Fair Value Measurement of Assets and Liabilities

3 Months Ended

Mar. 31, 2012

Fair Value Measurement of Assets and Liabilities [Abstract]

Fair Value Measurement of Assets and Liabilities

8. Fair Value Measurement of Assets and Liabilities

The following assets and liabilities are recorded at fair value on a recurring basis (in millions):

	As of March 31, 2012
Description	Recorded Balance		Fair Value Measurements at Reporting Date Using:
			Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets
Available-for-sale securities
Corporate debt securities	$	331.4	$	—	$	331.4	$	—
U.S. government and agency debt securities		200.4		—		200.4		—
Foreign government debt securities		2.8		—		2.8		—
Commercial paper		127.3		—		127.3		—
Certificates of deposit		90.1		—		90.1		—
Total available-for-sale securities		752.0		—		752.0		—
Derivatives, current and long-term
Foreign currency forward contracts and options		16.7		—		16.7		—
Interest rate swaps		24.6		—		24.6		—
	$	793.3	$	—	$	793.3	$	—
Liabilities
Derivatives, current and long-term
Foreign currency forward contracts and options	$	10.3	$	—	$	10.3	$	—

	As of December 31, 2011
			Fair Value Measurements at Reporting Date Using:
Description	Recorded Balance		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets
Available-for-sale securities
Corporate debt securities	$	324.7	$	—	$	324.7	$	—
U.S. government and agency debt securities		177.2		—		177.2		—
Municipal bonds		1.0		—		1.0		—
Foreign government debt securities		6.8		—		6.8		—
Commercial paper		74.5		—		74.5		—
Certificates of deposit		88.5		—		88.5		—
Total available-for-sale securities		672.7		—		672.7		—
Derivatives, current and long-term
Foreign currency forward contracts and options		18.3		—		18.3		—
Interest rate swaps		27.8		—		27.8		—
	$	718.8	$	—	$	718.8	$	—
Liabilities
Derivatives, current and long-term
Foreign currency forward contracts and options	$	25.2	$	—	$	25.2	$	—
Cross-currency interest rate swaps		8.2		—		8.2		—
	$	33.4	$	—	$	33.4	$	—

We value our available-for-sale securities using a market approach based on broker prices for identical assets in over-the-counter markets and perform ongoing assessments of counterparty credit risk.

We value our foreign currency forward contracts and foreign currency options using a market approach based on foreign currency exchange rates obtained from active markets and we perform ongoing assessments of counterparty credit risk.

We value our interest rate swaps using a market approach based on publicly available market yield curves and the terms of our swaps and we perform ongoing assessments of counterparty credit risk.

We value our cross-currency interest rate swaps using a market approach based upon publicly available market yield curves, foreign currency exchange rates obtained from active markets and the terms of our swaps. We also perform ongoing assessments of counterparty credit risk.