Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 27,478	$ 21,644	$ 62,951	$ 51,158
Unrealized gain (loss) on interest rate swap contracts, net of deferred income tax expense (benefit) of $4,590 and $(4,460) for the three months ended September 30, 2016 and 2015, respectively, and $(3,522) and $(2,752) for the nine months ended September 30, 2016 and 2015, respectively	8,452	(7,117)	(11,571)	(4,273)
Foreign currency translation adjustments, net of deferred income tax (benefit) of $(564) and $(2,555) for the three and nine months ended September 30, 2016, respectively	(6,745)	(13,502)	(26,686)	(2,745)
Other comprehensive income (loss)	1,707	(20,619)	(38,257)	(7,018)
Total comprehensive income	29,185	1,025	24,694	44,140
Less: comprehensive loss attributable to noncontrolling interests	198	1,570	97	965
Comprehensive (loss) income attributable to controlling interests	$ 28,987	$ (545)	$ 24,597	$ 43,175