Thoratec 10-Q 6 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2014	Oct. 24, 2014
Document and Entity Information	'	'
Entity Registrant Name	'THORATEC CORP	'
Entity Central Index Key	'0000350907	'
Document Type	'10-Q	'
Document Period End Date	27-Sep-14	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-28	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	55
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 27, 2014	Dec. 28, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$123,684	$139,099
Short-term available-for-sale investments	124,880	166,691
Receivables, net of allowances of $1,569 in 2014 and $2,163 in 2013	62,468	71,418
Inventories	71,541	60,293
Deferred tax assets	15,257	15,161
Income tax receivable	15,975	5,733
Prepaid expenses and other assets	9,922	7,272
Total current assets	423,727	465,667
Property, plant and equipment, net	54,943	55,163
Goodwill	231,465	205,764
Purchased intangible assets, net	60,434	36,403
Long-term available-for-sale investments	4,358	4,234
Other long-term assets	25,687	24,476
Total Assets	800,614	791,707
Current liabilities:	'	'
Accounts payable	15,948	17,599
Accrued compensation	20,491	22,759
Warranty and related accrual	18,952	9,899
Contingent liabilities, current portion	17,040	6,962
Other accrued liabilities	15,722	17,102
Total current liabilities	88,153	74,321
Long-term deferred tax liability	4,054	2,224
Other long-term liabilities	12,006	12,105
Contingent liabilities, non-current portion (Note 2)	44,079	36,384
Total Liabilities	148,292	125,034
Shareholders' equity:	'	'
Common shares: no par, authorized 100,000; issued and outstanding 55,133 in 2014 and 56,904 in 2013	'	'
Additional paid-in-capital	617,968	621,589
Retained earnings	51,432	57,587
Accumulated other comprehensive loss:	-17,078	-12,503
Total Shareholders' Equity	652,322	666,673
Total Liabilities and Shareholders' Equity	$800,614	$791,707

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 27, 2014	Dec. 28, 2013
In Thousands, except Per Share data, unless otherwise specified
CONDENSED CONSOLIDATED BALANCE SHEETS	'	'
Receivables, allowances (in dollars)	$1,569	$2,163
Common shares, par value (in dollars per share)	$0	$0
Common shares, authorized	100,000	100,000
Common shares, issued	55,133	56,904
Common shares, outstanding	55,133	56,904

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS	'	'	'	'
Product sales	$105,839	$126,444	$349,599	$374,648
Cost of product sales	42,627	40,958	116,960	117,031
Gross profit	63,212	85,486	232,639	257,617
Operating expenses:	'	'	'	'
Selling, general and administrative	35,004	37,679	105,982	107,348
Research and development	26,097	25,469	72,484	71,488
Total operating expenses	61,101	63,148	178,466	178,836
Income from operations	2,111	22,338	54,173	78,781
Other income and (expense):	'	'	'	'
Interest expense and other	-22	'	-24	-4
Interest income and other	-1,105	569	-299	1,899
Income before income taxes	984	22,907	53,850	80,676
Income tax (expense) benefit	1,913	-4,003	-15,301	-20,413
Net income	$2,897	$18,904	$38,549	$60,263
Net Income per share:	'	'	'	'
Basic (in dollars per share)	$0.05	$0.33	$0.68	$1.05
Diluted (in dollars per share)	$0.05	$0.32	$0.67	$1.03
Shares used to compute income per share:	'	'	'	'
Basic (in shares)	55,733	57,427	56,430	57,447
Diluted (in shares)	56,111	58,234	57,119	58,400

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)	'	'	'	'
Net income	$2,897	$18,904	$38,549	$60,263
Unrealized gains (losses) on investments (net of taxes (benefits) of $27 and $1,225 for the three months ended September 27, 2014 and September 28, 2013, respectively, and $(257) and $1,230 for the nine months ended September 27, 2014 and September 28, 2013, respectively)	40	1,858	-1,367	1,851
Foreign currency translation adjustments	-3,886	1,216	-3,208	-460
Total other comprehensive income (loss)	-3,846	3,074	-4,575	1,391
Comprehensive income (loss)	($949)	$21,978	$33,974	$61,654

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)	'	'	'	'
Unrealized gains (losses) on investments, taxes (benefits)	$27	$1,225	($257)	$1,230

CONDENSED_CONSOLIDATED_STATEME3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2014	Sep. 28, 2013
Cash flows from operating activities:	'	'
Net Income	$38,549	$60,263
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization	12,097	13,841
Fixed assets write down	520	1,961
Investment premium amortization, net	3,021	2,557
Reduction in bad debt reserve	-1,321	-199
Non-cash interest income (expense) and other	2,578	-151
Tax benefit related to stock options	905	1,551
Change in fair value of contingent consideration	-965	3,913
Share-based compensation expense	21,586	20,226
Excess tax benefits from share-based compensation	-1,082	-1,750
Loss on disposal of assets	707	70
Change in net deferred tax liability	-1,281	-515
Changes in assets and liabilities:	'	'
Receivables	9,393	3,957
Inventories	-13,455	-20,578
Other current and non-current assets	1,163	1,499
Accounts payable	-688	-92
Income taxes, net	-10,889	-1,650
Other current and non-current liabilities	7,214	1,548
Net cash provided by operating activities	68,052	86,451
Cash flows from investing activities:	'	'
Purchases of available-for-sale investments	-112,771	-132,351
Sales and maturities of available-for-sale investments	150,578	108,019
Acquisition of a business, net of cash acquired	-34,508	-13,000
Purchases of property, plant and equipment	-6,835	-6,916
Non-marketable equity investment	-1,500	'
Net cash used in investing activities	-5,036	-44,248
Cash flows from financing activities:	'	'
Payment of contingent consideration	-6,107	-4,220
Proceeds from stock option exercises	2,889	6,635
Proceeds from stock issued under employee stock purchase plan	2,800	2,536
Excess tax benefits from share-based compensation	1,082	1,750
Repurchase and retirement of common shares	-79,229	-47,089
Net cash used in financing activities	-78,565	-40,388
Effect of exchange rate changes on cash and cash equivalents	134	-294
Net increase (decrease) in cash and cash equivalents	-15,415	1,521
Net cash and cash equivalents at beginning of period	139,099	101,322
Net cash and cash equivalents at end of period	123,684	102,843
Supplemental disclosure of consolidated cash flow information:	'	'
Cash paid for taxes	26,804	21,237
Supplemental disclosure of consolidated non-cash investing and financing activities:	'	'
Transfers of equipment from inventory	1,496	1,754
Purchases of property, plant and equipment through accounts payable and accrued liabilities	180	670
Acquisitions of Apica (2014) and DuraHeart II (2013):	'	'
Contingent consideration included in contingent liabilities, non-current portion	25,700	18,800
Acquisition of business payment included in other accrued liabilities	$606	'

Operations_and_Significant_Acc

Operations and Significant Accounting Policies	9 Months Ended
	Sep. 27, 2014
Operations and Significant Accounting Policies	'
Operations and Significant Accounting Policies	'
	Note 1. Operations and Significant Accounting Policies
	Basis of Presentation
	The interim unaudited condensed consolidated financial statements of Thoratec Corporation (“we,” “our,” “us,” or the “Company”) have been prepared and presented in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and the rules and regulations of the Securities and Exchange Commission (“SEC”), without audit, and reflect all adjustments necessary (consisting only of normal recurring adjustments) to present fairly our financial position, results of operations and cash flows as of and for the periods presented. Certain information and footnote disclosures normally included in our annual financial statements, prepared in accordance with GAAP, have been condensed or omitted. The accompanying financial statements should be read in conjunction with our fiscal 2013 consolidated financial statements, and the accompanying notes thereto, filed with the SEC in our Annual Report on Form 10-K for the fiscal year ended December 28, 2013 (the “2013 Annual Report”). The operating results for any interim period are not necessarily indicative of the results that may be expected for any future period.
	The preparation of our unaudited condensed consolidated financial statements necessarily requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities on the unaudited condensed consolidated balance sheet dates and the reported amounts of revenues and expenses for the periods presented. The actual amounts could differ from those estimated amounts.
	Recent Accounting Pronouncements
	In August 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-15, Presentation of Financial Statements-Going Concern (Subtopic 205-40). This ASU provides guidance to determine when and how to disclose going-concern uncertainties in the financial statements. The new standard requires management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date that the financial statements are issued. An entity must provide certain disclosures if conditions or events raise substantial doubt about the entity’s ability to continue as a going concern. The standard will be effective for the Company starting in fiscal 2017. We do not expect the adoption of this ASU to have an impact on our condensed consolidated financial statements.
	In June 2014, the FASB issued ASU No. 2014-10, Elimination of Certain Financial Reporting Requirements, Including an Amendment to Variable Interest Entities Guidance in Topic 810, Consolidation, which eliminates the conditions that a development stage entity may be considered a variable interest entity (“VIE”) and requires that an equity investment to be evaluated both a qualitatively and quantitatively in accordance with Accounting Standard Codification 810-25-45 through 47 to determine whether the equity investment qualifies as a VIE. This standard is effective for annual periods beginning on or after December 15, 2014. We have not yet evaluated the impact of the adoption of this ASU on our condensed consolidated financial statements.
	In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), which provides guidance for revenue recognition. This ASU affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of non-financial assets. The guidance in this ASU supersedes the revenue recognition requirements in Topic 605, Revenue Recognition, and most industry-specific guidance. This ASU also supersedes some cost guidance included in Subtopic 605-35, Revenue Recognition-Construction-Type and Production-Type Contracts. The standard will be effective for the Company starting in fiscal 2017. We have not yet evaluated the impact of the adoption of this ASU on our condensed consolidated financial statements.
	In April 2014, the FASB issued ASU No. 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity, which raises the threshold for a disposal to qualify as a discontinued operation and requires new disclosures of both discontinued operations and certain other disposals that do not meet the definition of a discontinued operation. This standard is effective for annual periods beginning on or after December 15, 2014. Early adoption is permitted but only for disposals that have not been reported in financial statements previously issued. We are currently evaluating the impact of this ASU, however we do not expect it would have any significant impact on our condensed consolidated financial statements.

Acquisitions_and_AcquisitionRe

Acquisitions and Acquisition-Related Items	9 Months Ended
	Sep. 27, 2014
Acquisitions and Acquisition-Related Items	'
Acquisitions and Acquisition-Related Items	'
	Note 2. Acquisitions and Acquisition-Related Items
	Acquisitions in the nine months ended September 27, 2014 and September 27, 2013 were accounted for as business combinations. In accordance with authoritative guidance on business combination accounting, the assets and liabilities of the acquired companies were recorded as of the acquisition date, at their respective fair values, and are consolidated within our condensed consolidated financial statements. The results of operations related to each company acquired have been included in our consolidated statements of earnings since the date each company was acquired. All acquisition-related costs are expensed and recorded in selling, general and administrative expenses in our condensed consolidated statement of operations for the periods presented.
	Apica Acquisition in 2014
	On July 2, 2014, we acquired all of the outstanding equity interests of Apica Cardiovascular Limited (“Apica”) and certain related subsidiaries from the former stockholders of Apica (the “Apica Acquisition”). Under the terms of the Apica Acquisition, the initial purchase consideration was approximately $35.1 million (net of acquired cash and inclusive of the settlement of existing debt and
	Apica’s direct acquisition-related transaction costs) and we will be obligated to make potential future milestone payments (“contingent consideration”), based on regulatory approvals and commercial sales, of up to $40.0 million. Total purchase price allocation was estimated at $60.8 million, including the initial purchase consideration of approximately $35.1 million and the estimated fair values for contingent consideration totaling $25.7 million, which was recorded as a non-current liability because such contingent consideration is expected to be settled no earlier than 2016. Prior to the acquisition, Apica was developing a surgical implantation system (“SIS”) to improve the apical access and attachment of a Left Ventricular Assist Device to the apex of the heart. Thoratec plans to couple the SIS with our HeartMate product line with the intention to obtain regional regulatory approvals for commercialization. In addition, Apica had developed the apical access, stabilization, and closure (“ASC”) device, which is commercially sold in Europe and is used for transapical valve procedures. We incurred $2.1 million of acquisition-related costs in connection with the Apica Acquisition in the nine months ended September 27, 2014.
	The preliminary purchase price allocation as of the acquisition date is summarized as follows (in thousands):
	Current assets (excluding cash)	$	548
	Identifiable intangible assets:
	Developed technology (ASC)	5,300
	IPR&D asset (SIS)	26,500
	Goodwill	31,381
	Total assets	63,729
	Less: Liabilities assumed	(291		)
	Deferred tax liability	(2,624		)
	Total estimated purchase price consideration	60,814
	Less: Contingent consideration	(25,700		)
	Cash paid or payable at the acquisition closing	$	35,114
	We recorded an IPR&D asset of $26.5 million, which represents an estimate of the fair value of the in-process technology related to the SIS device. The fair value of the IPR&D asset was determined using the multi-period excess earnings method which is equal to the present value of the incremental after-tax cash flows attributable to that intangible asset, using a discount rate based on our best estimate of a market participant’s after-tax weighted average cost of capital. We also recorded a developed technology intangible asset of $5.3 million, which represents the estimated fair value of the technology associated with the ASC device. The fair value of the developed technology intangible asset was determined using the replacement cost method, which represents what a market participant’s estimated cost would be to obtain or develop the technology in its current state. The replacement cost method was utilized because of limited market opportunities associated with the ASC technology. The developed technology intangible asset related to the ASC device will be amortized over an estimated life of five years.
	The goodwill of $31.4 million equals to the amount by which the purchase consideration exceeded the fair value of the purchased assets and was allocated to our sole operating segment (Cardiovascular) and is not deductible for income tax purposes. Net deferred tax liabilities of $2.6 million were recorded for certain book to tax differences. The operating results of Apica from the date of acquisition, including $0.1 million in revenue from the ASC device and $0.8 million net loss, are included in our condensed consolidated statement of operations for the three- and nine-month period ended September 27, 2014.
	The following unaudited pro forma information presents the combined results of operations for the nine months ended September 27, 2014 and September 28, 2013 as if the Apica Acquisition had been completed as of the beginning of 2013. Actual 2014 acquisition-related transaction costs of $2.1 million were excluded from the 2014 pro forma results below and included in the 2013 pro forma results as if these costs were incurred during the 2013 period. All other adjustments to the pro forma results in 2014 and 2013 were not significant. The pro forma results do not reflect operating efficiencies or potential cost savings which may result from the consolidation of operations. The pro forma financial information is provided for comparative purposes only and does not purport to be indicative of condensed consolidated results of operations for the period ended on September 27, 2014, or for any other future period.
		Nine Months Ended			Nine Months Ended
		September 27, 2014			September 28, 2013
		(in thousands)
	Product sales	$	349,689		$	374,648
	Income before taxes	52,897			76,094
	Net income	37,867			56,841
	DuraHeart II Acquisition in 2013
	On June 30, 2013, we acquired certain assets (the “Purchased Assets”) and assumed certain liabilities from Terumo Corporation (“Terumo”) related to the DuraHeart II Left Ventricular Assist System product line (“DuraHeart II”) previously under development by Terumo (the “DuraHeart II Acquisition”). Under the terms of the DuraHeart II Acquisition, the initial purchase consideration was  $13.0 million and we will be obligated to make potential future milestone payments, based on regulatory approvals and product sales, of up to $43.5 million. Total purchase price allocation was estimated at $31.8 million, including the initial purchase consideration of $13.0 million and the estimated fair values for contingent consideration totaling $18.8 million, which was recorded as a non-current liability because such contingent consideration is expected to be settled no earlier than 2016. As part of the agreement, Terumo also maintains the right to repurchase the Purchased Assets in the event that we do not fulfill certain conditions by specified dates. Additionally, we entered into a distribution partnership with Terumo, in which Terumo will commercialize DuraHeart II in Japan and potentially other parts of Asia, if and when local regulatory approvals are obtained. We incurred $2.0 million of acquisition-related costs in connection with the DuraHeart II Acquisition in the nine months ended September 28, 2013. The goodwill of $9.9 million equals to the amount by which the purchase consideration exceeded the fair value of the purchased assets and was allocated to our sole operating segment and is deductible for U.S. income tax purposes.
	The purchase price allocation as of the acquisition date is summarized as follows (in thousands):
	Property, plant and equipment	$	8,900
	Identifiable intangible assets:
	Favorable lease contract	600
	IPR&D asset	12,400
	Goodwill	9,900
	Total estimated purchase price consideration	31,800
	Less: Contingent consideration	-18,800
	Cash paid at the acquisition closing	$	13,000
	The following pro forma information presents the combined results of operations for the nine months ended September 28, 2013 as if we had completed the DuraHeart II acquisition at the beginning of 2012. Actual 2013 acquisition-related transaction costs of $2.0 million were excluded from the 2013 pro forma results below as if these costs were incurred during the 2012 period. All other adjustments to the pro forma results in 2013 were not significant. The pro forma financial information is provided for comparative purposes only and does not purport to be indicative of condensed consolidated results of operations for the period ended on September 28, 2013, or for any other future period.
		Nine months
		Ended
		September 28,
		2013
	Product sales	$	374,648
	Income before taxes	65,922
	Net income	49,242
	Contingent Considerations
	The Company’s acquisitions of Apica and DuraHeart II include payments of future contingent consideration upon the achievement of certain regulatory approvals and commercial sales milestones. With respect to each acquisition, we determined the initial fair value of the contingent consideration in connection with the regulatory and commercial sales milestones using various estimates, including probabilities of success, discount rates and the estimated amount of time until the conditions of the milestone payments are met. This fair value measurement was based on significant inputs not observable in the market, representing a Level 3 measurement within the fair value hierarchy (see Note 3 for more information about fair value measurements). The key assumptions used to determine the fair value of each contingent consideration associated with the regulatory milestones at the acquisition date included a discount rate and probability-adjusted milestone payment date ranges. The key assumptions used to determine the fair value of each contingent consideration associated with the commercial sales milestones at the acquisition date included a discount rate and probability-weighted expected milestone payment date ranges based on the aggregate number of commercial units sold.
	The fair value of these payments of future contingent considerations are remeasured at each reporting period with the change in fair value recognized within operating expense in our condensed consolidated statements of operations. We measure the liabilities on a recurring basis using Level 3 inputs. See Note 3 for further information regarding fair value measurements.
	·         In the first nine months of 2014, the fair value of the Apica contingent consideration increased by $0.3 million, in which $0.2 million was reported as research and development (“R&D”) expense and $0.1 million was reported as selling, general and administrative (“SG&A”) expense. The overall increase was a result of accretion expense associated with the passage of time since the acquisition date.
	·         In the first nine months of 2014, the fair value of the DuraHeart II contingent consideration decreased by $3.0 million ($2.0 million reported as R&D expense and $1.0 million reported as SG&A expense) as a result of changes in the probabilities of possible outcomes, offset by accretion expense. In the first nine months of 2013, the fair value increased by $0.3 million ($0.1 million reported as R&D expense and $0.2 million reported as SG&A expense) as a result of accretion expense.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 27, 2014
Fair Value Measurements	'
Fair Value Measurements	'
	Note 3. Fair Value Measurements
	Our financial assets and liabilities carried at fair value are primarily comprised of investments in money market funds, certificates of deposit, municipal and corporate bonds, commercial paper, variable demand notes, asset-backed securities, auction rate securities (“ARS”), forward contracts, certain investments held as assets under the deferred compensation plan, marketable equity securities and the contingent consideration in connection with acquisitions. The fair value accounting guidance requires that assets and liabilities be carried at fair value and classified in one of the following three categories:
	Level 1: Quoted prices in active markets for identical assets or liabilities that we have the ability to access
	Level 2: Observable market based inputs or unobservable inputs that are corroborated by market data such as quoted prices, interest rates and yield curves
	Level 3: Inputs that are unobservable data points that are not corroborated by market data
	We review the fair value hierarchy classification on a quarterly basis. Changes in the ability to observe valuation inputs may result in a reclassification of levels of certain securities within the fair value hierarchy. We recognize transfers into and out of levels within the fair value hierarchy in the period in which the actual event or change in circumstances that caused the transfer occurs. There were no transfers between Level 1, Level 2 and Level 3 during either the first nine months of 2014 or first nine months of 2013.
	The following table represents the fair value hierarchy for our financial assets and financial liabilities measured at fair value on a recurring basis:
		Total Fair			Level 1			Level 2			Level 3
		Value
		(in thousands)
	As of September 27, 2014:
	Cash equivalents:
	Money market funds	$	85,886		$	85,886		$	—		$	—
	Commercial paper	10,729			—			10,729			—
	Municipal bonds	8,202			—			8,202			—
	Short-term investments:
	Municipal bonds	94,459			—			94,459			—
	Asset-backed securities	2,387			—			2,387			—
	Corporate bonds	20,237			—			20,237			—
	Commercial paper	7,797			—			7,797			—
	Prepaid expenses and other assets:
	Foreign exchange contracts	3,870			—			3,870			—
	Long-term investments:
	Auction rate securities	4,358			—			—			4,358
	Other long-term assets:
	Investments included in our deferred compensation plan	1,526			—			1,526			—
	Marketable equity securities	2,375			2,375			—			—
	Other accrued liabilities:
	Foreign exchange contracts	505			—			505			—
	Contingent consideration (current and non-current portions)	$	61,119		$	—		$	—		$	61,119
		Total Fair			Level 1			Level 2			Level 3
		Value
		(in thousands)
	As of December 28, 2013:
	Cash equivalents:
	Money market funds	$	97,200		$	97,200		$	—		$	—
	Commercial paper	13,899			—			13,899			—
	Short-term investments:
	Municipal bonds	142,486			—			142,486			—
	Variable demand notes	6,700			—			6,700			—
	Corporate bonds	5,507			—			5,507			—
	Commercial paper	9,998			—			9,998			—
	Certificate of deposit	2,000			—			2,000			—
	Prepaid expenses and other assets:
	Foreign exchange contracts	592			—			592			—
	Long-term investments:
	Auction rate securities	4,234			—			—			4,234
	Other long-term assets:
	Investments included in our deferred compensation plan	1,700			—			1,700			—
	Marketable equity securities	4,019			4,019			—			—
	Other accrued liabilities:
	Foreign exchange contracts	156			—			156			—
	Contingent consideration (current and non-current portions)	$	43,346		$	—		$	—		$	43,346
	Financial assets and liabilities are considered Level 2 when their fair values are determined using inputs that are observable in the market or can be derived principally from or corroborated by observable market data such as pricing for similar securities, recently executed transactions, cash flow models with yield curves and benchmark securities. Our Level 2 financial assets and liabilities include short-term investments, foreign exchange instruments and certain of our deferred compensation plan securities. In addition, Level 2 financial instruments are valued using comparisons to like-kind financial instruments and models that use readily observable market data as their basis.
	Financial assets and liabilities are considered Level 3 when their fair values are determined using pricing models, discounted cash flow methodologies or similar techniques, and at least one significant model assumption or input is unobservable. Level 3 financial assets and liabilities include the following:
	Auction rate securities—Due to limited market activity the determination of fair value requires significant judgment or estimation. These available-for-sale debt securities were valued using a discounted cash-flow model over a five-year period based on estimated interest rates, the present value of future principal payments, and interest payments discounted at rates considered to reflect the current market conditions and the credit quality of ARS.
	Contingent considerations—The fair value of the contingent consideration related to the acquisition of the medical business of Levitronix LLC (“Levitronix Medical”) in August 2011 requires significant management judgment or estimation and is calculated using the income approach, using various revenue assumptions and applying a probability to each outcome. The fair value of the contingent consideration is remeasured at the end of each reporting period with the change in fair value recorded within operating expense in our condensed consolidated statements of operations. Actual amounts paid may differ from the obligations recorded. The accretion of interest expense was not significant for all periods presented. Refer to Note 2 for a discussion of the fair value of the contingent considerations associated with the DuraHeart II and Apica acquisitions.
	Available-for-sale investments are carried at fair value and are included in the tables above under short- and long-term investments. The aggregate market value, cost basis and gross unrealized gains and losses of available-for-sale investments by major security type are as follows:
		Amortized			Gross			Gross			Fair
		Cost			Unrealized			Unrealized			Value
					Gains			Losses
		(in thousands)
	As of September 27, 2014:
Short-term investments:
Municipal bonds	$	94,357		$	104		$	(2	)	$	94,459
Corporate bonds	20,275			—			(38		)	20,237
Commercial paper	7,797			—			—			7,797
Asset-backed securities	2,388			—			(1		)	2,387
Total short-term investments	$	124,817		$	104		$	(41	)	$	124,880
Long-term investments:
Auction rate securities	$	4,900		$	—		$	(542	)	$	4,358
Other long-term assets:
Marketable equity securities	2,996			—			(621		)	2,375
Total long-term	$	7,896		$	—		$	(1,163	)	$	6,733
As of December 28, 2013:
Short-term investments:
Municipal bonds	$	142,321		$	178		$	(13	)	$	142,486
Variable demand notes	6,700			—			—			6,700
Corporate bonds	5,500			7			—			5,507
Commercial paper	9,998			—			—			9,998
Certificate of deposit	2,000			—			—			2,000
Total short-term investments	$	166,519		$	185		$	(13	)	$	166,691
Long-term investments:
Auction rate securities	$	4,900		$	—		$	(666	)	$	4,234
Other long-term assets:
Marketable equity securities	2,996			1,023			—			4,019
Total long-term	$	7,896		$	1,023		$	(666	)	$	8,253
Our deferred compensation plan includes our corporate owned life insurance policies and mutual fund investments. The underlying mutual fund investments are deemed trading securities. The mutual fund investments’ fair value and the cash surrender value of our corporate-owned life insurance policies are classified in the condensed consolidated balance sheets in “Other long-term assets.” The aggregate value of our deferred compensation plan assets as of September 27, 2014 and December 28, 2013 was $5.9 million and $5.2 million, respectively. The unrealized gain before tax from the change in the value of the deferred compensation plan was not significant during the first nine months of 2014 or first nine months of 2013.
The amortized cost and fair value of available-for-sale debt investments, by contractual maturity, were as follows as of September 27, 2014:
	Amortized			Fair
	Cost			Value
	(in thousands)
Maturing within 1 year	$	92,374		$	92,442
Maturing after 1 year through 5 years	32,444			32,438
Short-term available-for-sale investments	124,818			124,880
Maturing after 5 years	4,900			4,358
	$	129,718		$	129,238
The following table provides a roll forward of the fair value, as determined by Level 3 inputs, of the ARS during the first nine months of 2014:
	Auction
	Rate
	Securities
	(in thousands)
Balance as of December 28, 2013	$	4,234
Unrealized holding gain on auction rate securities, included in other comprehensive income (loss)	124
Balance as of September 27, 2014	$	4,358
The following table provides a roll forward of the fair value, as determined by Level 3 inputs, of contingent considerations during the first nine months of 2014:
	Contingent
	Consideration
	(in thousands)
Balance as of December 28, 2013	$	43,346
Addition from Apica acquisition (See Note 2)	25,700
Payments	(6,962		)
Change in fair value	(965		)
Balance as of September 27, 2014	$	61,119
The following table presents quantitative information about the inputs and valuation methodologies used for our fair value measurements classified in Level 3 of the fair value hierarchy as of September 27, 2014:
	Fair Value at			Valuation Methodology		Significant Unobservable Input		Weighted Average
	September 27,							(range, if applicable)
	2014
	(in thousands)
Auction rate securities	$	4,358		Discounted cash flow		Discount rate		1.8	%
						Market credit spread		2.33	%
						Liquidity factor		0	%
Levitronix Medical contingent consideration	$	17,040		Multiple outcome discounted cash flow		Annual Revenue		$34.2 million to $51.1 million
						Percent probabilities assigned to scenarios		5% to 70%
DuraHeart II contingent consideration	$	18,103		Multiple outcome discounted cash flow		Milestone dates		2016 to 2030
						Discount rate		4.8% to 17.0%
						Percent probabilities assigned to scenarios		5% to 80%
Apica contingent consideration	$	25,976		Multiple outcome discounted cash flow		Milestone dates		2016 to 2020
						Discount rate		4.8	%
						Percent probabilities assigned to scenarios		7.50% to 30.0%
Auction Rate Securities
The significant unobservable inputs used in the fair value measurement of ARS are the weighted average discount rate, market credit spread and liquidity factor. A significant increase (decrease) in the discount rate in isolation could result in a significantly higher (lower) fair value measurement, whereas a significant increase (decrease) in the market credit spread and liquidity factor in isolation could result in a significantly lower (higher) fair value measurement. Although the discount rate as compared to the market credit spread and liquidity factors are not directly related, they will generally move in opposite directions.
The fair value of ARS is calculated on a quarterly basis by senior management based on a collaborative effort of the corporate treasury and accounting groups. To assess the reasonableness of the fair value measurement, management compares its fair value measurement to the values calculated by independent third parties.
Contingent Considerations
The fair values of contingent considerations are measured using projected payment dates, discount rates, probabilities of payments, and projected revenues (for revenue-based considerations). Projected contingent payment amounts are discounted back to the current period using a discounted cash flow model. A significant increase (decrease) in the projected revenue in isolation could result in a significantly higher (lower) fair value measurement; a significant delay (acceleration) in the product development (including projected regulatory milestone) achievement date in isolation could result in a significantly lower (higher) fair value measurement; a significant increase (decrease) in the discount rate in isolation could result in a significantly lower (higher) fair value measurement; and the changes in the probability of occurrence between the outcomes in isolation could result in a significant change in fair value measurement.
The fair values of the contingent consideration are calculated on a quarterly basis by management based on a collaborative effort of our regulatory, research and development, operations, finance and accounting groups, as appropriate. Potential valuation adjustments are made as additional information becomes available, including the progress toward achieving revenue and milestone targets as compared to initial projections, the impact of market competition and changes in actual and projected product mix and average selling price, with the impact of such adjustments being recorded in the condensed consolidated statements of operations. In the first nine months of 2014 and 2013, the fair value of the Levitronix Medical contingent consideration increased by $1.7 million and $3.6 million, respectively, as a result of changes in the projected revenue and probabilities of possible outcomes. The increases in 2014 and 2013 were reported as SG&A expense. Refer to Note 2 for the Apica and DuraHeart II contingent considerations’ remeasurement adjustments.
Assets and Liabilities That Are Measured at Fair Value on a Nonrecurring Basis
Non-financial and financial assets such as goodwill, intangible assets, property, plant, and equipment and non-marketable equity investment are evaluated for impairment and adjusted to fair value using Level 3 inputs, only when impairment is recognized. Fair values are considered Level 3 when management makes significant assumptions in developing a discounted cash flow model based upon a number of considerations including projections of revenues, earnings and a discount rate. In addition, in evaluating the fair value of goodwill impairment, further corroboration is obtained using our market capitalization.

Foreign_Exchange_Instruments

Foreign Exchange Instruments	9 Months Ended
	Sep. 27, 2014
Foreign Exchange Instruments	'
Foreign Exchange Instruments	'
	Note 4. Foreign Exchange Instruments
	We utilize foreign currency forward exchange contracts and options with recognized financial institutions to manage our exposure to the impact of fluctuations in foreign currency exchange rates on certain intercompany balances and foreign currency denominated sales and purchase transactions. We do not use derivative financial instruments for speculative or trading purposes. These forward contracts are not designated as hedging instruments for accounting purposes. Principal hedged currencies include the Euro, British Pound Sterling and U.S. Dollar. The periods of these forward contracts range up to approximately three months and the notional amounts are intended to be consistent with changes in the underlying exposures. We intend to exchange foreign currencies for U.S. Dollars at maturity.
	Total gross notional amounts for outstanding derivatives instruments were as follows:
		September 27, 2014			December 28, 2013
	Forward contracts:
	Euro (sell)	€	17.7 million		€	20.2 million
	British Pound Sterling (sell)	£	1.3 million		£	1.3 million
	U.S. Dollar (sell)	$	12.6 million		$	23.5 million
	U.S. Dollar (buy)	$	59.8 million		$	60.0 million
	The following table shows the derivative instruments measured at gross fair value reported on the condensed consolidated balance sheets:
		As of September 27, 2014						As of December 28, 2013
		Prepaid expenses			Other accrued			Prepaid expenses			Other accrued
		and other assets			liabilities			and other assets			liabilities
		(in thousands)
	Derivatives not designated as hedging instruments (forward contracts)	$	3,870		$	505		$	592		$	156
	The following table shows the effect of derivative instruments not designated as hedging instruments and foreign currency transactions gains and losses which were included in “Interest income and other” in the condensed consolidated statements of operations:
		Three Months Ended						Nine Months Ended
		September 27,			September 28,			September 27,			September 28,
		2014			2013			2014			2013
		(in thousands)
	Foreign currency exchange gain (loss) on foreign contracts	$	4,823		$	(1,953	)	$	4,756		$	(649	)
	Foreign currency transactions gain (loss)	(5,997		)	2,122			(6,116		)	1,114

Balance_Sheet_Information

Balance Sheet Information	9 Months Ended
	Sep. 27, 2014
Balance Sheet Information	'
Balance Sheet Information	'
	Note 5. Balance Sheet Information
	The following tables provide details of selected condensed consolidated balance sheets items as of the end of each period:
	Inventories consisted of the following:
		September 27,			December 28,
		2014			2013
		(in thousands)
	Finished goods	$	28,736		$	22,885
	Work in process	18,243			13,739
	Raw materials	24,562			23,669
	Total	$	71,541		$	60,293
	Property, plant and equipment, net consisted of the following:
		September 27,			December 28,
		2014			2013
		(in thousands)
	Land, building and improvements	$	20,600		$	20,594
	Equipment and capitalized software	62,712			61,383
	Furniture and leasehold improvements	25,782			22,458
	Total	109,094			104,435
	Less accumulated depreciation	(54,151		)	(49,272		)
	Total	$	54,943		$	55,163
	As of September 27, 2014, we had $7.5 million of equipment that had not yet been placed in service (included in the “Equipment and capitalized software” line in the table above) from the DuraHeart II acquisition.
	Depreciation expense was $2.0 million and $6.4 million for the three and nine months ended September 27, 2014, respectively, and $2.0 million and $6.1 million for the three and nine months ended September 28, 2013, respectively.
	Warranty and related costs are accrued for based on our best estimates when management determines that it is probable a charge or liability has been incurred and the amount of loss can be reasonably estimated. Warranty and related accruals and the changes in the balances for the nine months ended September 27, 2014 and September 28, 2013 were as follows:
		September 27,			September 28,
		2014			2013
		(in thousands)
	Balance, beginning of the period	$	9,899		$	2,212
	Additions	13,194			2,982
	Change in estimate	(558		)	—
	Settlements	(3,583		)	(1,666		)
	Balance, end of the period	$	18,952		$	3,528
	Warranty activity in the first nine months of 2014 as compared to the prior period includes new warranty additions and settlements related to sales of our HeartMate II Pocket Controller, which was introduced in 2013. Additionally, in September 2014 we made available a new version of the Pocket Controller to customers who purchased a previous version. We recorded an incremental $10.7 million expense based on the number of units which we estimated will be exchanged.
	Changes in “Accumulated other comprehensive loss” by component during the nine months ended September 27, 2014:
		Foreign currency			Unrealized			Total
		items (net of tax)			gain (loss) on
					available-for-sale
					securities (net of tax)
		(in thousands)
	Balance as of December 28, 2013	$	(13,039	)	$	536		$	(12,503	)
	Other comprehensive loss before reclassification	(3,208		)	(1,367		)	(4,575		)
	Net current period other comprehensive loss	(3,208		)	(1,367		)	(4,575		)
	Balance as of September 27, 2014	$	(16,247	)	$	(831	)	$	(17,078	)

Goodwill_and_Purchased_Intangi

Goodwill and Purchased Intangible Assets, net	9 Months Ended
	Sep. 27, 2014
Goodwill and Purchased Intangible Assets, net	'
Goodwill and Purchased Intangible Assets, net	'
	Note 6. Goodwill and Purchased Intangible Assets, net
	The carrying amount of goodwill and the changes in the balance for the nine months ended September 27, 2014 were as follows (in thousands):
	Balance as of December 28, 2013	$	205,764
	Additions from Apica acquisition (Note 2)	31,381
	Foreign currency translation impact	(5,680		)
	Balance as of September 27, 2014	$	231,465
	Intangible assets (net of accumulated amortization and impairment) were as follows:
		As of September 27, 2014
		Gross			Accumulated			Accumulated			Net
		Amount			Amortization			Impairment			Amount
		(in thousands)
	Intangible assets subject to amortization:
	Patents and trademarks	$	43,532		$	(35,693	)	$	—		$	7,839
	Core technology	37,180			(23,637		)	(12,642		)	901
	Developed technology	133,373			(84,126		)	(37,600		)	11,647
	Pre-existing license agreement	2,300			(1,040		)	—			1,260
	Customer based relationships and other	7,246			(5,316		)	—			1,930
	Foreign currency translation impact	(574		)	—			—			(574		)
		223,057			(149,812		)	(50,242		)	23,003
	Intangible assets not yet subject to amortization:
	IPR&D (see Note 2)	38,900			—			—			38,900
	Foreign currency translation impact	(1,469		)	—			—			(1,469		)
	Total purchased intangible assets	$	260,488		$	(149,812	)	$	(50,242	)	$	60,434
		As of December 28, 2013
		Gross			Accumulated			Accumulated			Net
		Amount			Amortization			Impairment			Amount
		(in thousands)
	Intangible assets subject to amortization:
	Patents and trademarks	$	43,532		$	(34,755	)	$	—		$	8,777
	Core technology	37,180			(22,986		)	(12,642		)	1,552
	Developed technology	128,073			(81,635		)	(37,600		)	8,838
	Pre-existing license agreement	2,300			(794		)	—			1,506
	Customer based relationships and other	7,246			(4,043		)	—			3,203
	Foreign currency translation impact	127			—			—			127
		218,458			(144,213		)	(50,242		)	24,003
	Intangible assets not yet subject to amortization:
	IPR&D (see Note 2)	12,400			—			—			12,400
	Total purchased intangible assets	$	230,858		$	(144,213	)	$	(50,242	)	$	36,403
	Amortization expense related to identifiable intangible assets was $1.9 million and $5.7 million for the three and nine months ended September 27, 2014, respectively, and $2.6 million and $7.7 million for the three and nine months ended September 28, 2013, respectively.
	Estimated amortization expenses for the next five fiscal years and all years thereafter, excluding intangible assets not yet subject to amortization are as follows:
		(in thousands)
	Fiscal year:
	Remainder of 2014	$	1,896
	2015	5,715
	2016	4,416
	2017	3,543
	2018	3,129
	Thereafter	4,304
	Total	$	23,003

Credit_Facility

Credit Facility	9 Months Ended
	Sep. 27, 2014
Credit Facility	'
Credit Facility	'
	Note 7. Credit Facility
	On December 19, 2011, we signed an unsecured revolving credit facility agreement that provides for up to $50.0 million revolving credit that will expire on December 19, 2016. The interest rate charged on the amounts borrowed is LIBOR plus a margin (ranging from 0.75% to 1.25%). The agreement contains financial covenants with which we were in compliance as of September 27, 2014. The credit agreement permits us to use the facility for working capital and general corporate purposes. We did not have any borrowings under this credit facility during the nine months ended September 27, 2014 or September 28, 2013.

Legal_Proceedings

Legal Proceedings	9 Months Ended
	Sep. 27, 2014
Legal Proceedings	'
Legal Proceedings	'
	Note 8. Legal Proceedings
	From time to time we are involved in litigation arising out of claims in the normal course of business. Based on the information presently available, management believes that there are no claims or actions pending or threatened against us, the ultimate resolution of which will have a material effect on our financial position, liquidity or results of operations, although the results of litigation are inherently uncertain.
	On January 24, 2014, we and three of our present and former officers were named as defendants in a complaint filed in the United States District Court for the Northern District of California. The action, entitled Cooper v. Thoratec Corp., Case No. 4:14-cv-00360, is a putative class action brought on behalf of purchasers of our securities between April 29, 2010, and November 27, 2013, inclusive (the “Class Period”), and alleges violations of Section 10(b) of the Securities Exchange Act of 1934 (the “Exchange Act”), and Rule 10b-5 promulgated thereunder, as well as Section 20(a) of the Exchange Act. On April 21, 2014, the Court appointed Bradley Cooper as Lead Plaintiff (“Plaintiff”). On June 20, 2014, Plaintiff filed an amended class action complaint (“Complaint”), adding a former officer of the Company as a defendant. The Complaint alleges that during the Class Period, Defendants made false or misleading statements in various SEC filings, press releases, earnings calls, and healthcare conferences regarding the Company’s business and outlook, focusing primarily on Defendants’ alleged failure to disclose that the HeartMate II Left Ventricular Assist Device had a purported increased rate of pump thrombosis during the Class Period. Plaintiff seeks unspecified damages, among other relief. Defendants moved to dismiss the Complaint on August 19, 2014. The Court has not yet ruled on the motion. Although the results of litigation are inherently uncertain, based on the information currently available, we do not believe the ultimate resolution of this action will have a material effect on our financial position, liquidity or results of operations.

ShareBased_Compensation

Share-Based Compensation	9 Months Ended
	Sep. 27, 2014
Share-Based Compensation	'
Share-Based Compensation	'
	Note 9. Share-Based Compensation
	Our Amended and Restated 2006 Incentive Stock Plan (“2006 Plan”) permits the issuance of stock options (“options”), restricted stock units (“RSUs”), performance share units (“PSUs”) and other types of awards to employees, directors, and consultants. As of September 27, 2014, approximately 3.2 million shares remained available for issuance under the 2006 Plan.
	Share-based compensation consists of the following:
		Three Months Ended						Nine Months Ended
		September 27,			September 28,			September 27,		September 28,
		2014			2013			2014		2013
		(in thousands)
	Cost of product sales	$	529		$	586		$	1,906	$	1,773
	Selling, general and administrative expenses	4,486			4,373			13,305		12,681
	Research and development	1,956			1,896			6,375		5,772
	Total share-based compensation expense before taxes	6,971			6,855			21,586		20,226
	Tax benefit for share-based compensation expense	3,591			2,605			8,594		7,675
	Total share-based compensation (net of taxes)	$	3,380		$	4,250		$	12,992	$	12,551
	Stock Options
	The fair value of each option is estimated at the date of grant using the Black-Scholes option-pricing model with the following assumptions:
		Three Months Ended				Nine Months Ended
		September 27,		September 28,		September 27,		September 28,
		2014		2013		2014		2013
	Risk free interest rate (weighted average)	*		2	%	2.19	%	1.38	%
	Expected volatility	*		40	%	37	%	37	%
	Expected option term (years)	*		4.93		4.54 to 5.04		4.92 to 5.70
	Dividends	*		None		None		None
	* No stock options were granted in the three months ended September 27, 2014.
	Stock option activity is summarized as follows:
		Number of		Weighted			Weighted Average
		Options		Average Exercise			Remaining Contract
		(in thousands)		Price Per Share			Life (years)
	Outstanding options as of December 28, 2013	2,261		$	29.68		6.95
	Granted	586		34.86
	Exercised	(146	)	19.75
	Forfeited or expired	(45	)	35.88
	Outstanding options as of September 27, 2014	2,656		$	31.26		7.11
	Outstanding options vested as of September 27, 2014 and expected to vest	2,573		$	31.15		7.06
	Outstanding options exercisable as of September 27, 2014	1,252		$	27.94		5.63
	As of September 27, 2014, there was $8.5 million of unrecognized compensation expense, net of estimated forfeitures, related to options, which expense we expect to recognize over a weighted average period of 1.49 years. The weighted average grant-date fair value of options granted in the first nine months of 2014 was $12.39 per share.
	Restricted Stock Units
	RSU activity is summarized as follows:
		Number of		Weighted Average			Weighted Average
		Units		Grant-Date Fair			Remaining Contract
		(in thousands)		Value			Life (in years)
	Outstanding units as of December 28, 2013	1,461		$	33.4		1.27
	Granted	772		33.11
	Released	(528	)	32.29
	Forfeited or expired	(67	)	34.92
	Outstanding units as of September 27, 2014	1,638		$	33.56		1.5
	As of September 27, 2014, there was $40.4 million of unrecognized compensation expense, net of estimated forfeitures, related to RSUs, which amount we expect to recognize over 2.5 years.
	Performance Share Units
	We may issue PSUs representing hypothetical shares of our common stock. Each PSU reflects up to two shares that may be issued to the award recipient, with the number of shares to be issued determined based on performance and market conditions (referred to as either a “Performance Condition PSU” or a “Market Condition PSU”). The actual number of shares the recipient receives at the end of a performance period may range from 0% up to 200% of the Target Shares granted. Recipients generally must remain employed by us on a continuous basis through the end of the applicable performance period in order to receive shares subject to that award. The stock-based compensation costs for these PSUs, net of estimated forfeitures, are recorded over the three- or four-year vesting period based on a graded accelerated vesting method.
	With respect to Performance Condition PSUs, any change in estimates affecting the number of shares to be issued upon vesting of the PSUs would be accounted for as a cumulative adjustment to the compensation expense in the period in which the changes occur. In 2014, we issued approximately 69,000 Performance Condition PSUs, which based on a change in management’s estimate during the third quarter of 2014, resulted in no shares being issuable upon vesting of the PSUs.
	On September 22, 2014, we granted approximately 188,000 Market Condition PSUs to our President and Chief Executive Officer. Share-based compensation expense related to these Market Condition PSUs was not significant during the third quarter of 2014.

Common_and_Preferred_Stock

Common and Preferred Stock	9 Months Ended
	Sep. 27, 2014
Common and Preferred Stock	'
Common and Preferred Stock	'
	Note 10. Common and Preferred Stock
	On December 5, 2013, the Board of Directors authorized a new program to repurchase up to $200.0 million worth of shares of our common stock (“December 2013 program”), which will expire on December 31, 2015. In the three and nine months ended September 27, 2014, we repurchased $30.6 million and $68.1 million, respectively, worth of shares of our common stock under the December 2013 program. In addition, we repurchased $1.2 million worth of shares of our common stock in the first quarter of 2014 under our previous November 2012 program, which expired in the first quarter of fiscal 2014. As of September 27, 2014, $131.9 million was available for repurchases of shares of our common stock under the December 2013 program. The December 2013 program may be accelerated, suspended, delayed or discontinued at any time.
	We are incorporated in California, and as California law does not recognize treasury stock, the shares repurchased decreased the common shares outstanding. We recorded the $69.2 million of shares repurchased in the nine months ended September 27, 2014 by reducing the additional paid-in-capital (“APIC”) balance by the average value per share reflected in the account prior to the repurchase and allocating the excess as a reduction of retained earnings. Based on this allocation, APIC decreased by $29.3 million and retained earnings decreased by $39.9 million in the consolidated statement of shareholders’ equity.
	During the third quarter of 2014, we entered into and completed an Accelerated Share Repurchase (“2014 ASR”) program with an investment bank, under which we agreed to repurchase an aggregate of $30.0 million of our common stock. Under the 2014 ASR program, we paid $30.0 million and received an initial delivery of 1,055,408 shares, which represented 80% of the 2014 ASR program’s estimated value at inception. At maturity of the 2014 ASR program, an additional 152,120 shares were delivered to us. The total number of shares repurchased by us under the 2014 ASR program was based on a per share price of $24.84, representing the volume-weighted average price of our common stock during the purchase period, less an agreed upon discount. We recorded the $30.0 million of shares repurchased by reducing the APIC balance based on the average issuance price per share of all shares outstanding prior to the repurchase with the excess allocated to retained earnings. Based on this allocation, APIC decreased by $15.1 million and retained earnings decreased by $14.9 million in the condensed consolidated financial statements.
	We also purchased shares of our common stock that were not part of our publicly announced repurchase program, which represent the surrender value of shares of RSUs withheld in order to satisfy tax withholding obligations upon vesting. The shares purchased do not reduce the dollar value that may yet be purchased under our publicly announced repurchase programs. The aggregate value of shares purchased in the nine months ended September 27, 2014 was $7.3 million, which decreased APIC and retained earnings by $2.5 million and $4.8 million, respectively, based on the same allocation methodology discussed above. The aggregate value of shares purchased in the nine months ended September 28, 2013 was $7.1 million, which decreased APIC and retained earnings by $2.3 million and $4.8 million, respectively.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 27, 2014
Income Taxes	'
Income Taxes	'
	Note 11. Income Taxes
	Our effective income tax rates for the three months ended September 27, 2014 and September 28, 2013 were (194.4)% and 17.5%, respectively. Our effective income tax rates for the nine months ended September 27, 2014 and September 28, 2013 were 28.4% and 25.3%, respectively. The decrease in the three-month effective tax rate is primarily attributable to a decrease in income before taxes for the three months ended September 27, 2014 and a decrease in forecasted income before taxes for the year ending January 3, 2015. In addition, we recognized a tax benefit in the three months ended September 27, 2014 relating to changes in the deductibility of our executive compensation. The increase in the nine-month effective tax rate was primarily due to the lack of federal R&D credits in the absence of enacted legislation in 2014. In the first nine months of 2013, we recognized a benefit of approximately $2.3 million for these credits, of which $1.4 million relates to the 2012 credits recognized as a result of the timing of legislation reinstating the credit for the 2012 tax year.
	During the next 12 months, it is reasonably possible that audit resolutions and the expiration of statutes of limitations could potentially reduce our unrecognized tax benefits by up to $1.9 million. However, this amount may change because we continue to have ongoing negotiations with various taxing authorities throughout the year.

Segment_and_Geographic_Informa

Segment and Geographic Information	9 Months Ended
	Sep. 27, 2014
Segment and Geographic Information	'
Segment and Geographic Information	'
	Note 12. Segment and Geographic Information
	We have one operating segment and, and therefore, one reportable segment which develops, manufactures and markets proprietary medical devices used for mechanical circulatory support for the treatment of heart failure patients. Our chief operating decision-maker reviews financial information presented on a consolidated basis for purposes of making operating decisions and assessing financial performance, accompanied by disaggregated revenue information by product line. We do not assess the performance of our individual product lines on measures of profit or loss, or asset-based metrics. Therefore, the information below is presented only for revenues by product line, geography, and certain revenue category.
	Product sales attributed to a country or region include product sales to hospitals, physicians and distributors and are based on final destinations where the products are sold. No individual customer or individual country outside of the U.S. accounted for more than 10% of product sales during the three and nine months ended September 27, 2014 or during the three and nine months ended September 28, 2013.
		Three Months Ended				Nine Months Ended
		September 27,		September 28,		September 27,		September 28,
		2014		2013		2014		2013
		(in thousands)
	Product sales by geographic location:
	Domestic	$	85,762	$	99,608	$	275,539	$	290,643
	International	20,077		26,836		74,060		84,005
	Total	$	105,839	$	126,444	$	349,599	$	374,648
		Three Months Ended				Nine Months Ended
		September 27,		September 28,		September 27,		September 28,
		2014		2013		2014		2013
		(in thousands)
	Product sales by product line:
	HeartMate	$	91,599	$	112,837	$	303,585	$	331,404
	CentriMag	11,272		10,448		37,377		32,327
	PVAD and IVAD	2,463		2,592		7,212		9,108
	Other	505		567		1,425		1,809
	Total	$	105,839	$	126,444	$	349,599	$	374,648
		Three Months Ended				Nine Months Ended
		September 27,		September 28,		September 27,		September 28,
		2014		2013		2014		2013
		(in thousands)
	Product sales by category:
	Pump	$	74,189	$	87,108	$	245,072	$	264,867
	Non-Pump	31,145		38,769		103,102		107,972
	Other	505		567		1,425		1,809
	Total	$	105,839	$	126,444	$	349,599	$	374,648

Net_Income_Per_Share

Net Income Per Share	9 Months Ended
	Sep. 27, 2014
Net Income Per Share	'
Net Income Per Share	'
	Note 13. Net Income Per Share
	We calculate basic earnings per share (“EPS”) using net earnings and the weighted-average number of shares outstanding during the reporting period. Diluted EPS includes any dilutive effect of outstanding options and RSUs. PSUs are excluded from the shares used to compute diluted EPS until the performance or market conditions associated with the PSUs are met.
	The reconciliations of the numerators and denominators of each of the basic and diluted EPS calculations were as follows:
		Three Months Ended					Nine Months Ended
		September 27,			September 28,		September 27,		September 28,
		2014			2013		2014		2013
		(in thousands, except per share data)
	Numerator:
	Net Income	$	2,897		$	18,904	$	38,549	$	60,263
	Denominator:
	Weighted average shares used to compute basic EPS	55,733			57,427		56,430		57,447
	Dilutive effect of share-based compensation plans	378			807		689		953
	Weighted average shares used to compute diluted EPS	56,111			58,234		57,119		58,400
	Net income per share:
	Basic	$	0.05		$	0.33	$	0.68	$	1.05
	Diluted	$	0.05		$	0.32	$	0.67	$	1.03
	Potential common share equivalents excluded where the inclusion would be anti-dilutive are as follows:
		Three Months Ended				Nine Months Ended
		September 27,		September 28,		September 27,	September 28,
		2014		2013		2014	2013
		(in thousands)
	Options to purchase shares not included in the computation of diluted net income per share because their inclusion would be anti-dilutive	1,893		642		1,473	1,008

Operations_and_Significant_Acc1

Operations and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 27, 2014
Operations and Significant Accounting Policies	'
Basis of Presentation	'
	Basis of Presentation
	The interim unaudited condensed consolidated financial statements of Thoratec Corporation (“we,” “our,” “us,” or the “Company”) have been prepared and presented in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and the rules and regulations of the Securities and Exchange Commission (“SEC”), without audit, and reflect all adjustments necessary (consisting only of normal recurring adjustments) to present fairly our financial position, results of operations and cash flows as of and for the periods presented. Certain information and footnote disclosures normally included in our annual financial statements, prepared in accordance with GAAP, have been condensed or omitted. The accompanying financial statements should be read in conjunction with our fiscal 2013 consolidated financial statements, and the accompanying notes thereto, filed with the SEC in our Annual Report on Form 10-K for the fiscal year ended December 28, 2013 (the “2013 Annual Report”). The operating results for any interim period are not necessarily indicative of the results that may be expected for any future period.
	The preparation of our unaudited condensed consolidated financial statements necessarily requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities on the unaudited condensed consolidated balance sheet dates and the reported amounts of revenues and expenses for the periods presented. The actual amounts could differ from those estimated amounts.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In August 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-15, Presentation of Financial Statements-Going Concern (Subtopic 205-40). This ASU provides guidance to determine when and how to disclose going-concern uncertainties in the financial statements. The new standard requires management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date that the financial statements are issued. An entity must provide certain disclosures if conditions or events raise substantial doubt about the entity’s ability to continue as a going concern. The standard will be effective for the Company starting in fiscal 2017. We do not expect the adoption of this ASU to have an impact on our condensed consolidated financial statements.
	In June 2014, the FASB issued ASU No. 2014-10, Elimination of Certain Financial Reporting Requirements, Including an Amendment to Variable Interest Entities Guidance in Topic 810, Consolidation, which eliminates the conditions that a development stage entity may be considered a variable interest entity (“VIE”) and requires that an equity investment to be evaluated both a qualitatively and quantitatively in accordance with Accounting Standard Codification 810-25-45 through 47 to determine whether the equity investment qualifies as a VIE. This standard is effective for annual periods beginning on or after December 15, 2014. We have not yet evaluated the impact of the adoption of this ASU on our condensed consolidated financial statements.
	In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), which provides guidance for revenue recognition. This ASU affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of non-financial assets. The guidance in this ASU supersedes the revenue recognition requirements in Topic 605, Revenue Recognition, and most industry-specific guidance. This ASU also supersedes some cost guidance included in Subtopic 605-35, Revenue Recognition-Construction-Type and Production-Type Contracts. The standard will be effective for the Company starting in fiscal 2017. We have not yet evaluated the impact of the adoption of this ASU on our condensed consolidated financial statements.
	In April 2014, the FASB issued ASU No. 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity, which raises the threshold for a disposal to qualify as a discontinued operation and requires new disclosures of both discontinued operations and certain other disposals that do not meet the definition of a discontinued operation. This standard is effective for annual periods beginning on or after December 15, 2014. Early adoption is permitted but only for disposals that have not been reported in financial statements previously issued. We are currently evaluating the impact of this ASU, however we do not expect it would have any significant impact on our condensed consolidated financial statements.

Acquisitions_and_AcquisitionRe1

Acquisitions and Acquisition-Related Items (Tables)	9 Months Ended
	Sep. 27, 2014
Apica Acquisition	'
Acquisitions	'
Summary of preliminary purchase price allocation as of the acquisition date	'
	The preliminary purchase price allocation as of the acquisition date is summarized as follows (in thousands):
	Current assets (excluding cash)	$	548
	Identifiable intangible assets:
	Developed technology (ASC)	5,300
	IPR&D asset (SIS)	26,500
	Goodwill	31,381
	Total assets	63,729
	Less: Liabilities assumed	(291		)
	Deferred tax liability	(2,624		)
	Total estimated purchase price consideration	60,814
	Less: Contingent consideration	(25,700		)
	Cash paid or payable at the acquisition closing	$	35,114
Schedule of pro forma financial information	'
		Nine Months Ended			Nine Months Ended
		September 27, 2014			September 28, 2013
		(in thousands)
	Product sales	$	349,689		$	374,648
	Income before taxes	52,897			76,094
	Net income	37,867			56,841
DuraHeart II Acquisition	'
Acquisitions	'
Summary of preliminary purchase price allocation as of the acquisition date	'
	The purchase price allocation as of the acquisition date is summarized as follows (in thousands):
	Property, plant and equipment	$	8,900
	Identifiable intangible assets:
	Favorable lease contract	600
	IPR&D asset	12,400
	Goodwill	9,900
	Total estimated purchase price consideration	31,800
	Less: Contingent consideration	-18,800
	Cash paid at the acquisition closing	$	13,000
Schedule of pro forma financial information	'
		Nine months
		Ended
		September 28,
		2013
	Product sales	$	374,648
	Income before taxes	65,922
	Net income	49,242

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 27, 2014
Fair Value Measurements	'
Financial assets and financial liabilities measured at fair value on a recurring basis	'
		Total Fair			Level 1			Level 2			Level 3
		Value
		(in thousands)
	As of September 27, 2014:
	Cash equivalents:
	Money market funds	$	85,886		$	85,886		$	—		$	—
	Commercial paper	10,729			—			10,729			—
	Municipal bonds	8,202			—			8,202			—
	Short-term investments:
	Municipal bonds	94,459			—			94,459			—
	Asset-backed securities	2,387			—			2,387			—
	Corporate bonds	20,237			—			20,237			—
	Commercial paper	7,797			—			7,797			—
	Prepaid expenses and other assets:
	Foreign exchange contracts	3,870			—			3,870			—
	Long-term investments:
	Auction rate securities	4,358			—			—			4,358
	Other long-term assets:
	Investments included in our deferred compensation plan	1,526			—			1,526			—
	Marketable equity securities	2,375			2,375			—			—
	Other accrued liabilities:
	Foreign exchange contracts	505			—			505			—
	Contingent consideration (current and non-current portions)	$	61,119		$	—		$	—		$	61,119
		Total Fair			Level 1			Level 2			Level 3
		Value
		(in thousands)
	As of December 28, 2013:
	Cash equivalents:
	Money market funds	$	97,200		$	97,200		$	—		$	—
	Commercial paper	13,899			—			13,899			—
	Short-term investments:
	Municipal bonds	142,486			—			142,486			—
	Variable demand notes	6,700			—			6,700			—
	Corporate bonds	5,507			—			5,507			—
	Commercial paper	9,998			—			9,998			—
	Certificate of deposit	2,000			—			2,000			—
	Prepaid expenses and other assets:
	Foreign exchange contracts	592			—			592			—
	Long-term investments:
	Auction rate securities	4,234			—			—			4,234
	Other long-term assets:
	Investments included in our deferred compensation plan	1,700			—			1,700			—
	Marketable equity securities	4,019			4,019			—			—
	Other accrued liabilities:
	Foreign exchange contracts	156			—			156			—
	Contingent consideration (current and non-current portions)	$	43,346		$	—		$	—		$	43,346
Summary of aggregate market value, cost basis and gross unrealized gains and losses for available-for-sale investments	'
		Amortized			Gross			Gross			Fair
		Cost			Unrealized			Unrealized			Value
					Gains			Losses
		(in thousands)
	As of September 27, 2014:
	Short-term investments:
	Municipal bonds	$	94,357		$	104		$	(2	)	$	94,459
	Corporate bonds	20,275			—			(38		)	20,237
	Commercial paper	7,797			—			—			7,797
	Asset-backed securities	2,388			—			(1		)	2,387
	Total short-term investments	$	124,817		$	104		$	(41	)	$	124,880
	Long-term investments:
	Auction rate securities	$	4,900		$	—		$	(542	)	$	4,358
	Other long-term assets:
	Marketable equity securities	2,996			—			(621		)	2,375
	Total long-term	$	7,896		$	—		$	(1,163	)	$	6,733
	As of December 28, 2013:
	Short-term investments:
	Municipal bonds	$	142,321		$	178		$	(13	)	$	142,486
	Variable demand notes	6,700			—			—			6,700
	Corporate bonds	5,500			7			—			5,507
	Commercial paper	9,998			—			—			9,998
	Certificate of deposit	2,000			—			—			2,000
	Total short-term investments	$	166,519		$	185		$	(13	)	$	166,691
	Long-term investments:
	Auction rate securities	$	4,900		$	—		$	(666	)	$	4,234
	Other long-term assets:
	Marketable equity securities	2,996			1,023			—			4,019
	Total long-term	$	7,896		$	1,023		$	(666	)	$	8,253
Schedule of amortized cost and fair value of available-for-sale debt investments, by contractual maturity	'
	The amortized cost and fair value of available-for-sale debt investments, by contractual maturity, were as follows as of September 27, 2014:
		Amortized			Fair
		Cost			Value
		(in thousands)
	Maturing within 1 year	$	92,374		$	92,442
	Maturing after 1 year through 5 years	32,444			32,438
	Short-term available-for-sale investments	124,818			124,880
	Maturing after 5 years	4,900			4,358
		$	129,718		$	129,238
Schedule of roll forward of fair value, as determined by Level 3 inputs, of auction rate securities and contingent considerations (current and long-term portions)	'
		Auction
		Rate
		Securities
		(in thousands)
	Balance as of December 28, 2013	$	4,234
	Unrealized holding gain on auction rate securities, included in other comprehensive income (loss)	124
	Balance as of September 27, 2014	$	4,358
		Contingent
		Consideration
		(in thousands)
	Balance as of December 28, 2013	$	43,346
	Addition from Apica acquisition (See Note 2)	25,700
	Payments	(6,962		)
	Change in fair value	(965		)
	Balance as of September 27, 2014	$	61,119
Schedule of quantitative information for Level 3 Fair Value Measurements	'
		Fair Value at			Valuation Methodology		Significant Unobservable Input		Weighted Average
		September 27,							(range, if applicable)
		2014
		(in thousands)
	Auction rate securities	$	4,358		Discounted cash flow		Discount rate		1.8	%
							Market credit spread		2.33	%
							Liquidity factor		0	%
	Levitronix Medical contingent consideration	$	17,040		Multiple outcome discounted cash flow		Annual Revenue		$34.2 million to $51.1 million
							Percent probabilities assigned to scenarios		5% to 70%
	DuraHeart II contingent consideration	$	18,103		Multiple outcome discounted cash flow		Milestone dates		2016 to 2030
							Discount rate		4.8% to 17.0%
							Percent probabilities assigned to scenarios		5% to 80%
	Apica contingent consideration	$	25,976		Multiple outcome discounted cash flow		Milestone dates		2016 to 2020
							Discount rate		4.8	%
							Percent probabilities assigned to scenarios		7.50% to 30.0%

Foreign_Exchange_Instruments_T

Foreign Exchange Instruments (Tables)	9 Months Ended
	Sep. 27, 2014
Foreign Exchange Instruments	'
Schedule of notional amount of foreign currency contracts, which do not qualify for hedge accounting	'
		September 27, 2014			December 28, 2013
	Forward contracts:
	Euro (sell)	€	17.7 million		€	20.2 million
	British Pound Sterling (sell)	£	1.3 million		£	1.3 million
	U.S. Dollar (sell)	$	12.6 million		$	23.5 million
	U.S. Dollar (buy)	$	59.8 million		$	60.0 million
Schedule of derivative instruments measured at gross fair value reported on the condensed consolidated balance sheets	'
		As of September 27, 2014						As of December 28, 2013
		Prepaid expenses			Other accrued			Prepaid expenses			Other accrued
		and other assets			liabilities			and other assets			liabilities
		(in thousands)
	Derivatives not designated as hedging instruments (forward contracts)	$	3,870		$	505		$	592		$	156
Schedule of effect of derivative instruments not designated as hedging instruments and foreign currency transactions gains and losses	'
		Three Months Ended						Nine Months Ended
		September 27,			September 28,			September 27,			September 28,
		2014			2013			2014			2013
		(in thousands)
	Foreign currency exchange gain (loss) on foreign contracts	$	4,823		$	(1,953	)	$	4,756		$	(649	)
	Foreign currency transactions gain (loss)	(5,997		)	2,122			(6,116		)	1,114

Balance_Sheet_Information_Tabl

Balance Sheet Information (Tables)	9 Months Ended
	Sep. 27, 2014
Balance Sheet Information	'
Schedule of Inventories	'
		September 27,			December 28,
		2014			2013
		(in thousands)
	Finished goods	$	28,736		$	22,885
	Work in process	18,243			13,739
	Raw materials	24,562			23,669
	Total	$	71,541		$	60,293
Schedule of Property, Plant and Equipment, net	'
		September 27,			December 28,
		2014			2013
		(in thousands)
	Land, building and improvements	$	20,600		$	20,594
	Equipment and capitalized software	62,712			61,383
	Furniture and leasehold improvements	25,782			22,458
	Total	109,094			104,435
	Less accumulated depreciation	(54,151		)	(49,272		)
	Total	$	54,943		$	55,163
Changes in the warranty provision	'
		September 27,			September 28,
		2014			2013
		(in thousands)
	Balance, beginning of the period	$	9,899		$	2,212
	Additions	13,194			2,982
	Change in estimate	(558		)	—
	Settlements	(3,583		)	(1,666		)
	Balance, end of the period	$	18,952		$	3,528
Schedule of changes in accumulated other comprehensive loss by component	'
		Foreign currency			Unrealized			Total
		items (net of tax)			gain (loss) on
					available-for-sale
					securities (net of tax)
		(in thousands)
	Balance as of December 28, 2013	$	(13,039	)	$	536		$	(12,503	)
	Other comprehensive loss before reclassification	(3,208		)	(1,367		)	(4,575		)
	Net current period other comprehensive loss	(3,208		)	(1,367		)	(4,575		)
	Balance as of September 27, 2014	$	(16,247	)	$	(831	)	$	(17,078	)

Goodwill_and_Purchased_Intangi1

Goodwill and Purchased Intangible Assets, net (Tables)	9 Months Ended
	Sep. 27, 2014
Goodwill and Purchased Intangible Assets, net	'
Schedule of changes in carrying amount of goodwill	'
	The carrying amount of goodwill and the changes in the balance for the nine months ended September 27, 2014 were as follows (in thousands):
	Balance as of December 28, 2013	$	205,764
	Additions from Apica acquisition (Note 2)	31,381
	Foreign currency translation impact	(5,680		)
	Balance as of September 27, 2014	$	231,465
Schedule of intangible assets on the condensed consolidated balance sheets	'
		As of September 27, 2014
		Gross			Accumulated			Accumulated			Net
		Amount			Amortization			Impairment			Amount
		(in thousands)
	Intangible assets subject to amortization:
	Patents and trademarks	$	43,532		$	(35,693	)	$	—		$	7,839
	Core technology	37,180			(23,637		)	(12,642		)	901
	Developed technology	133,373			(84,126		)	(37,600		)	11,647
	Pre-existing license agreement	2,300			(1,040		)	—			1,260
	Customer based relationships and other	7,246			(5,316		)	—			1,930
	Foreign currency translation impact	(574		)	—			—			(574		)
		223,057			(149,812		)	(50,242		)	23,003
	Intangible assets not yet subject to amortization:
	IPR&D (see Note 2)	38,900			—			—			38,900
	Foreign currency translation impact	(1,469		)	—			—			(1,469		)
	Total purchased intangible assets	$	260,488		$	(149,812	)	$	(50,242	)	$	60,434
		As of December 28, 2013
		Gross			Accumulated			Accumulated			Net
		Amount			Amortization			Impairment			Amount
		(in thousands)
	Intangible assets subject to amortization:
	Patents and trademarks	$	43,532		$	(34,755	)	$	—		$	8,777
	Core technology	37,180			(22,986		)	(12,642		)	1,552
	Developed technology	128,073			(81,635		)	(37,600		)	8,838
	Pre-existing license agreement	2,300			(794		)	—			1,506
	Customer based relationships and other	7,246			(4,043		)	—			3,203
	Foreign currency translation impact	127			—			—			127
		218,458			(144,213		)	(50,242		)	24,003
	Intangible assets not yet subject to amortization:
	IPR&D (see Note 2)	12,400			—			—			12,400
	Total purchased intangible assets	$	230,858		$	(144,213	)	$	(50,242	)	$	36,403
Schedule of estimated amortization expense for the next five fiscal years and all years thereafter	'
		(in thousands)
	Fiscal year:
	Remainder of 2014	$	1,896
	2015	5,715
	2016	4,416
	2017	3,543
	2018	3,129
	Thereafter	4,304
	Total	$	23,003

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 27, 2014
Share-Based Compensation	'
Schedule of share-based compensation	'
		Three Months Ended						Nine Months Ended
		September 27,			September 28,			September 27,		September 28,
		2014			2013			2014		2013
		(in thousands)
	Cost of product sales	$	529		$	586		$	1,906	$	1,773
	Selling, general and administrative expenses	4,486			4,373			13,305		12,681
	Research and development	1,956			1,896			6,375		5,772
	Total share-based compensation expense before taxes	6,971			6,855			21,586		20,226
	Tax benefit for share-based compensation expense	3,591			2,605			8,594		7,675
	Total share-based compensation (net of taxes)	$	3,380		$	4,250		$	12,992	$	12,551
Schedule of assumptions used to estimate the grant date fair value of options	'
		Three Months Ended				Nine Months Ended
		September 27,		September 28,		September 27,		September 28,
		2014		2013		2014		2013
	Risk free interest rate (weighted average)	*		2	%	2.19	%	1.38	%
	Expected volatility	*		40	%	37	%	37	%
	Expected option term (years)	*		4.93		4.54 to 5.04		4.92 to 5.70
	Dividends	*		None		None		None
	* No stock options were granted in the three months ended September 27, 2014.
Summary of stock option activity	'
		Number of		Weighted			Weighted Average
		Options		Average Exercise			Remaining Contract
		(in thousands)		Price Per Share			Life (years)
	Outstanding options as of December 28, 2013	2,261		$	29.68		6.95
	Granted	586		34.86
	Exercised	(146	)	19.75
	Forfeited or expired	(45	)	35.88
	Outstanding options as of September 27, 2014	2,656		$	31.26		7.11
	Outstanding options vested as of September 27, 2014 and expected to vest	2,573		$	31.15		7.06
	Outstanding options exercisable as of September 27, 2014	1,252		$	27.94		5.63
Summary of RSU	'
		Number of		Weighted Average			Weighted Average
		Units		Grant-Date Fair			Remaining Contract
		(in thousands)		Value			Life (in years)
	Outstanding units as of December 28, 2013	1,461		$	33.4		1.27
	Granted	772		33.11
	Released	(528	)	32.29
	Forfeited or expired	(67	)	34.92
	Outstanding units as of September 27, 2014	1,638		$	33.56		1.5

Segment_and_Geographic_Informa1

Segment and Geographic Information (Tables)	9 Months Ended
	Sep. 27, 2014
Segment and Geographic Information	'
Schedule of product sales by geographic location	'
		Three Months Ended				Nine Months Ended
		September 27,		September 28,		September 27,		September 28,
		2014		2013		2014		2013
		(in thousands)
	Product sales by geographic location:
	Domestic	$	85,762	$	99,608	$	275,539	$	290,643
	International	20,077		26,836		74,060		84,005
	Total	$	105,839	$	126,444	$	349,599	$	374,648
Schedule of product sales by product line	'
		Three Months Ended				Nine Months Ended
		September 27,		September 28,		September 27,		September 28,
		2014		2013		2014		2013
		(in thousands)
	Product sales by product line:
	HeartMate	$	91,599	$	112,837	$	303,585	$	331,404
	CentriMag	11,272		10,448		37,377		32,327
	PVAD and IVAD	2,463		2,592		7,212		9,108
	Other	505		567		1,425		1,809
	Total	$	105,839	$	126,444	$	349,599	$	374,648
Schedule of product sales by category	'
		Three Months Ended				Nine Months Ended
		September 27,		September 28,		September 27,		September 28,
		2014		2013		2014		2013
		(in thousands)
	Product sales by category:
	Pump	$	74,189	$	87,108	$	245,072	$	264,867
	Non-Pump	31,145		38,769		103,102		107,972
	Other	505		567		1,425		1,809
	Total	$	105,839	$	126,444	$	349,599	$	374,648

Net_Income_Per_Share_Tables

Net Income Per Share (Tables)	9 Months Ended
	Sep. 27, 2014
Net Income Per Share	'
Schedule of reconciliations of the numerators and denominators of each of the basic and diluted EPS calculations	'
		Three Months Ended					Nine Months Ended
		September 27,			September 28,		September 27,		September 28,
		2014			2013		2014		2013
		(in thousands, except per share data)
	Numerator:
	Net Income	$	2,897		$	18,904	$	38,549	$	60,263
	Denominator:
	Weighted average shares used to compute basic EPS	55,733			57,427		56,430		57,447
	Dilutive effect of share-based compensation plans	378			807		689		953
	Weighted average shares used to compute diluted EPS	56,111			58,234		57,119		58,400
	Net income per share:
	Basic	$	0.05		$	0.33	$	0.68	$	1.05
	Diluted	$	0.05		$	0.32	$	0.67	$	1.03
Schedule of potential common share equivalents excluded where the inclusion would be anti-dilutive	'
		Three Months Ended				Nine Months Ended
		September 27,		September 28,		September 27,	September 28,
		2014		2013		2014	2013
		(in thousands)
	Options to purchase shares not included in the computation of diluted net income per share because their inclusion would be anti-dilutive	1,893		642		1,473	1,008

Acquisitions_and_AcquisitionRe2

Acquisitions and Acquisition-Related Items (Details) (USD $)

9 Months Ended

0 Months Ended

9 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

9 Months Ended

9 Months Ended

0 Months Ended

Sep. 27, 2014

Sep. 28, 2013

Dec. 28, 2013

Jul. 02, 2014

Sep. 27, 2014

Sep. 28, 2013

Sep. 27, 2014

Sep. 27, 2014

Jul. 02, 2014

Jul. 02, 2014

Sep. 27, 2014

Sep. 27, 2014

Jul. 02, 2014

Jun. 30, 2013

Sep. 27, 2014

Sep. 28, 2013

Jun. 30, 2013

Sep. 27, 2014

Sep. 28, 2013

Sep. 27, 2014

Sep. 28, 2013

Jun. 30, 2013

Jun. 30, 2013

item

item

Apica Acquisition

Apica Acquisition

Apica Acquisition

Apica Acquisition

Apica Acquisition

Apica Acquisition

Apica Acquisition

Apica Acquisition

Apica Acquisition

Apica Acquisition

DuraHeart II Acquisition

DuraHeart II Acquisition

DuraHeart II Acquisition

DuraHeart II Acquisition

DuraHeart II Acquisition

DuraHeart II Acquisition

DuraHeart II Acquisition

DuraHeart II Acquisition

DuraHeart II Acquisition

DuraHeart II Acquisition

Research and development

Selling, general and administrative expense

IPR&D asset (SIS)

Developed technology (ASC)

Developed technology (ASC)

Developed technology (ASC)

Contingent consideration payable upon reaching commercial sales milestone

Research and development

Research and development

Selling, general and administrative expense

Selling, general and administrative expense

IPR&D asset (SIS)

Favorable lease contract

Acquisitions

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of businesses acquired

2

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash paid

'

'

'

$35,100,000

'

'

'

'

'

'

'

'

'

$13,000,000

'

'

'

'

'

'

'

'

'

Potential future milestone payments

'

'

'

'

'

'

'

'

'

'

'

'

40,000,000

'

'

'

43,500,000

'

'

'

'

'

'

Acquisition-related costs

'

'

'

'

2,100,000

'

'

'

'

'

'

'

'

'

'

2,000,000

'

'

'

'

'

'

'

Summary of purchase price allocation

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property, plant and equipment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8,900,000

'

'

'

'

'

'

Current assets (excluding cash)

'

'

'

548,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-lived identifiable intangible assets

'

'

'

'

'

'

'

'

'

5,300,000

'

'

'

'

'

'

'

'

'

'

'

'

600,000

Indefinite-lived identifiable intangible assets

'

'

'

'

'

'

'

'

26,500,000

'

'

'

'

'

'

'

'

'

'

'

'

12,400,000

'

Goodwill

231,465,000

'

205,764,000

31,381,000

'

'

'

'

'

'

'

'

'

'

'

'

9,900,000

'

'

'

'

'

'

Total assets

'

'

'

63,729,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Less: Liabilities assumed

'

'

'

-291,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred tax liability

'

'

'

-2,624,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total estimated purchase price consideration

'

'

'

60,814,000

'

'

'

'

'

'

'

'

'

31,800,000

'

'

'

'

'

'

'

'

'

Less: Contingent consideration

'

'

'

25,700,000

'

'

'

'

'

'

'

'

'

'

'

'

-18,800,000

'

'

'

'

'

'

Cash paid or payable at the acquisition closing

'

'

'

35,114,000

'

'

'

'

'

'

'

'

'

'

'

'

13,000,000

'

'

'

'

'

'

Intangible assets, useful lives

'

'

'

'

'

'

'

'

'

'

'

'5 years

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

'

'

100,000

100,000

'

'

'

'

'

'

'

'

'

'

'

Net loss

'

'

'

'

'

'

'

'

'

'

800,000

800,000

'

'

'

'

'

'

'

'

'

'

'

Pro forma financial information

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Product sales

'

'

'

'

349,689,000

374,648,000

'

'

'

'

'

'

'

'

'

374,648,000

'

'

'

'

'

'

'

Income before taxes

'

'

'

'

52,897,000

76,094,000

'

'

'

'

'

'

'

'

'

65,922,000

'

'

'

'

'

'

'

Net income

'

'

'

'

37,867,000

56,841,000

'

'

'

'

'

'

'

'

'

49,242,000

'

'

'

'

'

'

'

Increase (decrease) in fair value of contingent consideration

'

'

'

'

$300,000

'

$200,000

$100,000

'

'

'

'

'

'

($3,000,000)

$300,000

'

($2,000,000)

$100,000

($1,000,000)

$200,000

'

'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)

9 Months Ended

In Thousands, unless otherwise specified

Sep. 27, 2014

Sep. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Commercial Paper

Commercial Paper

Municipal bonds

Municipal bonds

Asset-backed securities

Variable demand notes

Corporate bonds

Corporate bonds

Long-term investments - auction rate securities

Long-term investments - auction rate securities

Certificate of deposit

Marketable equity securities

Marketable equity securities

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Total fair value

Total fair value

Total fair value

Total fair value

Total fair value

Total fair value

Total fair value

Total fair value

Total fair value

Total fair value

Total fair value

Total fair value

Total fair value

Total fair value

Total fair value

Total fair value

Total fair value

Quoted prices in active markets for identical assets (Level 1)

Quoted prices in active markets for identical assets (Level 1)

Quoted prices in active markets for identical assets (Level 1)

Quoted prices in active markets for identical assets (Level 1)

Significant other observable inputs (Level 2)

Significant other observable inputs (Level 2)

Significant other observable inputs (Level 2)

Significant other observable inputs (Level 2)

Significant other observable inputs (Level 2)

Significant other observable inputs (Level 2)

Significant other observable inputs (Level 2)

Significant other observable inputs (Level 2)

Significant other observable inputs (Level 2)

Significant other observable inputs (Level 2)

Significant other observable inputs (Level 2)

Significant unobservable inputs (Level 3)

Significant unobservable inputs (Level 3)

Significant unobservable inputs (Level 3)

Significant unobservable inputs (Level 3)

Money market funds

Money market funds

Commercial Paper

Commercial Paper

Municipal bonds

Municipal bonds

Asset-backed securities

Variable demand notes

Corporate bonds

Corporate bonds

Long-term investments - auction rate securities

Long-term investments - auction rate securities

Certificate of deposit

Marketable equity securities

Marketable equity securities

Money market funds

Money market funds

Marketable equity securities

Marketable equity securities

Commercial Paper

Commercial Paper

Municipal bonds

Municipal bonds

Asset-backed securities

Variable demand notes

Corporate bonds

Corporate bonds

Certificate of deposit

Long-term investments - auction rate securities

Long-term investments - auction rate securities

Financial assets and liabilities measured at fair value on a recurring basis

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Transfers between the levels within the fair value hierarchy

$0

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Assets:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash equivalents

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

85,886

97,200

10,729

13,899

8,202

'

'

'

'

'

'

'

'

'

'

85,886

97,200

'

'

'

'

10,729

13,899

8,202

'

'

'

'

'

'

'

'

'

'

Investments

'

'

7,797

9,998

94,459

142,486

2,387

6,700

20,237

5,507

4,358

4,234

2,000

2,375

4,019

'

'

'

'

7,797

9,998

94,459

142,486

2,387

6,700

20,237

5,507

4,358

4,234

2,000

2,375

4,019

'

'

2,375

4,019

'

'

7,797

9,998

94,459

142,486

2,387

6,700

20,237

5,507

2,000

'

'

4,358

4,234

Prepaid expenses and other assets - Foreign exchange contracts

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,870

592

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,870

592

'

'

'

'

'

'

'

'

'

'

'

'

'

Other long term assets: Carrying value of investments included in our deferred compensation plan

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,526

1,700

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,526

1,700

'

'

'

'

'

'

'

'

'

'

'

'

'

Liabilities:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other accrued liabilities - Foreign exchange contracts

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

505

156

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

505

156

'

'

'

'

'

'

'

'

'

'

'

'

'

Contingent consideration (current and non-current portions)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$61,119

$43,346

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$61,119

$43,346

'

'

Cash flow model discount period

'5 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (USD $)	9 Months Ended	12 Months Ended
	Sep. 27, 2014	Dec. 28, 2013
Other long-term assets - investments - deferred compensation plan	'	'
Deferred compensation plan assets	$5,900,000	$5,200,000
Contractual maturities of available-for-sale investments, Amortized Cost	'	'
Total Amortized Cost	129,718,000	'
Contractual maturities of available-for-sale investments, Fair Value	'	'
Total Fair Value	129,238,000	'
Short-term investments	'	'
Available-for-sale investments by major security type:	'	'
Amortized Cost	124,817,000	166,519,000
Gross Unrealized Gains	104,000	185,000
Gross Unrealized Losses	-41,000	-13,000
Fair Value	124,880,000	166,691,000
Contractual maturities of available-for-sale investments, Amortized Cost	'	'
Maturing within 1 year	92,374,000	'
Maturing after 1 year through 5 years	32,444,000	'
Total Amortized Cost	124,818,000	'
Maturing after 5 years	4,900,000	'
Contractual maturities of available-for-sale investments, Fair Value	'	'
Maturing within 1 year	92,442,000	'
Maturing after 1 year through 5 years	32,438,000	'
Total Fair Value	124,880,000	'
Maturing after 5 years	4,358,000	'
Municipal bonds	'	'
Available-for-sale investments by major security type:	'	'
Amortized Cost	94,357,000	142,321,000
Gross Unrealized Gains	104,000	178,000
Gross Unrealized Losses	-2,000	-13,000
Fair Value	94,459,000	142,486,000
Variable demand notes	'	'
Available-for-sale investments by major security type:	'	'
Amortized Cost	'	6,700,000
Fair Value	'	6,700,000
Corporate bonds	'	'
Available-for-sale investments by major security type:	'	'
Amortized Cost	20,275,000	5,500,000
Gross Unrealized Gains	'	7,000
Gross Unrealized Losses	-38,000	'
Fair Value	20,237,000	5,507,000
Commercial Paper	'	'
Available-for-sale investments by major security type:	'	'
Amortized Cost	7,797,000	9,998,000
Fair Value	7,797,000	9,998,000
Asset-backed securities	'	'
Available-for-sale investments by major security type:	'	'
Amortized Cost	2,388,000	'
Gross Unrealized Losses	-1,000	'
Fair Value	2,387,000	'
Certificate of deposit	'	'
Available-for-sale investments by major security type:	'	'
Amortized Cost	'	2,000,000
Fair Value	'	2,000,000
Long-term investments	'	'
Available-for-sale investments by major security type:	'	'
Amortized Cost	7,896,000	7,896,000
Gross Unrealized Gains	'	1,023,000
Gross Unrealized Losses	-1,163,000	-666,000
Fair Value	6,733,000	8,253,000
Long-term investments - auction rate securities	'	'
Available-for-sale investments by major security type:	'	'
Amortized Cost	4,900,000	4,900,000
Gross Unrealized Losses	-542,000	-666,000
Fair Value	4,358,000	4,234,000
Marketable equity securities	'	'
Available-for-sale investments by major security type:	'	'
Amortized Cost	2,996,000	2,996,000
Gross Unrealized Gains	'	1,023,000
Gross Unrealized Losses	-621,000	'
Fair Value	$2,375,000	$4,019,000

Fair_Value_Measurements_Detail2

Fair Value Measurements (Details 3) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2014
Apica	'
Changes in liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)	'
Addition	$25,700
Auction rate securities	'
Reconciliation of the beginning and ending balances for the assets measured as fair value using significant unobservable inputs (Level 3):	'
Balance, beginning of the fiscal year	4,234
Unrealized holding gain on auction rate securities, included in other comprehensive income (loss)	124
Balance, end of the fiscal year	4,358
Contingent consideration	'
Changes in liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)	'
Balance, beginning of the fiscal year	43,346
Payments	-6,962
Change in fair value	-965
Balance, end of the fiscal year	$61,119

Fair_Value_Measurements_Detail3

Fair Value Measurements (Details 4) (Auction rate securities, Discounted cash flow, USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2014
Quantitative information for Level 3 Fair Value Measurements Assets	'
Fair value Assets	4,358
Weighted Average	'
Quantitative information for Level 3 Fair Value Measurements Assets	'
Discount rate (as a percent)	1.80%
Market credit spread (as a percent)	2.33%
Liquidity factor (as a percent)	0.00%

Fair_Value_Measurements_Detail4

Fair Value Measurements (Details 5) (USD $)	9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013
Levitronix Medical | Contingent consideration	'	'
Quantitative information for Level 3 Fair Value Measurements Liabilities	'	'
Increase in selling, general and administrative expense	$1,700,000	$3,600,000
Multiple outcome discounted cash flow | Levitronix Medical	'	'
Quantitative information for Level 3 Fair Value Measurements Liabilities	'	'
Fair value Liabilities	17,040,000	'
Multiple outcome discounted cash flow | DuraHeart II Acquisition	'	'
Quantitative information for Level 3 Fair Value Measurements Liabilities	'	'
Fair value Liabilities	18,103,000	'
Multiple outcome discounted cash flow | Apica	'	'
Quantitative information for Level 3 Fair Value Measurements Liabilities	'	'
Fair value Liabilities	25,976,000	'
Discount rate (as a percent)	4.80%	'
Multiple outcome discounted cash flow | Minimum | Levitronix Medical	'	'
Quantitative information for Level 3 Fair Value Measurements Liabilities	'	'
Annual Revenue	34,200,000	'
Probability of occurrence (as a percent)	5.00%	'
Multiple outcome discounted cash flow | Minimum | DuraHeart II Acquisition	'	'
Quantitative information for Level 3 Fair Value Measurements Liabilities	'	'
Discount rate (as a percent)	4.80%	'
Probability of occurrence (as a percent)	5.00%	'
Multiple outcome discounted cash flow | Minimum | Apica	'	'
Quantitative information for Level 3 Fair Value Measurements Liabilities	'	'
Probability of occurrence (as a percent)	7.50%	'
Multiple outcome discounted cash flow | Maximum | Levitronix Medical	'	'
Quantitative information for Level 3 Fair Value Measurements Liabilities	'	'
Annual Revenue	$51,100,000	'
Probability of occurrence (as a percent)	70.00%	'
Multiple outcome discounted cash flow | Maximum | DuraHeart II Acquisition	'	'
Quantitative information for Level 3 Fair Value Measurements Liabilities	'	'
Discount rate (as a percent)	17.00%	'
Probability of occurrence (as a percent)	80.00%	'
Multiple outcome discounted cash flow | Maximum | Apica	'	'
Quantitative information for Level 3 Fair Value Measurements Liabilities	'	'
Probability of occurrence (as a percent)	30.00%	'

Foreign_Exchange_Instruments_D

Foreign Exchange Instruments (Details)

3 Months Ended

9 Months Ended

9 Months Ended

Sep. 27, 2014

Sep. 28, 2013

Sep. 27, 2014

Sep. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

USD ($)

USD ($)

USD ($)

USD ($)

Prepaid expenses and other assets

Prepaid expenses and other assets

Other accrued liabilities

Other accrued liabilities

Not Designated

Not Designated

Not Designated

Not Designated

Not Designated

Not Designated

Not Designated

Not Designated

Not Designated

USD ($)

USD ($)

USD ($)

USD ($)

Maximum

Euro (sell)

Euro (sell)

British Pound Sterling (sell)

British Pound Sterling (sell)

U.S. Dollar (sell)

U.S. Dollar (sell)

U.S. Dollar (buy) 1

U.S. Dollar (buy) 1

EUR (€)

EUR (€)

GBP (£)

GBP (£)

USD ($)

USD ($)

USD ($)

USD ($)

Foreign currency forward exchange details

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Approximate period forward contracts

'

'

'

'

'

'

'

'

'3 months

'

'

'

'

'

'

'

'

Gross notional amounts for outstanding derivatives

'

'

'

'

'

'

'

'

'

€ 17,700,000

€ 20,200,000

£ 1,300,000

£ 1,300,000

$12,600,000

$23,500,000

$59,800,000

$60,000,000

Gross fair value of Derivatives not designated as hedging instruments (forward contracts)

'

'

'

'

3,870,000

592,000

505,000

156,000

'

'

'

'

'

'

'

'

'

Foreign currency exchange gain (loss) on foreign contracts

4,823,000

-1,953,000

4,756,000

-649,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Foreign currency transactions gain (loss)

($5,997,000)

$2,122,000

($6,116,000)

$1,114,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance_Sheet_Information_Deta

Balance Sheet Information (Details) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 27, 2014	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013	Dec. 28, 2013
Inventories	'	'	'	'	'	'
Finished goods	$28,736,000	$28,736,000	'	$28,736,000	'	$22,885,000
Work-in-process	18,243,000	18,243,000	'	18,243,000	'	13,739,000
Raw materials	24,562,000	24,562,000	'	24,562,000	'	23,669,000
Total inventories	71,541,000	71,541,000	'	71,541,000	'	60,293,000
Property, plant and equipment, net	'	'	'	'	'	'
Property, plant and equipment, gross	109,094,000	109,094,000	'	109,094,000	'	104,435,000
Less accumulated depreciation	-54,151,000	-54,151,000	'	-54,151,000	'	-49,272,000
Total property, plant and equipment, net	54,943,000	54,943,000	'	54,943,000	'	55,163,000
Depreciation expense	'	2,000,000	2,000,000	6,400,000	6,100,000	'
Changes in the warranty provision	'	'	'	'	'	'
Balance, beginning of the fiscal year	'	'	'	9,899,000	2,212,000	'
Additions	'	'	'	13,194,000	2,982,000	'
Change in estimate	'	'	'	-558,000	'	'
Settlements	'	'	'	-3,583,000	-1,666,000	'
Balance, end of the fiscal year	18,952,000	18,952,000	3,528,000	18,952,000	3,528,000	'
Standard Product Warranty Incremental Settlement Expense	10,700,000	'	'	'	'	'
Land, building and improvements	'	'	'	'	'	'
Property, plant and equipment, net	'	'	'	'	'	'
Property, plant and equipment, gross	20,600,000	20,600,000	'	20,600,000	'	20,594,000
Equipment and capitalized software	'	'	'	'	'	'
Property, plant and equipment, net	'	'	'	'	'	'
Property, plant and equipment, gross	62,712,000	62,712,000	'	62,712,000	'	61,383,000
Equipment and capitalized software | DuraHeart II Acquisition	'	'	'	'	'	'
Property, plant and equipment, net	'	'	'	'	'	'
Property, plant and equipment, gross	7,500,000	7,500,000	'	7,500,000	'	'
Furniture and leasehold improvements	'	'	'	'	'	'
Property, plant and equipment, net	'	'	'	'	'	'
Property, plant and equipment, gross	$25,782,000	$25,782,000	'	$25,782,000	'	$22,458,000

Balance_Sheet_Information_Deta1

Balance Sheet Information (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
Changes in accumulated other comprehensive loss	'	'	'	'
Balance at the beginning of the period	'	'	($12,503)	'
Other comprehensive loss before reclassification	'	'	-4,575	'
Total other comprehensive income (loss)	-3,846	3,074	-4,575	1,391
Balance at the end of the period	-17,078	'	-17,078	'
Foreign currency items (net of tax)	'	'	'	'
Changes in accumulated other comprehensive loss	'	'	'	'
Balance at the beginning of the period	'	'	-13,039	'
Other comprehensive loss before reclassification	'	'	-3,208	'
Total other comprehensive income (loss)	'	'	-3,208	'
Balance at the end of the period	-16,247	'	-16,247	'
Unrealized gain (loss) on available-for-sale securities (net of tax)	'	'	'	'
Changes in accumulated other comprehensive loss	'	'	'	'
Balance at the beginning of the period	'	'	536	'
Other comprehensive loss before reclassification	'	'	-1,367	'
Total other comprehensive income (loss)	'	'	-1,367	'
Balance at the end of the period	($831)	'	($831)	'

Goodwill_and_Purchased_Intangi2

Goodwill and Purchased Intangible Assets, net (Details) (USD $)

3 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

Sep. 27, 2014

Sep. 28, 2013

Sep. 27, 2014

Sep. 28, 2013

Dec. 28, 2013

Sep. 27, 2014

Jul. 02, 2014

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Sep. 27, 2014

Dec. 28, 2013

Sep. 27, 2014

Dec. 28, 2013

Apica Acquisition

Apica Acquisition

IPR&D

IPR&D

Patents and trademarks

Patents and trademarks

Core technology

Core technology

Developed technology

Developed technology

Developed technology

Pre-existing license agreement

Pre-existing license agreement

Customer based relationships and other

Customer based relationships and other

Apica Acquisition

Changes in carrying amount of goodwill

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance, beginning of the period

'

'

$205,764,000

'

'

'

$31,381,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Additions

'

'

'

'

'

31,381,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Foreign currency translation impact

'

'

-5,680,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance, end of period

231,465,000

'

231,465,000

'

'

'

31,381,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Intangible assets subject to amortization:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gross carrying amount before adjustments

'

'

'

'

'

'

'

'

'

43,532,000

43,532,000

37,180,000

37,180,000

133,373,000

128,073,000

'

2,300,000

2,300,000

7,246,000

7,246,000

Accumulated amortization before adjustments

'

'

'

'

'

'

'

'

'

-35,693,000

-34,755,000

-23,637,000

-22,986,000

-84,126,000

-81,635,000

'

-1,040,000

-794,000

-5,316,000

-4,043,000

Accumulated impairment before adjustments

-50,242,000

'

-50,242,000

'

-50,242,000

'

'

'

'

'

'

-12,642,000

-12,642,000

-37,600,000

-37,600,000

'

'

'

'

'

Net carrying amount before adjustments

'

'

'

'

'

'

'

'

'

7,839,000

8,777,000

901,000

1,552,000

11,647,000

8,838,000

'

1,260,000

1,506,000

1,930,000

3,203,000

Foreign currency translation adjustments, gross

-547,000

'

-547,000

'

127,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Foreign currency translation adjustments, net

-574,000

'

-574,000

'

127,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gross Carrying Amount

223,057,000

'

223,057,000

'

218,458,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accumulated Amortization

-149,812,000

'

-149,812,000

'

-144,213,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total

23,003,000

'

23,003,000

'

24,003,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Intangible assets not yet subject to amortization:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total intangible assets not yet subject to amortization

'

'

'

'

'

'

'

38,900,000

12,400,000

'

'

'

'

'

'

'

'

'

'

'

Foreign currency translation adjustments

'

'

-1,469,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total purchased intangible assets, gross

260,488,000

'

260,488,000

'

230,858,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total purchased intangible assets, net

60,434,000

'

60,434,000

'

36,403,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Intangible assets, useful lives

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'

'

'

'

Amortization expense related to identifiable intangible assets (subject to amortization)

1,900,000

2,600,000

5,700,000

7,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Estimated amortization expense for the next five fiscal years and all years thereafter

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Remainder of 2014

1,896,000

'

1,896,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2015

5,715,000

'

5,715,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2016

4,416,000

'

4,416,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2017

3,543,000

'

3,543,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2018

3,129,000

'

3,129,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Thereafter

4,304,000

'

4,304,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total

$23,003,000

'

$23,003,000

'

$24,003,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit_Facility_Details

Credit Facility (Details) (Credit Facility, USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2014	Dec. 19, 2011
Credit facility	'	'
Maximum borrowing capacity	'	$50
Reference rate for variable rate (as a percent)	'LIBOR plus	'
Minimum	'	'
Credit facility	'	'
Margin rate (as a percent)	0.75%	'
Maximum	'	'
Credit facility	'	'
Margin rate (as a percent)	1.25%	'

Legal_Proceedings_Details

Legal Proceedings (Details)	9 Months Ended
	Sep. 27, 2014
	item
Legal Proceedings	'
Number of present and former officers named as defendants in a complaint filed in the United States District Court	3

ShareBased_Compensation_Detail

Share-Based Compensation (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013	Dec. 28, 2013
Share-based compensation	'	'	'	'	'
Share-based compensation cost	$6,971,000	6,855,000	$21,586,000	20,226,000	'
Tax benefit for share-based compensation expense	3,591,000	2,605,000	8,594,000	7,675,000	'
Total share-based compensation (net of taxes)	3,380,000	4,250,000	12,992,000	12,551,000	'
Options	'	'	'	'	'
Share-based compensation	'	'	'	'	'
Remaining shares available for issuance	3,200,000	'	3,200,000	'	'
Method and assumptions on valuation of stock options	'	'	'	'	'
Risk-free interest rate (weighted average) (as a percent)	'	2.00%	2.19%	1.38%	'
Expected volatility (as a percent)	'	40.00%	37.00%	37.00%	'
Expected option term	'	'4 years 11 months 5 days	'	'	'
Dividends (as a percent)	0.00%	0.00%	0.00%	0.00%	'
Number of options	'	'	'	'	'
Outstanding options at the beginning of the period (in shares)	'	'	2,261,000	'	'
Granted (in shares)	0	'	586,000	'	'
Exercised (in shares)	'	'	-146,000	'	'
Forfeited or expired (in shares)	'	'	-45,000	'	'
Outstanding options at the end of the period (in shares)	2,656,000	'	2,656,000	'	2,261,000
Outstanding options vested at the end of the period and expected to vest (in shares)	2,573,000	'	2,573,000	'	'
Outstanding options exercisable at the end of the period (in shares)	1,252,000	'	1,252,000	'	'
Stock options, Weighted-Average Exercise Price Per Share	'	'	'	'	'
Outstanding options at the beginning of the period (in dollars per share)	'	'	$29.68	'	'
Granted (in dollars per share)	'	'	$34.86	'	'
Exercised (in dollars per share)	'	'	$19.75	'	'
Forfeited or expired (in dollars per share)	'	'	$35.88	'	'
Outstanding options at the end of the period (in dollars per share)	$31.26	'	$31.26	'	$29.68
Outstanding options vested at the end of the period and expected to vest (in dollars per share)	$31.15	'	$31.15	'	'
Outstanding options exercisable at the end of the period (in dollars per share)	$27.94	'	$27.94	'	'
Weighted Average Remaining Contract Life (years)	'	'	'	'	'
Outstanding options at the beginning of the period	'	'	'7 years 1 month 10 days	'	'6 years 11 months 12 days
Outstanding options at the end of the period	'	'	'7 years 1 month 10 days	'	'6 years 11 months 12 days
Outstanding options vested at the end of the period and expected to vest	'	'	'7 years 22 days	'	'
Outstanding options exercisable at the end of the period	'	'	'5 years 7 months 17 days	'	'
Unrecognized compensation expenses, net of estimated forfeitures	8,500,000	'	8,500,000	'	'
Weighted average period for unrecognized compensation cost expected to be recognized	'	'	'1 year 5 months 26 days	'	'
Weighted average grant-date fair value (in dollars per share)	'	'	$12.39	'	'
Options | Minimum	'	'	'	'	'
Method and assumptions on valuation of stock options	'	'	'	'	'
Expected option term	'	'	'4 years 6 months 14 days	'4 years 11 months 1 day	'
Options | Maximum	'	'	'	'	'
Method and assumptions on valuation of stock options	'	'	'	'	'
Expected option term	'	'	'5 years 14 days	'5 years 8 months 12 days	'
Cost of product sales	'	'	'	'	'
Share-based compensation	'	'	'	'	'
Share-based compensation cost	529,000	586,000	1,906,000	1,773,000	'
Selling, general and administrative expenses	'	'	'	'	'
Share-based compensation	'	'	'	'	'
Share-based compensation cost	4,486,000	4,373,000	13,305,000	12,681,000	'
Research and development	'	'	'	'	'
Share-based compensation	'	'	'	'	'
Share-based compensation cost	$1,956,000	1,896,000	$6,375,000	5,772,000	'

ShareBased_Compensation_Detail1

Share-Based Compensation (Details 2) (Restricted stock units, USD $)	9 Months Ended	12 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 27, 2014	Dec. 28, 2013
Restricted stock units	'	'
Number of Units	'	'
Outstanding units at the beginning of the period (in shares)	1,461,000	'
Granted (in shares)	772,000	'
Released (in shares)	-528,000	'
Forfeited or expired (in shares)	-67,000	'
Outstanding units at the end of the period (in shares)	1,638,000	1,461,000
Weighted average grant-date fair value	'	'
Outstanding units at the beginning of the year (in dollars per share)	$33.40	'
Granted (in dollars per share)	$33.11	'
Released (in dollars per share)	$32.29	'
Forfeited or expired (in dollars per share)	$34.92	'
Outstanding units at the end of the year (in dollars per share)	$33.56	$33.40
Weighted Average Remaining Contract Life (in years)	'	'
Weighted Average Remaining Contract Life	'1 year 6 months	'1 year 3 months 7 days
Weighted Average Remaining Contract Life	'1 year 6 months	'1 year 3 months 7 days
Unrecognized compensation expenses, net of estimated forfeitures	$40.40	'
Weighted average period for unrecognized compensation cost expected to be recognized	'2 years 6 months	'

ShareBased_Compensation_Detail2

Share-Based Compensation (Details 3) (Performance Share Units)	0 Months Ended	9 Months Ended
	Sep. 22, 2014	Sep. 27, 2014
Share-Based Compensation	'	'
Shares of common stock issued	'	69,000
Granted (in shares)	188,000	'
Performance period	'3 years	'
Maximum number of share issued against each performance share unit	'	2
Number of shares issuable upon vesting	'	0
Minimum	'	'
Share-Based Compensation	'	'
Percentage range of shares of common stock issued	'	0.00%
Vesting period	'	'3 years
Maximum	'	'
Share-Based Compensation	'	'
Percentage range of shares of common stock issued	'	200.00%
Vesting period	'	'4 years

Common_and_Preferred_Stock_Det

Common and Preferred Stock (Details) (USD $)	9 Months Ended		0 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 27, 2014	Sep. 28, 2013	Dec. 05, 2013	Sep. 27, 2014	Sep. 27, 2014	Mar. 29, 2014	Sep. 27, 2014
			December 2013 program	December 2013 program	December 2013 program	November 2012 program	2014 ASR
Common and Preferred Stock	'	'	'	'	'	'	'
Maximum amount for repurchase of common stock	'	'	$200	'	$131.90	$1.20	$30
Repurchases of shares of our common stock under stock repurchase programs	69.2	'	'	30.6	68.1	'	30
Decrease in additional-paid-in-capital	2.5	2.3	'	'	29.3	'	15.1
Decrease in retained earnings	4.8	4.8	'	'	39.9	'	14.9
Aggregate amount of common stock agreed to be repurchased	$7.30	$7.10	'	'	'	'	$30
Number of shares repurchased	'	'	'	'	'	'	1,055,408
Percentage of the ASR Program's value received	'	'	'	'	'	'	80.00%
Number of additional shares delivered at maturity date of the program	'	'	'	'	'	'	152,120
Common stock repurchase average price per share (in dollars per share)	'	'	'	'	'	'	$24.84

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
Income Taxes	'	'	'	'
Effective income tax rates (as a percent)	-194.40%	17.50%	28.40%	25.30%
Tax benefits recognized related to federal R&D credits	'	'	'	$2.30
Tax benefits recognized due to enactment of law	'	'	'	1.4
Reasonably possible potential reduction in unrecognized tax benefits over the next 12 months	$1.90	'	$1.90	'

Segment_and_Geographic_Informa2

Segment and Geographic Information (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
			segment
Segment and Geographic Information	'	'	'	'
Number of operating and reporting segment	'	'	1	'
Segment information	'	'	'	'
Product sales	$105,839	$126,444	$349,599	$374,648
HeartMate	'	'	'	'
Segment information	'	'	'	'
Product sales	91,599	112,837	303,585	331,404
CentriMag	'	'	'	'
Segment information	'	'	'	'
Product sales	11,272	10,448	37,377	32,327
PVAD and IVAD	'	'	'	'
Segment information	'	'	'	'
Product sales	2,463	2,592	7,212	9,108
Other	'	'	'	'
Segment information	'	'	'	'
Product sales	505	567	1,425	1,809
Pump	'	'	'	'
Segment information	'	'	'	'
Product sales	74,189	87,108	245,072	264,867
Non-Pump	'	'	'	'
Segment information	'	'	'	'
Product sales	31,145	38,769	103,102	107,972
Other	'	'	'	'
Segment information	'	'	'	'
Product sales	505	567	1,425	1,809
Domestic	'	'	'	'
Segment information	'	'	'	'
Product sales	85,762	99,608	275,539	290,643
International	'	'	'	'
Segment information	'	'	'	'
Product sales	$20,077	$26,836	$74,060	$84,005

Net_Income_Per_Share_Details

Net Income Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
Numerator:	'	'	'	'
Net Income	$2,897	$18,904	$38,549	$60,263
Denominator:	'	'	'	'
Weighted average shares used to compute basic EPS	55,733	57,427	56,430	57,447
Dilutive effect of share-based compensation plans	378	807	689	953
Weighted average shares used to compute diluted EPS	56,111	58,234	57,119	58,400
Net income per share:	'	'	'	'
Basic (in dollars per share)	$0.05	$0.33	$0.68	$1.05
Diluted (in dollars per share)	$0.05	$0.32	$0.67	$1.03
Options	'	'	'	'
Potential common share equivalents excluded	'	'	'	'
Options to purchase shares not included in the computation of diluted income per share because their inclusion would be anti-dilutive	1,893	642	1,473	1,008