Derivative Instruments, Hedging Activities and Fair Value (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Derivatives Designated as Hedging Instruments
Derivative contracts
Period over which gains and losses are reclassified to earnings, low end of range	10 years
Period over which gains and losses are reclassified to earnings, high end of range	15 years
Asset Derivatives	$ 55,367	$ 44,910
Liability Derivatives	0	1,792
Derivatives Designated as Hedging Instruments | Foreign currency forward exchange contracts | Other current assets
Derivative contracts
Asset Derivatives		274
Derivatives Designated as Hedging Instruments | Foreign currency forward exchange contracts | Other current liabilities
Derivative contracts
Liability Derivatives		0
Derivatives Designated as Hedging Instruments | Cross-currency interest rate swaps | Other assets
Derivative contracts
Asset Derivatives	55,367	44,636
Derivatives Designated as Hedging Instruments | Cross-currency interest rate swaps | Noncurrent liabilities
Derivative contracts
Liability Derivatives	0	1,792
Derivatives Not Designated as Hedging Instruments | Foreign currency forward exchange contracts | Other current assets
Derivative contracts
Asset Derivatives	1,241	2,912
Derivatives Not Designated as Hedging Instruments | Foreign currency forward exchange contracts | Other current liabilities
Derivative contracts
Liability Derivatives	$ 1,260	$ 1,207