CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (457,084)	$ 186,613	$ (341,541)	$ 364,460
Other comprehensive income, net of tax:
Unrealized investment gains arising during the period	62,505	36,336	206,461	238,656
Adjustment for reclassification of net realized investment (gains) losses and OTTI losses recognized in net income	(13,286)	(2,642)	10,169	42,620
Unrealized investment gains arising during the period, net of reclassification adjustment	49,219	33,694	216,630	281,276
Foreign currency translation adjustment	8,088	1,722	46,824	5,694
Total other comprehensive income, net of tax	57,307	35,416	263,454	286,970
Comprehensive income (loss)	$ (399,777)	$ 222,029	$ (78,087)	$ 651,430