Accumulated OCI (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
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	(182)	(155)
Amounts reclassified from accumulated OCI, net of tax	380	562
Net increase (decrease) in other comprehensive income (loss), net of tax	198	407
Accumulated OCI, net of tax Ending Balance	(731)	(1,382)
Reclassification adjustments out of AOCI [Abstract]
Reclassification to interest expense	3,321	3,187
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	(35)	(214)
Amounts reclassified from accumulated OCI, net of tax	380	562
Net increase (decrease) in other comprehensive income (loss), net of tax	345	348
Accumulated OCI, net of tax Ending Balance	(1,445)	(2,222)
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	629	929
Tax effect of reclassification	(249)	(367)
Reclassification Adjustment on Derivatives Included in Net Income	380	562
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	(147)	59
Amounts reclassified from accumulated OCI, net of tax	0	0
Net increase (decrease) in other comprehensive income (loss), net of tax	(147)	59
Accumulated OCI, net of tax Ending Balance	$ 714	$ 840