Condensesd Consolidated Statements of Equity - 9 months ended Sep. 30, 2015 - USD ($) $ in Millions	Total	Common stock	Additional paid-in capital	Accumulated other comprehensive income (loss)	Accumulated deficit	MPM Inc [Member]	MPM Inc [Member] Common stock	MPM Inc [Member] Additional paid-in capital	MPM Inc [Member] Accumulated other comprehensive income (loss)	MPM Inc [Member] Accumulated deficit
Common shares, outstanding (shares) at Dec. 31, 2014	47,989,000	47,989,000				48
Balance at Dec. 31, 2014	$ 769	$ 0	$ 857	$ (28)	$ (60)	$ 769	$ 0	$ 857	$ (28)	$ (60)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(46)	0	0	0		(45)	0	0	0
Other comprehensive income (loss), net of tax	(53)	0	0	(53)	0	(53)	0	0		0
Stock-based compensation expense	2	$ 0	2	0	0	2	0	2	0	0
Common stock issued, shares		39,594
Proceeds from issuance of common stock	$ 1	$ 0	1	0	0	$ 0
Common shares, outstanding (shares) at Sep. 30, 2015	48,028,594	48,028,594				48
Balance at Sep. 30, 2015	$ 673	$ 0	$ 860	$ (81)	$ (106)	$ 673	$ 0	$ 859	$ (81)	$ (105)