Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 65	$ 87
Other comprehensive income (loss), before tax:
Unrealized gains/losses on securities	633	(482)
Other-than-temporary impairments	0	7
Pension and other postretirement benefits liability	0	(1)
Other comprehensive income (loss), before tax	633	(476)
Income tax expense (benefit) related to items of other comprehensive income (loss)	131	(108)
Other comprehensive income (loss), after tax	502	(368)
Comprehensive income (loss)	$ 567	$ (281)