Assets Other Assets, noncurrent (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Schedule of Assets, noncurrent [Line Items]
Debt Issuance Costs, Line of Credit Arrangements, Net	$ 4	$ 4
Value Added Tax Receivable, Noncurrent	1	1
Other Assets, Miscellaneous, Noncurrent	37	39
Income Taxes Receivable, Noncurrent	43	57
Total Other long-term assets	113	122
Tula [Member]
Schedule of Assets, noncurrent [Line Items]
Other Long-term Investments	21	21
PolyCharge [Member]
Schedule of Assets, noncurrent [Line Items]
Other Long-term Investments	$ 7	$ 0