Contract Assets and Liabilities (Schedule of Contract Assets and Contract Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Abstract]
Contract assets	$ 122,688	$ 140,348
Allowance for expected credit losses	(921)	(1,059)
Contract assets, net	121,767	139,289
Contract liabilities	$ 7,899	$ 8,206