Acquisitions (Details) $ in Millions		3 Months Ended
	Jan. 01, 2016 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($) item
Acquisitions
Number of acquisitions | item			2
Environmental Air Systems
Acquisitions
Interest acquired (as a percent)	40.00%
Total purchase price	$ 46.6
Purchase price paid in cash	$ 42.0
Shoffner
Acquisitions
Interest acquired (as a percent)			100.00%
Total purchase price		$ 19.8
Amount allocated to goodwill and identifiable intangible assets for acquisitions		14.8
Purchase price paid in cash		$ 15.5
Other Acquisitions
Acquisitions
Purchase price paid in cash			$ 0.8