Consolidated Statements of Changes in Equity (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Stockholders' Equity [Abstract]
Changes in net unrealized gains on available-for-sale securities, net of tax	$ 151	$ 389	$ 529
Reclassification adjustment for gains included in net income, net of tax	253	123	157
Prior service cost and actuarial gains, net of amortization for defined benefit plans, net of tax	$ 0	$ 20	$ 68