Revenue (Narrative) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Revenue from Contracts with Customer [Line Items]
Accounts receivable, net	$ 299,383	$ 322,846
Contract assets	7,100	5,900
Contract liabilities	1,300	$ 1,300
Revenue recognized from contract liability during the period	$ 1,300
Average transit time	3 days