Contracts in Process (Tables)

12 Months Ended

Dec. 31, 2017

Costs in Excess of Billings and Billings in Excess of Costs [Table Text Block]

The net asset position for contracts in process consisted of the following at December 31:

(in thousands)	2017		2016
Costs and estimated earnings on uncompleted contracts	$	1,978,981	$	2,194,695
Less: Billings to date		1,929,640		2,167,066
	$	49,341	$	27,629

Consolidated Balance Sheet [Member]

Costs in Excess of Billings and Billings in Excess of Costs [Table Text Block]

  The net asset position for contracts in process is included in the accompanying consolidated balance sheets as follows at December 31:

(in thousands)	2017			2016
Costs and estimated earnings in excess of billings on uncompleted contracts	$	78,260		$	69,950
Billings in excess of costs and estimated earnings on uncompleted contracts		(28,919	)		(42,321	)
	$	49,341		$	27,629