Equity-Based Compensation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Equity-based compensation
Equity-based compensation	$ 2,174	$ 925	$ 5,755	$ 2,705
Unrecognized Equity-Based Compensation as of September 30, 2012	18,554		18,554
Equity-Based Compensation [Member]
Equity-based compensation
Equity-based compensation	1,485	871	4,353	2,335
Unrecognized Equity-Based Compensation as of September 30, 2012	13,640		13,640
Non-Controlling Interest [Member]
Equity-based compensation
Equity-based compensation	689	54	1,402	370
Unrecognized Equity-Based Compensation as of September 30, 2012	4,914		4,914
Weighted Average Years Remaining of Equity-Based Compensation as of September 30, 2012	3 years 3 months 18 days		3 years 3 months 18 days
SARs [Member]
Equity-based compensation
Equity-based compensation	661	611	1,887	1,645
Unrecognized Equity-Based Compensation as of September 30, 2012	4,610		4,610
Weighted Average Years Remaining of Equity-Based Compensation as of September 30, 2012	2 years 4 months 24 days		2 years 4 months 24 days
Restricted Stock [Member]
Equity-based compensation
Equity-based compensation	737	85	2,134	162
Unrecognized Equity-Based Compensation as of September 30, 2012	8,886		8,886
Weighted Average Years Remaining of Equity-Based Compensation as of September 30, 2012	3 years 2 months 12 days		3 years 2 months 12 days
DSUs [Member]
Equity-based compensation
Equity-based compensation	87	175	332	528
Unrecognized Equity-Based Compensation as of September 30, 2012	$ 144		$ 144
Weighted Average Years Remaining of Equity-Based Compensation as of September 30, 2012	4 months 24 days		4 months 24 days