Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
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			$ (118,532)	$ (64,075)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent			(3,913)	(20,595)
Other Comprehensive Income (Loss), Foreign Currency Translation Gain (Loss) Arising During Period, Tax			0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Tax			0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax			(3,913)	(20,595)
Accumulated Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Foreign Currency Translation, Net of Tax, Ending Balance	$ (122,445)	$ (84,670)	(122,445)	(84,670)
Accumulated Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Interest Rate Swaps, Net of Tax, Beginning Balance			(19,452)	(17,909)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax			(26,821)	(7,534)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	3,373	(1,082)	10,058	2,825
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	(1,285)	(1,188)	(2,553)	(2,368)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(3,480)	3,784	(12,507)	(762)
Accumulated Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Interest Rate Swaps, Net of Tax, Ending Balance	(31,959)	(18,671)	(31,959)	(18,671)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance			(137,984)	(81,984)
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent			(30,734)	(28,129)
Other Comprehensive Income (Loss) before Reclassifications, Tax			10,058	2,825
Other Comprehensive Income (Loss), Tax			(2,553)	(2,368)
Other comprehensive income (loss), net of tax			(16,420)	(21,357)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	$ (154,404)	$ (103,341)	(137,984)	(81,984)
Floorplan Interest Expense [Member]
Changes in the balances of each component of accumulated other comprehensive income
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax			0	0
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax			5,623	5,470
Other Comprehensive Income (Loss), before Tax			5,623	5,470
Interest Expense [Member]
Changes in the balances of each component of accumulated other comprehensive income
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax			0	0
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax			1,186	845
Other Comprehensive Income (Loss), before Tax			$ 1,186	$ 845