CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 38,401	$ 54,095	$ 324,227	$ 230,812
Other comprehensive income (loss), net of tax:
Unrealized investment gains (losses) arising during the period	39,569	(26,061)	361,220	(257,521)
Adjustment for reclassification of net realized investment (gains) losses and OTTI losses recognized in net income	(14,808)	25,924	(8,423)	77,189
Unrealized investment gains (losses) arising during the period, net of reclassification adjustment	24,761	(137)	352,797	(180,332)
Foreign currency translation adjustment	(4,610)	994	609	(6,864)
Total other comprehensive income (loss), net of tax	20,151	857	353,406	(187,196)
Comprehensive income	$ 58,552	$ 54,952	$ 677,633	$ 43,616