Accounts Receivable (Tables)

12 Months Ended

Dec. 31, 2016

Receivables [Abstract]

Schedule of Accounts Receivable

Accounts receivable at December 31 consisted of the following (in thousands):

	2016			2015
Trade accounts receivable	$	81,193		$	102,277
Contract receivables:
Amounts billed	41,569			53,830
Costs in excess of billings	6,582			13,730
Total contract receivables	48,151			67,560
Total accounts receivables	129,344			169,837
Less allowance for doubtful accounts	(5,272		)	(4,868		)
Accounts receivable	$	124,072		$	164,969