Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Operating activities:
Net income	$ 2,846	$ 4,555
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of property, equipment and improvements	1,606	1,453
Amortization of identifiable intangible assets	2,437	3,393
Stock-based compensation	1,886	1,713
Excess tax benefits from stock-based compensation	(67)	(226)
Deferred income tax benefit	(1,173)	(1,296)
Bad debt/product return provision	338	13
Inventory obsolescence	776	836
Restructuring	296	(70)
Other	(117)	(7)
Changes in operating assets and liabilities	(2,720)	(2,844)
Net cash provided by operating activities	6,108	7,520
Investing activities:
Purchase of marketable securities	(41,640)	(28,999)
Proceeds from maturities of marketable securities	30,566	26,950
Proceeds from sale of investment	135	0
Purchase of property, equipment, improvements and certain other intangible assets	(2,650)	(1,421)
Net cash (used in) provided by investing activities	(13,589)	(3,470)
Financing activities:
Excess tax benefits from stock-based compensation	67	226
Proceeds from stock option plan transactions	521	1,119
Proceeds from employee stock purchase plan transactions	568	486
Net cash provided by financing activities	1,156	1,831
Effect of exchange rate changes on cash and cash equivalents	(621)	458
Net (decrease) increase in cash and cash equivalents	(6,946)	6,339
Cash and cash equivalents, beginning of period	54,684	50,943
Cash and cash equivalents, end of period	47,738	57,282
Supplemental schedule of noncash investing activities:
Securities purchased, not settled	$ (3,600)	$ 0