Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
EQUITY, JANUARY 1	$ 1,603.2	$ 1,749.0
Other comprehensive income (loss) before reclassifications	11.7
Amounts reclassified from accumulated other comprehensive loss	1.8	1.2
Current period other comprehensive income (loss)	13.5
EQUITY, MARCH 31	1,588.8	1,575.7
Cash flow hedge (loss) gain
Increase (Decrease) in Stockholders' Equity [Roll Forward]
EQUITY, JANUARY 1	0.0
Other comprehensive income (loss) before reclassifications	(0.2)
Amounts reclassified from accumulated other comprehensive loss	0.1
Current period other comprehensive income (loss)	(0.1)
EQUITY, MARCH 31	(0.1)
Unrealized gain (loss) on available-for- sale securities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
EQUITY, JANUARY 1	(1.2)
Other comprehensive income (loss) before reclassifications	0.4
Amounts reclassified from accumulated other comprehensive loss	0.0
Current period other comprehensive income (loss)	0.4
EQUITY, MARCH 31	(0.8)
Pension and post retirement benefit plan adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
EQUITY, JANUARY 1	(180.5)
Other comprehensive income (loss) before reclassifications	0.0
Amounts reclassified from accumulated other comprehensive loss	1.7	$ 2.0
Current period other comprehensive income (loss)	1.7
EQUITY, MARCH 31	(178.8)
Cumulative translation adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
EQUITY, JANUARY 1	(120.8)
Other comprehensive income (loss) before reclassifications	11.5
Amounts reclassified from accumulated other comprehensive loss	0.0
Current period other comprehensive income (loss)	11.5
EQUITY, MARCH 31	(109.3)
AOCI Including Portion Attributable to Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
EQUITY, JANUARY 1	(302.5)
EQUITY, MARCH 31	$ (289.0)