Property and Equipment (Tables)

6 Months Ended

Jun. 30, 2018

Property, Plant and Equipment [Abstract]

Summary of property and equipment

Depreciation is computed using the straight-line method over the estimated useful lives of the related assets for financial statement purposes, as follows:

Automobiles and trucks	3 to 5 years
Buildings and improvements	5 to 30 years
Construction equipment	3 to 15 years
Vessels and other equipment	1 to 15 years
Office equipment	1 to 5 years

The following is a summary of property and equipment at June 30, 2018 and December 31, 2017:

	June 30, 2018			December 31, 2017
Automobiles and trucks	$	1,802		$	1,940
Building and improvements	42,555			38,062
Construction equipment	156,695			166,203
Vessels and other equipment	95,736			85,113
Office equipment	7,416			8,039
	304,204			299,357
Less: Accumulated depreciation	(195,843		)	(191,407		)
Net book value of depreciable assets	108,361			107,950
Construction in progress	3,459			245
Land	35,863			38,083
	$	147,683		$	146,278