Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income		$ 174,645	$ 83,243	$ 219,830
Other comprehensive income (loss):
Change in net unrealized investment gains/losses (1)	[1]	556,384	207,994	(797,374)
Noncredit component of OTTI losses (1)	[1]	915	556	(2,927)
Reclassification of unrealized investment gains/losses to net income (1)	[1]	4,496	4,224	703
Other comprehensive income (loss) before income tax		561,795	212,774	(799,598)
Income tax effect related to other comprehensive income (loss)		(177,162)	(74,471)	279,860
Other comprehensive income (loss)		384,633	138,303	(519,738)
Comprehensive income (loss)		$ 559,278	$ 221,546	$ (299,908)

[1] Net of related adjustments to amortization of deferred sales inducements and deferred policy acquisition costs.