Revenue From Contracts With Customers - Deferred Revenue (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($)
Revenue, Remaining Performance Obligation [Roll Forward]
Deferred revenue at December 31, 2017	$ 8,910
Cash collected in excess of revenue recognized	21,654
Recognition of deferred revenue	(20,237)
Deferred revenue at September 30, 2018	10,327
New Venture
Revenue, Remaining Performance Obligation [Roll Forward]
Deferred revenue at December 31, 2017	6,548
Deferred revenue at September 30, 2018	7,880
Imaging Services
Revenue, Remaining Performance Obligation [Roll Forward]
Deferred revenue at December 31, 2017	676
Deferred revenue at September 30, 2018	271
Devices
Revenue, Remaining Performance Obligation [Roll Forward]
Deferred revenue at December 31, 2017	633
Deferred revenue at September 30, 2018	1,198
Optimization Software & Services
Revenue, Remaining Performance Obligation [Roll Forward]
Deferred revenue at December 31, 2017	1,053
Deferred revenue at September 30, 2018	$ 978