CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Premiums written:
Direct	$ 1,106,632	$ 1,124,196	$ 1,103,332
Assumed	10,837	6,446	271
Ceded	(188,727)	(129,334)	(111,341)
Net premiums written	928,742	1,001,308	992,262
Decrease (increase) in unearned premiums	93,201	29,680	(17,100)
Net premiums earned	1,021,943	1,030,988	975,162
Investment income, net of expenses	154,396	167,045	141,331
Net realized investment gains (losses)	13,752	5,306	(1,353)
Other revenue	9,055	10,638	8,708
Total revenues	1,199,146	1,213,977	1,123,848
Losses and expenses:
Losses incurred, net	364,774	118,575	36,562
Amortization of deferred policy acquisition costs	12,380	12,001	11,932
Other underwriting and operating expenses, net	176,398	182,768	178,211
Loss on debt extinguishment	26,736	0	0
Interest expense	59,595	52,656	52,993
Total losses and expenses	639,883	366,000	279,698
Income before tax	559,263	847,977	844,150
Provision for income taxes	113,170	174,214	174,053
Net income	$ 446,093	$ 673,763	$ 670,097
Earnings per share:
Basic (in dollars per share)	$ 1.31	$ 1.91	$ 1.83
Diluted (in dollars per share)	$ 1.29	$ 1.85	$ 1.78
Weighted average common shares outstanding - basic (in shares)	339,953	352,827	365,406
Weighted average common shares outstanding - diluted (in shares)	359,293	373,924	386,078