The Company and Its Significant Accounting Policies Comprehensive Income (Details) (USD $) In Millions	12 Months Ended
	Sep. 25, 2011	Sep. 26, 2010	Sep. 27, 2009
Net income	$ 4,242	$ 3,247	$ 1,592
Foreign currency translation	(9)	(40)	(25)
Noncredit other-than-temporary impairment losses and subsequent changes in fair value related to certain marketable debt securities, net of income taxes of $10, ($5) and $12, respectively	(19)	21	135
Net unrealized (losses) gains on other marketable securities and derivative instruments, net of income taxes of $80, $74 and ($5), respectively	(145)	392	261
Reclassification of net realized gains on marketable securities and derivative instruments included in net income, net of income taxes of $112, ($12) and $75, respectively	(199)	(380)	(93)
Reclassification of other-than-temporary losses on marketable securities included in net income, net of income taxes of $14, ($5) and $130, respectively	25	116	613
Total other comprehensive (loss) income	(347)	109	891
Total comprehensive income	3,895	3,356	2,483
Comprehensive loss attributable to noncontrolling interests	21	0	0
Comprehensive income attributable to Qualcomm	$ 3,916	$ 3,356	$ 2,483