CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income	$ 342,517	$ 1,172,000	$ 251,949
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and other amortization	61,342	52,559	48,861
Deferred tax expense (benefit)	162,356	(692,810)	312
Net realized investment gains	(8,932)	(28,361)	(1,357)
Loss on debt extinguishment	90,531	507	837
Excess tax benefits related to share-based compensation	(67)	(2,117)	0
Change in certain assets and liabilities:
Accrued investment income	(3,849)	(9,706)	1,142
Prepaid reinsurance premium	101	47,457	(11,380)
Reinsurance recoverable on loss reserves	(6,006)	13,354	6,244
Reinsurance recoverable on paid losses	(1,645)	3,105	4,001
Premiums receivable	(3,923)	8,973	4,859
Deferred insurance policy acquisition costs	(2,518)	(3,001)	(2,519)
Profit commission receivable	(747)	64,525	(89,132)
Loss reserves	(454,589)	(503,405)	(664,594)
Premium deficiency reserve	0	(23,751)	(24,710)
Unearned premiums	49,764	76,559	48,935
Return premium accrual	(18,800)	(9,600)	22,200
Income taxes payable - current	1,123	2,518	(674)
Other, net	13,005	(16,770)	(251)
Net cash provided by (used in) operating activities	219,663	152,036	(405,277)
Purchases of investments:
Fixed income	(1,360,386)	(2,462,844)	(1,979,917)
Equity securities	(3,197)	(2,623)	(94)
Proceeds from sales of fixed income	728,042	1,796,153	1,147,624
Proceeds from maturity of fixed income	547,444	559,774	1,129,087
Proceeds from sale of equity securities	5,257	0	0
Net decrease in payables for securities	0	0	13
Net decrease in restricted cash	0	17,212	228
Additions to property and equipment	(10,552)	(4,630)	(4,707)
Net cash (used in) provided by investing activities	(93,392)	(96,958)	292,234
Cash flows from financing activities:
Proceeds from issuance of long-term debt	573,094	0	0
Repayment of long-term debt	0	(61,953)	(20,772)
Repurchase of convertible senior notes	(363,778)	(11,152)	0
Payment of original issue discount - convertible senior notes	(11,250)	(345)	(158)
Purchase of convertible junior subordinated debentures	(100,860)	0	0
Payment of original issue discount-convertible junior subordinated debentures	(41,540)	0	0
Cash portion of loss on debt extinguishment	(59,460)	(507)	(837)
Repurchase of common stock	(147,127)	0	0
Payment of debt issuance costs	(1,127)	0	0
Excess tax benefits related to share-based compensation	67	2,117	0
Net cash used in financing activities	(151,981)	(71,840)	(21,767)
Net decrease in cash and cash equivalents	(25,710)	(16,762)	(134,810)
Cash and cash equivalents at beginning of year	181,120	197,882	332,692
Cash and cash equivalents at end of year	$ 155,410	$ 181,120	$ 197,882