Costs and estimated earnings in excess of billings (Tables)

6 Months Ended

Jun. 30, 2015

Costs and estimated earnings in excess of billings [Abstract]

Costs and estimated earnings in excess of billings

	June 30,		December 31,
	2015		2014
	(in thousands)
Unbilled costs and profits incurred to date (a)	$	248,561	$	253,078
Unapproved change orders		274,134		161,375
Claims		293,785		311,949
	$	816,480	$	726,402

(a) Represents the excess of contract costs and profits recognized to date on the percentage of completion accounting method over the amount of contract billings to date on certain contracts.