Goodwill and Other Intangible Assets - Additional Information (Detail)	9 Months Ended
Sep. 30, 2012
Minimum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life	5 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life	9 years

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration