Summary of Significant Accounting Principles (Tables)

9 Months Ended

Sep. 30, 2015

Depreciable lives 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 dredges	1 to 15 years
Office equipment	1 to 5 years

The following is a summary of property and equipment at September 30, 2015 and December 31, 2014:



	September 30, 2015			December 31, 2014
Automobiles and trucks	$	1,959		$	2,006
Building and improvements	48,190			28,641
Construction equipment	150,997			146,088
Dredges and dredging equipment	95,753			96,275
Office equipment	5,573			4,891
	302,472			277,901
Less: accumulated depreciation	(173,904		)	(161,276		)
Net book value of depreciable assets	128,568			116,625
Construction in progress	1,088			5,274
Land	34,265			39,874
	$	163,921		$	161,773