Summary of Changes in Carrying Value of Goodwill by Reporting Unit (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill Beginning balance	$ 2,951
Impairment loss on goodwill	(2,951)
Goodwill Ending Balance	$ 0

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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

-Publisher FASB

-Name Accounting Standards Codification

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-Section 45

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration