Revenue (Schedule of Accounts Receivable) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Completed contracts	$ 8,592	$ 10,658
Contracts in progress	48,418	28,212
Retainage	7,969	17,545
Accounts receivable, gross	64,979	56,415
Allowance for doubtful accounts	(200)
Total accounts receivable—net	64,779	56,415
Accounts receivable—net	$ 64,779	51,940
Long-term accounts receivable and retainage		$ 4,475