Borrowings (Annual Maturities on Long-term Debt Outstanding) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	[1]
Borrowings [Abstract]
2017	$ 258
2018	908
2019	8
2020	709
2021	9
Thereafter	1,008
Total maturities	2,900
Unamortized discount, net	(14)
Debt issuance costs	(10)
Total long-term debt	$ 2,876	$ 2,877

[1] Adjusted for the retrospective adoption of ASU 2015-03. See New Accounting Standards in Note 2 for additional information.