Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Net sales	$ 79,123	$ 76,399
Cost of sales	53,594	51,908
Gross profit	25,529	24,491
Operating expenses:
Research and development	10,558	10,023
Selling, general and administrative	11,434	11,089
Total operating expenses	21,992	21,112
Operating income	3,537	3,379
Interest and other income (expense), net	431	268
Gain on sale of investments	3,121	0
Income before income taxes	7,089	3,647
Provision for income taxes	1,643	1,159
Consolidated net income	5,446	2,488
Net (income) loss attributable to noncontrolling interests	(11)	11
Net income attributable to ISSI	$ 5,435	$ 2,499
Basic net income per share (in dollars per share)	$ 0.19	$ 0.09
Shares used in basic per share calculation	29,318	27,696
Diluted net income per share (in dollars per share)	$ 0.18	$ 0.09
Shares used in diluted per share calculation	30,717	29,106