Segment Information (Components of Revenue) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Summary of components of revenue
Revenue	$ 114,418	$ 120,664	$ 224,800	$ 241,417
MRI [Member]
Summary of components of revenue
Revenue	47,359	49,157	93,440	99,234
PET/CT [Member]
Summary of components of revenue
Revenue	37,656	39,573	74,406	80,586
Radiation Oncology [Member]
Summary of components of revenue
Revenue	19,805	22,501	38,214	42,419
Other Modalities And Other Revenue [Member]
Summary of components of revenue
Revenue	$ 9,598	$ 9,433	$ 18,740	$ 19,178