CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Premiums written:
Direct	$ 1,103,332	$ 1,121,776	$ 1,107,923
Assumed	271	1,905	1,053
Ceded	(111,341)	(125,726)	(133,885)
Net premiums written	992,262	997,955	975,091
Increase in unearned premiums	(17,100)	(63,208)	(49,865)
Net premiums earned	975,162	934,747	925,226
Investment income, net of expenses	141,331	120,871	110,666
Net realized investment (losses) gains	(1,353)	231	8,921
Other revenue	8,708	10,205	17,670
Total revenues	1,123,848	1,066,054	1,062,483
Losses and expenses:
Losses incurred, net	36,562	53,709	240,157
Amortization of deferred policy acquisition costs	11,932	11,111	9,646
Other underwriting and operating expenses, net	178,211	159,638	150,763
Interest expense	52,993	57,035	56,672
Loss on debt extinguishment	0	65	90,531
Total losses and expenses	279,698	281,558	547,769
Income before tax	844,150	784,496	514,714
Provision for income taxes	174,053	428,735	172,197
Net income	$ 670,097	$ 355,761	$ 342,517
Earnings per share:
Basic (in dollars per share)	$ 1.83	$ 0.98	$ 1.00
Diluted (in dollars per share)	$ 1.78	$ 0.95	$ 0.86
Weighted average common shares outstanding - basic (in shares)	365,406	362,380	342,890
Weighted average common shares outstanding - diluted (in shares)	386,078	394,766	431,992