Revenue From Contracts With Customers - Unbilled Receivables (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Unbilled Revenues [Roll Forward]
Unbilled Receivables at December 31, 2017	$ 37,304
Recognition of unbilled receivables	25,843
Revenues billed to customers	(46,798)
Unbilled Receivables at March 31, 2018	16,349
New Venture
Unbilled Revenues [Roll Forward]
Unbilled Receivables at December 31, 2017	33,183
Unbilled Receivables at March 31, 2018	10,734
Imaging Services
Unbilled Revenues [Roll Forward]
Unbilled Receivables at December 31, 2017	4,121
Unbilled Receivables at March 31, 2018	5,412
Devices
Unbilled Revenues [Roll Forward]
Unbilled Receivables at December 31, 2017	0
Unbilled Receivables at March 31, 2018	$ 203