Consolidated Statements of Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss)	Parent Company [Member]	MPM Inc [Member]	MPM Inc [Member] Common Stock	MPM Inc [Member] Additional Paid-in Capital	MPM Inc [Member] Retained Earnings [Member]	MPM Inc [Member] Accumulated Other Comprehensive Income (Loss)
Common Stock, Shares, Outstanding	48
Payments of Ordinary Dividends, Common Stock	$ 0
Proceeds from Contributions from Parent									$ 3
Balance at Dec. 31, 2014	769	$ 0	$ 857	$ (60)	$ (28)		$ 769	$ 0	857	(60)	(28)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Allocated Share-based Compensation Expense	3		3
Net Income (Loss) Attributable to Parent	(83)						(82)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(83)			(83)		$ (82)	(82)			(82)
Other Comprehensive Income (Loss), Net of Tax	(64)				(64)		(64)				(64)
Balance at Dec. 31, 2015	626	$ 0	861	(143)	(92)		626	0	860	(142)	(92)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, New Issues		0
Proceeds from Issuance of Common Stock	$ 1		1
Common Stock, Shares, Outstanding	48
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (92)
Payments of Ordinary Dividends, Common Stock							(1)
Proceeds from Contributions from Parent									3
Allocated Share-based Compensation Expense	3		3
Net Income (Loss) Attributable to Parent	(163)						(161)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(163)					(161)	(161)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(1)
Other Comprehensive Income (Loss), Net of Tax	16						16
Balance at Dec. 31, 2016	482	$ 0	864	(306)	(76)		484	0	863	(303)	(76)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends						0	0
Stock Issued During Period, Shares, New Issues		0
Proceeds from Issuance of Common Stock	$ 0
Common Stock, Shares, Outstanding	48
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (76)						(76)
Payments of Ordinary Dividends, Common Stock							(1)
Proceeds from Contributions from Parent									3
Allocated Share-based Compensation Expense	4		4
Net Income (Loss) Attributable to Parent	0			(163)			1
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	0			0		1	1
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	45
Other Comprehensive Income (Loss), Net of Tax	58				58		58
Balance at Dec. 31, 2017	544	$ 0	$ 868	$ (306)	$ (18)		545	$ 0	$ 866	$ (303)	$ (18)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends	(1)					$ 0	0
Stock Issued During Period, Shares, New Issues		0
Proceeds from Issuance of Common Stock	$ 0
Common Stock, Shares, Outstanding	48
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (18)						$ (18)