Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent		$ 8,215
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	(10,420)	(4,032)
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(41,014)	4,183
Other Comprehensive Income (Loss), Tax	(1,180)us-gaap_OtherComprehensiveIncomeLossTax	(1,044)us-gaap_OtherComprehensiveIncomeLossTax
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	30,594	(8,215)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(4,546)	(780)
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	(64,075)	(37,827)
Accumulated Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Foreign Currency Translation, Net of Tax, Ending Balance	(94,669)	(29,612)
Accumulated Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Interest Rate Swaps, Net of Tax, Beginning Balance	(17,909)	(13,850)
Accumulated Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Interest Rate Swaps, Net of Tax, Ending Balance	(22,455)	(14,630)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	(81,984)	(51,677)
Other comprehensive income (loss), net of tax	(35,140)	7,435
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	(117,124)	(44,242)
Floorplan Interest Expense [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax	2,708	2,429
Interest Expense [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax	439	355
Gain (Loss) on Interest Rate Swaps \| Tax effect on other comprehensive income loss before reclassification [Member]
Other Comprehensive Income (Loss), Tax	3,907	1,512
Total \| Tax effect on other comprehensive income loss before reclassification [Member]
Other Comprehensive Income (Loss), Tax	$ 3,907	$ 1,512

Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

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Accumulated adjustment, net of tax, that results from the process of translating subsidiary financial statements and foreign equity investments into the reporting currency from the functional currency of the reporting entity, net of reclassification of realized foreign currency translation gains or losses.

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