Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Receivables [Abstract]
Trade accounts receivable	$ 164,429	$ 124,609
Costs in excess of billings	23,562	22,634
Total accounts receivables	187,991	147,243
Less allowance for doubtful accounts	(7,290)	(6,960)
Accounts receivable	$ 180,701	$ 140,283