Borrowings - Additional Information (Detail) (USD $)	Dec. 31, 2012
Credit Facility Short Term Borrowings [Line Items]
Outstanding letters of credit	$ 102,000
Letters of credit issued percentage of cash collateralized basis	100.00%

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

No definition available.

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant