Cadence Design Systems (CDNS) 10-Q 21 Apr 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 29, 2014
Document and Entity Information [Abstract]	'
Entity Registrant Name	'CADENCE DESIGN SYSTEMS INC
Entity Central Index Key	'0000813672
Document Type	'10-Q
Document Period End Date	29-Mar-14
Amendment Flag	'false
Document Fiscal Year Focus	'2014
Document Fiscal Period Focus	'Q1
Current Fiscal Year End Date	'--01-03
Entity Filer Category	'Large Accelerated Filer
Entity Common Stock, Shares Outstanding	289,512,000

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Current Assets:	'	'
Cash and cash equivalents	$532,761	$536,260
Short-term investments	97,006	96,788
Receivables, net	106,322	107,624
Inventories	55,605	50,220
2015 notes hedges	369,731	306,817
Prepaid expenses and other	136,300	123,382
Total current assets	1,297,725	1,221,091
Property, plant and equipment, net of accumulated depreciation of $576,562 and $568,494, respectively	239,425	238,715
Goodwill	478,990	456,905
Acquired intangibles, net of accumulated amortization of $107,521 and $139,820, respectively	316,498	311,693
Long-term receivables	6,193	3,672
Other assets	185,389	196,525
Total assets	2,524,220	2,428,601
Current Liabilities:	'	'
Convertible notes	329,058	324,826
2015 notes embedded conversion derivative	369,731	306,817
Accounts payable and accrued liabilities	189,200	216,594
Current portion of deferred revenue	304,705	299,973
Total current liabilities	1,192,694	1,148,210
Long-Term Liabilities:	'	'
Long-term portion of deferred revenue	48,299	52,850
Other long-term liabilities	69,025	71,436
Total long-term liabilities	117,324	124,286
Commitments and contingencies	'	'
Stockholders' Equity:	'	'
Common stock and capital in excess of par value	1,785,069	1,757,242
Treasury stock, at cost	-147,621	-140,142
Accumulated deficit	-452,236	-485,306
Accumulated other comprehensive income	28,990	24,311
Total stockholders’ equity	1,214,202	1,156,105
Total liabilities and stockholders’ equity	$2,524,220	$2,428,601

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Accumulated depreciation on property, plant and equipment	$576,562	$568,494
Accumulated amortization on acquired intangibles assets	$107,521	$139,820

Condensed_Consolidated_Income_

Condensed Consolidated Income Statements (Unaudited) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Revenue:	'	'
Product and maintenance	$357,350	$328,271
Services	21,200	25,995
Total revenue	378,550	354,266
Costs and Expenses:	'	'
Cost of product and maintenance	42,197	29,847
Cost of services	14,902	18,344
Marketing and sales	98,323	90,402
Research and development	146,466	124,084
General and administrative	28,744	29,810
Amortization of acquired intangibles	5,210	3,791
Restructuring and other charges (credits)	396	-148
Total costs and expenses	336,238	296,130
Income from operations	42,312	58,136
Interest expense	-7,268	-9,262
Other income, net	3,382	2,175
Income before provision (benefit) for income taxes	38,426	51,049
Provision (benefit) for income taxes	5,356	-27,560
Net income	$33,070	$78,609
Net income per share - basic (in usd per share)	$0.12	$0.29
Net income per share - diluted (in usd per share)	$0.11	$0.27
Weighted average common shares outstanding - basic (in shares)	281,615	274,936
Weighted average common shares outstanding - diluted (in shares)	301,034	292,151

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Statement of Comprehensive Income [Abstract]	'	'
Net income	$33,070	$78,609
Other comprehensive income (loss), net of tax effects:	'	'
Foreign currency translation adjustments	4,452	-6,162
Changes in unrealized holding gains or losses on available-for-sale securities, net of reclassification adjustment for realized gains and losses	-181	-284
Changes in defined benefit plan liabilities	408	318
Total other comprehensive income (loss), net of tax effects	4,679	-6,128
Comprehensive income	$37,749	$72,481

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Statement of Cash Flows [Abstract]	'	'
Cash and cash equivalents at beginning of period	$536,260	$726,357
Cash flows from operating activities:	'	'
Net income	33,070	78,609
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization	26,017	21,682
Amortization of debt discount and fees	4,882	6,281
Stock-based compensation	18,864	13,810
Gain on investments, net	-3,651	-1,006
Deferred income taxes	2,245	8,695
Other non-cash items	2,344	-1,007
Changes in operating assets and liabilities, net of effect of acquired businesses:	'	'
Receivables	-108	23,652
Inventories	-9,373	-979
Prepaid expenses and other	-9,753	-1,099
Other assets	3,157	4,148
Accounts payable and accrued liabilities	-29,680	-11,003
Deferred revenue	-5,508	-16,648
Other long-term liabilities	-4,408	-49,799
Net cash provided by operating activities	28,098	75,336
Cash flows from investing activities:	'	'
Purchases of available-for-sale securities	-47,005	-24,282
Proceeds from the sale of available-for-sale securities	32,586	14,985
Proceeds from the maturity of available-for-sale securities	13,905	8,700
Proceeds from the sale of long-term investments	0	6,102
Purchases of property, plant and equipment	-6,252	-6,569
Cash paid in business combinations and asset acquisitions, net of cash acquired	-27,422	-757
Net cash used for investing activities	-34,188	-1,821
Cash flows from financing activities:	'	'
Principal payments on receivable financing	0	-2,526
Payment of acquisition-related contingent consideration	-1,835	-582
Tax effect related to employee stock transactions allocated to equity	1,827	5,276
Proceeds from issuance of common stock	23,377	21,801
Stock received for payment of employee taxes on vesting of restricted stock	-10,981	-8,775
Payments for repurchases of common stock	-12,517	0
Net cash provided by (used for) financing activities	-129	15,194
Effect of exchange rate changes on cash and cash equivalents	2,720	-4,914
Increase (decrease) in cash and cash equivalents	-3,499	83,795
Cash and cash equivalents at end of period	532,761	810,152
Supplemental cash flow information:	'	'
Cash paid for interest	112	183
Cash paid for taxes, net	5,393	-21
Non-cash investing and financing activities:	'	'
Available-for-sale securities received from customer	$0	$209

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 29, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
BASIS OF PRESENTATION	'
	BASIS OF PRESENTATION
	The condensed consolidated financial statements included in this Quarterly Report on Form 10-Q have been prepared by Cadence Design Systems, Inc., or Cadence, without audit, pursuant to the rules and regulations of the United States Securities and Exchange Commission, or the SEC. Certain information and footnote disclosures normally included in consolidated financial statements prepared in accordance with generally accepted accounting principles have been condensed or omitted pursuant to such rules and regulations. However, Cadence believes that the disclosures contained in this Quarterly Report on Form 10-Q comply with the requirements of Section 13(a) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, for a Quarterly Report on Form 10-Q and are adequate to make the information presented not misleading. These condensed consolidated financial statements are meant to be, and should be, read in conjunction with the consolidated financial statements and the Notes thereto included in Cadence’s Annual Report on Form 10-K for the fiscal year ended December 28, 2013. Certain prior period balances have been reclassified to conform to current period presentation.
	The unaudited condensed consolidated financial statements included in this Quarterly Report on Form 10-Q reflect all adjustments (which include only normal, recurring adjustments and those items discussed in these Notes) that are, in the opinion of management, necessary to state fairly the results of operations, cash flows and financial position for the periods and dates presented. The results for such periods are not necessarily indicative of the results to be expected for the full fiscal year. Management has evaluated subsequent events through the issuance date of the unaudited condensed consolidated financial statements.
	Preparation of the condensed consolidated financial statements in conformity with United States generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.

Debt

Debt	3 Months Ended
	Mar. 29, 2014
Debt Disclosure [Abstract]	'
DEBT	'
	DEBT
	Cadence’s outstanding debt as of March 29, 2014 and December 28, 2013 was as follows:
		29-Mar-14								December 28, 2013
		(In thousands)
		Principal			Unamortized Discount			Carrying Value		Principal		Unamortized Discount			Carrying Value
	2015 Notes	$	350,000		$	(20,942	)	$	329,058	$	350,000	$	(25,174	)	$	324,826
	Revolving credit facility	—			—			—		—		—			—
	Total outstanding debt	$	350,000		$	(20,942	)	$	329,058	$	350,000	$	(25,174	)	$	324,826
	2015 Notes
	In June 2010, Cadence issued $350.0 million principal amount of 2.625% Cash Convertible Senior Notes Due 2015, or the 2015 Notes. At maturity, the holders of the 2015 Notes will be entitled to receive the principal amount of the 2015 Notes plus accrued interest. The 2015 Notes are convertible into cash prior to maturity upon the occurrence of certain conditions described in the table below. To the extent that the 2015 Notes are convertible prior to maturity and a holder of the 2015 Notes elects to convert its notes prior to maturity, that note holder will be entitled to receive cash equal to the principal amount of the notes plus any additional conversion value as described in the table below under the heading “Conversion feature.”
	Cadence entered into hedge transactions, or the 2015 Notes Hedges, in connection with the issuance of the 2015 Notes. The purpose of the 2015 Notes Hedges was to limit Cadence’s exposure to the additional cash payments above the principal amount of the 2015 Notes that may be due to the holders. As a result of the 2015 Notes Hedges, Cadence’s maximum expected cash exposure upon conversion of the 2015 Notes is the $350.0 million principal balance of the notes and accrued interest. In June 2010, Cadence also sold warrants in separate transactions, or the 2015 Warrants. As a result of the 2015 Warrants, Cadence will experience dilution to its diluted earnings per share if its average closing stock price exceeds $10.78 for any fiscal quarter. To the extent that Cadence’s stock price exceeds $10.78 at expiration of the 2015 Warrants, Cadence will issue shares to net settle the 2015 Warrants.
	A summary of key terms of the 2015 Notes is as follows:
			2015 Notes
			(In thousands, except percentages and per share amounts)
	Outstanding principal maturity value – at March 29, 2014		$350,000
	Contractual interest rate		2.63%
	Contractual maturity date		June 1, 2015
	Initial conversion rate		132.5205 shares of common stock per $1,000 principal amount of notes, which is equivalent to a conversion price of approximately $7.55 per share of Cadence common stock.
	Conversion feature (in addition to principal amount payable in cash)		Cash to the extent Cadence’s stock price exceeds approximately $7.55 per share, calculated based on the applicable conversion rate multiplied by the volume weighted average price of Cadence common stock over a specified period.
	Early conversion conditions (or the Early Conversion Conditions)		• Closing stock price greater than $9.81 for at least 20 of the last 30 trading days in a fiscal quarter (convertible only for subsequent quarter);
			• Specified corporate transactions; or
			• Note trading price falls below a calculated minimum.
	Conversion immediately preceding maturity		From March 1, 2015 until the second trading day immediately preceding the maturity date, holders may convert their 2015 Notes at any time into cash as described above under “Conversion feature.”
	Redemption at Cadence’s option prior to maturity		None.
	Fundamental change put right		Upon certain fundamental corporate changes prior to maturity, the 2015 Note holders could require Cadence to repurchase their notes for cash equal to the principal amount of the notes plus accrued interest.
	Make-whole premium		Upon certain fundamental changes prior to maturity, if Cadence’s stock price were between $6.16 and $40.00 per share at that time, the holders of the notes would be entitled to an increase to the conversion rate. This is referred to as a “make-whole premium.”
	Financial covenants		None.
	Impact of Early Conversion Conditions on Financial Statements
	The 2015 Notes are convertible into cash from March 30, 2014 through June 28, 2014 because Cadence’s closing stock price exceeded $9.81 for at least 20 days in the 30-day period prior to March 29, 2014. The net balance of the 2015 Notes of $329.1 million is classified as a current liability on Cadence’s condensed consolidated balance sheet as of March 29, 2014, as holders of the 2015 Notes have the ability to convert their notes into cash subsequent to March 1, 2015 as specified in the table above under “Conversion immediately preceding maturity.”
	If the note holders elect to convert their 2015 Notes prior to maturity, any unamortized discount and transaction fees will be expensed at the time of conversion. If the entire outstanding principal amount had been converted on March 29, 2014, Cadence would have recorded an expense of $23.8 million associated with the conversion, comprised of $20.9 million of unamortized debt discount and $2.9 million of unamortized transaction fees.
	As of March 29, 2014, the if-converted value of the 2015 Notes to the note holders of approximately $714.3 million exceeded the principal amount of $350.0 million. The fair value of the 2015 Notes was $719.7 million as of March 29, 2014 and $654.1 million as of December 28, 2013. The 2015 Notes currently trade at a premium to the if-converted value of the notes. As of March 29, 2014, none of the note holders had elected to convert their 2015 Notes.
	2015 Notes Embedded Conversion Derivative
	The conversion feature of the 2015 Notes, or the 2015 Notes Embedded Conversion Derivative, requires bifurcation from the 2015 Notes and is accounted for as a derivative liability. The fair value of the 2015 Notes Embedded Conversion Derivative at the time of issuance of the 2015 Notes was $76.6 million and was recorded as original debt discount for purposes of accounting for the debt component of the 2015 Notes. This discount is amortized as interest expense using the effective interest method over the term of the 2015 Notes. The 2015 Notes Embedded Conversion Derivative is carried on the condensed consolidated balance sheet at its estimated fair value. The fair value was $369.7 million as of March 29, 2014 and $306.8 million as of December 28, 2013.
	2015 Notes Hedges
	The 2015 Notes Hedges expire on June 1, 2015 and must be settled in cash. The aggregate cost of the 2015 Notes Hedges was $76.6 million. The 2015 Notes Hedges are accounted for as derivative assets and are carried on the condensed consolidated balance sheet at their estimated fair value. The 2015 Notes Hedges fair value was $369.7 million as of March 29, 2014 and $306.8 million as of December 28, 2013. The 2015 Notes Embedded Conversion Derivative liability and the 2015 Notes Hedges asset are adjusted to fair value each reporting period and unrealized gains and losses are reflected in the condensed consolidated income statements. The 2015 Notes Embedded Conversion Derivative and the 2015 Notes Hedges are designed to have similar fair values. Accordingly, the changes in the fair values of these instruments offset during the three months ended March 29, 2014 and March 30, 2013 and did not have a net impact on the condensed consolidated income statements for the respective periods.
	The classification of the 2015 Notes Embedded Conversion Derivative liability and the 2015 Notes Hedges asset as current on the condensed consolidated balance sheet corresponds with the classification of the 2015 Notes.
	2015 Warrants
	In June 2010, Cadence sold the 2015 Warrants in separate transactions for the purchase of up to approximately 46.4 million shares of Cadence’s common stock at a strike price of $10.78 per share, for total proceeds of $37.5 million, which was recorded as an increase in stockholders’ equity. The 2015 Warrants expire on various dates from September 2015 through December 2015 and must be settled in net shares of Cadence’s common stock. Upon expiration of the 2015 Warrants, Cadence will issue shares of common stock to the purchasers of the 2015 Warrants that represent the value by which the price of the common stock exceeds the strike price stipulated within the particular warrant agreement.
	The effective interest rate and components of interest expense of the 2015 Notes for the three months ended March 29, 2014 and March 30, 2013 were as follows:
		Three Months Ended
		March 29,			March 30,
		2014			2013
		(In thousands, except percentages)
	Effective interest rate	8.1		%	8.1		%
	Contractual interest expense	$	2,289		$	2,289
	Amortization of debt discount	$	4,232		$	3,910
	Revolving Credit Facility
	In December 2012, Cadence entered into a five-year senior secured revolving credit facility with a group of lenders led by Bank of America, N.A., as administrative agent. The credit facility provides for borrowings up to $250.0 million, with the right to request increased capacity up to an additional $150.0 million upon the receipt of lender commitments, for total maximum borrowings of $400.0 million.
	Any outstanding loans drawn under the credit facility are due at maturity on December 12, 2017. Outstanding amounts may be paid at any time prior to maturity. The facility is secured by certain accounts receivable and certain equity interests in Cadence’s subsidiaries.
	Interest accrues based on Cadence’s consolidated leverage ratio. Borrowings may be made at LIBOR plus a margin between 1.25% and 2.0% per annum or at the base rate plus a margin between 0.25% and 1.0% per annum, where in each case the margin is determined by reference to a specified leverage ratio. Interest is payable quarterly. A commitment fee ranging from 0.20% to 0.35% is assessed on the daily average undrawn portion of revolving commitments.
	The credit facility contains customary negative covenants that, among other things, restrict Cadence’s ability to incur additional indebtedness, grant liens, make certain investments (including acquisitions), dispose of certain assets and make certain payments, including share repurchases and dividends. In addition, the credit facility contains financial covenants that require Cadence to maintain a leverage ratio not to exceed 3 to 1, and a minimum interest coverage ratio of 3 to 1.
	As of March 29, 2014 and December 28, 2013, Cadence had no outstanding balance on the credit facility and was in compliance with all financial covenants.

Acquisitions_and_AcquisitionRe

Acquisitions and Acquisition-Related Contingent Consideration	3 Months Ended
	Mar. 29, 2014
Business Combinations [Abstract]	'
ACQUISITIONS AND ACQUISITION-RELATED CONTINGENT CONSIDERATION	'
	ACQUISITIONS AND ACQUISITION-RELATED CONTINGENT CONSIDERATION
	Acquisitions
	During the three months ended March 29, 2014, Cadence completed two business combinations for total cash consideration of $27.5 million, after taking into account cash acquired of $2.1 million. The total purchase consideration was preliminarily allocated to the assets acquired and liabilities assumed based on their respective estimated fair values on the acquisition dates. Cadence will continue to evaluate certain tax estimates and assumptions that are subject to change within the measurement period (up to one year from the acquisition date). Cadence recorded a total of $20.8 million of goodwill, $16.9 million of other intangible assets and $8.1 million of net liabilities consisting primarily of long-term deferred income taxes and deferred revenue.
	The goodwill related to Cadence’s acquisitions during the three months ended March 29, 2014 is primarily related to expected synergies from combining operations of the acquired companies with Cadence. Cadence expects that approximately $0.5 million of goodwill related to the acquisitions completed during the three months ended March 29, 2014 will be deductible for tax purposes.
	Cadence amortizes intangible assets with definite lives on a straight-line basis over the remaining estimated economic life of the underlying products and technologies. The weighted-average amortization period for definite-lived intangible assets acquired during the three months ended March 29, 2014 is approximately nine years.
	Transaction costs associated with Cadence’s acquisitions were $1.0 million and $3.4 million for the three months ended March 29, 2014 and March 30, 2013, respectively. These costs consisted of professional fees and administrative costs and were expensed as incurred in Cadence’s condensed consolidated income statements.
	Acquisition-related Contingent Consideration
	Cadence may be obligated to make cash payments in connection with its business combinations and asset acquisitions completed in prior fiscal years, subject to the satisfaction of future financial measures associated with the acquired technology. If performance is such that these payments are fully achieved, Cadence will be obligated to pay up to an aggregate of $11.8 million over the next 25 months. Of the $11.8 million, up to $9.2 million would be recorded as operating expenses in the condensed consolidated income statements.

Goodwill_and_Acquired_Intangib

Goodwill and Acquired Intangibles	3 Months Ended
	Mar. 29, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
GOODWILL AND ACQUIRED INTANGIBLES	'
	GOODWILL AND ACQUIRED INTANGIBLES
	Goodwill
	The changes in the carrying amount of goodwill during the three months ended March 29, 2014 were as follows:
		Gross Carrying
		Amount
		(In thousands)
	Balance as of December 28, 2013	$	456,905
	Goodwill resulting from acquisitions	20,756
	Effect of foreign currency translation	1,329
	Balance as of March 29, 2014	$	478,990
	Acquired Intangibles, Net
	Acquired intangibles as of March 29, 2014 were as follows, excluding intangibles that were fully amortized as of December 28, 2013:
		Gross Carrying		Accumulated			Acquired
		Amount		Amortization			Intangibles, Net
		(In thousands)
	Existing technology	$	248,836	$	(56,632	)	$	192,204
	Agreements and relationships	161,892		(47,679		)	114,213
	Tradenames, trademarks and patents	9,719		(3,210		)	6,509
	Total acquired intangibles with definite lives	420,447		(107,521		)	312,926
	In-process technology	3,572		—			3,572
	Total acquired intangibles	$	424,019	$	(107,521	)	$	316,498
	In-process technology as of March 29, 2014 consists of acquired projects that, if completed, will contribute to Cadence’s ability to offer additional IP solutions to its customers. As of March 29, 2014, these projects were expected to be complete in six to twelve months. During the three months ended March 29, 2014, there were no significant transfers from in-process technology to existing technology.
	Acquired intangibles as of December 28, 2013 were as follows, excluding intangibles that were fully amortized as of December 29, 2012:
		Gross Carrying		Accumulated			Acquired
		Amount		Amortization			Intangibles, Net
		(In thousands)
	Existing technology	$	237,624	$	(53,243	)	$	184,381
	Agreements and relationships	170,760		(53,607		)	117,153
	Distribution rights	30,100		(30,100		)	—
	Tradenames, trademarks and patents	9,519		(2,870		)	6,649
	Total acquired intangibles with definite lives	448,003		(139,820		)	308,183
	In-process technology	3,510		—			3,510
	Total acquired intangibles	$	451,513	$	(139,820	)	$	311,693
	Amortization expense from existing technology and maintenance agreements is included in cost of product and maintenance. Amortization of acquired intangibles for the three months ended March 29, 2014 and March 30, 2013 was as follows:
		Three Months Ended
		March 29,		March 30,
		2014		2013
		(In thousands)
	Cost of product and maintenance	$	7,576	$	3,807
	Amortization of acquired intangibles	5,210		3,791
	Total amortization of acquired intangibles	$	12,786	$	7,598
	Estimated amortization expense for intangible assets with definite lives for the following five fiscal years and thereafter is as follows:
		(In thousands)
	2014 – remaining period	$	38,792
	2015	51,220
	2016	45,360
	2017	41,550
	2018	38,609
	Thereafter	97,395
	Total estimated amortization expense	$	312,926

Income_Taxes_Income_Taxes

Income Taxes Income Taxes	3 Months Ended
	Mar. 29, 2014
Income Tax Disclosure [Abstract]	'
INCOME TAXES	'
	INCOME TAXES
	Cadence’s provision for income taxes of $5.4 million for the three months ended March 29, 2014 primarily resulted from federal, state and foreign income taxes on its anticipated fiscal 2014 income. Cadence’s foreign earnings are generally subject to lower statutory tax rates than its United States earnings. In addition, Cadence’s provision for income taxes for the three months ended March 29, 2014 does not include the potential tax benefit of the United States federal research tax credit which expired in December 2013. The expiration of the research tax credit is estimated to increase Cadence’s estimated annual effective tax rate for fiscal 2014 by 3%.
	Cadence’s benefit for income taxes of $27.6 million for the three months ended March 30, 2013 primarily resulted from a tax benefit of $33.7 million from the release of an uncertain tax position, including related interest and penalties, and a $5.9 million tax benefit from the retroactive enactment of the fiscal 2012 United States federal research tax credit during the period.

Receivables_and_Allowances_for

Receivables and Allowances for Doubtful Accounts	3 Months Ended
	Mar. 29, 2014
Receivables [Abstract]	'
RECEIVABLES AND ALLOWANCES FOR DOUBTFUL ACCOUNTS	'
	RECEIVABLES, NET
	Cadence’s current and long-term receivables balances as of March 29, 2014 and December 28, 2013 were as follows:
		As of
		March 29,		December 28,
		2014		2013
		(In thousands)
	Accounts receivable	$	81,330	$	76,057
	Unbilled accounts receivable	24,992		31,567
	Long-term receivables	6,193		3,672
	Total receivables	$	112,515	$	111,296
	Less allowance for doubtful accounts	—		—
	Total receivables, net	$	112,515	$	111,296
	Cadence’s customers are primarily concentrated within the semiconductor and electronics systems industries. As of March 29, 2014 and December 28, 2013, no single customer accounted for 10% of Cadence’s total receivables. As of March 29, 2014, approximately 45% of Cadence’s total receivables were attributable to the ten customers with the largest balances of total receivables. As of December 28, 2013, approximately 47% of Cadence’s total receivables were attributable to the ten customers with the largest balances of total receivables.

Fair_Value

Fair Value	3 Months Ended
	Mar. 29, 2014
Fair Value Disclosures [Abstract]	'
FAIR VALUE	'
	FAIR VALUE
	Inputs to valuation techniques are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect Cadence’s market assumptions. These two types of inputs have created the following fair value hierarchy:
	•	Level 1 – Quoted prices for identical instruments in active markets;
	•	Level 2 – Quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets; and
	•	Level 3 – Valuations derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable.
	This hierarchy requires Cadence to minimize the use of unobservable inputs and to use observable market data, if available, when determining fair value. Cadence recognizes transfers between levels of the hierarchy based on the fair values of the respective financial instruments at the end of the reporting period in which the transfer occurred. There were no transfers between levels of the fair value hierarchy during the three months ended March 29, 2014.
	On a quarterly basis, Cadence measures at fair value certain financial assets and liabilities. The fair value of financial assets and liabilities was determined using the following levels of inputs as of March 29, 2014 and December 28, 2013:
		Fair Value Measurements as of March 29, 2014:
		Total			Level 1		Level 2		Level 3
		(In thousands)
	Assets
	Cash equivalents:
	Money market funds	$	348,884		$	348,884	$	—	$	—
	Short-term investments:
	Corporate debt securities	36,906			—		36,906		—
	Bank certificates of deposit	26,362			—		26,362		—
	United States Treasury securities	18,944			18,944		—		—
	United States government agency securities	10,366			10,366		—		—
	Commercial paper	2,495			—		2,495		—
	Marketable equity securities	1,933			1,933		—		—
	Trading securities held in Non-Qualified Deferred Compensation, or NQDC, trust	23,786			23,786		—		—
	2015 Notes Hedges	369,731			—		369,731		—
	Total Assets	$	839,407		$	403,913	$	435,494	$	—
		Total			Level 1		Level 2		Level 3
		(In thousands)
	Liabilities
	Acquisition-related contingent consideration	$	1,805		$	—	$	—	$	1,805
	2015 Notes Embedded Conversion Derivative	369,731			—		369,731		—
	Foreign currency exchange contracts	$	367		$	—	$	367	$	—
	Total Liabilities	$	371,903		$	—	$	370,098	$	1,805
		Fair Value Measurements as of December 28, 2013:
		Total			Level 1		Level 2		Level 3
		(In thousands)
	Assets
	Cash equivalents:
	Money market funds	$	345,872		$	345,872	$	—	$	—
	Bank certificates of deposit	2,300			—		2,300		—
	Short-term investments:
	Corporate debt securities	37,441			—		37,441		—
	Bank certificates of deposit	20,308			—		20,308		—
	United States Treasury securities	24,246			24,246		—		—
	United States government agency securities	10,223			10,223		—		—
	Commercial paper	2,493			—		2,493		—
	Marketable equity securities	2,077			2,077		—		—
	Trading securities held in NQDC trust	23,960			23,960		—		—
	2015 Notes Hedges	306,817			—		306,817		—
	Foreign currency exchange contracts	262			—		262		—
	Total Assets	$	775,999		$	406,378	$	369,621	$	—
		Total			Level 1		Level 2		Level 3
		(In thousands)
	Liabilities
	Acquisition-related contingent consideration	$	4,091		$	—	$	—	$	4,091
	2015 Notes Embedded Conversion Derivative	306,817			—		306,817		—
	Total Liabilities	$	310,908		$	—	$	306,817	$	4,091
	Level 1 Measurements
	Cadence’s cash equivalents held in money market funds, available-for-sale United States Treasury securities, United States government agency securities, marketable equity securities and the trading securities held in Cadence’s NQDC trust are measured at fair value using level 1 inputs.
	Level 2 Measurements
	The 2015 Notes Hedges and the 2015 Notes Embedded Conversion Derivative are measured at fair value using level 1 and level 2 inputs. These instruments are not actively traded and are valued using an option pricing model that uses observable market data for all inputs, such as implied volatility of Cadence’s common stock, risk-free interest rate and other factors.
	Cadence’s available-for-sale corporate debt securities, bank certificates of deposit and commercial paper are measured at fair value using level 2 inputs. Cadence obtains the fair values of its level 2 available-for-sale securities from a professional pricing service and validates the fair values by assessing the pricing methods and inputs and by comparing the fair values to another independent source.
	The fair values of Cadence’s 2015 Notes, which differ from their carrying values, are influenced by interest rates and Cadence’s stock price and stock price volatility and are determined by prices for the 2015 Notes observed in market trading, which are level 2 inputs.
	Cadence’s foreign currency exchange contracts are measured at fair value using observable foreign currency exchange rates.
	Level 3 Measurements
	The liabilities included in level 3 represent the fair value of contingent consideration associated with certain of Cadence’s acquisitions. Cadence makes estimates regarding the fair value of contingent consideration liabilities on the acquisition date and at the end of each reporting period until the contingency is resolved. The fair value of these arrangements is determined by calculating the net present value of the expected payments using significant inputs that are not observable in the market, including revenue projections and discount rates consistent with the level of risk of achievement. The fair value of these contingent consideration arrangements is affected most significantly by the changes in the revenue projections, but is also impacted by the discount rate used to adjust the outcomes to their present values. If the revenue projections increase or decrease, the fair value of the contingent consideration will increase or decrease accordingly, in amounts that will vary based on the timing of the projected revenues, the timing of the expected payments and the discount rate used to calculate the present value of the expected payments. Cadence used discount rates ranging from 11% to 16% to value its contingent consideration liabilities as of March 29, 2014 and December 28, 2013. Cadence believes that its estimates and assumptions are reasonable, but significant judgment is involved.
Changes in the fair value of contingent consideration liabilities subsequent to the acquisition are recorded in general and administrative expense in the condensed consolidated income statements.
The following table summarizes the level 3 activity for the three months ended March 29, 2014:
	(In thousands)
Balance as of December 28, 2013	$	4,091
Payments	(2,329		)
Adjustments	43
Balance as of March 29, 2014	$	1,805

Cash_Cash_Equivalents_and_Inve

Cash, Cash Equivalents and Investments	3 Months Ended
	Mar. 29, 2014
Cash, Cash Equivalents and Investments [Abstract]	'
CASH, CASH EQUIVALENTS AND INVESTMENTS	'
	CASH, CASH EQUIVALENTS AND INVESTMENTS
	Cadence’s cash, cash equivalents and short-term investments at fair value as of March 29, 2014 and December 28, 2013 were as follows:
		As of
		March 29,		December 28,
		2014		2013
		(In thousands)
	Cash and cash equivalents	$	532,761	$	536,260
	Short-term investments	97,006		96,788
	Cash, cash equivalents and short-term investments	$	629,767	$	633,048
	Cash and Cash Equivalents
	Cadence considers all highly liquid investments with original maturities of three months or less on the date of purchase to be cash equivalents. The amortized cost of Cadence’s cash equivalents approximates fair value. The following table summarizes Cadence’s cash and cash equivalents at fair value as of March 29, 2014 and December 28, 2013:
		As of
		March 29,		December 28,
		2014		2013
		(In thousands)
	Cash and interest bearing deposits	$	183,877	$	188,088
	Money market funds	348,884		345,872
	Bank certificates of deposit	—		2,300
	Total cash and cash equivalents	$	532,761	$	536,260
	Short-Term Investments
	The following tables summarize Cadence’s short-term investments as of March 29, 2014 and December 28, 2013:
		As of March 29, 2014
		Amortized		Gross		Gross			Fair
		Cost		Unrealized		Unrealized			Value
				Gains		Losses
		(In thousands)
	Corporate debt securities	$	36,903	$	20	$	(17	)	$	36,906
	Bank certificates of deposit	26,350		12		—			26,362
	United States Treasury securities	18,921		24		(1		)	18,944
	United States government agency securities	10,356		11		(1		)	10,366
	Commercial paper	2,493		2		—			2,495
	Marketable debt securities	95,023		69		(19		)	95,073
	Marketable equity securities	1,817		116		—			1,933
	Total short-term investments	$	96,840	$	185	$	(19	)	$	97,006
		As of December 28, 2013
		Amortized		Gross		Gross			Fair
		Cost		Unrealized		Unrealized			Value
				Gains		Losses
		(In thousands)
	Corporate debt securities	$	37,422	$	30	$	(11	)	$	37,441
	Bank certificates of deposit	20,300		9		(1		)	20,308
	United States Treasury securities	24,219		28		(1		)	24,246
	United States government agency securities	10,212		11		—			10,223
	Commercial paper	2,492		1		—			2,493
	Marketable debt securities	94,645		79		(13		)	94,711
	Marketable equity securities	1,817		260		—			2,077
	Total short-term investments	$	96,462	$	339	$	(13	)	$	96,788
	As of March 29, 2014, no securities held by Cadence had been in an unrealized loss position for greater than twelve months.
	The amortized cost and estimated fair value of marketable debt securities included in short-term investments as of March 29, 2014, by contractual maturity, are shown in the table below. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations without penalties.
		Amortized		Fair
		Cost		Value
		(In thousands)
	Due in less than one year	$	42,803	$	42,823
	Due in one to three years	52,220		52,250
	Total marketable debt securities included in short-term investments	$	95,023	$	95,073
	Realized gains and losses from the sale of marketable debt and equity securities are recorded in other income, net in the condensed consolidated income statements.
	Non-Marketable Investments
	Cadence’s non-marketable investments generally consist of voting preferred stock or convertible debt of privately held companies and are included in other assets on Cadence’s condensed consolidated balance sheets. If Cadence determines that it has the ability to exercise significant influence over the issuer, which may include considering whether the investments are in-substance common stock, the investment is accounted for using the equity method.
	Cadence records in the condensed consolidated income statements as other income, net, realized gains and losses on non-marketable investments, write downs related to cost method investments due to other-than-temporary declines in value, and the proportional share of issuers’ gains or losses related to equity method investments.
	The equity method income or loss recorded by Cadence is based on its percentage ownership in the issuer.
	Cadence’s non-marketable investments as of March 29, 2014 and December 28, 2013 were as follows:
		As of
		March 29,		December 28,
2014		2013
	(In thousands)
Cost method	$	3,038	$	3,038
Equity method	5,163		3,639
Total non-marketable investments	$	8,201	$	6,677

Restructuring_and_Other_Charge

Restructuring and Other Charges Restructuring and Other Charges	3 Months Ended
	Mar. 29, 2014
Restructuring and Related Activities [Abstract]	'
RESTRUCTURING AND OTHER CHARGES	'
	RESTRUCTURING AND OTHER CHARGES
	Cadence has initiated various restructuring plans in the past, most recently in fiscal 2013, in an effort to operate more efficiently. These restructuring plans were primarily comprised of severance and termination benefits related to headcount reductions and estimated lease losses related to facilities vacated under the restructuring plans.
	The remaining accrual for Cadence’s restructuring plans is recorded in the condensed consolidated balance sheet as follows:
		As of
		March 29, 2014
		(In thousands)
	Accounts payable and accrued liabilities	$	4,433
	Other long-term liabilities	2,765
	Total accrued as of March 29, 2014	$	7,198
	The following table presents activity relating to Cadence’s restructuring plans during the three months ended March 29, 2014:
		Severance			Excess			Total
		and			Facilities
		Benefits
		(In thousands)
	Balance, December 28, 2013	$	10,672		$	3,552		$	14,224
	Restructuring and other charges, net	295			101			396
	Cash payments	(7,159		)	(286		)	(7,445		)
	Effect of foreign currency translation	11			12			23
	Balance, March 29, 2014	$	3,819		$	3,379		$	7,198

Net_Income_per_Share

Net Income per Share	3 Months Ended
	Mar. 29, 2014
Earnings Per Share [Abstract]	'
NET INCOME PER SHARE	'
	NET INCOME PER SHARE
	Basic net income per share is computed by dividing net income during the period by the weighted average number of shares of common stock outstanding during that period, less unvested restricted stock awards. Diluted net income per share is impacted by equity instruments considered to be potential common shares, if dilutive, computed using the treasury stock method of accounting.
	The calculations for basic and diluted net income per share for the three months ended March 29, 2014 and March 30, 2013 are as follows:
		Three Months Ended
		March 29,			March 30,
		2014			2013
		(In thousands, except per share amounts)
	Net income	$	33,070		$	78,609
	Weighted average common shares used to calculate basic net income per share	281,615			274,936
	Convertible notes	—			11
	2015 Warrants	12,576			10,668
	Stock-based awards	6,843			6,536
	Weighted average common shares used to calculate diluted net income per share	301,034			292,151
	Net income per share - basic	$	0.12		$	0.29
	Net income per share - diluted	$	0.11		$	0.27
	The following table presents shares of Cadence’s common stock outstanding for the three months ended March 29, 2014 and March 30, 2013 that were excluded from the computation of diluted net income per share because the effect of including these shares in the computation of diluted net income per share would have been anti-dilutive:
		Three Months Ended
		March 29,		March 30,
		2014		2013
		(In thousands)
	2013 Warrants	1,518		6,830
	Options to purchase shares of common stock	4,634		6,754
	Non-vested shares of restricted stock	11		—
	Total potential common shares excluded	6,163		13,584

Other_Comprehensive_Income

Other Comprehensive Income	3 Months Ended
	Mar. 29, 2014
Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
OTHER COMPREHENSIVE INCOME	'
	OTHER COMPREHENSIVE INCOME
	Cadence’s other comprehensive income is comprised of foreign currency translation gains and losses, changes in defined benefit plan liabilities, and changes in unrealized holding gains and losses on available-for-sale securities net of reclassifications for realized gains and losses as presented in Cadence’s condensed consolidated statements of comprehensive income.
	Accumulated other comprehensive income was comprised of the following as of March 29, 2014, and December 28, 2013:
		As of
		March 29,			December 28,
		2014			2013
		(In thousands)
	Foreign currency translation gain	$	31,635		$	27,183
	Changes in defined benefit plan liabilities	(2,810		)	(3,218		)
	Unrealized holding gains on available-for-sale securities	165			346
	Total accumulated other comprehensive income	$	28,990		$	24,311
	For the three months ended March 29, 2014 and March 30, 2013 there were no significant amounts reclassified from accumulated other comprehensive income to net income.

Contingencies

Contingencies	3 Months Ended
	Mar. 29, 2014
Commitments and Contingencies Disclosure [Abstract]	'
CONTINGENCIES	'
	CONTINGENCIES
	Legal Proceedings
	From time to time, Cadence is involved in various disputes and litigation that arise in the ordinary course of business. These include disputes and lawsuits related to intellectual property, indemnification obligations, mergers and acquisitions, licensing, contracts, distribution arrangements and employee relations matters. At least quarterly, Cadence reviews the status of each significant matter and assesses its potential financial exposure. If the potential loss from any claim or legal proceeding is considered probable and the amount or the range of loss can be estimated, Cadence accrues a liability for the estimated loss. Legal proceedings are subject to uncertainties, and the outcomes are difficult to predict. Because of such uncertainties, accruals are based on Cadence’s judgments using the best information available at the time. As additional information becomes available, Cadence reassesses the potential liability related to pending claims and litigation matters and may revise estimates.
	Other Contingencies
	Cadence provides its customers with a warranty on sales of emulation hardware products, generally for a 90-day period. Cadence did not incur any significant costs related to warranty obligations during the three months ended March 29, 2014 or March 30, 2013.
	Cadence’s product license and services agreements typically include a limited indemnification provision for claims from third parties relating to Cadence’s intellectual property. If the potential loss from any indemnification claim is considered probable and the amount or the range of loss can be estimated, Cadence accrues a liability for the estimated loss. The indemnification is generally limited to the amount paid by the customer. Cadence did not incur any significant losses from indemnification claims during the three months ended March 29, 2014 or March 30, 2013.

Other_Income_Net

Other Income, Net	3 Months Ended
	Mar. 29, 2014
Other Income and Expenses [Abstract]	'
OTHER INCOME, NET	'
	OTHER INCOME, NET
	Cadence’s other income, net for the three months ended March 29, 2014 and March 30, 2013 was as follows:
		Three Months Ended
		March 29,			March 30,
		2014			2013
		(In thousands)
	Interest income	$	486		$	425
	Gains on non-marketable investments, net	1,546			878
	Gains on securities in NQDC trust	2,063			152
	Gains (losses) on foreign exchange	(802		)	764
	Other income (expense), net	89			(44		)
	Total other income, net	$	3,382		$	2,175

Segment_Reporting

Segment Reporting	3 Months Ended
	Mar. 29, 2014
Segment Reporting [Abstract]	'
SEGMENT REPORTING	'
	SEGMENT REPORTING
	Segment reporting is based on the “management approach,” following the method that management organizes the company’s reportable segments for which separate financial information is made available to, and evaluated regularly by, the chief operating decision maker in allocating resources and in assessing performance. Cadence’s chief operating decision maker is its President and Chief Executive Officer, or CEO, who reviews Cadence’s consolidated results as one reportable segment. In making operating decisions, the CEO primarily considers consolidated financial information, accompanied by disaggregated information about revenues by geographic region.
	Outside the United States, Cadence markets and supports its products and services primarily through its subsidiaries. Revenue is attributed to geography based upon the country in which the product is used or services are delivered. Long-lived assets are attributed to geography based on the country where the assets are located.
	The following table presents a summary of revenue by geography for the three months ended March 29, 2014 and March 30, 2013:
		Three Months Ended
		March 29,		March 30,
		2014		2013
		(In thousands)
	Americas:
	United States	$	163,121	$	149,171
	Other Americas	5,784		4,615
	Total Americas	168,905		153,786
	Europe, Middle East and Africa	77,532		78,920
	Japan	44,890		53,474
	Asia	87,223		68,086
	Total	$	378,550	$	354,266
	The following table presents a summary of long-lived assets by geography as of March 29, 2014 and December 28, 2013:
		As of
		March 29,		December 28,
		2014		2013
		(In thousands)
	Americas:
	United States	$	209,612	$	207,694
	Other Americas	266		294
	Total Americas	209,878		207,988
	Europe, Middle East and Africa	6,441		6,326
	Japan	809		893
	Asia	22,297		23,508
	Total	$	239,425	$	238,715

Subsequent_Event

Subsequent Event	3 Months Ended
	Mar. 29, 2014
Subsequent Event [Abstract]	'
SUBSEQUENT EVENT	'
	SUBSEQUENT EVENT
	On April 18, 2014, Cadence entered into an agreement to acquire Jasper Design Automation, Inc., or Jasper, a provider of formal analysis solutions, for approximately $170.0 million in cash. Jasper had approximately $24.0 million of cash, cash equivalents and short-term investments as of December 31, 2013. The completion of the transaction is subject to certain conditions, including regulatory approval.

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 29, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation	'
	Preparation of the condensed consolidated financial statements in conformity with United States generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.
Fair Value of Financial Instruments	'
	Inputs to valuation techniques are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect Cadence’s market assumptions. These two types of inputs have created the following fair value hierarchy:
	•	Level 1 – Quoted prices for identical instruments in active markets;
	•	Level 2 – Quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets; and
	•	Level 3 – Valuations derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable.
	This hierarchy requires Cadence to minimize the use of unobservable inputs and to use observable market data, if available, when determining fair value. Cadence recognizes transfers between levels of the hierarchy based on the fair values of the respective financial instruments at the end of the reporting period in which the transfer occurred. There were no transfers between levels of the fair value hierarchy during the three months ended March 29, 2014.
Contingencies	'
	At least quarterly, Cadence reviews the status of each significant matter and assesses its potential financial exposure. If the potential loss from any claim or legal proceeding is considered probable and the amount or the range of loss can be estimated, Cadence accrues a liability for the estimated loss. Legal proceedings are subject to uncertainties, and the outcomes are difficult to predict. Because of such uncertainties, accruals are based on Cadence’s judgments using the best information available at the time. As additional information becomes available, Cadence reassesses the potential liability related to pending claims and litigation matters and may revise estimates.
Non-Marketable Investments	'
	Cadence’s non-marketable investments generally consist of voting preferred stock or convertible debt of privately held companies and are included in other assets on Cadence’s condensed consolidated balance sheets. If Cadence determines that it has the ability to exercise significant influence over the issuer, which may include considering whether the investments are in-substance common stock, the investment is accounted for using the equity method.

Debt_Tables

Debt (Tables)	3 Months Ended
	Mar. 29, 2014
Debt Disclosure [Abstract]	'
Summary of debt outstanding	'
	Cadence’s outstanding debt as of March 29, 2014 and December 28, 2013 was as follows:
		29-Mar-14								December 28, 2013
		(In thousands)
		Principal			Unamortized Discount			Carrying Value		Principal		Unamortized Discount			Carrying Value
	2015 Notes	$	350,000		$	(20,942	)	$	329,058	$	350,000	$	(25,174	)	$	324,826
	Revolving credit facility	—			—			—		—		—			—
	Total outstanding debt	$	350,000		$	(20,942	)	$	329,058	$	350,000	$	(25,174	)	$	324,826
Summary of key terms of 2015 notes	'
	A summary of key terms of the 2015 Notes is as follows:
			2015 Notes
			(In thousands, except percentages and per share amounts)
	Outstanding principal maturity value – at March 29, 2014		$350,000
	Contractual interest rate		2.63%
	Contractual maturity date		June 1, 2015
	Initial conversion rate		132.5205 shares of common stock per $1,000 principal amount of notes, which is equivalent to a conversion price of approximately $7.55 per share of Cadence common stock.
	Conversion feature (in addition to principal amount payable in cash)		Cash to the extent Cadence’s stock price exceeds approximately $7.55 per share, calculated based on the applicable conversion rate multiplied by the volume weighted average price of Cadence common stock over a specified period.
	Early conversion conditions (or the Early Conversion Conditions)		• Closing stock price greater than $9.81 for at least 20 of the last 30 trading days in a fiscal quarter (convertible only for subsequent quarter);
			• Specified corporate transactions; or
			• Note trading price falls below a calculated minimum.
	Conversion immediately preceding maturity		From March 1, 2015 until the second trading day immediately preceding the maturity date, holders may convert their 2015 Notes at any time into cash as described above under “Conversion feature.”
	Redemption at Cadence’s option prior to maturity		None.
	Fundamental change put right		Upon certain fundamental corporate changes prior to maturity, the 2015 Note holders could require Cadence to repurchase their notes for cash equal to the principal amount of the notes plus accrued interest.
	Make-whole premium		Upon certain fundamental changes prior to maturity, if Cadence’s stock price were between $6.16 and $40.00 per share at that time, the holders of the notes would be entitled to an increase to the conversion rate. This is referred to as a “make-whole premium.”
	Financial covenants		None.
Effective interest rate and components of interest expense of 2015 notes	'
	The effective interest rate and components of interest expense of the 2015 Notes for the three months ended March 29, 2014 and March 30, 2013 were as follows:
		Three Months Ended
		March 29,			March 30,
		2014			2013
		(In thousands, except percentages)
	Effective interest rate	8.1		%	8.1		%
	Contractual interest expense	$	2,289		$	2,289
	Amortization of debt discount	$	4,232		$	3,910

Goodwill_and_Acquired_Intangib1

Goodwill and Acquired Intangibles (Tables)	3 Months Ended
	Mar. 29, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Changes in the carrying amount of goodwill	'
	The changes in the carrying amount of goodwill during the three months ended March 29, 2014 were as follows:
		Gross Carrying
		Amount
		(In thousands)
	Balance as of December 28, 2013	$	456,905
	Goodwill resulting from acquisitions	20,756
	Effect of foreign currency translation	1,329
	Balance as of March 29, 2014	$	478,990
Schedule of acquired intangibles with finite and indefinite lives (excluding goodwill)	'
	Acquired intangibles as of March 29, 2014 were as follows, excluding intangibles that were fully amortized as of December 28, 2013:
		Gross Carrying		Accumulated			Acquired
		Amount		Amortization			Intangibles, Net
		(In thousands)
	Existing technology	$	248,836	$	(56,632	)	$	192,204
	Agreements and relationships	161,892		(47,679		)	114,213
	Tradenames, trademarks and patents	9,719		(3,210		)	6,509
	Total acquired intangibles with definite lives	420,447		(107,521		)	312,926
	In-process technology	3,572		—			3,572
	Total acquired intangibles	$	424,019	$	(107,521	)	$	316,498
	Acquired intangibles as of December 28, 2013 were as follows, excluding intangibles that were fully amortized as of December 29, 2012:
		Gross Carrying		Accumulated			Acquired
		Amount		Amortization			Intangibles, Net
		(In thousands)
	Existing technology	$	237,624	$	(53,243	)	$	184,381
	Agreements and relationships	170,760		(53,607		)	117,153
	Distribution rights	30,100		(30,100		)	—
	Tradenames, trademarks and patents	9,519		(2,870		)	6,649
	Total acquired intangibles with definite lives	448,003		(139,820		)	308,183
	In-process technology	3,510		—			3,510
	Total acquired intangibles	$	451,513	$	(139,820	)	$	311,693
Amortization of acquired intangibles	'
	Amortization of acquired intangibles for the three months ended March 29, 2014 and March 30, 2013 was as follows:
		Three Months Ended
		March 29,		March 30,
		2014		2013
		(In thousands)
	Cost of product and maintenance	$	7,576	$	3,807
	Amortization of acquired intangibles	5,210		3,791
	Total amortization of acquired intangibles	$	12,786	$	7,598
Estimated amortization expense	'
	Estimated amortization expense for intangible assets with definite lives for the following five fiscal years and thereafter is as follows:
		(In thousands)
	2014 – remaining period	$	38,792
	2015	51,220
	2016	45,360
	2017	41,550
	2018	38,609
	Thereafter	97,395
	Total estimated amortization expense	$	312,926

Receivables_and_Allowances_for1

Receivables and Allowances for Doubtful Accounts (Tables)	3 Months Ended
	Mar. 29, 2014
Receivables [Abstract]	'
Current and long-term accounts receivable balances	'
	Cadence’s current and long-term receivables balances as of March 29, 2014 and December 28, 2013 were as follows:
		As of
		March 29,		December 28,
		2014		2013
		(In thousands)
	Accounts receivable	$	81,330	$	76,057
	Unbilled accounts receivable	24,992		31,567
	Long-term receivables	6,193		3,672
	Total receivables	$	112,515	$	111,296
	Less allowance for doubtful accounts	—		—
	Total receivables, net	$	112,515	$	111,296

Fair_Value_Tables

Fair Value (Tables)	3 Months Ended
	Mar. 29, 2014
Fair Value Disclosures [Abstract]	'
Fair value of financial assets and liabilities	'
	The fair value of financial assets and liabilities was determined using the following levels of inputs as of March 29, 2014 and December 28, 2013:
		Fair Value Measurements as of March 29, 2014:
		Total			Level 1		Level 2		Level 3
		(In thousands)
	Assets
	Cash equivalents:
	Money market funds	$	348,884		$	348,884	$	—	$	—
	Short-term investments:
	Corporate debt securities	36,906			—		36,906		—
	Bank certificates of deposit	26,362			—		26,362		—
	United States Treasury securities	18,944			18,944		—		—
	United States government agency securities	10,366			10,366		—		—
	Commercial paper	2,495			—		2,495		—
	Marketable equity securities	1,933			1,933		—		—
	Trading securities held in Non-Qualified Deferred Compensation, or NQDC, trust	23,786			23,786		—		—
	2015 Notes Hedges	369,731			—		369,731		—
	Total Assets	$	839,407		$	403,913	$	435,494	$	—
		Total			Level 1		Level 2		Level 3
		(In thousands)
	Liabilities
	Acquisition-related contingent consideration	$	1,805		$	—	$	—	$	1,805
	2015 Notes Embedded Conversion Derivative	369,731			—		369,731		—
	Foreign currency exchange contracts	$	367		$	—	$	367	$	—
	Total Liabilities	$	371,903		$	—	$	370,098	$	1,805
		Fair Value Measurements as of December 28, 2013:
		Total			Level 1		Level 2		Level 3
		(In thousands)
	Assets
	Cash equivalents:
	Money market funds	$	345,872		$	345,872	$	—	$	—
	Bank certificates of deposit	2,300			—		2,300		—
	Short-term investments:
	Corporate debt securities	37,441			—		37,441		—
	Bank certificates of deposit	20,308			—		20,308		—
	United States Treasury securities	24,246			24,246		—		—
	United States government agency securities	10,223			10,223		—		—
	Commercial paper	2,493			—		2,493		—
	Marketable equity securities	2,077			2,077		—		—
	Trading securities held in NQDC trust	23,960			23,960		—		—
	2015 Notes Hedges	306,817			—		306,817		—
	Foreign currency exchange contracts	262			—		262		—
	Total Assets	$	775,999		$	406,378	$	369,621	$	—
		Total			Level 1		Level 2		Level 3
		(In thousands)
	Liabilities
	Acquisition-related contingent consideration	$	4,091		$	—	$	—	$	4,091
	2015 Notes Embedded Conversion Derivative	306,817			—		306,817		—
	Total Liabilities	$	310,908		$	—	$	306,817	$	4,091
Liabilities included in level 3 representing fair value of contingent consideration associated with acquisitions	'
	The following table summarizes the level 3 activity for the three months ended March 29, 2014:
		(In thousands)
	Balance as of December 28, 2013	$	4,091
	Payments	(2,329		)
	Adjustments	43
	Balance as of March 29, 2014	$	1,805

Cash_Cash_Equivalents_and_Inve1

Cash, Cash Equivalents and Investments (Tables)	3 Months Ended
	Mar. 29, 2014
Cash, Cash Equivalents and Investments [Abstract]	'
Summary of cash, cash equivalents and short-term investments	'
	Cadence’s cash, cash equivalents and short-term investments at fair value as of March 29, 2014 and December 28, 2013 were as follows:
		As of
		March 29,		December 28,
		2014		2013
		(In thousands)
	Cash and cash equivalents	$	532,761	$	536,260
	Short-term investments	97,006		96,788
	Cash, cash equivalents and short-term investments	$	629,767	$	633,048
Summary of cash and cash equivalents	'
	The following table summarizes Cadence’s cash and cash equivalents at fair value as of March 29, 2014 and December 28, 2013:
		As of
		March 29,		December 28,
		2014		2013
		(In thousands)
	Cash and interest bearing deposits	$	183,877	$	188,088
	Money market funds	348,884		345,872
	Bank certificates of deposit	—		2,300
	Total cash and cash equivalents	$	532,761	$	536,260
Summary of short-term investments	'
	The following tables summarize Cadence’s short-term investments as of March 29, 2014 and December 28, 2013:
		As of March 29, 2014
		Amortized		Gross		Gross			Fair
		Cost		Unrealized		Unrealized			Value
				Gains		Losses
		(In thousands)
	Corporate debt securities	$	36,903	$	20	$	(17	)	$	36,906
	Bank certificates of deposit	26,350		12		—			26,362
	United States Treasury securities	18,921		24		(1		)	18,944
	United States government agency securities	10,356		11		(1		)	10,366
	Commercial paper	2,493		2		—			2,495
	Marketable debt securities	95,023		69		(19		)	95,073
	Marketable equity securities	1,817		116		—			1,933
	Total short-term investments	$	96,840	$	185	$	(19	)	$	97,006
		As of December 28, 2013
		Amortized		Gross		Gross			Fair
		Cost		Unrealized		Unrealized			Value
				Gains		Losses
		(In thousands)
	Corporate debt securities	$	37,422	$	30	$	(11	)	$	37,441
	Bank certificates of deposit	20,300		9		(1		)	20,308
	United States Treasury securities	24,219		28		(1		)	24,246
	United States government agency securities	10,212		11		—			10,223
	Commercial paper	2,492		1		—			2,493
	Marketable debt securities	94,645		79		(13		)	94,711
	Marketable equity securities	1,817		260		—			2,077
	Total short-term investments	$	96,462	$	339	$	(13	)	$	96,788
Contractual maturity of marketable debt investments	'
	The amortized cost and estimated fair value of marketable debt securities included in short-term investments as of March 29, 2014, by contractual maturity, are shown in the table below. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations without penalties.
		Amortized		Fair
		Cost		Value
		(In thousands)
	Due in less than one year	$	42,803	$	42,823
	Due in one to three years	52,220		52,250
	Total marketable debt securities included in short-term investments	$	95,023	$	95,073
Carrying value of non-marketable securities	'
	Cadence’s non-marketable investments as of March 29, 2014 and December 28, 2013 were as follows:
		As of
		March 29,		December 28,
		2014		2013
		(In thousands)
	Cost method	$	3,038	$	3,038
	Equity method	5,163		3,639
	Total non-marketable investments	$	8,201	$	6,677

Restructuring_and_Other_Charge1

Restructuring and Other Charges Restructuring and Other Charges (Tables)	3 Months Ended
	Mar. 29, 2014
Restructuring and Related Activities [Abstract]	'
Amount accrued for restructuring plans	'
	The remaining accrual for Cadence’s restructuring plans is recorded in the condensed consolidated balance sheet as follows:
		As of
		March 29, 2014
		(In thousands)
	Accounts payable and accrued liabilities	$	4,433
	Other long-term liabilities	2,765
	Total accrued as of March 29, 2014	$	7,198
Restructuring plan activities	'
	The following table presents activity relating to Cadence’s restructuring plans during the three months ended March 29, 2014:
		Severance			Excess			Total
		and			Facilities
		Benefits
		(In thousands)
	Balance, December 28, 2013	$	10,672		$	3,552		$	14,224
	Restructuring and other charges, net	295			101			396
	Cash payments	(7,159		)	(286		)	(7,445		)
	Effect of foreign currency translation	11			12			23
	Balance, March 29, 2014	$	3,819		$	3,379		$	7,198

Net_Income_Per_Share_Tables

Net Income Per Share (Tables)	3 Months Ended
	Mar. 29, 2014
Earnings Per Share [Abstract]	'
Basic and diluted net income per share	'
	The calculations for basic and diluted net income per share for the three months ended March 29, 2014 and March 30, 2013 are as follows:
		Three Months Ended
		March 29,			March 30,
		2014			2013
		(In thousands, except per share amounts)
	Net income	$	33,070		$	78,609
	Weighted average common shares used to calculate basic net income per share	281,615			274,936
	Convertible notes	—			11
	2015 Warrants	12,576			10,668
	Stock-based awards	6,843			6,536
	Weighted average common shares used to calculate diluted net income per share	301,034			292,151
	Net income per share - basic	$	0.12		$	0.29
	Net income per share - diluted	$	0.11		$	0.27
Potential shares of Cadence's common stock excluded	'
	The following table presents shares of Cadence’s common stock outstanding for the three months ended March 29, 2014 and March 30, 2013 that were excluded from the computation of diluted net income per share because the effect of including these shares in the computation of diluted net income per share would have been anti-dilutive:
		Three Months Ended
		March 29,		March 30,
		2014		2013
		(In thousands)
	2013 Warrants	1,518		6,830
	Options to purchase shares of common stock	4,634		6,754
	Non-vested shares of restricted stock	11		—
	Total potential common shares excluded	6,163		13,584

Other_Comprehensive_Income_Tab

Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 29, 2014
Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
Accumulated other comprehensive income net of tax	'
	Accumulated other comprehensive income was comprised of the following as of March 29, 2014, and December 28, 2013:
		As of
		March 29,			December 28,
		2014			2013
		(In thousands)
	Foreign currency translation gain	$	31,635		$	27,183
	Changes in defined benefit plan liabilities	(2,810		)	(3,218		)
	Unrealized holding gains on available-for-sale securities	165			346
	Total accumulated other comprehensive income	$	28,990		$	24,311
	For the three months ended March 29, 2014 and March 30, 2013 there were no significant amounts reclassified from accumulated other comprehensive income to net income.

Other_Income_Net_Tables

Other Income, Net (Tables)	3 Months Ended
	Mar. 29, 2014
Other Income and Expenses [Abstract]	'
Other Income, Net	'
	Cadence’s other income, net for the three months ended March 29, 2014 and March 30, 2013 was as follows:
		Three Months Ended
		March 29,			March 30,
		2014			2013
		(In thousands)
	Interest income	$	486		$	425
	Gains on non-marketable investments, net	1,546			878
	Gains on securities in NQDC trust	2,063			152
	Gains (losses) on foreign exchange	(802		)	764
	Other income (expense), net	89			(44		)
	Total other income, net	$	3,382		$	2,175

Segment_Reporting_Tables

Segment Reporting (Tables)	3 Months Ended
	Mar. 29, 2014
Segment Reporting [Abstract]	'
Summary of revenue by geography	'
	The following table presents a summary of revenue by geography for the three months ended March 29, 2014 and March 30, 2013:
		Three Months Ended
		March 29,		March 30,
		2014		2013
		(In thousands)
	Americas:
	United States	$	163,121	$	149,171
	Other Americas	5,784		4,615
	Total Americas	168,905		153,786
	Europe, Middle East and Africa	77,532		78,920
	Japan	44,890		53,474
	Asia	87,223		68,086
	Total	$	378,550	$	354,266
Summary of long-lived assets by geography	'
	The following table presents a summary of long-lived assets by geography as of March 29, 2014 and December 28, 2013:
		As of
		March 29,		December 28,
		2014		2013
		(In thousands)
	Americas:
	United States	$	209,612	$	207,694
	Other Americas	266		294
	Total Americas	209,878		207,988
	Europe, Middle East and Africa	6,441		6,326
	Japan	809		893
	Asia	22,297		23,508
	Total	$	239,425	$	238,715

Debt_Details

Debt (Details) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Principal	$350,000	$350,000
Unamortized debt discount	-20,942	-25,174
Carrying value	329,058	324,826
Convertible Senior Notes Due 2015 [Member]	'	'
Debt Instrument [Line Items]	'	'
Principal	350,000	350,000
Unamortized debt discount	-20,942	-25,174
Carrying value	329,058	324,826
Revolving Credit Facility [Member]	'	'
Debt Instrument [Line Items]	'	'
Principal	0	0
Unamortized debt discount	0	0
Carrying value	$0	$0

Debt_Details_1

Debt (Details 1) (Convertible Senior Notes Due 2015 [Member], USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Convertible Senior Notes Due 2015 [Member]	'	'
Effective interest rate and components of interest expense of 2015 notes	'	'
Effective interest rate	8.10%	8.10%
Contractual interest expense	$2,289	$2,289
Amortization of debt discount	$4,232	$3,910

Debt_Details_Textual

Debt (Details Textual) (USD $)	1 Months Ended	3 Months Ended
	Jun. 30, 2010	Mar. 29, 2014	Mar. 30, 2013	Dec. 28, 2013
Convertible Notes (Textual) [Abstract]	'	'	'	'
Net current liability of convertible senior notes	'	$329,058,000	'	$324,826,000
Convertible Senior Notes Due 2015 [Member]	'	'	'	'
Convertible Notes (Textual) [Abstract]	'	'	'	'
Principal amount, issued	350,000,000	'	'	'
Principal amount outstanding	'	350,000,000	'	350,000,000
Stated interest rate of convertible senior notes	'	2.63%	'	'
Net current liability of convertible senior notes	'	329,100,000	'	'
Maturity date of convertible senior notes	'	1-Jun-15	'	'
Warrants to purchase shares of common stock price per share (in usd per share)	'	$10.78	'	'
Conversion rate of notes	'	'132.5205 shares of common stock per $1,000 principal amount of notes, which is equivalent to a conversion price of approximately $7.55 per share of Cadence common stock.	'	'
Minimum closing price of common stock for specified days for conversion of notes (in usd per share)	'	$9.81	'	'
Minimum number of trading days limit for which closing price exceeds fixed price for conversion of notes	'	'20 days	'	'
Number of final trading days range within which closing price exceeds the fixed price for conversion of notes	'	'30 days	'	'
Total expense if convertible notes are converted	'	23,800,000	'	'
Unamortized debt discount expensed if convertible notes are converted	'	20,900,000	'	'
Unamortized transaction fees expensed if convertible notes are converted	'	2,900,000	'	'
Event 1	'	'Closing stock price greater than $9.81 for at least 20 of the last 30 trading days in a fiscal quarter (convertible only for subsequent quarter).	'	'
Event 2	'	'Specified corporate transactions	'	'
Event 3	'	'Note trading price falls below a calculated minimum	'	'
Conversion rate of convertible senior notes subject to certain conversion rate adjustments (in usd per share)	'	$7.55	'	'
Condition 1	'	'Upon certain fundamental corporate changes prior to maturity, the 2015 Note holders could require Cadence to repurchase their notes for cash equal to the principal amount of the notes plus accrued interest. Upon certain fundamental changes prior to maturity, if Cadence’s stock price were between $6.16 and $40.00 per share at that time, the 2015 notes holder would be entitled to an increase to the conversion rate. This is referred to as a “make-whole premium.”	'	'
Minimum closing price of common stock to make whole premium in the form of increase to conversion rate (in usd per share)	'	$6.16	'	'
Maximum closing price of common stock to make whole premium in form of increase to conversion rate (in usd per share)	'	$40	'	'
Conversion rate for convertible senior notes per thousand principal amount of notes	'	132.5205	'	'
Debt instrument principal amount conversion rate for specified shares of common stock	'	1,000	'	'
If converted value of convertible senior notes	'	714,300,000	'	'
Total estimated fair value	'	719,700,000	'	654,100,000
Fair value of 2015 notes embedded conversion derivative at the time of issuance	76,600,000	'	'	'
Estimated fair value of 2015 Notes embedded conversion derivative at the balance sheet date	'	369,700,000	'	306,800,000
Cost of 2015 Notes Hedges	76,600,000	'	'	'
Estimated fair value of 2015 Notes hedges at the balance sheet date	'	369,700,000	'	306,800,000
Impact on Income statement related to fair value adjustments of 2015 Notes Embedded Conversion Derivative and 2015 Notes Hedges	'	0	0	'
Shares of common stock that can be purchased under warrants (in shares)	'	46,400,000	'	'
Amount received in cash proceeds from the sale of warrants	37,500,000	'	'	'
Notes Warrants expiration date description	'	'various dates from September 2015 through December 2015	'	'
Revolving Credit Facility [Member]	'	'	'	'
Convertible Notes (Textual) [Abstract]	'	'	'	'
Revolving credit facility	'	$0	'	$0

Debt_Credit_Facility_Details_T

Debt Credit Facility (Details Textual) (Revolving Credit Facility [Member], USD $)	3 Months Ended
	Mar. 29, 2014	Dec. 28, 2013
Line of Credit Facility [Line Items]	'	'
Credit facility, date of agreement	12-Dec-12	'
Credit facility, interest rate description	'Interest accrues based on Cadence’s consolidated leverage ratio. Borrowings may be made at LIBOR plus a margin between 1.25% and 2.0% per annum or at the base rate plus a margin between 0.25% and 1.0% per annum, where in each case the margin is determined by reference to a specified leverage ratio. Interest is payable quarterly.	'
Credit facility, term	'5 years	'
Credit facility, current borrowing capacity	$250,000,000	'
Credit facility additional borrowing capacity available	150,000,000	'
Credit facility, maximum borrowing capacity	400,000,000	'
Credit facility, maturity date	12-Dec-17	'
Credit facility, collateral description	'The facility is secured by certain accounts receivable and certain equity interests in Cadence’s subsidiaries.	'
Credit facility, covenant description	'The credit facility contains customary negative covenants that, among other things, restrict Cadence’s ability to incur additional indebtedness, grant liens and make certain investments, make acquisitions, dispose of certain assets and make certain restricted payments, including dividends. In addition, the credit facility contains financial covenants that require Cadence to maintain a leverage ratio not to exceed 3 to 1, and a minimum interest coverage ratio of 3 to 1.	'
Revolving credit facility	$0	$0
Credit facility, covenant compliance	'Cadence was in compliance with all financial covenants as of September 28, 2013 and December 29, 2012.	'
Maximum [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Credit facility, commitment fee percentage	0.35%	'
Minimum [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Credit facility, commitment fee percentage	0.20%	'
Credit Facility Interest LIBOR and spread [Member] | Maximum [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Credit facility, interest rate spread	2.00%	'
Credit Facility Interest LIBOR and spread [Member] | Minimum [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Credit facility, interest rate spread	1.25%	'
Credit facility interest base rate and spread [Member] | Maximum [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Credit facility, interest rate spread	1.00%	'
Credit facility interest base rate and spread [Member] | Minimum [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Credit facility, interest rate spread	0.25%	'

Acquisitions_and_AcquisitionRe1

Acquisitions and Acquisition-Related Contingent Consideration (Details Textual) (USD $)	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013
Business Acquisition [Line Items]	'	'
Acquisition related costs	$1,000,000	$3,400,000
2014 Acquisitions [Member]	'	'
Business Acquisition [Line Items]	'	'
Number of businesses acquired	2	'
Total cash consideration paid, net of cash acquired	27,500,000	'
Cash acquired	2,100,000	'
Goodwill acquired during period	20,800,000	'
Finite-lived intangibles acquired during period	16,900,000	'
Recognized identifiable assets acquired and liabilities assumed, net	-8,100,000	'
Goodwill, expected tax deductible amount	$545,000	'
Acquired definite-lived intangible assets, weighted average useful life	'9 years	'

Acquisitions_and_AcquisitionRe2

Acquisitions and Acquisition-Related Contingent Consideration (Details Textual 1) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 29, 2014
Business Acquisition, Contingent Consideration [Line Items]	'
Maximum amount obligated to pay by Cadence	$11.80
Period over which consideration may be paid	'25 months
Portion of amount of contingent consideration potential expense in future periods	$9.20

Goodwill_and_Acquired_Intangib2

Goodwill and Acquired Intangibles (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014
Changes in the carrying amount of goodwill	'
Balance as of December 28, 2013	$456,905
Effect of foreign currency translation	1,329
Balance as of March 29, 2014	478,990
Business Acquisition [Member]	'
Changes in the carrying amount of goodwill	'
Goodwill resulting from acquisitions	$20,756

Goodwill_and_Acquired_Intangib3

Goodwill and Acquired Intangibles (Details 1) (USD $)	3 Months Ended
	Mar. 29, 2014	Dec. 28, 2013
Finite-Lived Intangible Assets [Line Items]	'	'
In-process Technology Transferred to Existing Technology	$0	'
Acquired intangibles with finite lives, excluding intangibles fully amortized at end of prior fiscal year	'	'
Gross carrying amount	420,447,000	448,003,000
Accumulated amortization	-107,521,000	-139,820,000
Acquired intangibles, net	312,926,000	308,183,000
In-process technology	3,572,000	3,510,000
Intangible assets, gross (excluding goodwill)	424,019,000	451,513,000
Intangible assets, net (excluding goodwill)	316,498,000	311,693,000
Existing Technology [Member]	'	'
Acquired intangibles with finite lives, excluding intangibles fully amortized at end of prior fiscal year	'	'
Gross carrying amount	248,836,000	237,624,000
Accumulated amortization	-56,632,000	-53,243,000
Acquired intangibles, net	192,204,000	184,381,000
Agreements and relationships [Member]	'	'
Acquired intangibles with finite lives, excluding intangibles fully amortized at end of prior fiscal year	'	'
Gross carrying amount	161,892,000	170,760,000
Accumulated amortization	-47,679,000	-53,607,000
Acquired intangibles, net	114,213,000	117,153,000
Distribution rights [Member]	'	'
Acquired intangibles with finite lives, excluding intangibles fully amortized at end of prior fiscal year	'	'
Gross carrying amount	'	30,100,000
Accumulated amortization	'	-30,100,000
Acquired intangibles, net	'	0
Tradenames Trademarks And Patents [Member]	'	'
Acquired intangibles with finite lives, excluding intangibles fully amortized at end of prior fiscal year	'	'
Gross carrying amount	9,719,000	9,519,000
Accumulated amortization	-3,210,000	-2,870,000
Acquired intangibles, net	$6,509,000	$6,649,000
Minimum [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Expected Completion for In-process Technology	'6 months	'
Maximum [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Expected Completion for In-process Technology	'12 months	'

Goodwill_and_Acquired_Intangib4

Goodwill and Acquired Intangibles (Details 2) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Amortization of acquired intangibles	'	'
Cost of product and maintenance	$7,576	$3,807
Amortization of Intangible Assets	5,210	3,791
Total amortization of acquired intangibles	$12,786	$7,598

Goodwill_and_Acquired_Intangib5

Goodwill and Acquired Intangibles (Details 3) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Estimated amortization expense	'	'
2014 – remaining period	$38,792	'
2015	51,220	'
2016	45,360	'
2017	41,550	'
2018	38,609	'
Thereafter	97,395	'
Acquired intangibles, net	$312,926	$308,183

Income_Taxes_Income_Taxes_Deta

Income Taxes Income Taxes (Details Textual) (USD $)	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013
Income Tax Disclosure [Abstract]	'	'
Income tax expense (benefit)	$5,356,000	($27,560,000)
Estimated increase in annual effective tax rate due to expiration of research tax credit	3.00%	'
Tax benefit from release of uncertain tax position	'	33,669,000
Federal research tax credit research	'	$5,900,000

Receivables_and_Allowances_for2

Receivables and Allowances for Doubtful Accounts (Details) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Current and long-term receivables balances	'	'
Accounts receivable	$81,330	$76,057
Unbilled accounts receivable	24,992	31,567
Long-term receivables	6,193	3,672
Total receivables	112,515	111,296
Less allowance for doubtful accounts	0	0
Total receivables, net	$112,515	$111,296

Receivables_and_Allowances_for3

Receivables and Allowances for Doubtful Accounts (Details Textual)	Mar. 29, 2014	Dec. 28, 2013
	Customer	Customer
Accounts Receivable and Allowances for Doubtful Accounts (Textual) [Abstract]	'	'
Percentage of receivables, net attributable to single customer	10.00%	10.00%
Number of customers with receivables balance greater than ten percent of total balance	0	'
Percentage of receivables, net attributable to the ten customers with largest balance	45.00%	47.00%
Number of customers with largest balance of receivables	10	10

Fair_Value_Details

Fair Value (Details) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Short-term investments:	'	'
Available-for-sale securities	$97,006	$96,788
Trading securities held in non - qualified deferred compensation plan, or NQDC, trust	23,786	23,960
2015 Notes Hedges	369,731	306,817
Foreign currency exchange contracts	'	262
Total Assets	839,407	775,999
Liabilities	'	'
Acquisition-related contingent consideration	1,805	4,091
2015 Notes Embedded Conversion Derivative	369,731	306,817
Foreign currency exchange contracts	367	'
Total Liabilities	371,903	310,908
Money market funds [Member]	'	'
Assets	'	'
Cash equivalents	348,884	345,872
Corporate debt securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	36,906	37,441
Bank certificates of deposit [Member]	'	'
Assets	'	'
Cash equivalents	'	2,300
Short-term investments:	'	'
Available-for-sale securities	26,362	20,308
United States Treasury securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	18,944	24,246
United States government agency securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	10,366	10,223
Commercial paper [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	2,495	2,493
Marketable equity securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	1,933	2,077
Fair Value Measurements, Level 1 [Member]	'	'
Short-term investments:	'	'
Trading securities held in non - qualified deferred compensation plan, or NQDC, trust	23,786	23,960
2015 Notes Hedges	0	0
Foreign currency exchange contracts	'	0
Total Assets	403,913	406,378
Liabilities	'	'
Acquisition-related contingent consideration	0	0
2015 Notes Embedded Conversion Derivative	0	0
Foreign currency exchange contracts	0	'
Total Liabilities	0	0
Fair Value Measurements, Level 1 [Member] | Money market funds [Member]	'	'
Assets	'	'
Cash equivalents	348,884	345,872
Fair Value Measurements, Level 1 [Member] | Corporate debt securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	0	0
Fair Value Measurements, Level 1 [Member] | Bank certificates of deposit [Member]	'	'
Assets	'	'
Cash equivalents	'	0
Short-term investments:	'	'
Available-for-sale securities	0	0
Fair Value Measurements, Level 1 [Member] | United States Treasury securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	18,944	24,246
Fair Value Measurements, Level 1 [Member] | United States government agency securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	10,366	10,223
Fair Value Measurements, Level 1 [Member] | Commercial paper [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	0	0
Fair Value Measurements, Level 1 [Member] | Marketable equity securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	1,933	2,077
Fair Value Measurements, Level 2 [Member]	'	'
Short-term investments:	'	'
Trading securities held in non - qualified deferred compensation plan, or NQDC, trust	0	0
2015 Notes Hedges	369,731	306,817
Foreign currency exchange contracts	'	262
Total Assets	435,494	369,621
Liabilities	'	'
Acquisition-related contingent consideration	0	0
2015 Notes Embedded Conversion Derivative	369,731	306,817
Foreign currency exchange contracts	367	'
Total Liabilities	370,098	306,817
Fair Value Measurements, Level 2 [Member] | Money market funds [Member]	'	'
Assets	'	'
Cash equivalents	0	0
Fair Value Measurements, Level 2 [Member] | Corporate debt securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	36,906	37,441
Fair Value Measurements, Level 2 [Member] | Bank certificates of deposit [Member]	'	'
Assets	'	'
Cash equivalents	'	2,300
Short-term investments:	'	'
Available-for-sale securities	26,362	20,308
Fair Value Measurements, Level 2 [Member] | United States Treasury securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	0	0
Fair Value Measurements, Level 2 [Member] | United States government agency securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	0	0
Fair Value Measurements, Level 2 [Member] | Commercial paper [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	2,495	2,493
Fair Value Measurements, Level 2 [Member] | Marketable equity securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	0	0
Fair Value Measurements, Level 3 [Member]	'	'
Short-term investments:	'	'
Trading securities held in non - qualified deferred compensation plan, or NQDC, trust	0	0
2015 Notes Hedges	0	0
Foreign currency exchange contracts	'	0
Total Assets	0	0
Liabilities	'	'
Acquisition-related contingent consideration	1,805	4,091
2015 Notes Embedded Conversion Derivative	0	0
Foreign currency exchange contracts	0	'
Total Liabilities	1,805	4,091
Fair Value Measurements, Level 3 [Member] | Money market funds [Member]	'	'
Assets	'	'
Cash equivalents	0	0
Fair Value Measurements, Level 3 [Member] | Corporate debt securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	0	0
Fair Value Measurements, Level 3 [Member] | Bank certificates of deposit [Member]	'	'
Assets	'	'
Cash equivalents	'	0
Short-term investments:	'	'
Available-for-sale securities	0	0
Fair Value Measurements, Level 3 [Member] | United States Treasury securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	0	0
Fair Value Measurements, Level 3 [Member] | United States government agency securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	0	0
Fair Value Measurements, Level 3 [Member] | Commercial paper [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	0	0
Fair Value Measurements, Level 3 [Member] | Marketable equity securities [Member]	'	'
Short-term investments:	'	'
Available-for-sale securities	$0	$0

Fair_Value_Details_1

Fair Value (Details 1) (USD $)	Mar. 29, 2014	Dec. 28, 2013	Mar. 29, 2014
In Thousands, unless otherwise specified			Fair Value Measurements, Level 3 [Member]
Liabilities included in level 3 representing fair value of contingent consideration associated with acquisitions	'	'	'
Begining Balance	$1,805	$4,091	$4,091
Payments	'	'	2,329
Adjustments	'	'	43
Ending Balance	$1,805	$4,091	$1,805

Fair_Value_Details_Textual

Fair Value (Details Textual) (Contingent Consideration Liability [Member], Fair Value, Inputs, Level 3 [Member])	3 Months Ended	12 Months Ended
	Mar. 29, 2014	Dec. 28, 2013
Minimum [Member]	'	'
Fair Value of Financial Instrument (Textual) [Abstract]	'	'
Fair Value Inputs, Discount Rate	11.00%	11.00%
Maximum [Member]	'	'
Fair Value of Financial Instrument (Textual) [Abstract]	'	'
Fair Value Inputs, Discount Rate	16.00%	16.00%

Cash_Cash_Equivalents_and_Inve2

Cash, Cash Equivalents and Investments (Details) (USD $)	Mar. 29, 2014	Dec. 28, 2013	Mar. 30, 2013	Dec. 29, 2012
In Thousands, unless otherwise specified
Cash, Cash Equivalents and Investments [Abstract]	'	'	'	'
Cash and cash equivalents	$532,761	$536,260	$810,152	$726,357
Short-term investments	97,006	96,788	'	'
Cash, cash equivalents, and short-term investments	$629,767	$633,048	'	'

Cash_Cash_Equivalents_and_Inve3

Cash, Cash Equivalents and Investments (Details 1) (USD $)	Mar. 29, 2014	Dec. 28, 2013	Mar. 30, 2013	Dec. 29, 2012
In Thousands, unless otherwise specified
Classified as cash and cash equivalents	'	'	'	'
Cash and interest bearing deposits	$183,877	$188,088	'	'
Money market funds	348,884	345,872	'	'
Bank certificates of deposit	0	2,300	'	'
Total cash and cash equivalents	$532,761	$536,260	$810,152	$726,357

Cash_Cash_Equivalents_and_Inve4

Cash, Cash Equivalents and Investments (Details 2) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014	Dec. 28, 2013
Short-term investments	'	'
Amortized Cost	$96,840	$96,462
Gross Unrealized Gains	185	339
Gross Unrealized Losses	-19	-13
Fair Value	97,006	96,788
Corporate debt securities [Member]	'	'
Short-term investments	'	'
Amortized Cost	36,903	37,422
Gross Unrealized Gains	20	30
Gross Unrealized Losses	-17	-11
Fair Value	36,906	37,441
Bank certificates of deposit [Member]	'	'
Short-term investments	'	'
Amortized Cost	26,350	20,300
Gross Unrealized Gains	12	9
Gross Unrealized Losses	0	-1
Fair Value	26,362	20,308
United States Treasury securities [Member]	'	'
Short-term investments	'	'
Amortized Cost	18,921	24,219
Gross Unrealized Gains	24	28
Gross Unrealized Losses	-1	-1
Fair Value	18,944	24,246
United States government agency securities [Member]	'	'
Short-term investments	'	'
Amortized Cost	10,356	10,212
Gross Unrealized Gains	11	11
Gross Unrealized Losses	-1	0
Fair Value	10,366	10,223
Commercial paper [Member]	'	'
Short-term investments	'	'
Amortized Cost	2,493	2,492
Gross Unrealized Gains	2	1
Gross Unrealized Losses	0	0
Fair Value	2,495	2,493
Marketable debt securities [Member]	'	'
Short-term investments	'	'
Amortized Cost	95,023	94,645
Gross Unrealized Gains	69	79
Gross Unrealized Losses	-19	-13
Fair Value	95,073	94,711
Marketable equity securities [Member]	'	'
Short-term investments	'	'
Amortized Cost	1,817	1,817
Gross Unrealized Gains	116	260
Gross Unrealized Losses	0	0
Fair Value	$1,933	$2,077

Cash_Cash_Equivalents_and_Inve5

Cash, Cash Equivalents and Investments (Details 3) (USD $)	Mar. 29, 2014
In Thousands, unless otherwise specified
Contractual maturity of marketable debt investments	'
Marketable Investments, Debt Maturities, Within One Year, Amortized Cost	$42,803
Marketable Investments, Debt Maturities, Year One Through Three, Amortized Cost	52,220
Marketable investments, Debt Maturities, Amortized Cost, Total	95,023
Marketable Investments, Debt Maturities, Within One Year, Fair Value	42,823
Marketable Investments, Debt Maturities, Year One Through Three, Fair Value	52,250
Marketable Investments, Debt Maturities, Fair Value, Total	$95,073

Cash_Cash_Equivalents_and_Inve6

Cash, Cash Equivalents and Investments (Details 4) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Carrying value of non-marketable investments	'	'
Cost method	$3,038	$3,038
Equity method	5,163	3,639
Total non-marketable investments	$8,201	$6,677

Restructuring_and_Other_Charge2

Restructuring and Other Charges Restructuring and Other Charges (Details) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Restructuring Cost and Reserve [Line Items]	'	'
Restructuring reserve	$7,198	$14,224
Accounts Payable and Accrued Liabilities [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Restructuring reserve	4,433	'
Other Long Term Liabilities [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Restructuring reserve	$2,765	'

Restructuring_and_Other_Charge3

Restructuring and Other Charges Restructuring and Other Charges (Details 1) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Restructuring Cost and Reserve [Line Items]	'	'
Beginning balance	$14,224	'
Restructuring and other charges (credits), net	396	-148
Cash payments	-7,445	'
Effect of foreign currency translation	23	'
Ending balance	7,198	'
Employee Severance and Benefits [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Beginning balance	10,672	'
Restructuring and other charges (credits), net	295	'
Cash payments	-7,159	'
Effect of foreign currency translation	11	'
Ending balance	3,819	'
Excess Facilities [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Beginning balance	3,552	'
Restructuring and other charges (credits), net	101	'
Cash payments	-286	'
Effect of foreign currency translation	12	'
Ending balance	$3,379	'

Net_Income_Per_Share_Details

Net Income Per Share (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Earnings Per Share, Basic and Diluted [Abstract]	'	'
Net income	$33,070	$78,609
Weighted-average common shares used to calculate basic net income per share (in shares)	281,615	274,936
Convertible notes	0	11
2015 Warrants	12,576	10,668
Stock-based awards	6,843	6,536
Weighted average common shares used to calculate diluted net income per share (in shares)	301,034	292,151
Net income per share - basic (in usd per share)	$0.12	$0.29
Net income per share - diluted (in usd per share)	$0.11	$0.27

Net_Income_Per_Share_Details_1

Net Income Per Share (Details 1)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Potential shares of Cadence's common stock excluded	'	'
Total potential common shares excluded	6,163	13,584
2013 Warrants	'	'
Potential shares of Cadence's common stock excluded	'	'
Total potential common shares excluded	1,518	6,830
Options to purchase shares of common stock	'	'
Potential shares of Cadence's common stock excluded	'	'
Total potential common shares excluded	4,634	6,754
Non-vested shares of restricted stock	'	'
Potential shares of Cadence's common stock excluded	'	'
Total potential common shares excluded	11	0

Other_Comprehensive_Income_Det

Other Comprehensive Income (Details 1) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Accumulated other comprehensive income	'	'
Foreign currency translation gain	$31,635	$27,183
Changes in defined benefit plan liabilities	-2,810	-3,218
Unrealized holding gains on available-for-sale securities	165	346
Total accumulated other comprehensive income	$28,990	$24,311

Contingencies_Details_Textual

Contingencies (Details Textual)	3 Months Ended
	Mar. 29, 2014
Contingencies (Textual) [Abstract]	'
General period of warranty on sales of hardware products	'90 days

Other_Income_Net_Details

Other Income, Net (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Other Income, Net	'	'
Interest income	$486	$425
Gains on non-marketable investments, net	1,546	878
Gains on securities in NQDC trust	2,063	152
Gains (losses) on foreign exchange	-802	764
Other income (expense), net	89	-44
Total other income, net	$3,382	$2,175

Segment_Reporting_Details

Segment Reporting (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 29, 2014	Mar. 30, 2013
Entity Wide Disclosure on Geographic Areas Revenue from External Customers	'	'
Total revenue	$378,550	$354,266
Americas:	'	'
Total Americas	168,905	153,786
United States [Member]	'	'
Entity Wide Disclosure on Geographic Areas Revenue from External Customers	'	'
Geographic Areas, revenue from External Customers	163,121	149,171
Other Americas [Member]	'	'
Entity Wide Disclosure on Geographic Areas Revenue from External Customers	'	'
Geographic Areas, revenue from External Customers	5,784	4,615
EMEA [Member]	'	'
Entity Wide Disclosure on Geographic Areas Revenue from External Customers	'	'
Geographic Areas, revenue from External Customers	77,532	78,920
Japan [Member]	'	'
Entity Wide Disclosure on Geographic Areas Revenue from External Customers	'	'
Geographic Areas, revenue from External Customers	44,890	53,474
Asia [Member]	'	'
Entity Wide Disclosure on Geographic Areas Revenue from External Customers	'	'
Geographic Areas, revenue from External Customers	$87,223	$68,086

Segment_Reporting_Details_1

Segment Reporting (Details 1) (USD $)	Mar. 29, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Summary of long-lived assets by geography	'	'
Total long-lived assets	$239,425	$238,715
Americas:	'	'
Total Americas	209,878	207,988
United States [Member]	'	'
Summary of long-lived assets by geography	'	'
Long-Lived Assets in Individual Foreign Countries	209,612	207,694
Other Americas [Member]	'	'
Summary of long-lived assets by geography	'	'
Long-Lived Assets in Individual Foreign Countries	266	294
EMEA [Member]	'	'
Summary of long-lived assets by geography	'	'
Long-Lived Assets in Individual Foreign Countries	6,441	6,326
Japan [Member]	'	'
Summary of long-lived assets by geography	'	'
Long-Lived Assets in Individual Foreign Countries	809	893
Asia [Member]	'	'
Summary of long-lived assets by geography	'	'
Long-Lived Assets in Individual Foreign Countries	$22,297	$23,508

Subsequent_Event_Subsequent_Ev

Subsequent Event Subsequent Event (Details) (2014 Acquisitions [Member], Subsequent Event [Member], USD $)	Apr. 21, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
2014 Acquisitions [Member] | Subsequent Event [Member]	'	'
Subsequent Event [Line Items]	'	'
Gross cash payable acquire business	$170	'
Cash, cash equivalents, and short-term investments held by business to be acquired	'	$24