Property and Equipment

6 Months Ended

Jun. 30, 2018

Property, Plant and Equipment [Abstract]

Property and Equipment

Property and Equipment

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

For the three months ended June 30, 2018 and 2017, depreciation expense was $6.6 million and $6.2 million, respectively. For each of the six months ended June 30, 2018 and 2017, depreciation expense was $12.5 million. Substantially all depreciation expense is included in the cost of contract revenue in the Company’s Consolidated Statements of Operations.  Substantially all of the assets of the Company are pledged as collateral under the Company's Credit Agreement (as defined in Note 12).

Substantially all of the Company’s long-lived assets are located in the United States.

See Note 2 to the Company's consolidated financial statements for further discussion of property and equipment.