Product Warranties (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Jun. 30, 2012
Product Liability Contingency [Line Items]
Maximum product warranty term	3 years
Warranty accrual	$ 2,743,000	$ 6,930,000	$ 2,743,000
Reimbursement receivable				1,200,000
Cash received pursuant to settlement			1,100,000
Remaining reimbursement receivable after payment	100,000		100,000
Period of product rebates/price concessions under settlement agreement	39 months
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance, beginning of period	4,455,000	6,871,000	6,930,000
Charges to operations	118,000	368,000
Deductions for costs incurred	(1,021,000)	(309,000)
Changes in estimates	(809,000)	0
Balance, end of period	2,743,000	6,930,000	2,743,000
Power supply devices
Product Liability Contingency [Line Items]
Estimated product warranty liability	$ 200,000		$ 200,000