Goodwill and Intangible Assets (Weighted Average Amortization Period by Intangible Asset Class) (Details)	3 Months Ended
	Mar. 31, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Amortization Period	7 years 8 months 12 days
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Amortization Period	9 years
Covenants not to compete
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Amortization Period	1 year 10 months 24 days
Trademarks and patents
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Amortization Period	6 years
Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Amortization Period	4 years 9 months 18 days