Basis Of Presentation (Narrative) (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Jun. 30, 2015 USD ($)	Sep. 30, 2016 segment	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Average equipment-related costs of total costs of contract revenue		21.00%
Number of operating Segments | segment		2
Number of reportable segments | segment		2
Number of reportable segments with goodwill | segment		3
Impairment of goodwill | $			$ 2,750
Unamortized debt issuance costs | $				$ 3,502
Terra Contracting Services [Member]
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Impairment of goodwill | $	$ 2,750