New Accounting Pronouncements (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended
	Jan. 01, 2018	Mar. 31, 2018	Mar. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Recorded previously unrecognized revenue		$ 405.7	$ 343.8
Other components of net pension income		(2.3)	(1.7)
Cost of sales		$ 340.6	288.8
Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Recorded previously unrecognized revenue	$ 13.6
Cumulative effect adjustment to retained earnings	$ 2.6
Accounting Standards Update 2017-07
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Other components of net pension income			1.7
Cost of sales			$ 0.5