Revenue From Contracts With Customers - Unbilled Receivables (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($)
Unbilled Revenues [Roll Forward]
Unbilled Receivables at December 31, 2017	$ 37,304
Recognition of unbilled receivables	86,212
Revenues billed to customers	(97,792)
Unbilled receivables at September 30, 2018	25,724
New Venture
Unbilled Revenues [Roll Forward]
Unbilled Receivables at December 31, 2017	33,183
Unbilled receivables at September 30, 2018	20,056
Imaging Services
Unbilled Revenues [Roll Forward]
Unbilled Receivables at December 31, 2017	4,121
Unbilled receivables at September 30, 2018	4,685
Devices
Unbilled Revenues [Roll Forward]
Unbilled Receivables at December 31, 2017	0
Unbilled receivables at September 30, 2018	$ 983