Useful Life of Amortizable Intangible Assets Charged Against Earnings (Detail)	9 Months Ended
Sep. 30, 2011 Year
Content
Finite-Lived Intangible Assets [Line Items]
Useful Life (Years)	1.5
Trade Name
Finite-Lived Intangible Assets [Line Items]
Useful Life (Years)	5.0
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Useful Life (Years)	4.0

The average useful life of a major finite-lived intangible asset class. A major class is composed of intangible assets that can be grouped together because they are similar either by their nature or by their use in the operations of a company.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=6905858&loc=d3e16265-109275

Name:	us-gaap_FiniteLivedIntangibleAssetsAverageUsefulLife
Namespace Prefix:	us-gaap
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration