Segment Information - Textual (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) segment	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments (segment) | segment	3
Number of reportable segments (segment) | segment	2
Payments to acquire property, plant, and equipment	$ 55,511	$ 32,236	$ 27,048
Radiology
Segment Reporting Information [Line Items]
Payments to acquire property, plant, and equipment	27,478	18,311	21,288
Oncology
Segment Reporting Information [Line Items]
Payments to acquire property, plant, and equipment	21,694	3,994	762
Corporate / Other
Segment Reporting Information [Line Items]
Payments to acquire property, plant, and equipment	$ 6,339	$ 10,081	$ 4,998