CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 17.6	$ 19.2
Unrealized foreign currency translation gain	1.7	3.7
Reclassification of amortization of adjustments to pension and other postretirement benefit liabilities recognized in net periodic benefit cost (Note 5)	2.0	1.8
Unrealized gain on “available-for-sale” securities	0.1	0.0
Income from other comprehensive income items	3.8	5.5
Provision for income taxes	0.8	0.7
Other comprehensive income	3.0	4.8
Comprehensive income	$ 20.6	$ 24.0