CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income	$ 208,420,000	$ 178,412,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	33,191,000	28,477,000
Deferred tax expense	106,163,000	88,157,000
Net realized investment losses (gains)	164,000	(3,892,000)
Loss on debt extinguishment	65,000	15,308,000
Change in certain assets and liabilities:
Accrued investment income	43,000	515,000
Prepaid insurance premium	25,000	48,000
Reinsurance recoverable on loss reserves	5,710,000	(728,000)
Reinsurance recoverable on paid losses	(1,187,000)	(1,454,000)
Premium receivable	1,048,000	1,867,000
Deferred insurance policy acquisition costs	(918,000)	(1,439,000)
Profit commission receivable	(4,603,000)	(2,793,000)
Loss reserves	(251,724,000)	(261,069,000)
Unearned premiums	22,273,000	28,451,000
Return premium accrual	(11,900,000)	(7,300,000)
Income taxes payable - current	32,991,000	523,000
Other, net	(14,205,000)	(8,090,000)
Net cash provided by operating activities	125,556,000	54,993,000
Purchases of investments:
Fixed income	(545,281,000)	(723,409,000)
Equity securities	(38,000)	(3,128,000)
Proceeds from sales of fixed income	166,606,000	649,776,000
Proceeds from maturity of fixed income	390,344,000	313,484,000
Proceeds from sale of equity securities	0	2,525,000
Net increase in payable for securities	3,447,000	24,519,000
Additions to property and equipment	(9,659,000)	(2,724,000)
Net cash provided by investing activities	5,419,000	261,043,000
Cash flows from financing activities:
Proceeds from revolving credit facility	150,000,000	0
Repayment of revolving credit facility	(150,000,000)	0
Proceeds from issuance of long-term debt	0	155,000,000
Purchase or repayment of convertible senior notes	(145,620,000)	(182,846,000)
Payment of original issue discount - convertible senior notes	(4,504,000)	(5,655,000)
Purchase of convertible junior subordinated debentures	0	(100,860,000)
Payment of original issue discount - convertible junior subordinated debentures	0	(41,540,000)
Cash portion of loss on debt extinguishment	0	(15,308,000)
Payment of debt issuance costs	(1,630,000)	0
Payment of withholding taxes related to share-based compensation net share settlement	(6,723,000)	(4,973,000)
Net cash used in financing activities	(158,477,000)	(196,182,000)
Net (decrease) increase in cash and cash equivalents	(27,502,000)	119,854,000
Cash and cash equivalents at beginning of period	155,410,000	181,120,000
Cash and cash equivalents at end of period	$ 127,908,000	$ 300,974,000