securities of $3.5 million and $9.0 million, respectively.

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Securities In An Unrealized Loss Position Securities In An Unrealized Loss Position (Tables)

9 Months Ended

Sep. 30, 2016

Statement of Financial Position [Abstract]

Securities in an unrealized loss position

The following tables summarize all securities in an unrealized loss position at September 30, 2016 and December 31, 2015 by the length of time those securities have been continuously in an unrealized loss position:

	Less Than 12 Months				12 Months or Greater				Total
(In thousands)	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
September 30, 2016
U.S. government and government agency	$	54,550	$	279	$	39,092	$	652	$	93,642	$	931
State and municipal	217,215		1,095		138,082		1,490		355,297		2,585
Mortgage-backed securities	251,969		1,851		105,927		3,924		357,896		5,775
Asset-backed securities	918,983		5,718		214,436		6,356		1,133,419		12,074
Corporate	337,940		2,152		98,162		7,722		436,102		9,874
Foreign	52,233		640		30,842		1,850		83,075		2,490
Fixed maturity securities	1,832,890		11,735		626,541		21,994		2,459,431		33,729
Common stocks	18,112		779		8,116		1,662		26,228		2,441
Preferred stocks	46,135		8,199		24,845		829		70,980		9,028
Equity securities available for sale	64,247		8,978		32,961		2,491		97,208		11,469
Total	$	1,897,137	$	20,713	$	659,502	$	24,485	$	2,556,639	$	45,198
December 31, 2015
U.S. government and government agency	$	101,660	$	487	$	64,500	$	1,846	$	166,160	$	2,333
State and municipal	501,952		4,404		106,681		1,865		608,633		6,269
Mortgage-backed securities	381,986		3,639		184,807		7,669		566,793		11,308
Asset-backed securities	1,091,078		7,703		190,467		6,711		1,281,545		14,414
Corporate	1,232,940		35,406		76,797		8,987		1,309,737		44,393
Foreign	169,190		8,822		19,528		3,867		188,718		12,689
Fixed maturity securities	3,478,806		60,461		642,780		30,945		4,121,586		91,406
Common stocks	18,641		18,005		7,829		1,184		26,470		19,189
Preferred stocks	—		—		22,320		3,353		22,320		3,353
Equity securities available for sale	18,641		18,005		30,149		4,537		48,790		22,542
Total	$	3,497,447	$	78,466	$	672,929	$	35,482	$	4,170,376	$	113,948

Non-Investment Grade Fixed Maturity Securities

Fixed Maturity Securities – A summary of the Company’s non-investment grade fixed maturity securities that were in an unrealized loss position at September 30, 2016 is presented in the table below:

($ in thousands)	Number of Securities	Aggregate Fair Value		Gross Unrealized Loss
Corporate	10	$	27,531	$	3,045
Mortgage-backed securities	11	23,921		1,229
Foreign government	4	23,001		1,101
Asset-backed securities	5	8,418		405
State and municipal	1	7,007		25
Total	31	$	89,878	$	5,805

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Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2016

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Assets And Liabilities Measured At Fair value, On A Recurring Basis

The following tables present the assets and liabilities measured at fair value on a recurring basis as of September 30, 2016 and December 31, 2015 by level:

(In thousands)	Total		Level 1		Level 2		Level 3
September 30, 2016
Assets:
Fixed maturity securities available for sale:
U.S. government and government agency	$	554,993	$	—	$	554,993	$	—
State and municipal	4,561,715		—		4,561,715		—
Mortgage-backed securities	1,263,005		—		1,263,005		—
Asset-backed securities	2,268,861		—		2,268,676		185
Corporate	3,914,168		—		3,914,168		—
Foreign government	965,752		—		965,752		—
Total fixed maturity securities available for sale	13,528,494		—		13,528,309		185
Equity securities available for sale:
Common stocks	35,671		27,555		—		8,116
Preferred stocks	123,304		—		119,630		3,674
Total equity securities available for sale	158,975		27,555		119,630		11,790
Arbitrage trading account	602,965		320,280		282,685		—
Total	$	14,290,434	$	347,835	$	13,930,624	$	11,975
Liabilities:
Trading account securities sold but not yet purchased	$	60,959	$	60,947	$	12	$	—
December 31, 2015
Assets:
Fixed maturity securities available for sale:
U.S. government and government agency	$	670,419	$	—	$	670,419	$	—
State and municipal	4,460,179		—		4,460,179		—
Mortgage-backed securities	1,199,859		—		1,199,859		—
Asset-backed securities	1,705,172		—		1,704,973		199
Corporate	3,475,038		—		3,474,884		154
Foreign government	837,460		—		837,460		—
Total fixed maturity securities available for sale	12,348,127		—		12,347,774		353
Equity securities available for sale:
Common stocks	37,273		29,444		—		7,829
Preferred stocks	113,593		—		109,969		3,624
Total equity securities available for sale	150,866		29,444		109,969		11,453
Arbitrage trading account	376,697		256,914		119,607		176
Total	$	12,875,690	$	286,358	$	12,577,350	$	11,982
Liabilities:
Trading account securities sold but not yet purchased	$	37,035	$	35,559	$	1,476	$	—

Summarize Changes In Level 3 Assets

The following tables summarize changes in Level 3 assets and liabilities for the nine months ended September 30, 2016 and for the year ended December 31, 2015:

	Gains (Losses) Included in:
(In thousands)	Beginning Balance		Earnings (Losses)			Other Comprehensive Income (Loss)			Impairments			Purchases		(Sales)			Paydowns / Maturities			Transfers			Ending Balance
																				In / (Out)
Nine months ended September 30, 2016:
Assets:
Fixed maturities securities available for sale:
Asset-backed securities	$	199	$	3		$	13		$	—		$	—	$	—		$	(30	)	$	—		$	185
Corporate	154		177			—			—			—		(331		)	—			—			—
Total	353		180			13			—			—		(331		)	(30		)	—			185
Equity securities available for sale:
Common stocks	7,829		—			(478		)	—			765		—			—			—			8,116
Preferred stocks	3,624		50			—			—			—		—			—			—			3,674
Total	11,453		50			(478		)	—			765		—			—			—			11,790
Arbitrage trading account	176		(176		)	—			—			—		—			—			—			—
Total	$	11,982	$	54		$	(465	)	$	—		$	765	$	(331	)	$	(30	)	$	—		$	11,975
Year ended December 31, 2015:
Assets:
Fixed maturities securities available for sale:
Asset-backed securities	$	20,611	$	19		$	191		$	—		$	—	$	—		$	(1,820	)	$	(18,802	)	$	199
Corporate	154		—			—			—			—		—			—			—			154
Total	20,765		19			191			—			—		—			(1,820		)	(18,802		)	353
Equity securities available for sale:
Common stocks	10,741		—			(273		)	(2,331		)	—		(308		)	—			—			7,829
Preferred stocks	3,713		(89		)	—			—			—		—			—			—			3,624
Total	14,454		(89		)	(273		)	(2,331		)	—		(308		)	—			—			11,453
Arbitrage trading account	720		(799		)	—			—			72,640		(71,921		)	—			(464		)	176
Total	$	35,939	$	(869	)	$	(82	)	$	(2,331	)	$	72,640	$	(72,229	)	$	(1,820	)	$	(19,266	)	$	11,982

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Reinsurance (Tables)

9 Months Ended

Sep. 30, 2016

Reinsurance Disclosures [Abstract]

Reinsurance Financial Information

The following is a summary of reinsurance financial information:

	For the Three Months						For the Nine Months
	Ended September 30,						Ended September 30,
(In thousands)	2016			2015			2016			2015
Written premiums:
Direct	$	1,643,870		$	1,601,344		$	5,061,646		$	4,852,584
Assumed	224,979			221,237			702,265			633,200
Ceded	(261,484		)	(251,544		)	(850,255		)	(795,420		)
Total net premiums written	$	1,607,365		$	1,571,037		$	4,913,656		$	4,690,364
Earned premiums:
Direct	$	1,647,033		$	1,575,624		$	4,824,768		$	4,646,343
Assumed	216,758			217,668			635,443			632,362
Ceded	(277,847		)	(261,734		)	(787,139		)	(782,093		)
Total net premiums earned	$	1,585,944		$	1,531,558		$	4,673,072		$	4,496,612
Ceded losses and loss expenses incurred	$	213,065		$	123,765		$	507,258		$	374,084
Ceded commissions earned	$	47,315		$	45,946		$	143,809		$	129,766

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Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2016

Fair Value Disclosures [Abstract]

Carrying Amounts And Estimated Fair Values Of Financial Instruments

The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments:

	September 30, 2016				December 31, 2015
(In thousands)	Carrying Value		Fair Value		Carrying Value		Fair Value
Assets:
Fixed maturity securities	$	13,616,671	$	13,636,291	$	12,444,394	$	12,462,847
Equity securities available for sale	158,975		158,975		150,866		150,866
Arbitrage trading account	602,965		602,965		376,697		376,697
Loans receivable	113,996		116,483		273,103		275,747
Cash and cash equivalents	873,064		873,064		763,631		763,631
Trading account receivables from brokers and clearing organizations	185,548		185,548		383,115		383,115
Due from broker	—		—		1,713		1,713
Liabilities:
Due to broker	101,405		101,405		—		—
Trading account securities sold but not yet purchased	60,959		60,959		37,035		37,035
Subordinated debentures	727,390		779,056		340,320		355,880
Senior notes and other debt	1,762,487		1,997,430		1,844,621		2,029,572

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Restricted Stock Units (Tables)

9 Months Ended

Sep. 30, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary Of Restricted Stock Units Issued

A summary of RSUs issued in the nine months ended September 30, 2016 and 2015 follows:

($ in thousands)	Units	Fair Value
Nine months ended September 30,
2016	990,487	$	57,959
2015	971,457	$	54,439

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Industry Segments (Tables)

9 Months Ended

Sep. 30, 2016

Segment Reporting [Abstract]

Financial Information Of Company Operating Segments

	Revenues
(In thousands)	Earned Premiums		Investment Income		Other		Total		Pre-Tax Income (Loss)			Net Income (Loss) to Common Stockholders
Three months ended September 30, 2016
Insurance	$	1,431,664	$	117,388	$	22,819	$	1,571,871	$	215,649		$	144,310
Reinsurance	154,280		21,478		—		175,758		22,171			15,167
Corporate, other and eliminations (1)	—		6,802		89,560		96,362		(81,941		)	(53,055		)
Net investment gains	—		—		175,736		175,736		175,736			114,228
Total	$	1,585,944	$	145,668	$	288,115	$	2,019,727	$	331,615		$	220,650
Three months ended September 30, 2015
Insurance	$	1,379,501	$	106,989	$	23,021	$	1,509,511	$	204,109		$	139,446
Reinsurance	152,057		19,468		—		171,525		22,413			15,807
Corporate, other and eliminations (1)	—		6,757		119,260		126,017		(51,506		)	(37,684		)
Net investment gains	—		—		53,904		53,904		53,904			35,038
Total	$	1,531,558	$	133,214	$	196,185	$	1,860,957	$	228,920		$	152,607
Nine months ended September 30, 2016:
Insurance	$	4,206,887	322,779		$	77,215	$	4,606,881	$	604,825		$	407,346
Reinsurance	466,185		59,244		—		525,429		61,041			42,285
Corporate, other and eliminations (1)	—		22,827		338,009		360,836		(190,655		)	(123,610		)
Net investment gains	—		—		189,394		189,394		189,394			123,106
Total	$	4,673,072	$	404,850	$	604,618	$	5,682,540	$	664,605		$	449,127
Nine months ended September 30, 2015:
Insurance	$	4,042,159	$	309,337	$	72,981	$	4,424,477	$	575,748		$	395,581
Reinsurance	454,453		54,575		—		509,028		69,797			49,134
Corporate, other and eliminations (1)	—		21,124		340,267		361,391		(170,226		)	(116,094		)
Net investment gains	—		—		100,505		100,505		100,505			65,328
Total	$	4,496,612	$	385,036	$	513,753	$	5,395,401	$	575,824		$	393,949

________

(1) Corporate, other and eliminations represent corporate revenues and expenses that are not allocated to business segments.

Identifiable Assets By Segment

Identifiable Assets

(In thousands)	September 30, 2016		December 31, 2015
Insurance	$	18,972,237	$	18,063,730
Reinsurance	2,585,307		2,441,340
Corporate, other and eliminations	1,788,112		1,219,086
Consolidated	$	23,345,656	$	21,724,156

Net Premiums Earned By Major Line Of Business

Net premiums earned by major line of business are as follows:

	For the Three Months				For the Nine Months
	Ended September 30,				Ended September 30,
(In thousands)	2016		2015		2016		2015
Insurance:
Other liability	$	465,068	$	418,133	$	1,331,143	$	1,216,411
Workers’ compensation	355,604		347,745		1,047,412		1,010,279
Short-tail lines (1)	317,498		327,357		977,138		973,606
Commercial automobile	164,540		170,660		481,249		506,229
Professional liability	128,954		115,606		369,945		335,634
Total Insurance	1,431,664		1,379,501		4,206,887		4,042,159
Reinsurance:
Casualty	93,757		103,198		290,373		314,462
Property	60,523		48,859		175,812		139,991
Total Reinsurance	154,280		152,057		466,185		454,453
Total	$	1,585,944	$	1,531,558	$	4,673,072	$	4,496,612

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General General (Details)	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Federal Income Tax Rate	35.00%

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Per Share Data (Weighted Average Number of Common Shares Used In the Computation of Basic and Diluted Earnings per Share) (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Basic (shares)	122,562	123,163	122,652	124,294
Diluted (shares)	128,556	128,947	128,501	130,563

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Acquistions Acquisitions (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill	$ 134,146	$ 153,291
Premiums and fees receivable	1,742,210	1,669,186
Noncontrolling interests	36,059	32,962
Selling and Marketing Expense [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	$ 6,764
Business Acquisition, Percentage of Voting Interests Acquired	85.00%
Cash and cash equivalents	$ 4,266
Real estate, furniture and equipment	701
Goodwill and other intangibles assets	45,782
Premiums and fees receivable	3,845
Other assets	5,213
Total assets acquired	66,571
Other liabilities assumed	(4,931)
Noncontrolling interests	(3,850)
Net assets acquired	57,790	$ 42,300
Property and Casualty, Commercial Insurance Product Line [Member]
Business Acquisition [Line Items]
Business Acquisition, Transaction Costs	$ 15,500

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Acquistions Intangibles (Details)	Sep. 30, 2016
Selling and Marketing Expense [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	85.00%

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Statements of Comprehensive Income (Loss) Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period				$ (66,698)
Other comprehensive income (loss)		$ (67,146)	$ (58,038)	56,824	$ (155,545)
Accumulated Other Comprehensive Income (Loss), End of Period		(9,808)		(9,808)
Net realized investment gains		175,738	66,419	207,508	113,020
Income before income taxes		331,615	228,920	664,605	575,824
Income before taxes		606,348	573,541	1,770,450	1,698,169
Tax effect		(110,952)	(76,184)	(214,789)	(181,595)
After-tax amounts reclassified		220,663	152,736	449,816	394,229
Unrealized investment gains, pre-tax		(72,188)	(7,731)	198,808	(135,186)
Unrealized investment gains, tax effect		24,512	12,228	(64,595)	56,354
Unrealized investment gains, after-tax amounts		(47,676)	4,497	134,213	(78,832)
Currency translation adjustment, pre-tax		(19,470)	(62,535)	(77,389)	(76,713)
Currency translation adjustment, tax effect		0	0	0
Change in unrealized currency translation adjustments		(19,470)	(62,535)	(77,389)	(76,713)
Other comprehensive income (loss), pre-tax		(91,658)	(70,266)	121,419	(211,899)
Other comprehensive income (loss), tax effect		24,512	12,228	(64,595)	56,354
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period		362,593	222,882	180,695	306,199
Other comprehensive income (loss) before reclassifications		(20,968)	3,943	170,824	(69,078)
Amounts reclassified from AOCI		(26,708)	554	(36,611)	(9,754)
Other comprehensive income (loss)		(47,676)	4,497	134,213	(78,832)
Unrealized investment gain related to non-controlling interest		57	94	66	106
Accumulated Other Comprehensive Income (Loss), End of Period		314,974	227,473	314,974	227,473
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period		(305,312)	(136,827)	(247,393)	(122,649)
Other comprehensive income (loss) before reclassifications		(19,470)	(62,535)	(77,389)	(76,713)
Amounts reclassified from AOCI		0	0	0	0
Other comprehensive income (loss)		(19,470)	(62,535)	(77,389)	(76,713)
Unrealized investment gain related to non-controlling interest		0	0	0	0
Accumulated Other Comprehensive Income (Loss), End of Period		(324,782)	(199,362)	(324,782)	(199,362)
Change in unrealized currency translation adjustments				(77,389)	(76,713)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period		57,281	86,055	(66,698)	183,550
Other comprehensive income (loss) before reclassifications		(40,438)	(58,592)	93,435	(145,791)
Amounts reclassified from AOCI		(26,708)	554	(36,611)	(9,754)
Other comprehensive income (loss)		(67,146)	(58,038)	56,824	(155,545)
Unrealized investment gain related to non-controlling interest		57	94	66	106
Accumulated Other Comprehensive Income (Loss), End of Period		(9,808)	28,111	(9,808)	28,111
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Net realized investment gains	[1]	(41,090)	852	(56,325)	(15,006)
Tax effect	[2]	(14,382)	298	(19,714)	(5,252)
After-tax amounts reclassified		(26,708)	554	(36,611)	(9,754)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Income before income taxes		0	0	0	0
Tax effect		0	0	0	0
After-tax amounts reclassified		0	0	0	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Income before income taxes		(41,090)	852	(56,325)	(15,006)
Tax effect		14,382	(298)	19,714	5,252
After-tax amounts reclassified		$ (26,708)	$ 554	$ (36,611)	$ (9,754)

[1] Net investment (gains) losses in the consolidated statements of income.

[2] Income tax expense in the consolidated statements of income.

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Statements of Cash Flow (Details) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Supplemental Cash Flow Information [Abstract]
Interest payments	$ 124,791,000	$ 124,632,000
Income taxes paid	$ 99,161,000	$ 96,364,000

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Investments In Fixed Maturity Securities Investments in Fixed Maturity Securities (Investments in fixed maturity securities) (Details) - USD ($)		Sep. 30, 2016		Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Total held to maturity, Amortized Cost		$ 88,177,000		$ 96,267,000
Held to Maturity Securities Accumulated Unrecognized Holding Gain		19,620,000		(18,453,000)
Held to Maturity Securities Accumulated Unrecognized Holding Loss		0		0
Total held to maturity, Fair Value		107,797,000		114,720,000
Total held to maturity, Carrying Value		88,177,000		96,267,000
Total available for sale, Amortized Cost		13,019,875,000		12,012,041,000
Total available for sale, Gross Unrealized Gains		542,348,000		427,492,000
Total available for sale, Gross Unrealized Losses		(33,729,000)		(91,406,000)
Total available for sale, Fair Value		13,528,494,000		12,348,127,000
Total available for sale, Carrying Value		13,528,494,000		12,348,127,000
Total investments in fixed maturity securities, Amortized Value		13,108,052,000		12,108,308,000
Total investments in fixed maturity securities, Gross Unrealized Gains		561,968,000		445,945,000
Total investments in fixed maturity securities, Gross Unrealized Losses		(33,729,000)		(91,406,000)
Total investments in fixed maturity securities, Fair Value		13,636,291,000		12,462,847,000
Total investments in fixed maturity securities, Carrying Value		$ 13,616,671,000		12,444,394,000
Minimum ownership of Common stockholders equity		10.00%
Foreign government
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		$ 909,765,000		799,839,000
Total available for sale, Gross Unrealized Gains		58,477,000		50,310,000
Total available for sale, Gross Unrealized Losses		(2,490,000)		(12,689,000)
Total available for sale, Fair Value		965,752,000		837,460,000
Total available for sale, Carrying Value		965,752,000		837,460,000
Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		108,928,000		64,975,000
Total available for sale, Gross Unrealized Gains		1,032,000		875,000
Total available for sale, Gross Unrealized Losses		(916,000)		(128,000)
Total available for sale, Fair Value		109,044,000		65,722,000
Total available for sale, Carrying Value		109,044,000		65,722,000
U.S. government and government agency
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		530,541,000		645,092,000
Total available for sale, Gross Unrealized Gains		25,383,000		27,660,000
Total available for sale, Gross Unrealized Losses		(931,000)		(2,333,000)
Total available for sale, Fair Value		554,993,000		670,419,000
Total available for sale, Carrying Value		554,993,000		670,419,000
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		2,707,492,000		2,510,816,000
Total available for sale, Gross Unrealized Gains		124,159,000		102,909,000
Total available for sale, Gross Unrealized Losses		(1,767,000)		(3,737,000)
Total available for sale, Fair Value		2,829,884,000		2,609,988,000
Total available for sale, Carrying Value		2,829,884,000		2,609,988,000
Corporation [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		374,355,000		388,904,000
Total available for sale, Gross Unrealized Gains		15,424,000		14,039,000
Total available for sale, Gross Unrealized Losses		(235,000)		(402,000)
Total available for sale, Fair Value		389,544,000		402,541,000
Total available for sale, Carrying Value		389,544,000		402,541,000
Debt, State Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		528,380,000		583,456,000
Total available for sale, Gross Unrealized Gains		33,688,000		28,068,000
Total available for sale, Gross Unrealized Losses		(560,000)		(2,070,000)
Total available for sale, Fair Value		561,508,000		609,454,000
Total available for sale, Carrying Value		561,508,000		609,454,000
Revenue Subject to Refund [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		366,360,000		439,772,000
Total available for sale, Gross Unrealized Gains		31,900,000		32,056,000
Total available for sale, Gross Unrealized Losses		(9,000)		(31,000)
Total available for sale, Fair Value		398,251,000		471,797,000
Total available for sale, Carrying Value		398,251,000		471,797,000
Residential Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost	[1]	1,131,545,000		1,126,382,000
Total available for sale, Gross Unrealized Gains	[1]	27,275,000		18,935,000
Total available for sale, Gross Unrealized Losses	[1]	(4,859,000)		(11,180,000)
Total available for sale, Fair Value		1,153,961,000	[1]	1,134,137,000
Total available for sale, Carrying Value	[1]	1,153,961,000		1,134,137,000
Non-credit portion of other-than-temporary impairments (OTTI)		857,252		1,269,491
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		3,746,954,000		3,403,953,000
Total available for sale, Gross Unrealized Gains		177,088,000		115,478,000
Total available for sale, Gross Unrealized Losses		(9,874,000)		(44,393,000)
Total available for sale, Fair Value		3,914,168,000		3,475,038,000
Total available for sale, Carrying Value		3,914,168,000		3,475,038,000
State and municipal
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		4,326,936,000		4,265,106,000
Total available for sale, Gross Unrealized Gains		237,364,000		201,342,000
Total available for sale, Gross Unrealized Losses		(2,585,000)		(6,269,000)
Total available for sale, Fair Value		4,561,715,000		4,460,179,000
Total available for sale, Carrying Value		4,561,715,000		4,460,179,000
Debt, Local Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		350,349,000		342,158,000
Total available for sale, Gross Unrealized Gains		32,193,000		24,270,000
Total available for sale, Gross Unrealized Losses		(14,000)		(29,000)
Total available for sale, Fair Value		382,528,000		366,399,000
Total available for sale, Carrying Value		382,528,000		366,399,000
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		1,240,473,000		1,191,357,000
Total available for sale, Gross Unrealized Gains		28,307,000		19,810,000
Total available for sale, Gross Unrealized Losses		(5,775,000)		(11,308,000)
Total available for sale, Fair Value		1,263,005,000		1,199,859,000
Total available for sale, Carrying Value		1,263,005,000		1,199,859,000
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		2,265,206,000		1,706,694,000
Total available for sale, Gross Unrealized Gains		15,729,000		12,892,000
Total available for sale, Gross Unrealized Losses		(12,074,000)		(14,414,000)
Total available for sale, Fair Value		2,268,861,000		1,705,172,000
Total available for sale, Carrying Value		2,268,861,000		1,705,172,000
Industrial Property [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		2,168,312,000		1,976,393,000
Total available for sale, Gross Unrealized Gains		111,260,000		75,168,000
Total available for sale, Gross Unrealized Losses		(3,692,000)		(30,027,000)
Total available for sale, Fair Value		2,275,880,000		2,021,534,000
Total available for sale, Carrying Value		2,275,880,000		2,021,534,000
Domestic Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		1,288,472,000		1,153,096,000
Total available for sale, Gross Unrealized Gains		52,419,000		31,744,000
Total available for sale, Gross Unrealized Losses		(5,384,000)		(11,819,000)
Total available for sale, Fair Value		1,335,507,000		1,173,021,000
Total available for sale, Carrying Value		1,335,507,000		1,173,021,000
Public Utility, Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		199,941,000		192,857,000
Total available for sale, Gross Unrealized Gains		11,593,000		8,321,000
Total available for sale, Gross Unrealized Losses		(785,000)		(2,527,000)
Total available for sale, Fair Value		210,749,000		198,651,000
Total available for sale, Carrying Value		210,749,000		198,651,000
Other Security Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available for sale, Amortized Cost		90,229,000		81,607,000
Total available for sale, Gross Unrealized Gains		1,816,000		245,000
Total available for sale, Gross Unrealized Losses		(13,000)		(20,000)
Total available for sale, Fair Value		92,032,000		81,832,000
Total available for sale, Carrying Value		92,032,000		81,832,000
State and municipal
Schedule of Available-for-sale Securities [Line Items]
Total held to maturity, Amortized Cost		71,608,000		77,129,000
Held to Maturity Securities Accumulated Unrecognized Holding Gain		17,388,000		(16,246,000)
Held to Maturity Securities Accumulated Unrecognized Holding Loss		0		0
Total held to maturity, Fair Value		88,996,000		93,375,000
Total held to maturity, Carrying Value		71,608,000		77,129,000
Residential Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total held to maturity, Amortized Cost		16,569,000		19,138,000
Held to Maturity Securities Accumulated Unrecognized Holding Gain		2,232,000		(2,207,000)
Held to Maturity Securities Accumulated Unrecognized Holding Loss		0		0
Total held to maturity, Fair Value		18,801,000		21,345,000
Total held to maturity, Carrying Value		$ 16,569,000		$ 19,138,000

[1] Gross unrealized losses for residential mortgage-backed securities include $857,252 and $1,269,491 as of September 30, 2016 and December 31, 2015, respectively, related to the non-credit portion of other-than-temporary impairments (“OTTI”) recognized in accumulated other comprehensive income.

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Investments In Fixed Maturity Securities Investments in Fixed Maturity Securities (Amortized cost and fair value of fixed maturity securities) (Details) - USD ($) $ in Thousands		Sep. 30, 2016		Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment		$ 88,177		$ 96,267
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain		(19,620)		18,453
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		0		0
Held-to-maturity Securities, Fair Value		107,797		114,720
Held-to-maturity Securities		88,177		96,267
Available-for-sale Debt Securities, Amortized Cost Basis		13,019,875		12,012,041
Available For Sale Securities Debt Securities Gross Unrealized Gain		542,348		427,492
Available For Sale Securities Debt Securities Gross Unrealized Losses		(33,729)		(91,406)
Available For Sale Securities Debt Securities Fair Value		13,528,494		12,348,127
Available-for-sale Securities, Debt Securities		13,528,494		12,348,127
Marketable Securities Fixed Maturities Gross Unrealized Gains		561,968		445,945
Fixed maturity securities		13,616,671		12,444,394
Marketable Securities Fixed Maturities Gross Unrealized Losses		33,729		91,406
Amortized Cost, Due in one year or less		1,032,042
Amortized Cost, Due after one year through five years		5,068,197
Amortized Cost, Due after five years through ten years		3,287,833
Amortized Cost, Due after ten years		2,462,938
Amortized Cost, Mortgaged-backed securities		1,257,042
Total investments in fixed maturity securities, Amortized Value		13,108,052		12,108,308
Fair Value, Due in one year or less		1,054,113
Fair Value, Due after one year through five years		5,246,081
Fair Value, Due after five years through ten years		3,500,463
Fair Value, Due after ten years		2,553,828
Fair Value, Mortgage-backed securities		1,281,806
Total investments in fixed maturity securities, Fair Value		13,636,291		12,462,847
Foreign government
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		909,765		799,839
Available For Sale Securities Debt Securities Gross Unrealized Gain		58,477		50,310
Available For Sale Securities Debt Securities Gross Unrealized Losses		(2,490)		(12,689)
Available For Sale Securities Debt Securities Fair Value		965,752		837,460
Available-for-sale Securities, Debt Securities		965,752		837,460
Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		108,928		64,975
Available For Sale Securities Debt Securities Gross Unrealized Gain		1,032		875
Available For Sale Securities Debt Securities Gross Unrealized Losses		(916)		(128)
Available For Sale Securities Debt Securities Fair Value		109,044		65,722
Available-for-sale Securities, Debt Securities		109,044		65,722
Residential Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	[1]	1,131,545		1,126,382
Available For Sale Securities Debt Securities Gross Unrealized Gain	[1]	27,275		18,935
Available For Sale Securities Debt Securities Gross Unrealized Losses	[1]	(4,859)		(11,180)
Available For Sale Securities Debt Securities Fair Value		1,153,961	[1]	1,134,137
Available-for-sale Securities, Debt Securities	[1]	1,153,961		1,134,137
State and municipal
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		4,326,936		4,265,106
Available For Sale Securities Debt Securities Gross Unrealized Gain		237,364		201,342
Available For Sale Securities Debt Securities Gross Unrealized Losses		(2,585)		(6,269)
Available For Sale Securities Debt Securities Fair Value		4,561,715		4,460,179
Available-for-sale Securities, Debt Securities		4,561,715		4,460,179
U.S. government and government agency
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		530,541		645,092
Available For Sale Securities Debt Securities Gross Unrealized Gain		25,383		27,660
Available For Sale Securities Debt Securities Gross Unrealized Losses		(931)		(2,333)
Available For Sale Securities Debt Securities Fair Value		554,993		670,419
Available-for-sale Securities, Debt Securities		554,993		670,419
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		2,707,492		2,510,816
Available For Sale Securities Debt Securities Gross Unrealized Gain		124,159		102,909
Available For Sale Securities Debt Securities Gross Unrealized Losses		(1,767)		(3,737)
Available For Sale Securities Debt Securities Fair Value		2,829,884		2,609,988
Available-for-sale Securities, Debt Securities		2,829,884		2,609,988
Debt, State Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		528,380		583,456
Available For Sale Securities Debt Securities Gross Unrealized Gain		33,688		28,068
Available For Sale Securities Debt Securities Gross Unrealized Losses		(560)		(2,070)
Available For Sale Securities Debt Securities Fair Value		561,508		609,454
Available-for-sale Securities, Debt Securities		561,508		609,454
Revenue Subject to Refund [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		366,360		439,772
Available For Sale Securities Debt Securities Gross Unrealized Gain		31,900		32,056
Available For Sale Securities Debt Securities Gross Unrealized Losses		(9)		(31)
Available For Sale Securities Debt Securities Fair Value		398,251		471,797
Available-for-sale Securities, Debt Securities		398,251		471,797
Corporation [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		374,355		388,904
Available For Sale Securities Debt Securities Gross Unrealized Gain		15,424		14,039
Available For Sale Securities Debt Securities Gross Unrealized Losses		(235)		(402)
Available For Sale Securities Debt Securities Fair Value		389,544		402,541
Available-for-sale Securities, Debt Securities		389,544		402,541
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		3,746,954		3,403,953
Available For Sale Securities Debt Securities Gross Unrealized Gain		177,088		115,478
Available For Sale Securities Debt Securities Gross Unrealized Losses		(9,874)		(44,393)
Available For Sale Securities Debt Securities Fair Value		3,914,168		3,475,038
Available-for-sale Securities, Debt Securities		3,914,168		3,475,038
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		1,240,473		1,191,357
Available For Sale Securities Debt Securities Gross Unrealized Gain		28,307		19,810
Available For Sale Securities Debt Securities Gross Unrealized Losses		(5,775)		(11,308)
Available For Sale Securities Debt Securities Fair Value		1,263,005		1,199,859
Available-for-sale Securities, Debt Securities		1,263,005		1,199,859
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		2,265,206		1,706,694
Available For Sale Securities Debt Securities Gross Unrealized Gain		15,729		12,892
Available For Sale Securities Debt Securities Gross Unrealized Losses		(12,074)		(14,414)
Available For Sale Securities Debt Securities Fair Value		2,268,861		1,705,172
Available-for-sale Securities, Debt Securities		2,268,861		1,705,172
Industrial Property [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		2,168,312		1,976,393
Available For Sale Securities Debt Securities Gross Unrealized Gain		111,260		75,168
Available For Sale Securities Debt Securities Gross Unrealized Losses		(3,692)		(30,027)
Available For Sale Securities Debt Securities Fair Value		2,275,880		2,021,534
Available-for-sale Securities, Debt Securities		2,275,880		2,021,534
Domestic Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		1,288,472		1,153,096
Available For Sale Securities Debt Securities Gross Unrealized Gain		52,419		31,744
Available For Sale Securities Debt Securities Gross Unrealized Losses		(5,384)		(11,819)
Available For Sale Securities Debt Securities Fair Value		1,335,507		1,173,021
Available-for-sale Securities, Debt Securities		1,335,507		1,173,021
Public Utility, Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		199,941		192,857
Available For Sale Securities Debt Securities Gross Unrealized Gain		11,593		8,321
Available For Sale Securities Debt Securities Gross Unrealized Losses		(785)		(2,527)
Available For Sale Securities Debt Securities Fair Value		210,749		198,651
Available-for-sale Securities, Debt Securities		210,749		198,651
Other Security Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		90,229		81,607
Available For Sale Securities Debt Securities Gross Unrealized Gain		1,816		245
Available For Sale Securities Debt Securities Gross Unrealized Losses		(13)		(20)
Available For Sale Securities Debt Securities Fair Value		92,032		81,832
Available-for-sale Securities, Debt Securities		92,032		81,832
State and municipal
Schedule of Available-for-sale Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment		71,608		77,129
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain		(17,388)		16,246
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		0		0
Held-to-maturity Securities, Fair Value		88,996		93,375
Held-to-maturity Securities		71,608		77,129
Residential Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment		16,569		19,138
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain		(2,232)		2,207
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss		0		0
Held-to-maturity Securities, Fair Value		18,801		21,345
Held-to-maturity Securities		$ 16,569		$ 19,138

[1] Gross unrealized losses for residential mortgage-backed securities include $857,252 and $1,269,491 as of September 30, 2016 and December 31, 2015, respectively, related to the non-credit portion of other-than-temporary impairments (“OTTI”) recognized in accumulated other comprehensive income.

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Investments in Equity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Cost	$ 163,656	$ 165,192
Gross Unrealized, Gains	6,788	8,216
Gross Unrealized, Losses	(11,469)	(22,542)
Carrying and fair value of equity securities	158,975	150,866
Common stocks
Schedule of Available-for-sale Securities [Line Items]
Cost	37,897	56,462
Gross Unrealized, Gains	215	0
Gross Unrealized, Losses	(2,441)	(19,189)
Carrying and fair value of equity securities	35,671	37,273
Preferred stocks
Schedule of Available-for-sale Securities [Line Items]
Cost	125,759	108,730
Gross Unrealized, Gains	6,573	8,216
Gross Unrealized, Losses	(9,028)	(3,353)
Carrying and fair value of equity securities	$ 123,304	$ 113,593

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Arbitrage Trading Account (Details) - Options Held [Member] $ in Millions	Sep. 30, 2016 USD ($)
Short [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	$ 0.7
Derivative, Notional Amount	103.6
Long [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	1.2
Derivative, Notional Amount	$ 53.9

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Net Investment Income Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net Investment Income [Line Items]
Investment income	$ 147,659	$ 135,968	$ 412,485	$ 393,186
Investment expense	(1,991)	(2,754)	(7,635)	(8,150)
Net investment income	145,668	133,214	404,850	385,036
Fixed maturity securities, including cash and cash equivalents and loans receivable
Net Investment Income [Line Items]
Investment income	114,271	104,936	331,448	318,095
Investment funds
Net Investment Income [Line Items]
Investment income	25,293	22,926	60,385	50,838
Arbitrage trading account
Net Investment Income [Line Items]
Investment income	6,441	2,608	12,883	11,470
Equity securities available for sale
Net Investment Income [Line Items]
Investment income	1,069	1,109	3,217	3,513
Real estate
Net Investment Income [Line Items]
Investment income	$ 585	$ 4,389	$ 4,552	$ 9,270

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Investment Funds Investment Funds (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	21.00%
Investment funds	$ 1,231,700		$ 1,170,040
Income (Loss) from Investment Funds	60,385	$ 50,838
Alternative Investments, Fair Value Disclosure	453,000
Real estate
Schedule of Equity Method Investments [Line Items]
Investment funds	646,102		580,830
Income (Loss) from Investment Funds	33,028
Wholly Owned Properties [Member]
Schedule of Equity Method Investments [Line Items]
Income (Loss) from Investment Funds		51,467
Energy
Schedule of Equity Method Investments [Line Items]
Investment funds	80,900		93,719
Income (Loss) from Investment Funds	7,174	(25,124)
Hedge equity
Schedule of Equity Method Investments [Line Items]
Investment funds	71,371		70,580
Income (Loss) from Investment Funds	791	(3,925)
Other funds
Schedule of Equity Method Investments [Line Items]
Investment funds	433,327		$ 424,911
Income (Loss) from Investment Funds	19,392	$ 28,420
Equity Method Investee [Member]
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 53,100

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Real Estate Real Estate (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Real Estate [Abstract]
Properties in operation	$ 441,795,000	$ 226,055,000
Properties under development	666,687,000	710,312,000
Total	1,108,482,000	936,367,000
Real Estate Investment Property, Accumulated Depreciation	$ 13,345,000	$ 9,073,000

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Real Estate Real Estate (Details 1) - USD ($)	3 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Real Estate [Abstract]
Accumulated depreciation and amortization on properties	$ 13,345,000		$ 9,073,000
Real estate depreciation expense	4,117,000	$ 5,991,000
Operating Leases, Future Minimum Payments Receivable, Remainder of Fiscal Year	2,982,866
Lease future minimum payments Current	16,900,586
Operating Leases, Future Minimum Payments Receivable, in Two Years	22,572,465
Lease future minimum payments 2017	20,707,015
Future Minimum Payments 2018	19,471,136
Lease future minimum payments 2019	19,649,571
Lease future minimum payments there after	$ 411,667,096

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Loans Receivable (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 9,100		$ 9,100		$ 3,100
Loans and Leases Receivable, Gross	113,996		113,996		273,103
Loans receivable	116,483		116,483		275,747
Valuation allowance, specific	1,025		1,025		0
Valuation allowance, general	2,197		2,197		2,094
Valuation allowance of loans receivable	3,222		3,222		2,094
Decrease in valuation allowance	467	$ 19	1,128	$ (81)
Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross	96,312		96,312		200,499
Loans receivable	97,296		97,296		201,641
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross	17,684		17,684		72,604
Loans receivable	$ 19,187		$ 19,187		$ 74,106

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Realized And Unrealized Investment Gains Realized and Unrealized Investment Gains (Loss) (Realized and unrealized investmetns gains(losses)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Fixed maturity securities, gains	$ 33,798	$ 1,341	$ 66,972	$ 8,178
Fixed maturity securities, losses	(1,150)	(2,171)	(5,570)	(2,810)
Equity securities available for sale	8,441	(21)	13,037	9,639
Investment funds	(3,788)	70,648	(9,041)	92,821
Real Estate Realized Gain (Loss) on Disposal	687	0	5,247	0
Other (1)	137,750	(3,378)	136,863	5,192
Realized Gain (Loss) on Investments, Including Equity Method Investments, Excluding Other than Temporary Impairments and Allowances	175,738	66,419	207,508	113,020
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	0	(12,515)	(18,114)	(12,515)
Gain (Loss) on Investments	175,738	53,904	189,394	100,505
Net investment gains	175,736	53,904	189,394	100,505
Income tax expense	(61,508)	(18,866)	(66,288)	(35,177)
After-tax net realized investment gains	$ 114,230	$ 35,038	$ 123,106	$ 65,328

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Realized and Unrealized Investment Gains (Losses) (Change in Unrealized Gains (Losses) of Available For Sales Securities) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Realized and Unrealized Investment Gains Losses [Line Items]
pre tax realized gain from sale of wholly owned non insurance business	$ 253,100		$ 135,000
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	0	$ 12,515	18,114	$ 12,515
Change in unrealized gains (losses) before income taxes and noncontrolling interests	(72,168)	(7,730)	198,807	(135,184)
Income tax benefit (expense)	24,493	12,229	(64,594)	56,354
Noncontrolling interests	57	94	66	106
Total change in unrealized gains	(47,618)	4,593	134,279	(78,724)
Proceeds from Divestiture of Businesses	118,200
Debt Securities [Member]
Realized and Unrealized Investment Gains Losses [Line Items]
Change in unrealized gains (losses) before income taxes and noncontrolling interests	(45,388)	2,449	169,933	(102,863)
Debt Securities Previously Impaired [Member]
Realized and Unrealized Investment Gains Losses [Line Items]
Change in unrealized gains (losses) before income taxes and noncontrolling interests	(1,406)	50	413	73
Equity securities available for sale
Realized and Unrealized Investment Gains Losses [Line Items]
Change in unrealized gains (losses) before income taxes and noncontrolling interests	(28,517)	(2,353)	12,433	(15,977)
Investment funds
Realized and Unrealized Investment Gains Losses [Line Items]
Change in unrealized gains (losses) before income taxes and noncontrolling interests	$ 3,143	$ (7,876)	$ 16,028	$ (16,417)

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Securities In An Unrealized Loss Position Securities in an Unrealized Loss Position (Securities in an Unrealized Loss Position) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	$ 1,897,137	$ 3,497,447
Gross Unrealized Losses, Less than 12 Months	20,713	78,466
Fair Value, 12 Months or Greater	659,502	672,929
Gross Unrealized Losses, 12 Months or Greater	24,485	35,482
Fair Value, Total	2,556,639	4,170,376
Gross Unrealized Losses, Total	45,198	113,948
U.S. government and government agency
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	54,550	101,660
Gross Unrealized Losses, Less than 12 Months	279	487
Fair Value, 12 Months or Greater	39,092	64,500
Gross Unrealized Losses, 12 Months or Greater	652	1,846
Fair Value, Total	93,642	166,160
Gross Unrealized Losses, Total	931	2,333
State and municipal
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	217,215	501,952
Gross Unrealized Losses, Less than 12 Months	1,095	4,404
Fair Value, 12 Months or Greater	138,082	106,681
Gross Unrealized Losses, 12 Months or Greater	1,490	1,865
Fair Value, Total	355,297	608,633
Gross Unrealized Losses, Total	2,585	6,269
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	251,969	381,986
Gross Unrealized Losses, Less than 12 Months	1,851	3,639
Fair Value, 12 Months or Greater	105,927	184,807
Gross Unrealized Losses, 12 Months or Greater	3,924	7,669
Fair Value, Total	357,896	566,793
Gross Unrealized Losses, Total	5,775	11,308
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	918,983	1,091,078
Gross Unrealized Losses, Less than 12 Months	5,718	7,703
Fair Value, 12 Months or Greater	214,436	190,467
Gross Unrealized Losses, 12 Months or Greater	6,356	6,711
Fair Value, Total	1,133,419	1,281,545
Gross Unrealized Losses, Total	12,074	14,414
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	337,940	1,232,940
Gross Unrealized Losses, Less than 12 Months	2,152	35,406
Fair Value, 12 Months or Greater	98,162	76,797
Gross Unrealized Losses, 12 Months or Greater	7,722	8,987
Fair Value, Total	436,102	1,309,737
Gross Unrealized Losses, Total	9,874	44,393
Foreign government
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	52,233	169,190
Gross Unrealized Losses, Less than 12 Months	640	8,822
Fair Value, 12 Months or Greater	30,842	19,528
Gross Unrealized Losses, 12 Months or Greater	1,850	3,867
Fair Value, Total	83,075	188,718
Gross Unrealized Losses, Total	2,490	12,689
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	1,832,890	3,478,806
Gross Unrealized Losses, Less than 12 Months	11,735	60,461
Fair Value, 12 Months or Greater	626,541	642,780
Gross Unrealized Losses, 12 Months or Greater	21,994	30,945
Fair Value, Total	2,459,431	4,121,586
Gross Unrealized Losses, Total	33,729	91,406
Preferred stocks
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	46,135	0
Gross Unrealized Losses, Less than 12 Months	8,199	0
Fair Value, 12 Months or Greater	24,845	22,320
Gross Unrealized Losses, 12 Months or Greater	829	3,353
Fair Value, Total	70,980	22,320
Gross Unrealized Losses, Total	9,028	3,353
Equity securities available for sale
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	64,247	18,641
Gross Unrealized Losses, Less than 12 Months	8,978	18,005
Fair Value, 12 Months or Greater	32,961	30,149
Gross Unrealized Losses, 12 Months or Greater	2,491	4,537
Fair Value, Total	97,208	48,790
Gross Unrealized Losses, Total	11,469	22,542
Common stocks
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	18,112	18,641
Gross Unrealized Losses, Less than 12 Months	779	18,005
Fair Value, 12 Months or Greater	8,116	7,829
Gross Unrealized Losses, 12 Months or Greater	1,662	1,184
Fair Value, Total	26,228	26,470
Gross Unrealized Losses, Total	2,441	$ 19,189
Noninvestment Grade Investments at Loss Less than 5 Million [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Total	89,878
Noninvestment Grade Investments at Loss Less than 5 Million [Member] | Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Total	23,921
Noninvestment Grade Investments at Loss Less than 5 Million [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Total	$ 27,531

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Securities In An Unrealized Loss Position Non-Investment Grade Fixed Maturity Securities (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2016 USD ($) shares position	Dec. 31, 2015 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	$ 2,556,639	$ 4,170,376
Available For Sale Equity Securities Gross Unrealized Gains	6,788	8,216
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	45,198	113,948
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	2,459,431	4,121,586
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	33,729	91,406
Preferred stocks
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	70,980	22,320
Available For Sale Equity Securities Gross Unrealized Gains	6,573	8,216
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	9,028	3,353
Common stocks
Schedule of Available-for-sale Securities [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	26,000
Aggregate fair value of securities in a continuous unrealized loss position	26,228	26,470
Available For Sale Equity Securities Gross Unrealized Gains	215	0
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	2,441	19,189
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	357,896	566,793
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	5,775	11,308
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	1,133,419	1,281,545
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	12,074	14,414
State and municipal
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	355,297	608,633
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	2,585	6,269
Foreign government
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	83,075	188,718
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	2,490	12,689
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	436,102	1,309,737
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	$ 9,874	$ 44,393
Noninvestment Grade Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | shares	3
Noninvestment Grade Investments at Loss Less than 5 Million [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities	31
Aggregate fair value of securities in a continuous unrealized loss position	$ 89,878
Gross Unrealized Loss	$ 5,805
Noninvestment Grade Investments at Loss Less than 5 Million [Member] | Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Number of Securities	11
Aggregate fair value of securities in a continuous unrealized loss position	$ 23,921
Gross Unrealized Loss	$ 1,229
Noninvestment Grade Investments at Loss Less than 5 Million [Member] | Foreign Government Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities	4
Aggregate fair value of securities in a continuous unrealized loss position	$ 23,001
Gross Unrealized Loss	$ 1,101
Noninvestment Grade Investments at Loss Less than 5 Million [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities	10
Aggregate fair value of securities in a continuous unrealized loss position	$ 27,531
Gross Unrealized Loss	3,045
Common stocks
Schedule of Available-for-sale Securities [Line Items]
Available For Sale Equity Securities Gross Unrealized Gains	$ 2,000
Noninvestment Grade Investments at Loss Less than 5 Million [Member] | Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | position	5
Aggregate fair value of securities in a continuous unrealized loss position	$ 8,418
Gross Unrealized Loss	$ 405

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Securities In An Unrealized Loss Position Securities In An Unrealized Loss Position (Narrative) (Details) $ in Thousands	Sep. 30, 2016 USD ($) shares	Dec. 31, 2015 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	$ 2,556,639	$ 4,170,376
Gross Unrealized Losses	45,198	113,948
Available For Sale Equity Securities Gross Unrealized Gains	6,788	8,216
Loans and Leases Receivable, Other, Allowance	$ 3,000	2,000
Noninvestment Grade Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | shares	3
Preferred stocks
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	$ 70,980	22,320
Gross Unrealized Losses	9,028	3,353
Available For Sale Equity Securities Gross Unrealized Gains	6,573	8,216
Common stocks
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	26,228	26,470
Gross Unrealized Losses	2,441	19,189
Available For Sale Equity Securities Gross Unrealized Gains	215	$ 0
Common stocks
Schedule of Available-for-sale Securities [Line Items]
Available For Sale Equity Securities Gross Unrealized Gains	$ 2,000

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Fair Value Measurements (Assets and Liabilities Measured At Fair Value, On a Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	$ 13,528,494	$ 12,348,127
Loans receivable	158,975	150,866
Arbitrage trading account	602,965	376,697
Fair Value, Measurements, Recurring [Member]
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	13,528,494	12,348,127
Loans receivable	158,975	150,866
Assets, fair value disclosure	14,290,434	12,875,690
Arbitrage trading account	602,965	376,697
Securities sold but not yet purchased	60,959	37,035
Fair Value, Measurements, Recurring [Member] | U.S. government and government agency
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	554,993	670,419
Fair Value, Measurements, Recurring [Member] | State and municipal
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	4,561,715	4,460,179
Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	1,263,005	1,199,859
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member]
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	2,268,861	1,705,172
Fair Value, Measurements, Recurring [Member] | Corporate
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	3,914,168	3,475,038
Fair Value, Measurements, Recurring [Member] | Foreign government
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	965,752	837,460
Fair Value, Measurements, Recurring [Member] | Common stocks
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Loans receivable	35,671	37,273
Fair Value, Measurements, Recurring [Member] | Preferred stocks
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Loans receivable	123,304	113,593
Level 1 | Fair Value, Measurements, Recurring [Member]
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	0	0
Loans receivable	27,555	29,444
Assets, fair value disclosure	347,835	286,358
Arbitrage trading account	320,280	256,914
Securities sold but not yet purchased	60,947	35,559
Level 1 | Fair Value, Measurements, Recurring [Member] | U.S. government and government agency
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	0	0
Level 1 | Fair Value, Measurements, Recurring [Member] | State and municipal
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	0	0
Level 1 | Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	0	0
Level 1 | Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member]
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	0	0
Level 1 | Fair Value, Measurements, Recurring [Member] | Corporate
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	0	0
Level 1 | Fair Value, Measurements, Recurring [Member] | Foreign government
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	0	0
Level 1 | Fair Value, Measurements, Recurring [Member] | Common stocks
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Loans receivable	27,555	29,444
Level 1 | Fair Value, Measurements, Recurring [Member] | Preferred stocks
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Loans receivable	0	0
Level 2 | Fair Value, Measurements, Recurring [Member]
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	13,528,309	12,347,774
Loans receivable	119,630	109,969
Assets, fair value disclosure	13,930,624	12,577,350
Arbitrage trading account	282,685	119,607
Securities sold but not yet purchased	12	1,476
Level 2 | Fair Value, Measurements, Recurring [Member] | U.S. government and government agency
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	554,993	670,419
Level 2 | Fair Value, Measurements, Recurring [Member] | State and municipal
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	4,561,715	4,460,179
Level 2 | Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	1,263,005	1,199,859
Level 2 | Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member]
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	2,268,676	1,704,973
Level 2 | Fair Value, Measurements, Recurring [Member] | Corporate
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	3,914,168	3,474,884
Level 2 | Fair Value, Measurements, Recurring [Member] | Foreign government
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	965,752	837,460
Level 2 | Fair Value, Measurements, Recurring [Member] | Common stocks
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Loans receivable	0	0
Level 2 | Fair Value, Measurements, Recurring [Member] | Preferred stocks
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Loans receivable	119,630	109,969
Level 3 | Fair Value, Measurements, Recurring [Member]
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	185	353
Loans receivable	11,790	11,453
Assets, fair value disclosure	11,975	11,982
Arbitrage trading account	0	176
Securities sold but not yet purchased	0	0
Level 3 | Fair Value, Measurements, Recurring [Member] | U.S. government and government agency
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	0	0
Level 3 | Fair Value, Measurements, Recurring [Member] | State and municipal
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	0	0
Level 3 | Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	0	0
Level 3 | Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member]
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	185	199
Level 3 | Fair Value, Measurements, Recurring [Member] | Corporate
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	0	154
Level 3 | Fair Value, Measurements, Recurring [Member] | Foreign government
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	0	0
Level 3 | Fair Value, Measurements, Recurring [Member] | Common stocks
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Loans receivable	8,116	7,829
Level 3 | Fair Value, Measurements, Recurring [Member] | Preferred stocks
Fair Value Measurements, Recurring and Nonrecurring Basis [Line Items]
Loans receivable	$ 3,674	$ 3,624

XML

Fair Value Measurements Fair Value Measurements (Summarize Changes in Level 3 Assets) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings, Description	0	-2331
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	$ 11,982	$ 35,939
Assets, earnings	54	(869)
Assets, other comprehensive income	(465)	(82)
Assets, purchases	765	72,640
Assets, (sales)	(331)	(72,229)
Assets, maturities	30	1,820
Assets, ending balance	11,975	11,982
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		19,266
Level 3 | Asset-backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	199	20,611
Assets, earnings	3	19
Assets, other comprehensive income	13	191
Assets, purchases	0	0
Assets, (sales)	0	0
Assets, maturities	(30)	(1,820)
Assets, ending balance	185	199
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	18,802
Impairment of Intangible Assets (Excluding Goodwill)	0	0
Level 3 | Equity securities available for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	11,453	14,454
Assets, earnings	50	(89)
Assets, other comprehensive income	(478)	(273)
Assets, purchases	765	0
Assets, (sales)	0	(308)
Assets, ending balance	11,790	11,453
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	0
Level 3 | Preferred stocks
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	3,624	3,713
Assets, earnings	50	(89)
Assets, other comprehensive income	$ 0	$ 0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings, Description	0	0
Assets, purchases	$ 0	$ 0
Assets, (sales)	0	0
Assets, ending balance	3,674	3,624
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	0
Level 3 | Common stocks
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	7,829	10,741
Assets, earnings	0	0
Assets, other comprehensive income	$ (478)	$ (273)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings, Description	0	-2331
Assets, purchases	$ 765	$ 0
Assets, (sales)	0	(308)
Assets, ending balance	8,116	7,829
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	0
Level 3 | Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	353	20,765
Assets, earnings	180	19
Assets, other comprehensive income	$ 13	$ 191
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings, Description	0	0
Assets, purchases	$ 0	$ 0
Assets, (sales)	(331)	0
Assets, maturities	30	1,820
Assets, ending balance	185	353
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	18,802
Level 3 | Corporate Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	154	154
Assets, earnings	177	0
Assets, other comprehensive income	$ 0	$ 0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings, Description	0	0
Assets, purchases	$ 0	$ 0
Assets, (sales)	(331)	0
Assets, ending balance	0	154
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	0
Level 3 | Trading Assets, Excluding Debt and Equity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	176	720
Assets, earnings	(176)	(799)
Assets, other comprehensive income	$ 0	$ 0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings, Description	0	0
Assets, purchases	$ 0	$ 72,640
Assets, (sales)	0	(71,921)
Assets, ending balance	0	176
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	$ 0	$ 464

XML

Reinsurance Reinsurance (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Premiums Written
Written premiums, direct	$ 1,643,870	$ 1,601,344	$ 5,061,646	$ 4,852,584
Written premiums, assumed	224,979	221,237	702,265	633,200
Written premiums, ceded	(261,484)	(251,544)	(850,255)	(795,420)
Total net premiums written	1,607,365	1,571,037	4,913,656	4,690,364
Premiums Earned
Earned premiums, direct	1,647,033	1,575,624	4,824,768	4,646,343
Earned premiums, assumed	216,758	217,668	635,443	632,362
Earned premiums, ceded	(277,847)	(261,734)	(787,139)	(782,093)
Net premiums earned	1,585,944	1,531,558	4,673,072	4,496,612
Ceded losses and loss expenses incurred	213,065	123,765	507,258	374,084
Uncollectible reinsurance	1,000		1,000		$ 1,000
Fees and Commissions, Other	$ 47,315	$ 45,946	$ 143,809	$ 129,766

XML

Fair Value of Financial Instruments (Carrying Amounts and Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Assets:
Equity securities available for sale	$ 602,965	$ 376,697
Loans receivable	116,483	275,747
Fair Value
Assets:
Fixed maturity securities	13,636,291	12,462,847
Equity securities available for sale	158,975	150,866
Equity securities available for sale	602,965	376,697
Loans receivable	116,483	275,747
Cash and cash equivalents	873,064	763,631
Trading account receivables from brokers and clearing organizations	185,548	383,115
Due From Brokers, Fair Value Disclosure	0	1,713
Due from broker fair value	101,405	0
Liabilities:
Trading account securities sold but not yet purchased	60,959	37,035
Subordinated debentures	779,056	355,880
Senior notes and other debt	1,997,430	2,029,572
Carrying Value
Assets:
Fixed maturity securities	13,616,671	12,444,394
Equity securities available for sale	158,975	150,866
Equity securities available for sale	602,965	376,697
Loans receivable	113,996	273,103
Cash and cash equivalents	873,064	763,631
Trading account receivables from brokers and clearing organizations	185,548	383,115
Due From Brokers, Fair Value Disclosure	0	1,713
Due from broker fair value	101,405	0
Liabilities:
Trading account securities sold but not yet purchased	60,959	37,035
Subordinated debentures	727,390	340,320
Senior notes and other debt	$ 1,762,487	$ 1,844,621

XML

Restricted Stock Units (Summary of Restricted Stock Units Issued) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Share-Based Compensation Arrangement by Share-based Payment Award [Line Item]
Share based compensation expense	$ 25,000	$ 23,000
Restricted Stock [Member]
Share-Based Compensation Arrangement by Share-based Payment Award [Line Item]
Restricted Stock Units	990,487	971,457,000
Restricted Stock Units, Fair Value	$ 57,959	$ 54,439
Minimum [Member] | Restricted Stock [Member]
Share-Based Compensation Arrangement by Share-based Payment Award [Line Item]
Award vesting period	3 years
Maximum [Member] | Restricted Stock [Member]
Share-Based Compensation Arrangement by Share-based Payment Award [Line Item]
Award vesting period	5 years

XML

Industry Segments (Financial Information of Company Operating Segments) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Earned Premiums		$ 1,585,944	$ 1,531,558	$ 4,673,072	$ 4,496,612
Investment Income and Funds		145,668	133,214	404,850	385,036
Other Revenues		288,115	196,185	604,618	513,753
Total revenues		2,019,727	1,860,957	5,682,540	5,395,401
Pre-Tax Income (Loss)		331,615	228,920	664,605	575,824
Net Income (Loss)		220,650	152,607	449,127	393,949
Net investment gains		175,736	53,904	189,394	100,505
Net investment gains, net of tax		114,228	35,038	123,106	65,328
Intersegment Eliminations and Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Earned Premiums	[1]	0	0	0	0
Investment Income and Funds	[1]	6,802	6,757	22,827	21,124
Other Revenues	[1]	89,560	119,260	338,009	340,267
Total revenues	[1]	96,362	126,017	360,836	361,391
Pre-Tax Income (Loss)	[1]	(81,941)	(51,506)		(170,226)
Net Income (Loss)	[1]	(53,055)	(37,684)	(123,610)	(116,094)
Insurance-Domestic Segment [Member]
Segment Reporting Information [Line Items]
Earned Premiums		1,431,664	1,379,501	4,206,887	4,042,159
Insurance-Domestic Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Earned Premiums		1,431,664	1,379,501	4,206,887	4,042,159
Investment Income and Funds		117,388	106,989	322,779	309,337
Other Revenues		22,819	23,021	77,215	72,981
Total revenues		1,571,871	1,509,511	4,606,881	4,424,477
Pre-Tax Income (Loss)		215,649	204,109	604,825	575,748
Net Income (Loss)		144,310	139,446	407,346	395,581
Insurance-International Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Other Revenues					0
Reinsurance-Global Segment [Member]
Segment Reporting Information [Line Items]
Earned Premiums		154,280	152,057	466,185	454,453
Reinsurance-Global Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Earned Premiums		154,280	152,057	466,185	454,453
Investment Income and Funds		21,478	19,468	59,244	54,575
Other Revenues		0	0	0
Total revenues		175,758	171,525	525,429	509,028
Pre-Tax Income (Loss)		22,171	22,413	61,041	69,797
Net Income (Loss)		15,167	15,807	42,285	49,134
Corporate, Other and Eliminations Segment [Member] | Intersegment Eliminations and Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Pre-Tax Income (Loss)	[1]			(190,655)
Net Investment Gains Segment [Member]
Segment Reporting Information [Line Items]
Earned Premiums		0	0	0
Investment Income and Funds		$ 0	$ 0	$ 0	$ 0

[1] Corporate, other and eliminations represent corporate revenues and expenses that are not allocated to business segments.

XML

Industry Segments (Identifiable Assets by Segment) (Details) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated Assets		$ 23,345,656	$ 21,724,156
Operating Segments [Member] | Reinsurance-Global Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated Assets		2,585,307	2,441,340
Operating Segments [Member] | Insurance-Domestic Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated Assets		18,972,237	18,063,730
Intersegment Eliminations and Corporate, Non-Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated Assets	[1]	$ 1,788,112	$ 1,219,086

[1] Corporate, other and eliminations represent corporate revenues and expenses that are not allocated to business segments.

XML

Industry Segments Industry Segments (Net Premiums Earned By Major Line of Business) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue from External Customer [Line Items]
Premiums Earned, Net	$ 1,585,944	$ 1,531,558	$ 4,673,072	$ 4,496,612
Insurance-Domestic Segment [Member]
Revenue from External Customer [Line Items]
Premiums Earned, Net	1,431,664	1,379,501	4,206,887	4,042,159
Insurance-Domestic Segment [Member] | Other Insurance Liabilities [Member]
Revenue from External Customer [Line Items]
Premiums Earned, Net	465,068	418,133	1,331,143	1,216,411
Insurance-Domestic Segment [Member] | Workers' Compensation [Member]
Revenue from External Customer [Line Items]
Premiums Earned, Net	355,604	347,745	1,047,412	1,010,279
Insurance-Domestic Segment [Member] | Property [Member]
Revenue from External Customer [Line Items]
Premiums Earned, Net	317,498	327,357	977,138	973,606
Insurance-Domestic Segment [Member] | Commercial Automobile [Member]
Revenue from External Customer [Line Items]
Premiums Earned, Net	164,540	170,660	481,249	506,229
Insurance-Domestic Segment [Member] | Products Liability [Member]
Revenue from External Customer [Line Items]
Premiums Earned, Net	128,954	115,606	369,945	335,634
Reinsurance-Global Segment [Member]
Revenue from External Customer [Line Items]
Premiums Earned, Net	154,280	152,057	466,185	454,453
Reinsurance-Global Segment [Member] | Property [Member]
Revenue from External Customer [Line Items]
Premiums Earned, Net	60,523	48,859	175,812	139,991
Reinsurance-Global Segment [Member] | Casualty [Member]
Revenue from External Customer [Line Items]
Premiums Earned, Net	$ 93,757	$ 103,198	$ 290,373	$ 314,462

XML

Subsequent Event Subsequent Event (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016
Subsequent Event [Line Items]
pre tax realized gain from sale of wholly owned non insurance business	$ 253.1	$ 135.0