Borrowings (Interest on Debt) (Details 5) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Interest on Debt
Cost of financing	$ 276	$ 279
Interest expense	225	239
Net investment derivative activity	(3)	1
Interest capitalized	(3)	3
Total interest paid and accrued	$ 496	$ 522