Condensed Consolidated Balance Sheets (Unaudited) Statement - USD ($) $ in Thousands		Jun. 30, 2018	Dec. 31, 2017
ASSETS
Fixed-maturities available for sale—at fair value (amortized cost $3,659,311 and $3,426,217)		$ 3,586,055	$ 3,458,719
Trading Securities—at fair value		535,634	606,401
Equity Securities-at fair value		122,977
Equity securities available for sale—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 $39,224 and $19,357 of reinvested cash collateral held under securities lending agreements)		626,060	415,658
Other invested assets—at fair value (amortized cost at December 31, 2017)		3,193	334
Total investments		4,873,919	4,643,942
Cash		95,573	80,569
Restricted cash		9,152	15,675
Accounts and notes receivable		94,848	72,558
Property, Plant and Equipment, Net	[1]	90,184	87,042
Deferred income taxes, net (Note 9)		171,293	229,567
Goodwill and other intangible assets, net (Note 6)		59,179	64,212
Prepaid reinsurance premium		405,447	386,509
Other assets (Note 8)		430,077	407,849
Total assets		6,139,488	5,900,881
Liabilities and Stockholders’ Equity
Unearned premiums		741,296	723,938
Reserve for losses and loss adjustment expense (“LAE”) (Note 10)		451,542	507,588
Senior notes (Note 11)		1,028,687	1,027,074
Reinsurance funds withheld		331,776	288,398
Other liabilities (Note 12)		385,051	353,845
Total liabilities		2,938,352	2,900,843
Commitments and contingencies (Note 13)
Stockholders’ equity
Common stock: par value $0.001 per share; 485,000,000 shares authorized at June 30, 2018 and December 31, 2017; 230,875,884 and 233,416,989 shares issued at June 30, 2018 and December 31, 2017, respectively; 213,232,370 and 215,814,188 shares outstanding at June 30, 2018 and December 31, 2017, respectively		231	233
Treasury stock, at cost: 17,643,514 and 17,602,801 shares at June 30, 2018 and December 31, 2017, respectively		(894,610)	(893,888)
Additional paid-in capital		2,715,426	2,754,275
Retained earnings		1,438,032	1,116,333
Accumulated other comprehensive income (loss) (Note 15)		(57,943)	23,085
Total stockholders’ equity		3,201,136	3,000,038
Total liabilities and stockholders’ equity		6,139,488	5,900,881
Deferred policy acquisition costs		16,266	16,987
Accrued Investment Income Receivable		$ 33,762	$ 31,389

[1] Property and equipment at cost, less accumulated depreciation of $115.5 million and $106.0 million at June 30, 2018 and December 31, 2017, respectively. Depreciation expense was $4.8 million and $4.1 million for the three-month periods ended June 30, 2018 and 2017, respectively, and $9.5 million and $8.3 million for the six-month periods ended June 30, 2018 and 2017, respectively.