Variable Interest Entities - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Oct. 14, 2011 Store	Dec. 31, 2011
Variable Interest Entity [Line Items]
Held to maturity securities		$ 98,132,000
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Percentage of common stock outstanding	11.50%
Number of retail stores	40
Held to maturity securities		15,900,000
Gains/losses related to the investment		228,000
Maximum exposure to any potential losses associated with VIE		15,900,000
Variable Interest Entity, Not Primary Beneficiary | Maximum
Variable Interest Entity [Line Items]
Investment included in prepaid expenses and other assets		$ 1,000