Condensed Consolidated Balance Sheets (Unaudited) Statement - USD ($) $ in Thousands		Mar. 31, 2018	Dec. 31, 2017
ASSETS
Fixed-maturities available for sale—at fair value (amortized cost $3,594,591 and $3,426,217)		$ 3,554,734	$ 3,458,719
Trading Securities—at fair value		563,377	606,401
Equity Securities		111,032
Equity securities—at fair value (at December 31, 2017, classified as available for sale with related cost of $163,106)			162,830
Short-term investments—at fair value (includes $39,077 and $19,357 of reinvested cash collateral held under securities lending agreements)		435,756	415,658
Other invested assets—at fair value (amortized cost at December 31, 2017)		3,318	334
Total investments		4,668,217	4,643,942
Cash		122,481	80,569
Restricted cash		7,623	15,675
Accounts and notes receivable		80,068	72,558
Property, Plant and Equipment, Net	[1]	87,332	87,042
Deferred income taxes, net (Note 9)		253,381	229,567
Goodwill and other intangible assets, net (Note 6)		61,465	64,212
Prepaid reinsurance premium		390,241	386,509
Other assets (Note 8)		426,773	407,849
Total assets		6,010,249	5,900,881
Liabilities and Stockholders’ Equity
Unearned premiums		723,100	723,938
Reserve for losses and loss adjustment expense (“LAE”) (Note 10)		488,656	507,588
Senior notes (Note 11)		1,027,875	1,027,074
Reinsurance funds withheld		305,409	288,398
Other liabilities (Note 12)		412,793	353,845
Total liabilities		2,957,833	2,900,843
Commitments and contingencies (Note 13)
Stockholders’ equity
Common stock: par value $0.001 per share; 485,000,000 shares authorized at March 31, 2018 and December 31, 2017; 233,160,146 and 233,416,989 shares issued at March 31, 2018 and December 31, 2017, respectively; 215,542,607 and 215,814,188 shares outstanding at March 31, 2018 and December 31, 2017, respectively		233	233
Treasury stock, at cost: 17,617,539 and 17,602,801 shares at March 31, 2018 and December 31, 2017, respectively		(894,191)	(893,888)
Additional paid-in capital		2,748,233	2,754,275
Retained earnings		1,229,616	1,116,333
Accumulated other comprehensive income (loss) (Note 15)		(31,475)	23,085
Total stockholders’ equity		3,052,416	3,000,038
Total liabilities and stockholders’ equity		6,010,249	5,900,881
Deferred policy acquisition costs		16,026	16,987
Accrued Investment Income Receivable		$ 33,542	$ 31,389

[1] Property and equipment at cost, less accumulated depreciation of $112.1 million and $106.0 million at March 31, 2018 and December 31, 2017, respectively. Depreciation expense was $4.7 million and $4.1 million for the three-month periods ended March 31, 2018 and 2017, respectively.