Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent				$ (23,487)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax			(9,259)	7,998
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent			(16,588)	(15,489)
Other Comprehensive Income (Loss), Tax			(3,176)	(3,120)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax			0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(21,938)	3,237	(7,329)	(23,487)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	2,366	(900)	(494)	10,199
Changes in the balances of each component of accumulated other comprehensive income
Accumulated Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Foreign Currency Translation, Net of Tax, Beginning Balance			(37,827)	(6,126)
Accumulated Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Foreign Currency Translation, Net of Tax, Ending Balance	(45,156)	(29,613)	(45,156)	(29,613)
Accumulated Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Interest Rate Swaps, Net of Tax, Beginning Balance			(13,850)	(26,931)
Accumulated Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Interest Rate Swaps, Net of Tax, Ending Balance	(14,344)	(16,732)	(14,344)	(16,732)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance			(51,677)	(33,057)
Other comprehensive income, net of tax			(7,823)	(13,288)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	(59,500)	(46,345)	(59,500)	(46,345)
Floorplan Interest Expense [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax			7,331	7,390
Interest Expense [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax			1,138	930
Gain (Loss) on Interest Rate Swaps | Tax effect on other comprehensive income loss before reclassification [Member]
Other Comprehensive Income (Loss), Tax			3,472	(2,999)
Total | Tax effect on other comprehensive income loss before reclassification [Member]
Other Comprehensive Income (Loss), Tax			$ 3,472	$ (2,999)