4. Costs and Estimated Earnings in Excess of Billings (Tables)

12 Months Ended

Apr. 30, 2017

Contractors [Abstract]

Costs and Estimated Earnings in Excess of Billings, Net [Table Text Block]

At April 30, 2017 and 2016, costs and estimated earnings in excess of billings, net, consist of the following:

	2017			2016
	(in thousands)
Costs and estimated earnings in excess of billings	$	8,890		$	12,460
Billings in excess of costs and estimated earnings		(926	)		(83	)
Net asset	$	7,964		$	12,377