Leases - Operating Lease Assets and Liabilities in the Consolidated Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Right-of-use assets classified in Other noncurrent assets	$ 242	$ 252
Current portion of lease liabilities classified in Other current liabilities	70	71
Long-term portion of lease liabilities classified in Other noncurrent liabilities and deferred credits	188	194
Total lease liabilities	$ 258	$ 265