Acquisition (Intangible Assets) (Details) - Quarton - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jan. 02, 2019
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross		$ 22,200
Trade name
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross		900
Finite-Lived Intangible Asset, Useful Life	3 years
Customer relationships
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross		7,100
Finite-Lived Intangible Asset, Useful Life	4 years
Backlog
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross		12,600
Finite-Lived Intangible Asset, Useful Life	2 years
Proprietary software
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross		$ 1,600
Finite-Lived Intangible Asset, Useful Life	3 years