Nature Of Business And Summary Of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Estimated Useful Lives By Class Of Assets

The estimated useful lives by class of assets are:

Class	Useful Life (years)
Buildings and improvements	10
Furniture and fixtures	5-10
Vehicles, dozers, and other light operating equipment and systems	3-5
Heavy operating equipment (dredges and barges)	10-30