Segment Information (Summary of Segment Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Summary of segment income
Segment income	$ 34,953	$ 38,556	$ 104,574	$ 112,302
Imaging
Summary of segment income
Segment income	32,265	39,251	96,523	112,725
Radiation Oncology
Summary of segment income
Segment income	10,910	8,871	31,400	25,678
Corporate / Other
Summary of segment income
Segment income	$ (8,222)	$ (9,566)	$ (23,349)	$ (26,101)