Marketable Securities Other-than-temporary Impairments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Dec. 29, 2013	Dec. 30, 2012
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Beginning balance of credit losses	$ 4	$ 31
Credit losses recognized on securities previously impaired	2	0
Reductions in credit losses related to securities sold	0	(12)
Ending balance of credit losses	$ 6	$ 19

This item represents an increase to the cumulative amount of credit losses recognized in earnings for an other than temporary impairment of a debt security held for which other than temporary impairment was previously recognized.

No definition available.

+ Details

Name:	qcom_OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsPreviouslyImpairedDebtSecurities
Namespace Prefix:	qcom_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cumulative amount of credit losses recognized in earnings related to debt securities held for which a portion of an other than temporary impairment (OTTI) was recognized in other comprehensive income (a component of shareholders' equity).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27340-111563

+ Details

Name:	us-gaap_OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents reductions in the cumulative amount of credit losses recognized in earnings for an other than temporary impairment (OTTI) of a debt security because of the sale of impaired securities during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 8

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27340-111563

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration