Goodwill and Intangible Assets (Details) (USD $)	3 Months Ended			9 Months Ended		12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Jun. 30, 2014	Sep. 30, 2013
Changes in the carrying amount of goodwill
Balance at the beginning of the period				$ 58,091,000	$ 59,368,000	$ 59,368,000
Currency translation and other adjustment				(71,000)		(1,277,000)
Balance at the end of the period	58,020,000			58,020,000		58,091,000
Impairment of goodwill		0
Goodwill	58,020,000			58,020,000		58,091,000
Total gross carrying amount	46,747,000			46,747,000		46,747,000
Accumulated Amortization	(29,195,000)			(29,195,000)		(23,230,000)
Net Amount, Finite Lived Intangibles	17,552,000			17,552,000		23,517,000
Amortization expense	2,000,000		2,000,000	6,000,000	6,400,000
Estimated future amortization expense of purchased intangible assets
2015 (remaining 9 months)	1,988,000			1,988,000
2016	7,953,000			7,953,000
2017	7,568,000			7,568,000
2018	43,000			43,000
Net Amount, Finite Lived Intangibles	17,552,000			17,552,000		23,517,000
Minimum
Changes in the carrying amount of goodwill
Useful Lives				5 years
Maximum
Changes in the carrying amount of goodwill
Useful Lives				6 years
TomoTherapy | Liabilities related to unrecognized tax
Changes in the carrying amount of goodwill
Accrued liabilities							$ 1,300,000