Additional Information Related to Equity-Based Compensation (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity-based compensation	$ 3,876	$ 2,063
Unrecognized Equity-Based Compensation	56,501
Weighted Average Years Remaining of Equity-Based Compensation
DSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity-based compensation	146	90
Unrecognized Equity-Based Compensation	314
Weighted Average Years Remaining of Equity-Based Compensation	9 months 18 days
SARs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity-based compensation	250	601
Unrecognized Equity-Based Compensation	1,088
Weighted Average Years Remaining of Equity-Based Compensation	1 year 8 months 12 days
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity-based compensation	3,293	1,189
Unrecognized Equity-Based Compensation	53,844
Weighted Average Years Remaining of Equity-Based Compensation	2 years 10 months 24 days
Equity-Based Compensation
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity-based compensation	3,689	1,880
Unrecognized Equity-Based Compensation	55,246
Weighted Average Years Remaining of Equity-Based Compensation
Non- Controlling Interest
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity-based compensation	187	183
Unrecognized Equity-Based Compensation	$ 1,255
Weighted Average Years Remaining of Equity-Based Compensation	2 years 1 month 6 days