Derivative Instruments, Hedging Activities and Fair Value (Details 6) (USD $)			3 Months Ended		6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 Contingent consideration for acquisition	Jun. 30, 2011 Contingent consideration for acquisition	Jun. 30, 2012 Contingent consideration for acquisition	Jun. 30, 2011 Contingent consideration for acquisition
Reconciliation of the beginning and ending balances for liabilities measured on a recurring basis using unobservable inputs (Level 3)
Balance at beginning of period			$ 0	$ 0	$ 0	$ 3,872,000
Fair value adjustments included in earnings			0	0	0	3,966,000
Effect of exchange rate changes			0	0	0	94,000
Balance at end of period			0	0	0	0
Long-term debt, including current maturities
Fair value of long-term debt	1,000,000,000	935,100,000
Commercial paper outstanding, long-term	$ 951,800,000	$ 857,400,000