Costs and estimated earnings in excess of billings (Tables)

9 Months Ended

Sep. 30, 2015

Costs and estimated earnings in excess of billings [Abstract]

Costs and estimated earnings in excess of billings

	September 30,		December 31,
	2015		2014
	(in thousands)
Unbilled costs and profits incurred to date (a)	$	275,079	$	253,078
Unapproved change orders		312,090		161,375
Claims		296,640		311,949
	$	883,809	$	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.