2.2.0.7 false Investment Income (Loss), Net (Details) (USD $) 009050 - Disclosure - Investment Income (Loss), Net (Details) true false In Millions false false 1 USD false false u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u002 Standard http://www.xbrl.org/2003/instance shares xbrli 0 u003 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 $ false 2 USD false false u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u003 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 u002 Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 3 USD false false u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u001 Standard http://www.xbrl.org/2003/instance pure xbrli 0 u003 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 u002 Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 4 USD false false u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u001 Standard http://www.xbrl.org/2003/instance pure xbrli 0 u003 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 u002 Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ 2 Notes to Financial Statements [Abstract] 0 qcom_NotesToFinancialStatementsAbstract qcom false na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 3 Interest and dividend income 1 us-gaap_InvestmentIncomeInterestAndDividend us-gaap true credit duration No definition available. false false false false false false false false false false false false 1 true true false false 131000000 131 false false false 2 true true false false 132000000 132 false false false 3 true true false false 405000000 405 false false false 4 true true false false 389000000 389 false false false xbrli:monetaryItemType monetary Income derived from investments in debt and equity securities and on cash and cash equivalents. Interest income represents earnings which reflect the time value of money or transactions in which the payments are for the use or forbearance of money. Dividend income represents a distribution of earnings to shareholders by investee companies. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 14 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph a, b -Article 5 false 4 Interest expense 1 us-gaap_InterestExpense us-gaap true debit duration No definition available. false false false false false false false false false false false false 1 false true false false -14000000 -14 false false false 2 false true false false -8000000 -8 false false false 3 false true false false -30000000 -30 false false false 4 false true false false -16000000 -16 false false false xbrli:monetaryItemType monetary The cost of borrowed funds accounted for as interest that was charged against earnings during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 34 -Paragraph 21 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher OTS -Name Federal Regulation (FR) -Number Title 12 -Chapter V -Section 563c.102 -Paragraph 9 -Subsection II Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 9 -Article 9 false 5 Net realized gains on marketable securities 1 us-gaap_MarketableSecuritiesRealizedGainLoss us-gaap true credit duration No definition available. false false false false false false false false false false false false 1 false true false false 90000000 90 false false false 2 false true false false 90000000 90 false false false 3 false true false false 272000000 272 false false false 4 false true false false 57000000 57 false false false xbrli:monetaryItemType monetary This item represents the total realized gain (loss) included in earnings for the period as a result of selling marketable securities categorized as trading, available-for-sale, or held-to-maturity. Additionally, this item would include any losses recognized for other than temporary impairments of the subject investments in debt and equity securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 16 false 6 Net realized gains on other investments 1 us-gaap_GainLossOnSaleOfOtherInvestments us-gaap true credit duration No definition available. false false false false false false false false false false false false 1 false true false false 2000000 2 false false false 2 false true false false 0 0 false false false 3 false true false false 2000000 2 false false false 4 false true false false 0 0 false false false xbrli:monetaryItemType monetary The difference between the book value and the sale price of other nonspecific investments. This element is used when other, more specific, elements are not appropriate. This element refers to the gain (loss) included in earnings. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 false 7 Impairment losses on marketable securities 1 us-gaap_MarketableSecuritiesRealizedGainLossOtherThanTemporaryImpairmentsAmount us-gaap true debit duration No definition available. false false false false false false false false false false false false 1 false true false false -28000000 -28 false false false 2 false true false false -112000000 -112 false false false 3 false true false false -95000000 -95 false false false 4 false true false false -704000000 -704 false false false xbrli:monetaryItemType monetary This element represents the amount of loss recognized for other than temporary impairments of investments in debt and equity securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 16 false 8 Impairment losses on other investments 1 qcom_ImpairmentLossesOnOtherInvestments qcom false debit duration This element represents losses recognized for other-than-temporary impairments on investments accounted for under the cost... false false false false false false false false false false false false 1 false true false false -1000000 -1 false false false 2 false true false false -4000000 -4 false false false 3 false true false false -7000000 -7 false false false 4 false true false false -13000000 -13 false false false xbrli:monetaryItemType monetary This element represents losses recognized for other-than-temporary impairments on investments accounted for under the cost and equity methods of accounting. No authoritative reference available. false 9 (Losses) gains on derivative instruments 1 us-gaap_DerivativeGainLossOnDerivativeNet us-gaap true credit duration No definition available. false false false false false false false false false false false false 1 false true false false -2000000 -2 false false false 2 false true false false -7000000 -7 false false false 3 false true false false -3000000 -3 false false false 4 false true false false 5000000 5 false false false xbrli:monetaryItemType monetary Net increase (decrease) in the fair value of the derivative or group of derivatives included in earnings. No authoritative reference available. false 10 Equity in earnings (losses) of investees 1 us-gaap_IncomeLossFromEquityMethodInvestments us-gaap true credit duration No definition available. false false false false false false false false false false false false 1 false true false false 1000000 1 false false false 2 false true false false -1000000 -1 false false false 3 false true false false -3000000 -3 false false false 4 false true false false -14000000 -14 false false false xbrli:monetaryItemType monetary This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. Such amount typically reflects adjustments similar to those made in preparing consolidated statements, including adjustments to eliminate intercompany gains and losses, and to amortize, if appropriate, any difference between cost and underlying equity in net assets of the investee at the date of investment. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 18 -Paragraph 19 -Subparagraph c Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 11 -Article 7 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 9 -Article 5 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 18 -Paragraph 6 -Subparagraph b false 11 Investment income (loss), net 1 qcom_InvestmentIncomeLossNet qcom false na duration This item represents the aggregate of (1) interest and dividend income derived from investments in debt and equity securities... false false false false false false false false false false false totallabel false 1 false true false false 179000000 179 false false false 2 false true false false 90000000 90 false false false 3 false true false false 541000000 541 false false false 4 false true false false -296000000 -296 false false false xbrli:monetaryItemType monetary This item represents the aggregate of (1) interest and dividend income derived from investments in debt and equity securities and on cash and cash equivalents and (2) realized and unrealized gains and losses reported in the statement of income which have resulted from the sale and holding of marketable securities, respectively, as well as the sale or disposal of cost and equity method investments. No authoritative reference available. true 12 Total other-than-temporary impairment losses 1 qcom_TotalOtherThanTemporaryImpairmentLosses qcom false na duration This element represents the amount of loss recognized for other than temporary impairments of investments in debt and equity... false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 712000000 712 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary This element represents the amount of loss recognized for other than temporary impairments of investments in debt and equity securities. No authoritative reference available. false 13 Noncredit portion of impairment losses on debt securities 1 qcom_NoncreditPortionOfImpairmentLossesOnDebtSecurities qcom false na duration This element represents the amount related to the noncredit portion of losses on debt securities recognized in other... false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 true true false false 8000000 8 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary This element represents the amount related to the noncredit portion of losses on debt securities recognized in other comprehensive income. No authoritative reference available. false 4 12 false Millions UnKnown UnKnown false true