Fair Value - Additional Information (Detail) (Revolving Credit Facility [Member])	6 Months Ended
Jun. 30, 2013
Revolving Credit Facility [Member]
Fair Value Liabilities Measured On Recurring and Nonrecurring Basis [Line Items]
Debt instrument variable interest rate, description	30 day LIBOR
Debt instrument variable interest rate	2.75%

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

No definition available.

Name:	us-gaap_DebtInstrumentDescriptionOfVariableRateBasis
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration