Condensed Consolidated Balance Sheets (Unaudited) Statement - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
ASSETS
Fixed-maturities available for sale—at fair value, net of allowance for credit losses of $2,476 as of June 30, 2020 (amortized cost of $4,804,453 and $4,549,534)	$ 5,070,091	$ 4,688,911
Trading securities—at fair value (amortized cost of $266,940 and $297,505)	297,609	317,150
Equity securities—at fair value (cost of $110,719 and $125,311)	104,513	130,221
Short-term investments—at fair value (includes $8,727 and $25,561 of reinvested cash collateral held under securities lending agreements)	955,090	518,393
Other invested assets—at fair value	4,047	4,072
Investments, Total	6,431,350	5,658,747
Cash	68,387	92,729
Restricted cash	16,279	3,545
Accounts and notes receivable	110,722	93,630
Goodwill and other acquired intangible assets, net (Note 6)	26,229	28,187
Prepaid reinsurance premium	330,476	363,856
Other assets (Note 8)	585,866	567,619
Assets, Total	7,569,309	6,808,313
Liabilities and Stockholders’ Equity
Unearned premiums	561,280	626,822
Reserve for losses and loss adjustment expense (Note 10)	738,885	404,765
Senior notes (Note 11)	1,403,857	887,110
FHLB advances (Note 11)	175,122	134,875
Reinsurance funds withheld	312,350	291,829
Other Liabilities	391,810	414,189
Total liabilities	3,583,304	2,759,590
Stockholders’ equity
Common stock: par value $0.001 per share; 485,000 shares authorized at June 30, 2020 and December 31, 2019; 209,997 and 219,123 shares issued at June 30, 2020 and December 31, 2019, respectively; 191,492 and 201,164 shares outstanding at June 30, 2020 and December 31, 2019, respectively	210	219
Treasury stock, at cost: 18,505 and 17,959 shares at June 30, 2020 and December 31, 2019, respectively	(909,738)	(901,657)
Additional paid-in capital	2,232,949	2,449,884
Retained earnings	2,450,423	2,389,789
Accumulated other comprehensive income (loss) (Note 14)	212,161	110,488
Total stockholders’ equity	3,986,005	4,048,723
Total liabilities and stockholders’ equity	7,569,309	6,808,313
Equity Securities, FV-NI, Cost	110,719	125,311
Debt Securities, Trading, Amortized Cost	266,940	297,505
Fixed-maturities available for sale—at amortized cost	4,804,453	$ 4,549,534
Debt Securities, Available-for-sale, Allowance for Credit Loss	$ (2,476)
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Common Stock, Shares Authorized	485,000,000	485,000,000
Common Stock, Shares, Issued	209,997,000	219,123,000
Common Stock, Shares, Outstanding	191,492,000	201,164,000
Treasury Stock, Shares	18,505,000	17,959,000
Reinvested Cash Collateral Held Under Securities Lending Agreements	$ 8,727	$ 25,561