Consolidated Statements of Equity (USD $)	Total	Common Stock Value [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Translation Adjustment [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]
Beginning balance at Dec. 31, 2010	$ 569,088,000	$ 797,000	$ 220,144,000	$ (14,841,000)	$ (2,877,000)	$ 323,923,000	$ 41,942,000
Stockholders' equity rollforward
Net income (loss)	18,757,000					15,960,000	2,797,000
Translation adjustment, net of taxes	1,383,000				1,383,000
Net change in derivative fair value, net of tax	20,140,000
Comprehensive income (loss)	20,140,000
Proceeds from issuance of common stock	931,000
Distributions to public unitholders	(167,000)
Exercise of common stock options	9,441,000		7,536,000
Grants of restricted stock, net	(33,000)
Equity compensation expense	(1,669,000)		(1,669,000)
Ending balance at Dec. 31, 2011
Stockholders' equity rollforward
Distributions to public unitholders	4,489,000						4,489,000
Exercise of common stock options		7,000	943,000	(19,000)
Grants of restricted stock, net				167,000
Equity compensation expense							1,905,000
Other noncontrolling interests							(33,000)
Ending balance at Dec. 31, 2012	593,308,000	804,000	226,954,000	(15,027,000)	(1,494,000)	339,883,000	42,188,000
Stockholders' equity rollforward
Net income (loss)	3,325,000					153,000	3,172,000
Translation adjustment, net of taxes	(2,409,000)				(2,409,000)
Comprehensive income (loss)	916,000
Distributions to public unitholders	(4,846,000)						4,846,000
Exercise of common stock options	1,978,000	9,000	2,245,000	(276,000)
Grants of restricted stock, net	(462,000)			(462,000)
Equity compensation expense	6,724,000		5,265,000				1,459,000
Tax benefit related to equity-based compensation, net	(104,000)		(104,000)
Other noncontrolling interests	16,000						16,000
Ending balance at Dec. 31, 2013	597,498,000	813,000	234,360,000	(15,765,000)	(3,903,000)	340,036,000	41,957,000
Stockholders' equity rollforward
Net income (loss)	(167,575,000)					(169,678,000)	2,103,000
Translation adjustment, net of taxes	(22,312,000)				(22,312,000)
Comprehensive income (loss)	(189,887,000)
Proceeds from issuance of common stock	363,149,000						363,149,000
Distributions to public unitholders	12,569,000						12,569,000
Exercise of common stock options	1,610,000	10,000	1,678,000	(78,000)
Grants of restricted stock, net	(576,000)			576,000
Equity compensation expense	6,775,000		5,231,000				1,544,000
Tax benefit related to equity-based compensation, net	(103,000)		(103,000)
Other noncontrolling interests	(296,000)						(296,000)
Ending balance at Dec. 31, 2014	$ 765,601,000	$ 823,000	$ 241,166,000	$ (16,419,000)	$ (26,215,000)	$ 170,358,000	$ 395,888,000