Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 13,406	$ 14,765	$ 22,905	$ 23,913
Unrealized gains on interest rate swap contracts, net of deferred income tax expense (benefit) of $(1,012) and $10,545 for the three months ended June 30, 2014 and 2013, respectively, and $(93) and $13,981 for the six months ended June 30, 2014 and 2013, respectively	(1,566)	17,548	(380)	23,251
Foreign currency translation adjustments	3,429	(497)	4,169	(4,537)
Other comprehensive income	1,863	17,051	3,789	18,714
Total comprehensive income	15,269	31,816	26,694	42,627
Less: comprehensive loss attributable to noncontrolling interests	(586)	(597)	(664)	(819)
Comprehensive income (loss) attributable to controlling interests	$ 15,855	$ 32,413	$ 27,358	$ 43,446