Consolidated Statements Of Shareholders' Equity - USD ($) $ in Thousands	Total	Cumulative effect of change in accounting principle	Common Shares	Additional Paid-In Capital	Accumulated Other Comprehensive Loss, Net	Accumulated Other Comprehensive Loss, Net Cumulative effect of change in accounting principle	Retained Earnings	Retained Earnings Cumulative effect of change in accounting principle	Noncontrolling Interests
Balance at beginning of period (in shares) at Dec. 31, 2018			46,134,000
Balance at beginning of period at Dec. 31, 2018	$ 376,772	$ 0	$ 461	$ 327,009	$ (66,877)	$ 366	$ 116,276	$ (366)	$ (97)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares for share-based compensation, net of forfeitures (in shares)			201,000
Issuance of common shares for share-based compensation, net of forfeitures	2		$ 2
Share-based compensation expense	15,367			15,367
Tax payments related to share-based compensation	(2,224)			(2,224)
Repurchase of common shares	(50,252)		$ (17)	(11,812)			(38,423)
Unrealized loss on interest rate derivatives, interest rate swap and foreign currency forward contracts, net of deferred income tax benefit	(29,473)				(29,473)
Net income attributable to controlling interests	35,654						35,654
Net loss attributable to noncontrolling interests	(3)								(3)
Foreign currency translation adjustments, net of deferred income tax benefit	2,378				2,378
Repurchase of common shares (in shares)			(1,732,000)
Balance at end of period (in shares) at Sep. 30, 2019			44,603,000
Balance at end of period at Sep. 30, 2019	348,221		$ 446	328,340	(93,606)		113,141		(100)
Balance at beginning of period (in shares) at Dec. 31, 2018			46,134,000
Balance at beginning of period at Dec. 31, 2018	376,772	0	$ 461	327,009	(66,877)	$ 366	116,276	(366)	(97)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to controlling interests	$ 48,274
Balance at end of period (in shares) at Dec. 31, 2019	44,676,132		44,676,000
Balance at end of period at Dec. 31, 2019	$ 380,326	(1,871)	$ 447	332,109	(77,887)		125,763	(1,871)	(106)
Balance at beginning of period (in shares) at Jun. 30, 2019			45,645,000
Balance at beginning of period at Jun. 30, 2019	361,873		$ 456	330,131	(83,810)		115,197		(101)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares for share-based compensation, net of forfeitures (in shares)			12,000
Issuance of common shares for share-based compensation, net of forfeitures	0
Share-based compensation expense	5,633			5,633
Tax payments related to share-based compensation	(202)			(202)
Repurchase of common shares	(30,152)		$ (10)	(7,222)			(22,920)
Unrealized loss on interest rate derivatives, interest rate swap and foreign currency forward contracts, net of deferred income tax benefit	(2,798)				(2,798)
Net income attributable to controlling interests	20,864						20,864
Net loss attributable to noncontrolling interests	3								3
Foreign currency translation adjustments, net of deferred income tax benefit	(7,000)				(6,998)				(2)
Repurchase of common shares (in shares)			(1,054,000)
Balance at end of period (in shares) at Sep. 30, 2019			44,603,000
Balance at end of period at Sep. 30, 2019	$ 348,221		$ 446	328,340	(93,606)		113,141		(100)
Balance at beginning of period (in shares) at Dec. 31, 2019	44,676,132		44,676,000
Balance at beginning of period at Dec. 31, 2019	$ 380,326	$ (1,871)	$ 447	332,109	(77,887)		125,763	$ (1,871)	(106)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares for share-based compensation, net of forfeitures (in shares)			309,000
Issuance of common shares for share-based compensation, net of forfeitures	315		$ 3	312
Share-based compensation expense	16,143			16,143
Tax payments related to share-based compensation	(5,792)			(5,792)
Repurchase of common shares	(16,873)		$ (5)	(3,530)			(13,338)
Settlement of note hedge and warrants associated with the convertible senior notes	(1,197)			(1,197)
Unrealized loss on interest rate derivatives, interest rate swap and foreign currency forward contracts, net of deferred income tax benefit	(39,534)				(39,534)
Net income attributable to controlling interests	9,565						9,565
Net loss attributable to noncontrolling interests	(10)								(10)
Foreign currency translation adjustments, net of deferred income tax benefit	$ (6,737)				(6,790)		(3)		56
Repurchase of common shares (in shares)			(506,000)
Balance at end of period (in shares) at Sep. 30, 2020	44,478,988		44,479,000
Balance at end of period at Sep. 30, 2020	$ 334,335		$ 445	338,045	(124,211)		120,116		(60)
Balance at beginning of period (in shares) at Jun. 30, 2020			44,477,000
Balance at beginning of period at Jun. 30, 2020	308,089		$ 445	332,157	(138,827)		114,384		(70)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares for share-based compensation, net of forfeitures (in shares)			2,000
Issuance of common shares for share-based compensation, net of forfeitures	24			24
Share-based compensation expense	5,921			5,921
Tax payments related to share-based compensation	(43)			(43)
Settlement of note hedge and warrants associated with the convertible senior notes	(14)			(14)
Unrealized loss on interest rate derivatives, interest rate swap and foreign currency forward contracts, net of deferred income tax benefit	3,548				3,548
Net income attributable to controlling interests	5,732						5,732
Net loss attributable to noncontrolling interests	(5)								(5)
Foreign currency translation adjustments, net of deferred income tax benefit	$ 11,083				11,068				15
Balance at end of period (in shares) at Sep. 30, 2020	44,478,988		44,479,000
Balance at end of period at Sep. 30, 2020	$ 334,335		$ 445	$ 338,045	$ (124,211)		$ 120,116		$ (60)