Accumulated OCI (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated OCI, net of tax Beginning Balance	$ (929)	$ (1,789)
Other comprehensive loss before reclassifications, net of tax	(566)	(1,164)
Amounts reclassified from accumulated OCI, net of tax	1,088	2,024
Net increase (decrease) in other comprehensive income (loss), net of tax	522	860	1,644
Accumulated OCI, net of tax Ending Balance	(407)	(929)	(1,789)
Reclassification adjustments out of AOCI [Abstract]
Reclassification to interest expense	(16,079)	(14,149)	(13,193)
Net Change in Fair Value of Interest Rate Swaps [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated OCI, net of tax Beginning Balance	(1,790)	(2,570)
Other comprehensive loss before reclassifications, net of tax	189	(1,244)
Amounts reclassified from accumulated OCI, net of tax	1,088	2,024
Net increase (decrease) in other comprehensive income (loss), net of tax	1,277	780
Accumulated OCI, net of tax Ending Balance	(513)	(1,790)
Net Change in Fair Value of Interest Rate Swaps [Member] | Amounts reclassified from accumulated other comprehensive income to: [Member]
Reclassification adjustments out of AOCI [Abstract]
Reclassification to interest expense	1,916	3,302
Tax effect of reclassification	(828)	(1,278)
Reclassification Adjustment on Derivatives Included in Net Income	1,088	2,024
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated OCI, net of tax Beginning Balance	861	781
Other comprehensive loss before reclassifications, net of tax	(755)	80
Amounts reclassified from accumulated OCI, net of tax	0	0
Net increase (decrease) in other comprehensive income (loss), net of tax	(755)	80
Accumulated OCI, net of tax Ending Balance	$ 106	$ 861