Borrowings - Interest on Debt (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Interest on Debt
Interest capitalized	$ 5	$ 2
Total interest paid and accrued	449	391
Cost of financing
Interest on Debt
Interest paid	119	179
Interest expense
Interest on Debt
Interest paid	$ 326	$ 210