Costs and estimated earnings in excess of billings (Tables)

6 Months Ended

Jun. 30, 2016

Costs and estimated earnings in excess of billings [Abstract]

Costs and estimated earnings in excess of billings

	June 30,		December 31,
(in thousands)	2016		2015
Claims	$	427,558	$	407,164
Unapproved change orders		220,427		270,019
Other unbilled costs and profits		163,421		227,992
Total costs and estimated earnings in excess of billings	$	811,406	$	905,175