BACKGROUND AND BASIS OF PRESENTATION (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Dec. 31, 2012
BACKGROUND AND BASIS OF PRESENTATION [Abstract]
Foreign income tax adjustment	$ 1,686
Diluted earnings per share effect of foreign income tax adjustment	$ 0.07

Dilutive earnings per share effect of income tax expense related to foreign tax adjustment.

No definition available.

Name:	ccmp_DilutedEarningsPerShareEffectOfForeignIncomeTaxAdjustment
Namespace Prefix:	ccmp_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration