CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Premiums written:
Direct	$ 1,107,923,000	$ 1,074,490,000	$ 999,943,000
Assumed	1,053,000	1,178,000	1,653,000
Ceded	(133,885,000)	(55,391,000)	(119,634,000)
Net premiums written	975,091,000	1,020,277,000	881,962,000
Increase in unearned premiums	(49,865,000)	(124,055,000)	(37,591,000)
Net premiums earned	925,226,000	896,222,000	844,371,000
Investment income, net of expenses	110,666,000	103,741,000	87,647,000
Net realized investment gains (losses):
Total other-than-temporary impairment losses	0	0	(144,000)
Portion of losses recognized in other comprehensive income (loss), before taxes	0	0	0
Net impairment losses recognized in earnings	0	0	(144,000)
Other realized investment gains	8,932,000	28,361,000	1,501,000
Net realized investment gains	8,932,000	28,361,000	1,357,000
Other revenue	17,659,000	12,964,000	9,259,000
Total revenues	1,062,483,000	1,041,288,000	942,634,000
Losses and expenses:
Losses incurred, net	240,157,000	343,547,000	496,077,000
Change in premium deficiency reserve	0	(23,751,000)	(24,710,000)
Amortization of deferred policy acquisition costs	9,646,000	8,789,000	7,618,000
Other underwriting and operating expenses, net	150,763,000	155,577,000	138,441,000
Interest expense	56,672,000	68,932,000	69,648,000
Loss on debt extinguishment	90,531,000	507,000	837,000
Total losses and expenses	547,769,000	553,601,000	687,911,000
Income before tax	514,714,000	487,687,000	254,723,000
Provision for (benefit from) income taxes	172,197,000	(684,313,000)	2,774,000
Net income	$ 342,517,000	$ 1,172,000,000	$ 251,949,000
Earnings per share:
Basic (in dollars per share)	$ 1.00	$ 3.45	$ 0.74
Diluted (in dollars per share)	$ 0.86	$ 2.60	$ 0.64
Weighted average common shares outstanding - basic (in shares)	342,890	339,552	338,523
Weighted average common shares outstanding - diluted (in shares)	431,992	468,039	413,522
Dividends per share (in dollars per share)	$ 0	$ 0	$ 0