Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Aug. 31, 2019	Mar. 01, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group Including Discontinued Operation Revenue	$ 0	$ 0
Disposal Group, Including Discontinued Operation, Cost of Revenue	(60)	22
Disposal Group, Including Discontinued Operation, Depreciation and Amortization	0	0
Disposal Group, Including Discontinued Operation, General and Administrative Expense	205	404
Disposal Group, Including Discontinued Operation, Other Income		0
Disposal Group, Including Discontinued Operation, Other Expense	0
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, before Income Tax	(145)	(426)
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	0	0
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	(145)	(426)
Discontinued Operation, Tax Effect of Discontinued Operation	0	0
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(145)	(426)
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net	0		$ 0
Disposal Group, Including Discontinued Operation, Other Assets, Current	0		0
Disposal Group, Including Discontinued Operation, Assets, Current	0		0
Disposal Group, Including Discontinued Operation, Accounts Payable, Current	1,303		1,233
Disposal Group, Including Discontinued Operation, Accrued Liabilities, Current	708		865
Disposal Group, Including Discontinued Operation, Liabilities, Current	2,011		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
Disposal Group, Including Discontinued Operation, Cost of Revenue	0	0
Disposal Group, Including Discontinued Operation, Depreciation and Amortization	0	0
Disposal Group, Including Discontinued Operation, General and Administrative Expense	0	0
Disposal Group, Including Discontinued Operation, Other Expense	0	0
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, before Income Tax	0	0
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net	0		0
Disposal Group, Including Discontinued Operation, Other Assets, Current	0		0
Disposal Group, Including Discontinued Operation, Assets, Current	0		0
Disposal Group, Including Discontinued Operation, Accounts Payable, Current	0		0
Disposal Group, Including Discontinued Operation, Accrued Liabilities, Current	228		120
Disposal Group, Including Discontinued Operation, Liabilities, Current	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
Disposal Group, Including Discontinued Operation, Cost of Revenue	(60)	22
Disposal Group, Including Discontinued Operation, Depreciation and Amortization	0	0
Disposal Group, Including Discontinued Operation, General and Administrative Expense	205	404
Disposal Group, Including Discontinued Operation, Other Income		0
Disposal Group, Including Discontinued Operation, Other Expense	0
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, before Income Tax	(145)	$ (426)
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net	0		0
Disposal Group, Including Discontinued Operation, Other Assets, Current	0		0
Disposal Group, Including Discontinued Operation, Assets, Current	0		0
Disposal Group, Including Discontinued Operation, Accounts Payable, Current	1,303		1,233
Disposal Group, Including Discontinued Operation, Accrued Liabilities, Current	480		745
Disposal Group, Including Discontinued Operation, Liabilities, Current	$ 1,783		$ 1,978
Discontinued Operations, Disposed of by Sale | Offshore Division
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Reserve, Other Receivables				$ 1,500
Disposal Group, Including Discontinued Operation, Consideration, Additional Receivable					$ 7,500