Derivative Financial Instruments Fair Value of the Company's Derivative Instruments (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Designated as hedging instrument [Member] \| Interest rate swap [Member] \| Accrued expenses [Member]
Derivative Fair Value [Line Items]
Fair value of derivative liabilities	$ 2,034	$ 1,601
Designated as hedging instrument [Member] \| Interest rate swap [Member] \| Other long-term liabilities [Member]
Derivative Fair Value [Line Items]
Fair value of derivative liabilities	887	838
Fair Value, Inputs, Level 2 [Member]
Derivative Fair Value [Line Items]
Fair value of derivative asset	38,364	53,043
Fair value of derivative liabilities	2,921	2,439
Fair Value, Inputs, Level 2 [Member] \| Designated as hedging instrument [Member] \| Interest rate swap [Member]
Derivative Fair Value [Line Items]
Fair value of derivative liabilities	2,921	2,439
Fair Value, Inputs, Level 2 [Member] \| Designated as hedging instrument [Member] \| Interest rate swap [Member] \| Other assets, net [Member]
Derivative Fair Value [Line Items]
Fair value of derivative asset	25,869	36,987
Fair Value, Inputs, Level 2 [Member] \| Not Designated as Hedging Instrument [Member] \| Cross-currency swap [Member] \| Prepaid expenses and other [Member]
Derivative Fair Value [Line Items]
Fair value of derivative asset	$ 12,495	$ 16,056

Designated as hedging instrument [Member] | Interest rate swap [Member] | Accrued expenses [Member]

Designated as hedging instrument [Member] | Interest rate swap [Member] | Other long-term liabilities [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member] | Designated as hedging instrument [Member] | Interest rate swap [Member]

Fair Value, Inputs, Level 2 [Member] | Designated as hedging instrument [Member] | Interest rate swap [Member] | Other assets, net [Member]

Fair Value, Inputs, Level 2 [Member] | Not Designated as Hedging Instrument [Member] | Cross-currency swap [Member] | Prepaid expenses and other [Member]