Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2015

Property, Plant and Equipment [Abstract]

Summary of gross components of property and equipment

The following is a summary of the gross components of property and equipment (dollars in thousands):

		December 31,
	Estimated Useful Life	2015		2014
Vessels	15 to 30 years	$	1,944,753	$	1,657,448
ROVs, trenchers and ROVDrills	10 years	311,971		310,841
Machinery, equipment, buildings and leasehold improvements	5 to 30 years	288,133		273,155
Total property and equipment		$	2,544,857	$	2,241,444