Condensed Consolidated Balance Sheets (Unaudited) Statement - USD ($) $ in Thousands		Sep. 30, 2018	Dec. 31, 2017
ASSETS
Fixed-maturities available for sale—at fair value (amortized cost $3,838,823 and $3,426,217)		$ 3,763,710	$ 3,458,719
Trading Securities—at fair value		493,956	606,401
Equity Securities-at fair value		121,865
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 $31,799 and $19,357 of reinvested cash collateral held under securities lending agreements)		645,119	415,658
Other invested assets—at fair value (amortized cost at December 31, 2017)		3,585	334
Total investments		5,028,235	4,643,942
Cash		104,413	80,569
Restricted cash		9,925	15,675
Accounts and notes receivable		108,003	72,558
Property, Plant and Equipment, Net	[1]	38,060	38,291
Deferred income taxes, net (Note 9)		134,201	229,567
Goodwill and other acquired intangible assets, net (Note 6)		55,707	64,212
Prepaid reinsurance premium		413,728	386,509
Other assets (Note 8)		415,272	407,849
Total assets		6,269,484	5,900,881
Liabilities and Stockholders’ Equity
Unearned premiums		747,921	723,938
Reserve for losses and loss adjustment expense (“LAE”) (Note 10)		412,460	507,588
Senior notes (Note 11)		1,029,511	1,027,074
Reinsurance funds withheld		352,952	288,398
Other liabilities (Note 12)		379,362	353,845
Total liabilities		2,922,206	2,900,843
Commitments and contingencies (Note 13)
Stockholders’ equity
Common stock: par value $0.001 per share; 485,000,000 shares authorized at September 30, 2018 and December 31, 2017; 230,978,401 and 233,416,989 shares issued at September 30, 2018 and December 31, 2017, respectively; 213,333,428 and 215,814,188 shares outstanding at September 30, 2018 and December 31, 2017, respectively		231	233
Treasury stock, at cost: 17,644,973 and 17,602,801 shares at September 30, 2018 and December 31, 2017, respectively		(894,635)	(893,888)
Additional paid-in capital		2,720,626	2,754,275
Retained earnings		1,580,296	1,116,333
Accumulated other comprehensive income (loss) (Note 15)		(59,240)	23,085
Total stockholders’ equity		3,347,278	3,000,038
Total liabilities and stockholders’ equity		6,269,484	5,900,881
Deferred policy acquisition costs		16,922	16,987
Accrued Investment Income Receivable		$ 34,430	$ 31,389

[1] Property and equipment at cost, less accumulated depreciation of $61.0 million and $57.6 million at September 30, 2018 and December 31, 2017, respectively. Depreciation expense was $2.1 million and $1.9 million for the three-month periods ended September 30, 2018 and 2017, respectively, and $5.9 million and $4.9 million for the nine-month periods ended September 30, 2018 and 2017, respectively.