Leases - Operating Lease Assets and Liabilities in the Consolidated Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019
Leases [Abstract]
Right-of-use assets classified in Other noncurrent assets	$ 252	$ 320
Current portion of lease liabilities classified in Other current liabilities	71
Long-term portion of lease liabilities classified in Other noncurrent liabilities and deferred credits	194
Total lease liabilities	$ 265