Debt (Tables)

3 Months Ended

Mar. 31, 2014

Debt Instruments [Abstract]

Convertible Debenture Terms

The following table summarizes at March 31, 2014 the related balances, conversion rate and conversion price of the Debentures:

Outstanding principal amount	$	1,500.0
Unamortized debt discount	531.9
Net debt carrying amount	968.1
Equity component carrying amount	543.6
Conversion rate (shares of common stock per $1,000 of principal amount)	13.3135
Effective conversion price (per $1,000 of principal amount)	$	75.1113