Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group Including Discontinued Operation Revenue	$ 0	$ 0	$ 0	$ 0
Disposal Group, Including Discontinued Operation, Cost of Revenue	2	(273)	(332)	(251)
Disposal Group, Including Discontinued Operation, Depreciation and Amortization	0	52	0	52
Disposal Group, Including Discontinued Operation, General and Administrative Expense	171	1,734	487	2,483
Disposal Group, Including Discontinued Operation, Other Expense	0	117	0	117
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, before Income Tax	(173)	(1,630)	(155)	(2,401)
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	0	(7,500)	0	(7,500)
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	(173)	(9,130)	(155)	(9,901)
Discontinued Operation, Tax Effect of Discontinued Operation	0	0	0	0
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(173)	(9,130)	(155)	(9,901)
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net	0		0		$ 0
Disposal Group, Including Discontinued Operation, Other Assets, Current	0		0		0
Disposal Group, Including Discontinued Operation, Assets, Current	0		0		0
Disposal Group, Including Discontinued Operation, Accounts Payable, Current	1,223		1,223		1,233
Disposal Group, Including Discontinued Operation, Accrued Liabilities, Current	629		629		865
Disposal Group, Including Discontinued Operation, Liabilities, Current	1,852		1,852		2,098
Maritech [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group Including Discontinued Operation Revenue	0	0	0	0
Disposal Group, Including Discontinued Operation, Cost of Revenue	0	0	0	0
Disposal Group, Including Discontinued Operation, Depreciation and Amortization	0	0	0	0
Disposal Group, Including Discontinued Operation, General and Administrative Expense	0	0	0	0
Disposal Group, Including Discontinued Operation, Other Expense	0	0	0	0
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, before Income Tax	0	0	0	0
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net	0		0		0
Disposal Group, Including Discontinued Operation, Other Assets, Current	0		0		0
Disposal Group, Including Discontinued Operation, Assets, Current	0		0		0
Disposal Group, Including Discontinued Operation, Accounts Payable, Current	0		0		0
Disposal Group, Including Discontinued Operation, Accrued Liabilities, Current	228		228		120
Disposal Group, Including Discontinued Operation, Liabilities, Current	228		228		120
Offshore Services [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group Including Discontinued Operation Revenue	0	0	0	0
Disposal Group, Including Discontinued Operation, Cost of Revenue	2	(273)	(332)	(251)
Disposal Group, Including Discontinued Operation, Depreciation and Amortization	0	52	0	52
Disposal Group, Including Discontinued Operation, General and Administrative Expense	171	1,734	487	2,483
Disposal Group, Including Discontinued Operation, Other Expense	0	117	0	117
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, before Income Tax	(173)	$ (1,630)	(155)	$ (2,401)
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net	0		0		0
Disposal Group, Including Discontinued Operation, Other Assets, Current	0		0		0
Disposal Group, Including Discontinued Operation, Assets, Current	0		0		0
Disposal Group, Including Discontinued Operation, Accounts Payable, Current	1,223		1,223		1,233
Disposal Group, Including Discontinued Operation, Accrued Liabilities, Current	401		401		745
Disposal Group, Including Discontinued Operation, Liabilities, Current	$ 1,624		$ 1,624		$ 1,978