Contracts in Progress (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Contractors [Abstract]
Costs incurred on uncompleted contracts	$ 949,578	$ 884,244
Estimated earnings	162,348	144,160
Costs incurred and estimated earnings on uncompleted contracts	1,111,926	1,028,404
Less: Billings to date	(1,133,905)	(1,035,796)
Costs and estimated earnings in excess of billings on uncompleted contracts, net	(21,979)	(7,392)
Costs and estimated earnings in excess of billings on uncompleted contracts	31,433	41,389
Billings in excess of costs and estimated earnings on uncompleted contracts	$ (53,412)	$ (48,781)