Accumulated Other Comprehensive Income / (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	$ (41,505)	$ (6,833)
Other comprehensive income before reclassifications	37,899	2,450
Amounts reclassified from accumulated other comprehensive income - net of tax	552	1,329
Net current-period other comprehensive income	38,451	3,779
Balance at the end of the period	(3,054)	(3,054)
Interest Rate Swaps
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	(6,505)	(8,678)
Other comprehensive income before reclassifications	272	784
Amounts reclassified from accumulated other comprehensive income - net of tax	552	2,213
Net current-period other comprehensive income	824	2,997
Balance at the end of the period	(5,681)	(5,681)
Interest Rate Swaps | Floor plan interest expense
Changes in accumulated other comprehensive income (loss) by component
Amounts reclassified from accumulated other comprehensive income - net of tax	552	2,213
Foreign Currency Translation
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	(36,825)	(1,194)
Other comprehensive income before reclassifications	41,811	7,064
Amounts reclassified from accumulated other comprehensive income - net of tax		(884)
Net current-period other comprehensive income	41,811	6,180
Balance at the end of the period	4,986	4,986
Foreign Currency Translation | Selling, general, and administrative expenses
Changes in accumulated other comprehensive income (loss) by component
Amounts reclassified from accumulated other comprehensive income - net of tax		(884)
Other
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	1,825	3,039
Other comprehensive income before reclassifications	(4,184)	(5,398)
Net current-period other comprehensive income	(4,184)	(5,398)
Balance at the end of the period	$ (2,359)	$ (2,359)