Discontinued Operations (Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents	$ 1,965	$ 0	$ 0
DMT | Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents	1,965	0
Accounts receivable, net	1,057	97,402
Inventories	849	48,910
Other current assets and prepayments	278	3,365
Property, plant and equipment, net	526	5,541
Rental property and equipment, net	179	1,786
Goodwill	0	177,799
Other assets	0	45
Assets of discontinued operations	4,854	334,848
Accounts payable and accrued liabilities	662	36,592
Advance billings	593	30,607
Other current liabilities	2,021	0
Other noncurrent liabilities	0	5,609
Liabilities of discontinued operations	$ 3,276	$ 72,808