Acquisitions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Acquisition of Business, Net of Cash Acquired	$ 0.0	$ 0.0	$ 59.9
Goodwill	$ 30.1	30.1	30.1
Cape Electrical Supply
Business Acquisition [Line Items]
Acquisition of Business, Net of Cash Acquired			$ 59.9
Goodwill		16.4
Other Intangible Assets		$ 23.6