Income Taxes: (Details 4) (USD $)	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Tax credit carryforward
Decrease in valuation allowance	$ 2,400,000	$ 48,000
Reconciliation of beginning and ending balances of total amounts of gross unrecognized tax benefits
Balance at beginning of year	491,000	425,000	474,000
Unrecognized tax benefits related to current year	12,000	67,000	34,000
Decrease in unrecognized tax benefits due to the lapse of applicable statute of limitations	(100,000)	(1,000)	(83,000)
Balance at end of year	403,000	491,000	425,000
Unrecognized tax benefits , if recognized, would impact effective tax rate	403,000	491,000	425,000
Interest accrued, net of tax benefits	4,000	12,000
Expense (benefit) for interest (net of federal impact) recognized	(8,000)	4,000	(10,000)
R&D | Federal
Tax credit carryforward
Tax Credit carryforwards	646,000
Reversal in valuation allowance	2,400,000
R&D | State
Tax credit carryforward
Tax Credit carryforwards	$ 208,000