Revenue From Contracts With Customers - Deferred Revenue (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Revenue, Remaining Performance Obligation [Roll Forward]
Deferred revenue at December 31, 2017	$ 8,910
Cash collected in excess of revenue recognized	10,083
Recognition of deferred revenue	(7,663)
Deferred revenue at March 31, 2018	11,330
New Venture
Revenue, Remaining Performance Obligation [Roll Forward]
Deferred revenue at December 31, 2017	6,548
Deferred revenue at March 31, 2018	9,611
Imaging Services
Revenue, Remaining Performance Obligation [Roll Forward]
Deferred revenue at December 31, 2017	676
Deferred revenue at March 31, 2018	453
Devices
Revenue, Remaining Performance Obligation [Roll Forward]
Deferred revenue at December 31, 2017	633
Deferred revenue at March 31, 2018	360
Optimization Software & Services
Revenue, Remaining Performance Obligation [Roll Forward]
Deferred revenue at December 31, 2017	1,053
Deferred revenue at March 31, 2018	$ 906