Income Taxes Income Taxes (Schedule of Effective Tax Rate Reconciliation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Line Items]
Income tax provision computed at US federal statutory tax rate	$ 361	$ 171	$ 329
Change in valuation allowance	(18)	124	49
Equity income and dividends	(60)	(33)	(50)
(Income) expense not resulting in tax impact, net	(152)	(32)	(34)
US tax effect of foreign earnings and dividends	302	15	49
Foreign tax credits	(293)	(4)	(34)
Other foreign tax rate differentials	(44)	(41)	(33)
Tax-deductible interest on foreign equity investments and other related items	0	0	12
State income taxes, net of federal benefit	8	6	9
Other, net	18	(5)	17
Income tax provision (benefit)	$ 122	$ 201	$ 314
Effective income tax rate	12.00%	41.00%	33.00%
UNITED STATES
Income Taxes [Line Items]
US federal statutory tax rate	35.00%