Financial Instruments (Details) In Thousands, unless otherwise specified	Mar. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Mar. 31, 2012 Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2011 Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2012 Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2011 Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2012 Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] USD ($)	Mar. 31, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member] USD ($)	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member] USD ($)	Mar. 31, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Mar. 31, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member] USD ($)	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member] USD ($)	Mar. 31, 2012 Cross Currency Interest Rate Contract [Member] Designated as Hedging Instrument [Member] Net Investment Hedging [Member] Other Liabilities [Member] USD ($)	Mar. 31, 2012 Cross Currency Interest Rate Contract [Member] Designated as Hedging Instrument [Member] Net Investment Hedging [Member] Other Liabilities [Member] CHF	Dec. 31, 2011 Cross Currency Interest Rate Contract [Member] Designated as Hedging Instrument [Member] Net Investment Hedging [Member] Other Liabilities [Member] USD ($)	Mar. 31, 2012 Foreign Exchange Forward [Member] Designated as Hedging Instrument [Member] Cash Flow Hedging [Member] Prepaid and Other Assets [Member] USD ($)	Dec. 31, 2011 Foreign Exchange Forward [Member] Designated as Hedging Instrument [Member] Cash Flow Hedging [Member] Prepaid and Other Assets [Member] USD ($)	Mar. 31, 2012 Foreign Exchange Forward [Member] Designated as Hedging Instrument [Member] Cash Flow Hedging [Member] Other Accrued Expenses [Member] USD ($)	Dec. 31, 2011 Foreign Exchange Forward [Member] Designated as Hedging Instrument [Member] Cash Flow Hedging [Member] Other Accrued Expenses [Member] USD ($)
Derivatives, Fair Value [Line Items]
Notional amounts of financial instruments	$ 71,787	$ 83,541													$ 50,000	65,100
Fair Value - Asset (Liability)															(23,669)		(21,656)	241	394	(214)	(1,284)
Assets [Abstract]
Short-term investments									0	0	0	0	0	0
Foreign currency cash flow hedges									0	0	241	394	0	0
Liabilities [Abstract]
Net investment hedge derivative - cross currency swap							23,669	21,656	0	0			0	0
Foreign currency cash flow hedges									0	0	214	1,284	0	0
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt			$ 2,590,620	$ 2,679,793	$ 2,195,267	$ 2,187,252