CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$ 127.1	$ 112.3	$ 80.7
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(71.3)	(0.9)	7.0
Net actuarial (loss) gain arising during period, net of tax of $(10.6), $20.3 and $(6.2)	(18.9)	33.7	(13.2)
Less: amortization of actuarial loss, net of tax of $1.1, $3.6 and $2.8	2.0	4.9	5.7
Less: amortization of prior service credit, net of tax of $(0.5), $(0.5) and $(0.5)	(0.8)	(0.8)	(0.8)
Less: amortization of transition obligation	0.1	0.1	0.1
Net gains on investment securities, net of tax of $0.2, $2.1 and $0.2	0.4	3.5	0.4
Net gains (losses) on derivatives, net of tax of $0.9, 1.8 and $(2.1)	1.7	3.0	(3.6)
Other comprehensive (loss) income, net of tax	(86.8)	43.5	(4.4)
Comprehensive income	$ 40.3	$ 155.8	$ 76.3