Consolidated Statements of Changes in Equity (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Stockholders' Equity [Abstract]
Changes in net unrealized gains on available-for-sale securities, net of tax	$ 30	$ 151	$ 389
Reclassification adjustment for gains included in net income, net of tax	$ 316	$ 253	123
Prior service cost and actuarial gains, net of amortization for defined benefit plans, net of tax			$ 20