Discontinued Operations - Applied Utility Systems, Inc. (Details) - Applied Utility Systems, Inc. - Sales And Use Tax Audit - USD ($) $ in Millions	1 Months Ended	6 Months Ended	12 Months Ended
	Oct. 31, 2015	Jun. 30, 2017	Dec. 31, 2016	Mar. 31, 2017	Jul. 21, 2014	Dec. 31, 2013
Discontinued Operations
Loss Contingency Accrual			$ 0.1	$ 0.1
Sales tax owed					$ 1.5
Basis for determining sales tax owed					12.2
Adjusted basis for determining sales tax owed					9.0
Amount offered to settle the case	$ 0.1	$ 0.1	$ 0.1
Maximum
Discontinued Operations
Sales tax owed					$ 0.9	$ 1.5