Discontinued Operations - Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Current assets of discontinued operations	$ 89	$ 155	$ 889
Current liabilities of discontinued operations	1,504	1,430
WD Services | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents	89	155
Current assets of discontinued operations	89	155
Accounts payable	41	16
Accrued expenses	1,463	1,414
Current liabilities of discontinued operations	$ 1,504	$ 1,430