Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Net premiums earned—insurance	$ 251,344	$ 229,096	$ 493,894	$ 450,896
Services revenue	36,828	37,802	69,992	75,829
Net investment income	37,473	30,071	71,429	61,103
Net gains (losses) on investments and other financial instruments	(7,404)	5,331	(26,291)	2,480
Other income	1,016	612	1,823	1,358
Total revenues	319,257	302,912	610,847	591,666
Expenses:
Provision for losses	19,337	17,222	56,620	64,135
Policy acquisition costs	5,996	6,123	13,113	12,852
Cost of services	24,205	25,635	47,331	54,010
Other operating expenses	70,184	68,750	133,427	137,127
Restructuring and other exit costs (Note 1)	925	0	1,476	0
Interest expense	15,291	16,179	30,371	32,117
Loss on induced conversion and debt extinguishment	0	1,247	0	5,703
Impairment of goodwill (Note 6)	0	184,374	0	184,374
Amortization and impairment of other intangible assets	2,748	18,856	5,496	22,152
Total expenses	138,686	338,386	287,834	512,470
Pretax income (loss)	180,571	(35,474)	323,013	79,196
Income tax provision (benefit)	(28,378)	(8,132)	(422)	30,066
Net income (loss)	$ 208,949	$ (27,342)	$ 323,435	$ 49,130
Earnings Per Share, Basic [Abstract]
Basic net income (loss) per share	$ 0.98	$ (0.13)	$ 1.50	$ 0.23
Earnings Per Share, Diluted [Abstract]
Diluted net income (loss) per share	$ 0.96	$ (0.13)	$ 1.48	$ 0.22
Weighted-average number of common shares outstanding—basic	213,976	215,152	215,049	215,054
Weighted-average number of common and common equivalent shares outstanding—diluted	217,830	215,152	218,741	220,474
Dividends per share	$ 0.0025	$ 0.0025	$ 0.0050	$ 0.0050