Revenue From Contracts With Customers - Unbilled Receivables (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($)
Unbilled Revenues [Roll Forward]
Unbilled Receivables at December 31, 2017	$ 37,304
Recognition of unbilled receivables	47,005
Revenues billed to customers	(69,263)
Unbilled receivables at June 30, 2018	15,046
New Venture
Unbilled Revenues [Roll Forward]
Unbilled Receivables at December 31, 2017	33,183
Unbilled receivables at June 30, 2018	9,797
Imaging Services
Unbilled Revenues [Roll Forward]
Unbilled Receivables at December 31, 2017	4,121
Unbilled receivables at June 30, 2018	4,941
Devices
Unbilled Revenues [Roll Forward]
Unbilled Receivables at December 31, 2017	0
Unbilled receivables at June 30, 2018	$ 308