Equity and Other Investments - Additional Information (Detail) (USD $)	12 Months Ended		1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Jul. 31, 2012 TRA Preferred Stock	Dec. 31, 2011 TRA Preferred Stock	Dec. 31, 2012 TRA Preferred Stock	Dec. 31, 2011 TRA Preferred Stock	Dec. 31, 2012 Scarborough	Dec. 31, 2011 Scarborough	Dec. 31, 2010 Scarborough
Schedule of Equity and Cost Investments [Line Items]
Equity method investment, ownership percentage							49.50%
Royalty fees							$ 29,200,000	$ 26,200,000	$ 26,200,000
Accrued royalties							5,298,000	5,061,000
Revenue							67,500,000	65,700,000	64,300,000
Net income							15,200,000	14,500,000	14,200,000
Total assets							26,000,000	25,000,000
Total liabilities							4,600,000	2,900,000
Sale of investment			1,700,000
Proceeds from sale of investment	1,466,000				1,466,000
Receivable from sale of investment	214,000				214,000
Impairment charge		$ 3,477,000		$ 3,477,000		$ 3,477,000