Goodwill And Intangible Assets (Narrative) (Details) - USD ($)		3 Months Ended		9 Months Ended
	Jul. 31, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule of Goodwill and Intangible Assets [Line Items]
Indicators of impairment	$ 0
Amortization of intangible assets		$ 2,900,000	$ 2,600,000	$ 9,092,000	$ 10,558,000
Customer Relationships [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Weighted-average remaining lives of intangible assets				10 years 10 months 25 days
Trade Name [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Weighted-average remaining lives of intangible assets				10 years 9 months 19 days
Non-Compete Agreements [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Weighted-average remaining lives of intangible assets				9 years 10 months 25 days
Backlog [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Weighted-average remaining lives of intangible assets				3 months