Debt (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended	6 Months Ended
	May 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Debt
Total debt, Carrying Amount		$ 2,343,561	$ 2,132,874
Less short-term debt, Carrying Amount		(800,670)	(701,437)
Long-term debt, Carrying Amount		1,542,891	1,431,437
Total debt, Approximate Fair Value		2,383,661	2,146,088
Less short-term debt, Approximate Fair Value		(811,425)	(722,624)
Long-term debt, Approximate Fair Value		1,572,236	1,423,464
4.75% Senior Notes due November 2014
Debt
Total debt, Carrying Amount		599,925	599,813
Stated interest rate (as a percent)		4.75%
4.75% Senior Notes due November 2014 | Level 1
Debt
Total debt, Approximate Fair Value		610,680	621,000
4.00% Senior Notes due February 2022
Debt
Total debt, Carrying Amount		499,037	498,973
Stated interest rate (as a percent)		4.00%
4.00% Senior Notes due February 2022 | Level 1
Debt
Total debt, Approximate Fair Value		516,000	491,000
2.55% Senior Notes due January 2019
Debt
Total debt, Carrying Amount		748,943
Stated interest rate (as a percent)		2.55%
2.55% Senior Notes due January 2019 | Level 1
Debt
Total debt, Approximate Fair Value		761,325
Revolving Credit Facility
Debt
Total debt, Carrying Amount		290,000	927,300
Commitment under the Revolving Credit Facility		1,500,000
Interest rate on borrowings under the Revolving Credit Facility, variable rate		LIBOR
Borrowings under the Revolving Credit Facility		290,000
Availability under the Revolving Credit Facility		1,210,000
Revolving Credit Facility | Level 2
Debt
Total debt, Approximate Fair Value		290,000	927,300
Credit Agreement
Debt
Total debt, Carrying Amount		200,000	100,000
Interest rate on borrowings under the Revolving Credit Facility, variable rate		LIBOR
Uncommitted Line of Credit		200,000
Increase the borrowing capacity under amended and restated Credit Agreement	100,000
Increasing the uncommitted line of credit under amended and restated Credit Agreement	200,000
Credit Agreement | Level 2
Debt
Total debt, Approximate Fair Value		200,000	100,000
Notes payable to foreign banks and other debt
Debt
Total debt, Carrying Amount		5,656	6,788
Notes payable to foreign banks and other debt | Level 2
Debt
Total debt, Approximate Fair Value		$ 5,656	$ 6,788