Accrued Warranty Costs (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Changes in product warranty liability
Balance at beginning of period	$ 6.9	$ 4.2
Claims paid during the year	(1.9)	(0.9)
Warranty expense	2.6	1.4
Acquired warranty liabilities	0	3.3
Balance at end of period	$ 7.6	$ 8.0