CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income	$ 446,093	$ 673,763	$ 670,097
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and other amortization	57,812	48,784	58,215
Deferred tax expense	27,475	11,096	186,572
Loss on debt extinguishment	26,736	0	0
Net realized investment (gains) losses	(13,752)	(5,306)	1,353
Change in certain assets and liabilities:
Accrued investment income	(292)	(1,704)	(1,941)
Reinsurance recoverable on loss reserves	(73,401)	11,687	15,146
Reinsurance recoverable on paid losses	852	1,427	924
Premiums receivable	(457)	(497)	(1,045)
Deferred insurance policy acquisition costs	(3,030)	(643)	953
Profit commission receivable	4,586	4,945	(5,479)
Loss reserves	325,203	(118,685)	(311,616)
Unearned premiums	(93,203)	(29,683)	17,051
Return premium accrual	(500)	(11,500)	(22,900)
Current income taxes	6,271	1,057	(77,551)
Other, net	21,916	24,791	14,738
Net cash provided by operating activities	732,309	609,532	544,517
Cash flows from investing activities:
Purchases of investments	(2,636,972)	(1,394,126)	(1,459,473)
Proceeds from sales of investments	836,851	229,796	370,449
Proceeds from maturity of fixed income securities	1,030,926	748,165	785,175
Net decrease in payables for securities	0	(307)	307
Additions to property and equipment	(3,311)	(5,636)	(14,238)
Net cash used in investing activities	(772,506)	(422,108)	(317,780)
Cash flows from financing activities:
Proceeds from issuance of senior notes	640,250	0	0
Purchase of senior notes	(179,735)	0	0
Payment of original issue discount - senior notes	(2,969)	0	0
Purchase of convertible junior subordinated debentures	(36,392)	0	0
Payment of original issue discount- convertible junior subordinated debentures	(15,049)	0	0
Cash portion of loss on debt extinguishment	(25,266)	0	0
Repurchase of common stock	(119,997)	(125,766)	(163,419)
Dividends paid	(82,061)	(41,914)	0
Payment of debt issuance costs	(2,020)	0	0
Payment of withholding taxes related to share-based compensation net share settlement	(8,940)	(5,726)	(8,131)
Net cash provided by (used in) financing activities	167,821	(173,406)	(171,550)
Net increase in cash and cash equivalents and restricted cash and cash equivalents	127,624	14,018	55,187
Cash and cash equivalents and restricted cash and cash equivalents at beginning of year	169,056	155,038	99,851
Cash and cash equivalents and restricted cash and cash equivalents at end of year	$ 296,680	$ 169,056	$ 155,038