Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Net premiums earned (Note 8)	$ 1,115,321	$ 1,145,349	$ 1,014,007
Services revenue (Note 4)	105,385	154,596	144,972
Net investment income (Note 6)	154,037	171,796	152,475
Net gains (losses) on investments and other financial instruments	60,277	51,719	(42,476)
Other income	3,597	3,495	4,028
Total revenues	1,438,617	1,526,955	1,273,006
Expenses:
Provision for losses	485,117	132,031	104,641
Policy acquisition costs	30,989	25,314	25,265
Cost of services	86,066	108,324	98,124
Other operating expenses	280,710	306,129	280,818
Restructuring and other exit costs	0	0	6,053
Interest expense	71,150	56,310	61,490
Loss on extinguishment of debt (Note 12)	0	22,738	0
Impairment of goodwill (Note 7)	0	4,828	0
Amortization and impairment of other acquired intangible assets	5,144	22,288	12,429
Total expenses	959,176	677,962	588,820
Pretax income	479,441	848,993	684,186
Income tax provision (Note 10)	85,815	176,684	78,175
Net income	$ 393,626	$ 672,309	$ 606,011
Earnings Per Share, Basic:
Net income (loss), per basic share	$ 2.01	$ 3.22	$ 2.83
Earnings Per Share, Diluted:
Net income (loss) per diluted share	$ 2.00	$ 3.20	$ 2.77
Weighted-average number of common shares outstanding—basic	195,443	208,773	214,267
Weighted-average number of common and common equivalent shares outstanding—diluted	196,642	210,340	218,553