Revenue from Contracts With Customers - Contract balances (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Abstract]
Contract assets	$ 0		$ 0
Contract Liabilities (Current)	89,000,000		108,000,000
Contract Liabilities (Noncurrent)	28,000,000		$ 29,000,000
Increase (decrease) current contract liabilities	(19,000,000)
Increase (decrease) noncurrent contract liabilities	(1,000,000)
Total increase (decrease) in contract liabilities	(20,000,000)
Cash received on contract liabilities	103,000,000
Revenue recognized as sales	123,000,000
Revenue recognized from opening balance of contract liabilities	108,000,000
Revenue recognized from obligations satisfied or partially satisfied in prior periods	$ 7,000,000	$ 9,000,000