Goodwill and Intangible Assets (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended	3 Months Ended				6 Months Ended						6 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2012	Sep. 30, 2012 In-process research and development (CPAC)	Jun. 30, 2012 In-process research and development (CPAC)	Dec. 31, 2012 Developed technology	Jun. 30, 2012 Developed technology	Dec. 31, 2012 Developed technology Minimum	Dec. 31, 2012 Developed technology Maximum	Dec. 31, 2012 Backlog	Jun. 30, 2012 Backlog	Dec. 31, 2012 Distributor license	Jun. 30, 2012 Distributor license	Dec. 31, 2012 Distributor license Minimum	Dec. 31, 2012 Distributor license Maximum
Changes in the carrying amount of goodwill
Balance at the beginning of the period			$ 59,215,000	$ 54,474,000	$ 54,474,000
Goodwill resulting from acquisition of TomoTherapy			77,000
Currency translation and other adjustment			97,000
Adjustments related to acquisition of TomoTherapy					4,741,000
Balance at the end of the period	59,389,000		59,389,000		59,215,000
Intangible Assets
Useful Lives										5 years	6 years	1 year 3 months				1 year 6 months	2 years 6 months
Gross Carrying Amount, Finite Lived Intangibles								48,556,000	43,455,000			10,500,000	10,500,000	2,070,000	1,860,000
Gross Carrying Amount, Indefinite Lived Intangibles							12,800,000
Total gross carrying amount	61,126,000		61,126,000		68,615,000
Impairment Charges			12,200,000			12,200,000
Accumulated Amortization	(24,809,000)		(24,809,000)		(18,796,000)			(13,107,000)	(9,161,000)			(10,500,000)	(8,867,000)	(1,202,000)	(768,000)
Net Amount, Finite Lived Intangibles	36,317,000		36,317,000					35,449,000	34,294,000				1,633,000	868,000	1,092,000
Net Amount, Indefinite Lived Intangibles							12,800,000
Total net carrying amount	36,317,000		36,317,000		49,819,000
Amortization expense	2,200,000	4,100,000	6,000,000	8,200,000
Estimated future amortization expense of purchased intangible assets
2013 (remaining 6 months)	4,412,000		4,412,000
2014	8,388,000		8,388,000
2015	7,953,000		7,953,000
2016	7,953,000		7,953,000
2017	7,568,000		7,568,000
Thereafter	43,000		43,000
Net Amount, Finite Lived Intangibles	$ 36,317,000		$ 36,317,000					$ 35,449,000	$ 34,294,000				$ 1,633,000	$ 868,000	$ 1,092,000