Borrowings (Interest on Debt) (Details 5) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Interest on Debt
Cost of financing	$ 138	$ 140
Interest expense	157	108
Net investment derivative activity	(10)	0
Interest capitalized	1	(2)
Total interest paid and accrued	$ 286	$ 245