Other Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014
Components of Other Comprehensive Income (Loss) [Abstract]
Net unrealized holding (losses) gains arising during the period		$ 27,271	$ (17,377)	$ (17,126)		$ 67,102
Income tax benefit (expense)		(9,531)	6,069	5,955		(23,436)
Valuation allowance	[1]	77,555	(5,993)	62,383		23,132
Net of taxes		95,295	(17,301)	51,212		66,798
Net changes in benefit plan assets and obligations		(546)	(1,732)	(1,638)		(5,198)
Income tax benefit		192	606	574		1,819
Valuation allowance	[1]	(7,001)	(606)	(7,383)		(1,819)
Net of taxes		(7,355)	(1,732)	(8,447)		(5,198)
Net changes in unrealized foreign currency translation adjustment		(3,724)	(3,835)	(6,228)		(1,000)
Income tax benefit (expense)		1,306	1,345	2,186		350
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent, Valuation Allowance	[1]	(529)	0	(529)		0
Net of taxes		(2,947)	(2,490)	(4,571)		(650)
Total other comprehensive income (loss)		23,001	(22,944)	(24,992)		60,904
Total income tax benefit (expense), net of valuation allowance		61,992	1,421	63,186		46
Other comprehensive income (loss), net of tax		84,993	(21,523)	38,194		60,950
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications		127,248	72,266	378,685		179,614
Income tax (expense) benefit		(43,694)	(25,030)	(131,568)		(65,322)
Change in valuation allowance		(739,298)	(24,781)	(822,465)		(63,229)
Total income tax expense, net of valuation allowance		695,604	(249)	690,897		(2,093)
Net income		822,852	72,017	1,069,582		177,521
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period, net of tax				(81,341)
Other comprehensive loss before reclassifications				50,361
Less: Amounts reclassified from AOCL				12,167
Balance at end of period, net of tax		(43,147)		(43,147)
Unrealized gains and losses on available-for- sale securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period, net of tax				(57,551)
Other comprehensive loss before reclassifications				61,741
Less: Amounts reclassified from AOCL	[2]			10,529
Balance at end of period, net of tax		(6,339)		(6,339)
Defined benefit plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period, net of tax				(28,938)
Other comprehensive loss before reclassifications				(6,809)
Less: Amounts reclassified from AOCL	[3]			1,638
Balance at end of period, net of tax		(37,385)		(37,385)
Foreign currency translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period, net of tax				5,148
Other comprehensive loss before reclassifications				(4,571)
Less: Amounts reclassified from AOCL				0
Balance at end of period, net of tax		577		577
Reclassification from Accumulated Other Comprehensive Income
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications		(574)	892	12,229		(527)
Total income tax expense, net of valuation allowance		(18)	(31)	(62)		(61)
Net income		(592)	861	12,167		(588)
Reclassification from Accumulated Other Comprehensive Income | Unrealized gains and losses on available-for- sale securities
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications		(1,120)	(840)	10,591	[4]	(5,725)	[4]
Income tax (expense) benefit		395	299	(3,697)		2,014
Change in valuation allowance		(413)	(330)	3,635		(2,075)
Net income		(1,138)	(871)	10,529		(5,786)
Reclassification from Accumulated Other Comprehensive Income | Defined benefit plans
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications		546	1,732	1,638		5,198
Income tax (expense) benefit		(192)	(606)	(574)		(1,819)
Change in valuation allowance		192	606	574		1,819
Net income		$ 546	$ 1,732	$ 1,638		$ 5,198

[1] See Note 11 – “Income Taxes” for a discussion of the valuation allowance recorded against deferred tax assets.

[2] Increases Net realized investment gains on the consolidated statements of operations.

[3] Decreases Other underwriting and operating expenses, net on the consolidated statements of operations.

[4] The reclassification adjustment for the nine months ended September 30, 2014 has been recast to conform to the 2015 method for determining amounts included in net income. This revision had no impact to our consolidated financial statements and is not material to amounts disclosed by us in prior periods.