2.4.0.82402404 - Disclosure - Debt (Details 2)truefalseIn Thousands, unless otherwise specifiedfalse1false USDfalsefalse$D2013Q2_us-gaap_DebtInstrumentAxis_cdns_NotesDueTwentyThirteenMemberhttp://www.sec.gov/CIK0000813672duration2013-03-31T00:00:002013-06-29T00:00:00numberStandardhttp://www.xbrl.org/2003/instancepurexbrli0usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$D2012Q2_us-gaap_DebtInstrumentAxis_cdns_NotesDueTwentyThirteenMemberhttp://www.sec.gov/CIK0000813672duration2012-04-01T00:00:002012-06-30T00:00:00numberStandardhttp://www.xbrl.org/2003/instancepurexbrli0usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3false USDfalsefalse$D2013Q2YTD_us-gaap_DebtInstrumentAxis_cdns_NotesDueTwentyThirteenMemberhttp://www.sec.gov/CIK0000813672duration2012-12-30T00:00:002013-06-29T00:00:00numberStandardhttp://www.xbrl.org/2003/instancepurexbrli0usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$4false USDfalsefalse$D2012Q2YTD_us-gaap_DebtInstrumentAxis_cdns_NotesDueTwentyThirteenMemberhttp://www.sec.gov/CIK0000813672duration2012-01-01T00:00:002012-06-30T00:00:00numberStandardhttp://www.xbrl.org/2003/instancepurexbrli0usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse1false USDtruefalse$D2013Q2_us-gaap_DebtInstrumentAxis_cdns_NotesDueTwentyThirteenMemberhttp://www.sec.gov/CIK0000813672duration2013-03-31T00:00:002013-06-29T00:00:00falsefalseConvertible Senior Notes Due 2013 [Member]us-gaap_DebtInstrumentAxisxbrldihttp://xbrl.org/2006/xbrldicdns_NotesDueTwentyThirteenMemberus-gaap_DebtInstrumentAxisexplicitMembernumberStandardhttp://www.xbrl.org/2003/instancepurexbrli0usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Convertible Senior Notes Due 2013 [Member]2true 4cdns_EffectiveInterestRateContractualInterestExpenseAndAmortizationOfDebtDiscountOfSeniorNotesAbstractcdns_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Effective interest rate and components of interest expense of 2013 notes3false 5us-gaap_DebtInstrumentConvertibleEffectiveInterestRateus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.0640.064falsefalsefalse2truetruefalse0.0640.064falsefalsefalse3truetruefalse0.0640.064falsefalsefalse4truetruefalse0.0640.064falsefalsefalsenum:percentItemTypepureThe effective interest rate on the liability component of convertible debt instrument which may be settled in cash upon conversion, including partial cash settlement.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6036836-161870 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number APB14-1 -Paragraph 33 -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false0Effective interest rate4false 5cdns_DebtInstrumentConvertibleContractualInterestCouponcdns_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse540000540USD$falsetruefalse2truefalsefalse540000540USD$falsetruefalse3truefalsefalse10800001080USD$falsetruefalse4truefalsefalse10800001080USD$falsetruefalsexbrli:monetaryItemTypemonetaryInterest expense related to convertible debt instruments which has been recognized for the period, for the contractual interest coupon.No definition available.false2Contractual interest expense5false 5us-gaap_AmortizationOfDebtDiscountPremiumus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse16570001657USD$falsetruefalse2truefalsefalse15470001547USD$falsetruefalse3truefalsefalse33070003307USD$falsetruefalse4truefalsefalse30860003086USD$falsetruefalsexbrli:monetaryItemTypemonetaryAmount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 21 -Paragraph 16 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.8) -URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 5 false2Amortization of debt discountfalseDebt (Details 2) (Convertible Senior Notes Due 2013 [Member], USD $)ThousandsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.cadence.com/role/DebtDetails245