Derivative Financial Instruments (Details 2) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value of derivative liability	$ 4,429	$ 7,025
Designated as Hedging Instrument [Member] | Accrued expenses [Member] | Interest rate swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value of derivative liability	4,429	4,143
Designated as Hedging Instrument [Member] | Other long-term liabilities [Member] | Interest rate swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value of derivative liability	0	2,882
Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value of derivative liability	58,815	7,170
Not Designated as Hedging Instrument [Member] | Accrued expenses [Member] | Cross-currency swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value of derivative liability	8,709	7,170
Not Designated as Hedging Instrument [Member] | Contingent forward sale contract [Member] | Other long-term liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value of derivative liability		0
Fair Value, Inputs, Level 1 [Member] | Contingent forward sale contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value of derivative liability	$ 50,106	$ 0