Summary of Significant Accounting Policies (Changes in Product Warranty Liability) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Changes in product warranty liability
Balance at beginning of period	$ 6.1	$ 6.9	$ 5.4
Claims paid during the year	(3.7)	(4.7)	(2.9)
Warranty expense	2.0	4.0	4.0
Acquired warranty liabilities	2.8	0.0	0.0
Other	(0.1)	(0.1)	0.4
Balance at end of period	$ 7.1	$ 6.1	$ 6.9