Other Income (Expense), Net (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Other Income and Expenses [Abstract]
Interest income	$ 0.2		$ 0		$ 0.5		$ 0.1
Unrealized gains (losses) on financial derivatives	0.5	[1]	(0.9)	[1]	1.4	[1]	(0.5)	[1]
Realized gains on investments	0.2		0.3		0.4		0.8
All other, net	0.9		(0.2)		1.4		(0.2)
Other non-operating income (expense), net	$ 1.8		$ (0.8)		$ 3.7		$ 0.2

[1] See “Hedges Relating to the Convertible Notes” in Note 8 for discussion of such instruments.