Contract Assets and Liabilities (Schedule of Contract Assets and Contract Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred Income Tax Expense Benefit Provision For Gain Loss On Extinguishment Of Debt
Contract assets	$ 140,348	$ 79,070
Allowance for expected credit losses	(1,059)	0
Contract assets, net	139,289	79,070
Contract liabilities	$ 8,206	$ 5,656