Investment Activity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule Of Equity And Other Investments [Line Items]
Beginning balance, equity and other investments		$ 14,913	$ 18,385	$ 16,938
Beginning balance, equity method investments		13,210
Beginning balance, cost method investments		1,703
Equity in net (income) loss of affiliate		7,216	7,255	7,092
Impairment loss			(3,477)
Distributions from affiliate		(7,925)	(7,250)	(7,425)
Proceeds from sale of investment		(1,466)
Receivable from sale of investment		(214)
Loss on sale of investment		(23)
Purchases of equity and other investments				1,780
Ending balance, equity and other investments	14,913	12,501	14,913	18,385
Ending balance, equity method investments	13,210	12,501	13,210
Ending balance, cost method investments	1,703		1,703
TRA Preferred Stock
Schedule Of Equity And Other Investments [Line Items]
Beginning balance, cost method investments		1,703	5,180	3,400
Impairment loss	(3,477)		(3,477)
Proceeds from sale of investment		(1,466)
Receivable from sale of investment		(214)
Loss on sale of investment		(23)
Cash investments				1,780
Ending balance, cost method investments	1,703		1,703	5,180
Scarborough
Schedule Of Equity And Other Investments [Line Items]
Beginning balance, equity method investments		13,210	13,205	13,538
Equity in net (income) loss of affiliate		7,216	7,255	7,092
Distributions from affiliate		(7,925)	(7,250)	(7,425)
Ending balance, equity method investments	$ 13,210	$ 12,501	$ 13,210	$ 13,205