Long-Term Debt, Capital Lease Obligations and Hedging Arrangements Derivative Instruments Recognized in OCI (Details) (Designated as Hedging Instrument [Member], Interest Rate Contract [Member], Cash Flow Hedging [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate hedging agreements	$ (79)	$ (651)	$ (761)	$ 402
Other Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate hedging agreements	$ 0	$ 0	$ 0	$ 0