Accumumlated Other Comprehensive Income / (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	$ (44,486)	$ (6,833)
Other comprehensive income before reclassifications	2,425	(35,449)
Amounts reclassified from accumulated other comprehensive income - net of tax	556	777
Net current-period other comprehensive income	2,981	(34,672)
Balance at the end of the period	(41,505)	(41,505)
Interest Rate Swaps
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	(7,627)	(8,678)
Other comprehensive income before reclassifications	566	512
Amounts reclassified from accumulated other comprehensive income - net of tax	556	1,661
Net current-period other comprehensive income	1,122	2,173
Balance at the end of the period	(6,505)	(6,505)
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	556	1,661
Foreign Currency Translation
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	(38,381)	(1,194)
Other comprehensive income before reclassifications	1,556	(34,747)
Amounts reclassified from accumulated other comprehensive income - net of tax		(884)
Net current-period other comprehensive income	1,556	(35,631)
Balance at the end of the period	(36,825)	(36,825)
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	1,522	3,039
Other comprehensive income before reclassifications	303	(1,214)
Net current-period other comprehensive income	303	(1,214)
Balance at the end of the period	$ 1,825	$ 1,825