Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as noncurrent.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=118944033&loc=SL49130532-203044

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118944033&loc=SL49130531-203044

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130549-203045

Name:	us-gaap_ContractWithCustomerLiabilityNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Revenue - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended
Revenue - Narrative (Details) - USD ($) $ in Thousands	Sep. 06, 2019	Mar. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Non-current deferred revenue		$ 20	$ 15
Camera
Disaggregation of Revenue [Line Items]
Warranty term		1 year
Diagnostic Imaging \| Camera Support \| Minimum
Disaggregation of Revenue [Line Items]
Service contract term		12 months
Diagnostic Imaging \| Camera Support \| Maximum
Disaggregation of Revenue [Line Items]
Service contract term		48 months
North Country Steel Inc.
Disaggregation of Revenue [Line Items]
Lease period	5 years