CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 2,171	$ 2,850	$ 2,280
Changes in:
Unrealized net capital gains and losses	(1,306)	280	(1,188)
Unrealized foreign currency translation adjustments	(58)	(40)	(32)
Unrecognized pension and other postretirement benefit cost	48	(725)	1,091
Other comprehensive loss, after-tax	(1,316)	(485)	(129)
Comprehensive income	$ 855	$ 2,365	$ 2,151