Business Combinations (Narrative) (Details) - USD ($)	3 Months Ended	6 Months Ended	9 Months Ended
	Sep. 30, 2017	Jul. 05, 2017	Sep. 30, 2017	Sep. 30, 2016	Jun. 08, 2017
Business Acquisition [Line Items]
Purchase price, net of cash acquired		$ 163,800,000	$ 163,800,000	$ 158,300,000
Goodwill		76,800,000	75,400,000
Intangible assets acquired		76,800,000
Net working capital acquired		21,900,000
Deferred tax liabilities acquired		$ 25,100,000
Sales from companies acquired since acquisition date	$ 23,800,000		$ 35,500,000
Rutland
Business Acquisition [Line Items]
Goodwill expected to be deductible for tax purposes					$ 0
Minimum
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		5 years
Maximum
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		20 years