Fair Value of Financial Instruments Financial Instruments Carried at Fair Value(Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets carried at fair value	$ 4,557	$ 0
Financial liabilities carried at fair value	4,806	14,195
Designated as Hedging Instrument [Member] | Fair Value, Inputs, Level 2 [Member] | Interest rate swap agreement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities carried at fair value	4,663	7,025
Derivatives not designated as hedges [Member] | Fair Value, Inputs, Level 2 [Member] | Cross-currency swap agreement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities carried at fair value	143	7,170
Prepaid expenses and other [Member] | Derivatives not designated as hedges [Member] | Fair Value, Inputs, Level 2 [Member] | Cross-currency swap agreement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets carried at fair value	255	0
Interest Rate Swap [Member] | Other Assets [Member] | Designated as Hedging Instrument [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets carried at fair value	$ 4,302	$ 0