Accrual for Warranty Costs (Detail) (USD $)	3 Months Ended		6 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Warranties [Line Items]
Balances, beginning of period	$ 585,000	$ 678,000	$ 526,000	$ 688,000
Accruals during the period	38,000	134,000	186,000	271,000
Changes in estimates of prior period accruals	41,000	137,000	50,000	228,000
Warranty expenditures	(303,000)	(254,000)	(401,000)	(492,000)
Balances, end of period	$ 361,000	$ 695,000	$ 361,000	$ 695,000