Accounts and Notes Receivable and Credit Quality of Receivables - Components of Notes Receivable, Net (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total accounts and notes receivable, net	$ 778	$ 753
Notes receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Notes receivable	185	178
Notes receivable allowance	(23)	(24)	$ (23)	$ (21)
Total accounts and notes receivable, net	162	154
Domestic | Notes receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Notes receivable	71	55
Notes receivable allowance	(5)	(6)
International | Notes receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Notes receivable	114	123
Notes receivable allowance	(18)	(18)
Balances over 90 days past due | Notes receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Notes receivable over 90 days past due	35	31
Notes receivable allowance for balances over 90 days past due	(23)	(24)
Notes receivable, net, balances over 90 days past due	12	7
Balances over 90 days past due | Domestic | Notes receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Notes receivable over 90 days past due	12	6
Notes receivable allowance for balances over 90 days past due	(5)	(6)
Balances over 90 days past due | International | Notes receivable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Notes receivable over 90 days past due	23	25
Notes receivable allowance for balances over 90 days past due	$ (18)	$ (18)