Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 319	$ 472
Postretirement benefits, including pensions	119	152
Research and development costs	85	113
Expense accruals	78	54
Other tax credits recoverable	122	67
Capital loss carryforwards	43	40
Inventory reserves	16	18
Postemployment and other benefits	5	8
Other		20
Total	787	944
Valuation allowance	(301)	(285)
Deferred tax assets	486	659
Unremitted earnings	(30)	(27)
Intangibles	(22)	(29)
Depreciation	(60)	(52)
Other	(13)
Deferred tax liabilities	(125)	(108)
Net deferred tax assets	$ 361	$ 551