Genomic Health (GHDX) 10-Q 7 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 31, 2013
Document and Entity Information	'	'
Entity Registrant Name	'GENOMIC HEALTH INC	'
Entity Central Index Key	'0001131324	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-31	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	30,738,244
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$39,781	$18,005
Short-term marketable securities	74,265	81,060
Accounts receivable (net of allowance for doubtful accounts; 2013 - $1,847, 2012 - $1,133)	25,594	22,253
Prepaid expenses and other current assets	9,314	8,891
Total current assets	148,954	130,209
Property and equipment, net	18,242	14,104
Other assets	9,504	9,421
Total assets	176,700	153,734
Current liabilities:	'	'
Accounts payable	3,545	4,881
Accrued compensation	11,190	11,210
Accrued license fees	2,319	2,292
Accrued expenses and other current liabilities	10,451	6,340
Deferred revenues	1,134	374
Other current liabilities	292	243
Total current liabilities	28,931	25,340
Other liabilities	2,141	2,068
Commitments and contingencies	'	'
Stockholders' equity:	'	'
Common stock	3	3
Additional paid-in capital	336,617	313,915
Accumulated other comprehensive income	18	15
Accumulated deficit	-160,900	-157,512
Treasury stock, at cost	-30,110	-30,095
Total stockholders' equity	145,628	126,326
Total liabilities and stockholders' equity	$176,700	$153,734

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Condensed Consolidated Balance Sheets	'	'
Accounts receivable, allowance for doubtful accounts	$1,847	$1,133

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. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues:	'	'	'	'
Product revenues	$65,732	$58,371	$192,132	$173,459
Contract revenues	258	277	644	1,287
Total revenues	65,990	58,648	192,776	174,746
Operating expenses:	'	'	'	'
Cost of product revenues	10,781	9,037	31,285	27,377
Research and development	14,726	12,267	42,189	35,775
Selling and marketing	26,013	21,526	81,587	69,657
General and administrative	14,007	12,107	41,052	35,518
Total operating expenses	65,527	54,937	196,113	168,327
Income (loss) from operations	463	3,711	-3,337	6,419
Interest income	52	77	174	226
Other income (expense), net	89	33	-2	-112
Income (loss) before income taxes	604	3,821	-3,165	6,533
Income tax expense	116	109	223	243
Net income (loss)	$488	$3,712	($3,388)	$6,290
Basic net income (loss) per share (in dollars per share)	$0.02	$0.12	($0.11)	$0.21
Diluted net income (loss) per share (in dollars per share)	$0.02	$0.11	($0.11)	$0.20
Shares used in computing basic net income per share (in shares)	30,661	30,580	30,368	30,233
Shares used in computing diluted net income per share (in shares)	32,324	32,578	30,368	32,095

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (Loss) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Condensed Consolidated Statements of Comprehensive Income (Loss)	'	'	'	'
Net income (loss)	$488	$3,712	($3,388)	$6,290
Other comprehensive income (loss):	'	'	'	'
Unrealized gain (loss) on available-for-sale marketable securities, net of tax	-3	18	3	46
Comprehensive income (loss)	$485	$3,730	($3,385)	$6,336

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating activities	'	'
Net income (loss)	($3,388)	$6,290
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'
Depreciation and amortization	4,770	3,974
Employee stock-based compensation	12,845	10,807
Outside director restricted stock awarded in lieu of fees	170	120
Gain on disposal of property and equipment	-5	-3
Share of loss of equity method investee	'	98
Changes in assets and liabilities:	'	'
Accounts receivable	-3,341	1,151
Prepaid expenses and other assets	-623	-1,269
Accounts payable	-1,396	-3,633
Accrued compensation	-20	62
Accrued expenses and other liabilities	2,977	3,046
Deferred revenues	760	-818
Net cash provided by operating activities	12,749	19,825
Investing activities	'	'
Purchases of property and equipment	-7,443	-6,170
Purchases of marketable securities	-71,914	-61,496
Maturities of marketable securities	78,712	60,125
Purchase of other investments	'	-1,409
Net cash used in investing activities	-645	-8,950
Financing activities	'	'
Net proceeds from issuance of common stock under stock plans	9,687	14,215
Repurchase of common stock	-15	'
Net cash provided by financing activities	9,672	14,215
Net increase in cash and cash equivalents	21,776	25,090
Cash and cash equivalents at the beginning of the period	18,005	32,869
Cash and cash equivalents at the end of the period	$39,781	$57,959

Organization_and_Summary_of_Si

Organization and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2013
Organization and Summary of Significant Accounting Policies	'
Organization and Summary of Significant Accounting Policies	'
	Note 1. Organization and Summary of Significant Accounting Policies
	The Company
	Genomic Health, Inc. (the “Company”) is a global healthcare company that provides actionable genomic information to personalize cancer treatment decisions. The Company develops and globally commercializes genomic-based clinical laboratory services that analyze the underlying biology of cancer, allowing physicians and patients to make individualized treatment decisions. The Company was incorporated in Delaware in August 2000. The Company’s first product, the Oncotype DX invasive breast cancer test, was launched in 2004 and is used for early stage invasive breast cancer patients to predict the likelihood of breast cancer recurrence and the likelihood of chemotherapy benefit. In January 2010, the Company launched its second product, the Oncotype DX colon cancer test, which is used to predict the likelihood of colon cancer recurrence in patients with stage II disease. In December 2011, the Company made the Oncotype DX breast cancer test available for patients with ductal carcinoma in situ (“DCIS”), a pre-invasive form of breast cancer. This test provides a DCIS score that is used to predict the likelihood of local recurrence. In June 2012, the Company began offering the Oncotype DX colon cancer test for use in patients with stage III disease treated with oxaliplatin-containing adjuvant therapy. In May 2013, the Company launched the Oncotype DX prostate cancer test. The test provides a Genomic Prostate Score, or GPS, to predict disease aggressiveness in men with low risk disease. This test may be used to improve treatment decisions for prostate cancer patients, in conjunction with the Gleason score, or tumor grading.
	Principles of Consolidation
	The condensed consolidated financial statements include all the accounts of the Company and its wholly-owned subsidiaries. The Company had three wholly-owned subsidiaries at September 30, 2013: Genomic Health International Sarl, which was established in Switzerland in 2009, and Genomic Health International Holdings, LLC, which was established in Delaware in 2010, both of which support the Company’s international sales and marketing efforts; and Oncotype Laboratories, Inc., which was established in 2003, and is inactive. Genomic Health International Holdings, LLC has five wholly-owned subsidiaries: Genomic Health U.K., Ltd. and Genomic Health Germany GmbH, both of which were established in 2011, Genomic Health Canada, which was established in 2012 and Genomic Health France and Genomic Health India, which were established in 2013. The functional currency for the Company’s wholly-owned subsidiaries incorporated outside the United States is the U.S. dollar. All significant intercompany balances and transactions have been eliminated.
	Basis of Presentation and Use of Estimates
	The accompanying interim period condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The condensed consolidated balance sheet as of September 30, 2013, condensed consolidated statements of operations, condensed consolidated statements of comprehensive income (loss) and condensed consolidated statements of cash flows for the three and nine months ended September 30, 2013 and 2012 are unaudited, but include all adjustments, consisting only of normal recurring adjustments, which the Company considers necessary for a fair presentation of its financial position, operating results and cash flows for the periods presented. The condensed consolidated balance sheet at December 31, 2012 has been derived from audited financial statements, but it does not include certain information and notes required by GAAP for complete consolidated financial statements.
	The preparation of financial statements in conformity with GAAP requires management to make judgments, assumptions and estimates that affect the amounts reported in the Company’s condensed consolidated financial statements and accompanying notes. Actual results could differ materially from those estimates.
	The accompanying interim period condensed consolidated financial statements and related financial information should be read in conjunction with the audited consolidated financial statements and the related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.
	Revenue Recognition
	The Company derives its revenues primarily from product sales and, to a lesser extent, contract research arrangements. The majority of the Company’s historical product revenues have been derived from the sale of the Oncotype DX breast cancer test. The Company generally bills third-party payors upon generation and delivery of a patient report to the physician. As such, the Company takes assignment of benefits and the risk of collection with the third-party payor. The Company usually bills the patient directly for amounts owed after multiple requests for payment have been denied or only partially paid by the insurance carrier. The Company pursues case-by-case reimbursement where policies are not in place or payment history has not been established.
	The Company’s product revenues for tests performed are recognized when the following revenue recognition criteria are met: (1) persuasive evidence that an arrangement exists; (2) delivery has occurred or services have been rendered; (3) the fee is fixed or determinable; and (4) collectibility is reasonably assured. Criterion (1) is satisfied when the Company has an arrangement to pay or a contract with the payor in place addressing reimbursement for the Oncotype DX test. In the absence of such arrangements, the Company considers that criterion (1) is satisfied when a third-party payor pays the Company for the test performed. Criterion (2) is satisfied when the Company performs the test and generates and delivers to the physician, or makes available on its web portal, a patient report. Determinations of criteria (3) and (4) are based on management’s judgments regarding whether the fee charged for products or services delivered is fixed or determinable, and the collectibility of those fees under any contract or arrangement. When evaluating collectibility, the Company considers whether it has sufficient history to reliably estimate a payor’s individual payment patterns. Based upon at least several months of payment history, the Company reviews the number of tests paid against the number of tests billed and the payor’s outstanding balance for unpaid tests to determine whether payments are being made at a consistently high percentage of tests billed and at appropriate amounts given the contracted payment amount. To the extent all criteria set forth above are not met when test results are delivered, product revenues are recognized when cash is received from the payor.
	The Company has exclusive distribution agreements for one or more of its Oncotype DX tests with approximately 20 distributors covering more than 80 countries. The distributor generally provides certain marketing and administrative services to the Company within its territory. As a condition of these agreements, the distributor generally pays the Company an agreed upon fee per test and the Company processes the tests. The same revenue recognition criteria described above generally apply to tests received through distributors. To the extent all criteria set forth above are not met when test results are delivered, product revenues are generally recognized when cash is received from the distributor.
	From time to time, the Company receives duplicate payments or overpayments made by third-party payors or patients. When a duplicate payment or overpayment is identified, the Company establishes an accrued liability for the overpaid amount until such time as the Company determines whether or not a refund is due. Accrued refunds were $946,000 and $664,000 at September 30, 2013 and December 31, 2012, respectively, and included in accrued expenses and other current liabilities.
	Contract revenues are generally derived from studies conducted with biopharmaceutical and pharmaceutical companies. The specific methodology for revenue recognition is determined on a case-by-case basis according to the facts and circumstances applicable to a given contract. Under certain contracts, the Company’s input, measured in terms of full-time equivalent level of effort or running a set of assays through its clinical reference laboratory under a contractual protocol, triggers payment obligations, and revenues are recognized as costs are incurred or assays are processed. Certain contracts have payments that are triggered as milestones are completed, such as completion of a successful set of experiments. Milestones are assessed on an individual basis and revenue is recognized when these milestones are achieved, as evidenced by acknowledgment from collaborators, provided that (1) the milestone event is substantive and its achievability was not reasonably assured at the inception of the agreement and (2) the milestone payment is non-refundable. Where separate milestones do not meet these criteria, the Company defaults to a performance-based model, such as revenue recognition following delivery of effort as compared to an estimate of total expected effort.
	Advance payments received in excess of revenues recognized are classified as deferred revenue until such time as the revenue recognition criteria have been met.
	Allowance for Doubtful Accounts
	The Company accrues an allowance for doubtful accounts against its accounts receivable based on estimates consistent with historical payment experience. Bad debt expense is included in general and administrative expense on the Company’s condensed consolidated statements of operations. Accounts receivable are written off against the allowance when the appeals process is exhausted, when an unfavorable coverage decision is received or when there is other substantive evidence that the account will not be paid. The Company’s allowance for doubtful accounts as of September 30, 2013 and December 31, 2012 was $1.8 million and $1.1 million, respectively. Write-offs for doubtful accounts of $1.7 million and $4.1 million were recorded against the allowance during the three and nine months ended September 30, 2013, respectively, and write-offs of $972,000 and $2.6 million were recorded against the allowance during the three and nine months ended September 30, 2012, respectively. Bad debt expense was $1.8 million and $4.8 million for the three and nine months ended September 30, 2013, respectively, and $998,000 and $2.6 million for the three and nine months ended September 30, 2012, respectively.
	Research and Development Expenses
	Research and development expenses are comprised of costs incurred to develop technology and carry out clinical studies and include salaries and benefits, reagents and supplies used in research and development laboratory work, infrastructure expenses, including allocated facility occupancy and information technology costs, contract services, and other outside costs. Research and development expenses also include costs related to activities performed under contracts with biopharmaceutical and pharmaceutical companies. Research and development costs are expensed as incurred.
	The Company enters into collaboration and clinical trial agreements with clinical collaborators and records the costs associated with these agreements as research and development expenses. The Company records accruals for estimated study costs comprised of work performed by its collaborators under contract terms. Advance payments for goods or services that will be used or rendered for future research and development activities are deferred and capitalized and recognized as expense as the goods are delivered or the related services are performed.
	Income Taxes
	The Company uses the liability method for income taxes, whereby deferred income taxes are provided on items recognized for financial reporting purposes over different periods than for income tax purposes. Valuation allowances are provided when the expected realization of tax assets does not meet a more-likely-than-not criterion.
	The Company accounts for uncertain income tax positions using a benefit recognition model with a two-step approach, a more-likely-than-not recognition criterion and a measurement attribute that measures the position as the largest amount of tax benefit that is greater than 50% likely of being realized upon ultimate settlement, in accordance with the accounting guidance for uncertain tax positions. If it is not more likely than not that the benefit will be sustained on its technical merits, no benefit is recorded. Uncertain tax positions that relate only to timing of when an item is included on a tax return are considered to have met the recognition threshold. The Company recognizes accrued interest and penalties related to unrecognized tax benefits in income tax expense when and if incurred. See Note 8, “Income Taxes,” for additional information regarding unrecognized tax benefits.
	Investments in PrivatelyHeld Companies
	The Company determines whether its investments in privately held companies are debt or equity based on their characteristics, in accordance with the applicable accounting guidance for such investments. The Company also evaluates the investee to determine if the entity is a variable interest entity (“VIE”) and, if so, whether the Company is the primary beneficiary of the VIE, in order to determine whether consolidation of the VIE is required in accordance with accounting guidance for consolidations. If consolidation is not required and the Company owns less than 50.1% of the voting interest of the entity, the investment is evaluated to determine if the equity method of accounting should be applied. The equity method applies to investments in common stock or in-substance common stock where the Company exercises significant influence over the investee, typically represented by ownership of 20% or more of the voting interests of an entity. If the equity method does not apply, investments in privately held companies determined to be equity securities are accounted for using the cost method. Investments in privately held companies determined to be debt securities are accounted for as available-for-sale or held-to-maturity securities, in accordance with accounting guidance for investments.
	The Company reviews long-lived assets, which include investments in privately held companies, for impairment whenever events or changes in business circumstances indicate that the carrying amounts of the assets may not be fully recoverable. For investments in privately held companies, evidence of impairment might include the absence of an ability to recover the carrying amount of the investment or the inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment. The Company’s assessment as to whether any impairment is other than temporary is based on its ability and intent to hold the investment and whether evidence indicating the carrying value of the investment is recoverable within a reasonable period of time outweighs evidence to the contrary. If the fair value of the investment is determined to be less than the carrying value and the decline in value is considered to be other than temporary, the asset is written down to its fair value.
	In December 2010, the Company invested $500,000 in the preferred stock of a private company representing 21% of the entity’s outstanding voting shares. The Company determined that it was not the primary beneficiary of this VIE and, accordingly, applied the equity method of accounting. In June 2012, the Company invested an additional $400,000 in the preferred stock of this company as part of a new equity financing which included other investors, and reduced the Company’s holdings to approximately 16%. As of June 30, 2012, the Company changed its method of accounting for this investment to the cost method because the Company’s ownership fell below 20% and the Company does not have the ability to exercise significant influence over the investee entity. As of September 30, 2013, the Company considered the investment to be temporarily impaired based on the private company’s low cash balances resulting from the delay of its commercial product launch. The private company is in the process of raising additional capital combined with executing new customer agreements and the Company has the ability and intent to hold the investment and expects the fair value of their investment to ultimately exceed the carrying value. The net carrying value of this investment was $643,000 at September 30, 2013 and at December 31, 2012, and no impairment was recognized through September 30, 2013.
	In March 2011, the Company invested $2.3 million in the redeemable preferred stock of a private company representing 21% of the entity’s outstanding voting shares. The Company determined that the investment was a held-to-maturity debt security and that the investee was not subject to consolidation. In August 2012, the Company participated in the first tranche of a second preferred stock financing of this private company and purchased $1.0 million of preferred stock with no redemption privileges. In connection with this financing, the terms of the Company’s initial redeemable preferred stock investment were modified to become preferred stock with no redemption privileges. As a result of this transaction, the Company’s ownership interest was reduced to approximately 19% and the investment held by the Company is considered to be an investment in non-marketable equity securities. In October 2012, the Company participated in the second tranche of the second financing and purchased an additional $3.6 million of preferred stock, resulting in an ownership percentage of approximately 18%. In May 2013, the investee completed an additional round of financing to new investors. As of September 30, 2013, the Company’s ownership percentage was approximately 13%. The investee is not consolidated because the Company owns less than 20% of the investee and the Company does not have the ability to exercise significant influence over the investee. As a result, the Company will continue to use the cost method of accounting for this investment. The carrying value of this investment was $6.9 million at September 30, 2013 and at December 31, 2012, and no impairment was recognized through September 30, 2013.
	The aggregate carryng value of the Company’s investments in privately held companies was $7.5 million at September 30, 2013 and at December 31, 2012, and were included in other assets in the accompanying condensed consolidated balance sheets. It is not practicable for the Company to estimate the fair value of its cost method investments in privately held companies since they are non-marketable securities and, therefore, quoted market prices are not available.
	Recently Issued Accounting Pronouncements
	In February 2013, the Financial Accounting Standards Board issued authoritative guidance requiring companies to report, in one place, information about reclassifications out of accumulated other comprehensive income (“AOCI”). Companies are also required to present reclassifications by component when reporting changes to AOCI balances. This guidance is effective for the Company for interim and annual periods beginning after December 15, 2012. As this guidance provides only presentation requirements, the adoption of this guidance does not impact the Company’s financial condition or results of operations. The Company adopted this standard in January 2013, as reflected by the inclusion of the Condensed Consolidated Statements of Comprehensive Income (Loss) as part of its Condensed Consolidated Financial Statements.

Net_Income_Loss_Per_Share

Net Income (Loss) Per Share	9 Months Ended
	Sep. 30, 2013
Net Income (Loss) Per Share	'
Net Income (Loss) Per Share	'
	Note 2.  Net Income (Loss) Per Share
	Basic net income (loss) per share is calculated by dividing net income (loss) for the period by the weighted-average number of common shares outstanding for the period without consideration of potential common shares. Diluted net income (loss) per share is calculated by dividing net income (loss) by the weighted-average number of common shares outstanding for the period and dilutive potential common shares for the period determined using the treasury-stock method. For purposes of this calculation, options to purchase common stock and restricted stock unit awards are considered to be potential common shares and are not included in the calculation of diluted net loss per share because their effect is anti-dilutive.
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013			2012
		(In thousands)
	Numerator:
	Net income (loss)	$	488	$	3,712	$	(3,388	)	$	6,290
	Denominator:
	Weighted-average shares of common stock outstanding used in the calculation of basic net income (loss) per share	30,661		30,580		30,368			30,233
	Effect of dilutive securities:
	Options to purchase common stock	1,486		1,844		—			1,758
	Restricted stock units	177		154		—			104
	Total	1,663		1,998		—			1,862
	Weighted-average shares of common stock outstanding used in the calculation of diluted net income (loss) per share	32,324		32,578		30,368			32,095
	Basic net income (loss) per share	$	0.02	$	0.12	$	(0.11	)	$	0.21
	Diluted net income (loss) per share	$	0.02	$	0.11	$	(0.11	)	$	0.2
	Options to purchase approximately 829,000 and 834,000 weighted average shares of the Company’s common stock that were outstanding during the three and nine months ended September 30, 2013, respectively, were not included in the computation of diluted net loss per share because their effect was anti-dilutive. Options to purchase approximately 556,000 and 486,000 weighted average shares of the Company’s common stock were outstanding during the three and nine months ended September 30, 2012, respectively, but were not included in the computation of diluted net income per share because their effect was anti-dilutive.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Measurements	'
Fair Value Measurements	'
	Note 3.  Fair Value Measurements
	The Company measures certain financial assets, including cash equivalents and marketable securities, at their fair value on a recurring basis. The fair value of these financial assets was determined based on a hierarchy of three levels of inputs, of which the first two are considered observable and the last unobservable, as follows:
	Level 1:  Quoted prices in active markets for identical assets or liabilities;
	Level 2:  Observable inputs other than Level 1 inputs, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and
	Level 3:  Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. The Company did not have any non-financial assets or liabilities that were measured or disclosed at fair value on a recurring basis at September 30, 2013 and December 31, 2012, respectively. The following tables set forth the Company’s financial instruments that were measured at fair value on a recurring basis at September 30, 2013 and December 31, 2012 by level within the fair value hierarchy:
		Actively Quoted		Significant Other		Significant			Balance at
		Markets for		Observable		Unobservable			September 30,
		Identical Assets		Inputs		Inputs			2013
		Level 1		Level 2		Level 3
		(In thousands)
	As of September 30, 2013:
	Assets
	Money market deposits	$	9,357	$	—	$	—		$	9,357
	U.S. Treasury securities	751		—		—			751
	Debt securities of U.S. government-sponsored entities	—		1,107		—			1,107
	Commercial paper	—		47,149		—			47,149
	Corporate debt securities	—		30,358		—			30,358
	Total	$	10,108	$	78,614	$	—		$	88,722
		Actively Quoted		Significant Other		Significant			Balance at
		Markets for		Observable		Unobservable			December 31,
		Identical Assets		Inputs		Inputs			2012
		Level 1		Level 2		Level 3
		(In thousands)
	As of December 31, 2012:
	Assets
	Money market deposits	$	7,403	$	—	$	—		$	7,403
	U.S. Treasury securities	1,276		—		—			1,276
	Debt securities of U.S. government-sponsored entities	—		761		—			761
	Commercial paper	—		33,888		—			33,888
	Corporate debt securities	—		52,102		—			52,102
	Total	$	8,679	$	86,751	$	—		$	95,430
	The Company’s debt securities of U.S. government-sponsored entities, commercial paper and corporate bonds are classified as Level 2 as they are valued using multi-dimensional relational pricing models that use observable market inputs, including benchmark yields, reported trades, broker-dealer quotes, issuer spreads, benchmark securities, bids, offers and reference data. Not all inputs listed are available for use in the evaluation process on any given day for each security evaluation. In addition, market indicators, industry and economic events are monitored and may serve as a trigger to acquire further corroborating market data. There were no transfers between Level 1 and Level 2 categories during the three and nine months ended September 30, 2013 and 2012, respectively.
	All of the Company’s marketable securities are classified as available-for-sale. The following tables illustrate the Company’s available-for-sale marketable securities as of the dates indicated:
		September 30, 2013
		Amortized		Unrealized		Unrealized			Estimated
		Cost		Gains		Losses			Fair Value
		(In thousands)
	U.S. Treasury securities	$	751	$	—	$	—		$	751
	Debt securities of U.S. government-sponsored entities	1,106		1		—			1,107
	Commercial paper	42,875		24		—			42,899
	Corporate debt securities	29,515		4		(11		)	29,508
	Total	$	74,247	$	29	$	(11	)	$	74,265
		December 31, 2012
		Amortized		Unrealized		Unrealized			Estimated
		Cost		Gains		Losses			Fair Value
		(In thousands)
	U.S. Treasury securities	$	1,275	$	1	$	—		$	1,276
	Debt securities of U.S. government-sponsored entities	761		—		—			761
	Commercial paper	28,854		35		—			28,889
	Corporate debt securities	50,155		2		(23		)	50,134
	Total	$	81,045	$	38	$	(23	)	$	81,060
	The Company had no realized gains or losses on available-for-sale marketable securities for the three and nine months ended September 30, 2013 and 2012, respectively.
	All of the Company’s available-for-sale marketable securities had contractual maturities of one year or less as of September 30, 2013 and December 31, 2012, respectively.

Collaboration_and_Commercial_T

Collaboration and Commercial Technology Licensing Agreements	9 Months Ended
	Sep. 30, 2013
Collaboration and Commercial Technology Licensing Agreements	'
Collaboration and Commercial Technology Licensing Agreements	'
	Note 4. Collaboration and Commercial Technology Licensing Agreements
	The Company has entered into a variety of collaboration and specimen transfer agreements relating to its development efforts. The Company recorded collaboration expenses of $1.0 million and $2.1 million for the three and nine months ended September 30, 2013 and $370,000 and $1.4 million for the three and nine months ended September 30, 2012, respectively, relating to services provided in connection with these agreements. In addition to these expenses, some of the agreements contain provisions for royalties from inventions resulting from these collaborations. The Company has specified options and rights relating to joint inventions arising out of the collaborations.
	In August 2013, the Company entered into a collaboration agreement to conduct an additional large DCIS clinical study to validate the relationship between the Oncotype DX DCIS score and the likelihood of local recurrence in patients with DCIS. The agreement, which is estimated to be completed in 2017, includes a study fee and milestone payments dependent on the completion of certain key milestones. During the three and nine months ended September 30, 2013, the Company made milestone payments of $392,000 related to this agreement. All future milestone payments are contingent on certain milestone accomplishments, and therefore the timing for future milestone payments cannot be estimated.
	The Company is a party to various agreements under which it licenses technology on a non-exclusive basis in the field of human diagnostics. Access to these licenses enables the Company to process its Oncotype DX tests. While certain agreements contain provisions for fixed annual payments, license fees are generally calculated as a percentage of product revenues, with rates that vary by agreement and may be tiered, and payments that may be capped at annual minimum or maximum amounts. The Company recognized costs recorded under these agreements totaling $2.2 million and $6.7 million for the three and nine months ended September 30, 2013 and $2.0 million and $6.0 million for the three and nine months ended September 30, 2012, respectively, which were included in cost of product revenues.
	At September 30, 2013, fixed future annual payments, exclusive of royalty payments, relating to the launch and commercialization of the Oncotype DX colon cancer test and the Oncotype DX prostate cancer test totaled $1.1 million and are payable as follows:
		Fixed Future
		Annual Payments
		(In thousands)
	Payment Due:
	2014	$	550
	2015	550
	Total	$	1,100
	These payments are recorded in cost of product revenues as license fees. Expense for payments included in the table above is recorded ratably over the year before the relevant payment is due. If at any time the Company discontinues the sale of the products covered by the agreement, no future annual payments will be payable and the Company will have no further obligation under the applicable agreement.
	Contract Research Arrangements
	In November 2007, the Company entered into a Collaborative Diagnostic Development Agreement with Pfizer Inc. to provide research and development services for the development of a diagnostic product for renal cell cancer. The Company received an initial payment of $1.5 million and was initially eligible to receive a payment of $2.2 million upon joint agreement on a gene identification plan, $5.0 million in additional payments upon the earlier of Pfizer’s election to initiate the next phase of development or a specified number of months from the date the Company received the sample set and related clinical data necessary to conduct the first phase of development, and a final payment of $1.5 million upon completion of clinical validation. Completion of clinical validation represents a substantive milestone and the Company will recognize the $1.5 million payment upon completion. All other payments were not considered substantive milestones as they are not based solely on the Company’s past performance. Such payments are recognized using a performance- based model and revenue is recognized following delivery of effort as compared to an estimate of total expected effort. The Company did not recognize any revenue related to substantive milestones under this agreement during the three and nine months ended and September 30, 2013 and 2012, respectively.

Commitments

Commitments	9 Months Ended
	Sep. 30, 2013
Commitments	'
Commitments	'
	Note 5. Commitments
	Lease Obligations
	In September 2005, the Company entered into a non-cancelable lease for 48,000 square feet of laboratory and office space that the Company currently occupies in Redwood City, California. In November 2010, the Company executed an amendment to extend the term of the lease through March 2019, with an option to extend the term of the lease for an additional five years. The agreement included lease incentive obligations of $834,000 that are being amortized on a straight-line basis over the life of the lease.
	In January 2007, the Company entered into a non-cancelable lease for an additional 48,000 square feet of laboratory and office space in a nearby location. In November 2010, the Company executed an amendment to extend the term of the lease through March 2018, with an option to extend the term of the lease for an additional five years. The agreement included lease incentive obligations totaling $283,000 that are being amortized on a straight-line basis over the life of the lease.
	In October 2009, the Company entered into a non-cancelable agreement to lease an additional 30,500 square feet of office space near the locations the Company currently occupies. The lease expires in March 2018, with an option for the Company to extend the term of the lease for an additional five years. The agreement includes lease incentive obligations of $307,000 which are being amortized on a straight-line basis over the life of the lease.
	In August 2013, the Company entered into a non-cancelable agreement to lease an additional 18,400 square feet of laboratory and office space near the locations the Company currently occupies. The lease expires in March 2019, with an option for the Company to extend the term of the lease for an additional five years. In addition, there is an additional 5,500 square feet that may become available during the initial term of the lease, which the Company has agreed to lease on the same terms. The agreement includes lease incentive obligations of $276,000 which are being amortized on a straight-line basis over the life of the lease.
	In May 2010, the Company’s European subsidiary entered into a non-cancelable lease for approximately 2,500 square feet of office space in Geneva, Switzerland. The lease expires in May 2015.  Additionally, the Company has offices in the United Kingdom and Germany with short-term rental agreements.
	Future non-cancelable commitments under these operating leases at September 30, 2013 were as follows:
		Annual
		Payments
		(In thousands)
	Years Ending December 31,
	2013 (remainder of year)	$	771
	2014	3,603
	2015	3,539
	2016	3,597
	2017	3,706
	2018 and thereafter	2,771
	Total minimum payments	$	17,987

StockBased_Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2013
Stock-Based Compensation	'
Stock-Based Compensation	'
	Note 6. Stock-Based Compensation
	The Company recognized employee stock-based compensation expense of $4.4 million and $12.8 million for the three and nine months ended September 30, 2013, respectively, and $3.4 million and $10.8 million for the three and nine months ended September 30, 2012, respectively. Employee stock-based compensation expense includes expense related to stock option grants, restricted stock unit (“RSU”) awards to employees, restricted stock issued in lieu of outside director fees and stock purchased under the Company’s Employee Stock Purchase Plan (“ESPP”). Stock-based compensation expense is calculated based on options and RSUs ultimately expected to vest and has been reduced for estimated forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.
	Stock Option Grants
	The Company granted options to purchase 83,105 shares and 458,355 shares of common stock to employees during the three and nine months ended September 30, 2013, respectively and 41,500 shares and 608,000 shares of common stock to employees during the three and nine months ended September 30, 2012, respectively. For the three and nine months ended September 30, 2013, the Company issued 123,796 and 631,114 shares of common stock in connection with the exercise of stock options with a weighted-average exercise price of $15.37 and $16.44 per share, respectively. For the three and nine months ended September 30, 2012, the Company issued 303,577 and 835,865 shares of common stock in connection with the exercise of stock options with a weighted-average exercise price of $17.96 and $16.53 per share, respectively.
	Restricted Stock Units
	During the three and nine months ended September 30, 2013, the Company awarded 110,635 and 379,158 RSUs with a grant-date fair value equal to $3.9 million and $11.6 million, respectively. During the three and nine months ended September 30, 2012, the Company awarded 31,550 and 415,566 RSUs with a grant-date fair value equal to $1.1 million and $12.3 million, respectively. Each RSU entitles the recipient to receive one share of the Company’s common stock upon vesting. RSUs awarded to employees generally vest as to one-third of the total number of shares awarded annually over a three-year period. During the three and nine months ended September 30, 2013, the Company issued 12,328 and 223,791 shares of common stock in connection with the vesting of RSUs with a weighted-average grant date fair value of $31.35 and $26.94 per share, respectively. During the three and nine months ended September 30, 2012, the Company issued 2,819 and 64,909 shares of common stock, respectively, in connection with the vesting of RSUs with a weighted-average grant date fair value of $22.80 and $23.29 per share, respectively.
	Restricted Stock in Lieu of Directors’ Fees
	Outside members of the Company’s Board of Directors may elect to receive fully-vested restricted stock in lieu of cash compensation for services as a director. During the three and nine months ended September 30, 2013, the Company issued 1,818 and 5,795 shares of restricted stock to outside directors, with a grant date fair value of $60,000 and $170,000, respectively, and a weighted-average grant date fair value of $32.85 and $29.28 per share, respectively. During the three and nine months ended September 30, 2012, the Company issued 1,196 and 4,072 shares of restricted stock to outside directors, with a grant date fair value of $40,000 and $120,000, respectively, and a weighted-average grant date fair value of $33.40 and $29.41 per share, respectively.
	Employee Stock Purchase Plan
	During the nine months ended September 30, 2013, 86,683 shares were issued under the ESPP. There were no shares issued under the ESPP during the three months ended September 30, 2013. A total of 1,250,000 shares of common stock have been reserved for issuance under the ESPP, of which 1,017,254 shares were available for issuance as of September 30, 2013. As of September 30, 2013, there was $171,000 of unrecognized compensation expense related to the ESPP, which is expected to be recognized over an estimated weighted-average period of two months.
	Valuation Assumptions
	The Company values its stock option grants using the Black-Scholes option valuation model. Option valuation models require the input of highly subjective assumptions that can vary over time. The Company’s assumptions regarding expected volatility are based on the historical volatility of the Company’s common stock. The expected life of options granted is estimated based on historical option exercise data and assumptions related to unsettled options. The risk-free interest rate is estimated using published rates for U.S. Treasury securities with a remaining term approximating the expected life of the options granted. The Company uses a dividend yield of zero as it has never paid cash dividends and does not anticipate paying cash dividends in the foreseeable future. The weighted-average fair values and assumptions used in calculating such values during each period are as follows:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Expected volatility:
	Stock options	45		%	45		%	46		%	46		%
	ESPP	29		%	38		%	41		%	43		%
	Risk-free interest rate:
	Stock options	1.9		%	1.43		%	1.4		%	1.23		%
	ESPP	0.08		%	0.12		%	0.11		%	0.08		%
	Expected life in years:
	Stock options	6.59			6.68			6.64			6.98
	ESPP	0.5			0.5			0.5			0.5
	Weighted-average fair value:
	Stock options	$	15.83		$	18.4		$	14.11		$	14.51
	ESPP	$	8.04		$	8.12		$	7.74		$	7.59

Segment_Information

Segment Information	9 Months Ended
	Sep. 30, 2013
Segment Information	'
Segment Information	'
	Note 7. Segment Information
	The Company operates in one business segment, which primarily focuses on the development and global commercialization of genomic based clinical laboratory services that analyze the underlying biology of cancer. As of September 30, 2013, the majority of the Company’s product revenues have been derived from sales of one product, the Oncotype DX breast cancer test. All Oncotype DX tests are included in one segment, because they have similar economic and other characteristics, including the nature of the tests and laboratory processes, type of customers, distribution methods and regulatory environment.
	The following table summarizes total revenues from customers and collaboration partners by geographic region. Product revenues are attributed to countries based on ship-to location. Contract revenues are attributed to countries based on the location of the collaboration partner.
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
		(in thousands)
	United States	$	55,890	$	50,564	$	164,973	$	155,798
	Outside of the United States	10,100		8,084		27,803		18,948
	Total revenues	$	65,990	$	58,648	$	192,776	$	174,746

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Taxes	'
Income Taxes	'
	Note 8. Income Taxes
	The Company recorded income tax expense of $116,000 and $223,000 for the three and nine months ended September 30, 2013, respectively, which was computed using the “discrete” (or “cut-off”) method and was principally comprised of state income taxes and foreign taxes. The Company recorded income tax expense of $109,000 and $243,000 for the three and nine months ended September 30, 2012, respectively, which was computed using the same method and was principally comprised of California alternative minimum tax, other state income taxes and foreign taxes. The difference between the income tax expense actually recorded and the statutory rate applied to the Company’s income (loss) before income taxes was primarily due to the impact of nondeductible meals and entertainment for the three and nine months ended September 30, 2013 and nondeductible stock-based compensation expenses for the three and nine months ended September 30, 2012.
	Based on all available objective evidence, the Company believes that it is more likely than not that its net deferred tax assets will not be fully realized. Accordingly, the Company maintained a valuation allowance against all of its net deferred tax assets as of both September 30, 2013 and December 31, 2012. The Company will continue to maintain a full valuation allowance until there is sufficient evidence to support recoverability of its deferred tax assets.
	The Company had $967,000 and $875,000 of unrecognized tax benefits as of September 30, 2013 and December 31, 2012, respectively. The Company does not anticipate a material change to its unrecognized tax benefits over the next twelve months. Unrecognized tax benefits may change during the next twelve months for items that arise in the ordinary course of business.
	Accrued interest and penalties related to unrecognized tax benefits are recognized as part of the Company’s income tax provision in its condensed consolidated statements of operations. All tax years from 2000 forward remain subject to future examination by federal, state and foreign tax authorities.

Organization_and_Summary_of_Si1

Organization and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Organization and Summary of Significant Accounting Policies	'
Principles of Consolidation	'
	Principles of Consolidation
	The condensed consolidated financial statements include all the accounts of the Company and its wholly-owned subsidiaries. The Company had three wholly-owned subsidiaries at September 30, 2013: Genomic Health International Sarl, which was established in Switzerland in 2009, and Genomic Health International Holdings, LLC, which was established in Delaware in 2010, both of which support the Company’s international sales and marketing efforts; and Oncotype Laboratories, Inc., which was established in 2003, and is inactive. Genomic Health International Holdings, LLC has five wholly-owned subsidiaries: Genomic Health U.K., Ltd. and Genomic Health Germany GmbH, both of which were established in 2011, Genomic Health Canada, which was established in 2012 and Genomic Health France and Genomic Health India, which were established in 2013. The functional currency for the Company’s wholly-owned subsidiaries incorporated outside the United States is the U.S. dollar. All significant intercompany balances and transactions have been eliminated.
Basis of Presentation and Use of Estimates	'
	Basis of Presentation and Use of Estimates
	The accompanying interim period condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The condensed consolidated balance sheet as of September 30, 2013, condensed consolidated statements of operations, condensed consolidated statements of comprehensive income (loss) and condensed consolidated statements of cash flows for the three and nine months ended September 30, 2013 and 2012 are unaudited, but include all adjustments, consisting only of normal recurring adjustments, which the Company considers necessary for a fair presentation of its financial position, operating results and cash flows for the periods presented. The condensed consolidated balance sheet at December 31, 2012 has been derived from audited financial statements, but it does not include certain information and notes required by GAAP for complete consolidated financial statements.
	The preparation of financial statements in conformity with GAAP requires management to make judgments, assumptions and estimates that affect the amounts reported in the Company’s condensed consolidated financial statements and accompanying notes. Actual results could differ materially from those estimates.
	The accompanying interim period condensed consolidated financial statements and related financial information should be read in conjunction with the audited consolidated financial statements and the related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.
Revenue Recognition	'
	Revenue Recognition
	The Company derives its revenues primarily from product sales and, to a lesser extent, contract research arrangements. The majority of the Company’s historical product revenues have been derived from the sale of the Oncotype DX breast cancer test. The Company generally bills third-party payors upon generation and delivery of a patient report to the physician. As such, the Company takes assignment of benefits and the risk of collection with the third-party payor. The Company usually bills the patient directly for amounts owed after multiple requests for payment have been denied or only partially paid by the insurance carrier. The Company pursues case-by-case reimbursement where policies are not in place or payment history has not been established.
	The Company’s product revenues for tests performed are recognized when the following revenue recognition criteria are met: (1) persuasive evidence that an arrangement exists; (2) delivery has occurred or services have been rendered; (3) the fee is fixed or determinable; and (4) collectibility is reasonably assured. Criterion (1) is satisfied when the Company has an arrangement to pay or a contract with the payor in place addressing reimbursement for the Oncotype DX test. In the absence of such arrangements, the Company considers that criterion (1) is satisfied when a third-party payor pays the Company for the test performed. Criterion (2) is satisfied when the Company performs the test and generates and delivers to the physician, or makes available on its web portal, a patient report. Determinations of criteria (3) and (4) are based on management’s judgments regarding whether the fee charged for products or services delivered is fixed or determinable, and the collectibility of those fees under any contract or arrangement. When evaluating collectibility, the Company considers whether it has sufficient history to reliably estimate a payor’s individual payment patterns. Based upon at least several months of payment history, the Company reviews the number of tests paid against the number of tests billed and the payor’s outstanding balance for unpaid tests to determine whether payments are being made at a consistently high percentage of tests billed and at appropriate amounts given the contracted payment amount. To the extent all criteria set forth above are not met when test results are delivered, product revenues are recognized when cash is received from the payor.
	The Company has exclusive distribution agreements for one or more of its Oncotype DX tests with approximately 20 distributors covering more than 80 countries. The distributor generally provides certain marketing and administrative services to the Company within its territory. As a condition of these agreements, the distributor generally pays the Company an agreed upon fee per test and the Company processes the tests. The same revenue recognition criteria described above generally apply to tests received through distributors. To the extent all criteria set forth above are not met when test results are delivered, product revenues are generally recognized when cash is received from the distributor.
	From time to time, the Company receives duplicate payments or overpayments made by third-party payors or patients. When a duplicate payment or overpayment is identified, the Company establishes an accrued liability for the overpaid amount until such time as the Company determines whether or not a refund is due. Accrued refunds were $946,000 and $664,000 at September 30, 2013 and December 31, 2012, respectively, and included in accrued expenses and other current liabilities.
	Contract revenues are generally derived from studies conducted with biopharmaceutical and pharmaceutical companies. The specific methodology for revenue recognition is determined on a case-by-case basis according to the facts and circumstances applicable to a given contract. Under certain contracts, the Company’s input, measured in terms of full-time equivalent level of effort or running a set of assays through its clinical reference laboratory under a contractual protocol, triggers payment obligations, and revenues are recognized as costs are incurred or assays are processed. Certain contracts have payments that are triggered as milestones are completed, such as completion of a successful set of experiments. Milestones are assessed on an individual basis and revenue is recognized when these milestones are achieved, as evidenced by acknowledgment from collaborators, provided that (1) the milestone event is substantive and its achievability was not reasonably assured at the inception of the agreement and (2) the milestone payment is non-refundable. Where separate milestones do not meet these criteria, the Company defaults to a performance-based model, such as revenue recognition following delivery of effort as compared to an estimate of total expected effort.
	Advance payments received in excess of revenues recognized are classified as deferred revenue until such time as the revenue recognition criteria have been met.
Allowance for Doubtful Accounts	'
	Allowance for Doubtful Accounts
	The Company accrues an allowance for doubtful accounts against its accounts receivable based on estimates consistent with historical payment experience. Bad debt expense is included in general and administrative expense on the Company’s condensed consolidated statements of operations. Accounts receivable are written off against the allowance when the appeals process is exhausted, when an unfavorable coverage decision is received or when there is other substantive evidence that the account will not be paid. The Company’s allowance for doubtful accounts as of September 30, 2013 and December 31, 2012 was $1.8 million and $1.1 million, respectively. Write-offs for doubtful accounts of $1.7 million and $4.1 million were recorded against the allowance during the three and nine months ended September 30, 2013, respectively, and write-offs of $972,000 and $2.6 million were recorded against the allowance during the three and nine months ended September 30, 2012, respectively. Bad debt expense was $1.8 million and $4.8 million for the three and nine months ended September 30, 2013, respectively, and $998,000 and $2.6 million for the three and nine months ended September 30, 2012, respectively.
Research and Development Expenses	'
	Research and Development Expenses
	Research and development expenses are comprised of costs incurred to develop technology and carry out clinical studies and include salaries and benefits, reagents and supplies used in research and development laboratory work, infrastructure expenses, including allocated facility occupancy and information technology costs, contract services, and other outside costs. Research and development expenses also include costs related to activities performed under contracts with biopharmaceutical and pharmaceutical companies. Research and development costs are expensed as incurred.
	The Company enters into collaboration and clinical trial agreements with clinical collaborators and records the costs associated with these agreements as research and development expenses. The Company records accruals for estimated study costs comprised of work performed by its collaborators under contract terms. Advance payments for goods or services that will be used or rendered for future research and development activities are deferred and capitalized and recognized as expense as the goods are delivered or the related services are performed.
Income Taxes	'
	Income Taxes
	The Company uses the liability method for income taxes, whereby deferred income taxes are provided on items recognized for financial reporting purposes over different periods than for income tax purposes. Valuation allowances are provided when the expected realization of tax assets does not meet a more-likely-than-not criterion.
	The Company accounts for uncertain income tax positions using a benefit recognition model with a two-step approach, a more-likely-than-not recognition criterion and a measurement attribute that measures the position as the largest amount of tax benefit that is greater than 50% likely of being realized upon ultimate settlement, in accordance with the accounting guidance for uncertain tax positions. If it is not more likely than not that the benefit will be sustained on its technical merits, no benefit is recorded. Uncertain tax positions that relate only to timing of when an item is included on a tax return are considered to have met the recognition threshold. The Company recognizes accrued interest and penalties related to unrecognized tax benefits in income tax expense when and if incurred. See Note 8, “Income Taxes,” for additional information regarding unrecognized tax benefits.
Investments in Privately Held Companies	'
	Investments in PrivatelyHeld Companies
	The Company determines whether its investments in privately held companies are debt or equity based on their characteristics, in accordance with the applicable accounting guidance for such investments. The Company also evaluates the investee to determine if the entity is a variable interest entity (“VIE”) and, if so, whether the Company is the primary beneficiary of the VIE, in order to determine whether consolidation of the VIE is required in accordance with accounting guidance for consolidations. If consolidation is not required and the Company owns less than 50.1% of the voting interest of the entity, the investment is evaluated to determine if the equity method of accounting should be applied. The equity method applies to investments in common stock or in-substance common stock where the Company exercises significant influence over the investee, typically represented by ownership of 20% or more of the voting interests of an entity. If the equity method does not apply, investments in privately held companies determined to be equity securities are accounted for using the cost method. Investments in privately held companies determined to be debt securities are accounted for as available-for-sale or held-to-maturity securities, in accordance with accounting guidance for investments.
	The Company reviews long-lived assets, which include investments in privately held companies, for impairment whenever events or changes in business circumstances indicate that the carrying amounts of the assets may not be fully recoverable. For investments in privately held companies, evidence of impairment might include the absence of an ability to recover the carrying amount of the investment or the inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment. The Company’s assessment as to whether any impairment is other than temporary is based on its ability and intent to hold the investment and whether evidence indicating the carrying value of the investment is recoverable within a reasonable period of time outweighs evidence to the contrary. If the fair value of the investment is determined to be less than the carrying value and the decline in value is considered to be other than temporary, the asset is written down to its fair value.
	In December 2010, the Company invested $500,000 in the preferred stock of a private company representing 21% of the entity’s outstanding voting shares. The Company determined that it was not the primary beneficiary of this VIE and, accordingly, applied the equity method of accounting. In June 2012, the Company invested an additional $400,000 in the preferred stock of this company as part of a new equity financing which included other investors, and reduced the Company’s holdings to approximately 16%. As of June 30, 2012, the Company changed its method of accounting for this investment to the cost method because the Company’s ownership fell below 20% and the Company does not have the ability to exercise significant influence over the investee entity. As of September 30, 2013, the Company considered the investment to be temporarily impaired based on the private company’s low cash balances resulting from the delay of its commercial product launch. The private company is in the process of raising additional capital combined with executing new customer agreements and the Company has the ability and intent to hold the investment and expects the fair value of their investment to ultimately exceed the carrying value. The net carrying value of this investment was $643,000 at September 30, 2013 and at December 31, 2012, and no impairment was recognized through September 30, 2013.
	In March 2011, the Company invested $2.3 million in the redeemable preferred stock of a private company representing 21% of the entity’s outstanding voting shares. The Company determined that the investment was a held-to-maturity debt security and that the investee was not subject to consolidation. In August 2012, the Company participated in the first tranche of a second preferred stock financing of this private company and purchased $1.0 million of preferred stock with no redemption privileges. In connection with this financing, the terms of the Company’s initial redeemable preferred stock investment were modified to become preferred stock with no redemption privileges. As a result of this transaction, the Company’s ownership interest was reduced to approximately 19% and the investment held by the Company is considered to be an investment in non-marketable equity securities. In October 2012, the Company participated in the second tranche of the second financing and purchased an additional $3.6 million of preferred stock, resulting in an ownership percentage of approximately 18%. In May 2013, the investee completed an additional round of financing to new investors. As of September 30, 2013, the Company’s ownership percentage was approximately 13%. The investee is not consolidated because the Company owns less than 20% of the investee and the Company does not have the ability to exercise significant influence over the investee. As a result, the Company will continue to use the cost method of accounting for this investment. The carrying value of this investment was $6.9 million at September 30, 2013 and at December 31, 2012, and no impairment was recognized through September 30, 2013.
	The aggregate carryng value of the Company’s investments in privately held companies was $7.5 million at September 30, 2013 and at December 31, 2012, and were included in other assets in the accompanying condensed consolidated balance sheets. It is not practicable for the Company to estimate the fair value of its cost method investments in privately held companies since they are non-marketable securities and, therefore, quoted market prices are not available.
Recently Issued Accounting Pronouncements	'
	Recently Issued Accounting Pronouncements
	In February 2013, the Financial Accounting Standards Board issued authoritative guidance requiring companies to report, in one place, information about reclassifications out of accumulated other comprehensive income (“AOCI”). Companies are also required to present reclassifications by component when reporting changes to AOCI balances. This guidance is effective for the Company for interim and annual periods beginning after December 15, 2012. As this guidance provides only presentation requirements, the adoption of this guidance does not impact the Company’s financial condition or results of operations. The Company adopted this standard in January 2013, as reflected by the inclusion of the Condensed Consolidated Statements of Comprehensive Income (Loss) as part of its Condensed Consolidated Financial Statements.

Net_Income_Loss_Per_Share_Tabl

Net Income (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2013
Net Income (Loss) Per Share	'
Schedule of reconciliation of numerator and denominator used in calculation of basic and diluted net income (loss) per share	'
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013			2012
		(In thousands)
	Numerator:
	Net income (loss)	$	488	$	3,712	$	(3,388	)	$	6,290
	Denominator:
	Weighted-average shares of common stock outstanding used in the calculation of basic net income (loss) per share	30,661		30,580		30,368			30,233
	Effect of dilutive securities:
	Options to purchase common stock	1,486		1,844		—			1,758
	Restricted stock units	177		154		—			104
	Total	1,663		1,998		—			1,862
	Weighted-average shares of common stock outstanding used in the calculation of diluted net income (loss) per share	32,324		32,578		30,368			32,095
	Basic net income (loss) per share	$	0.02	$	0.12	$	(0.11	)	$	0.21
	Diluted net income (loss) per share	$	0.02	$	0.11	$	(0.11	)	$	0.2

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Measurements	'
Schedule of financial instruments measured at fair value on recurring basis	'
		Actively Quoted		Significant Other		Significant			Balance at
		Markets for		Observable		Unobservable			September 30,
		Identical Assets		Inputs		Inputs			2013
		Level 1		Level 2		Level 3
		(In thousands)
	As of September 30, 2013:
	Assets
	Money market deposits	$	9,357	$	—	$	—		$	9,357
	U.S. Treasury securities	751		—		—			751
	Debt securities of U.S. government-sponsored entities	—		1,107		—			1,107
	Commercial paper	—		47,149		—			47,149
	Corporate debt securities	—		30,358		—			30,358
	Total	$	10,108	$	78,614	$	—		$	88,722
		Actively Quoted		Significant Other		Significant			Balance at
		Markets for		Observable		Unobservable			December 31,
		Identical Assets		Inputs		Inputs			2012
		Level 1		Level 2		Level 3
		(In thousands)
	As of December 31, 2012:
	Assets
	Money market deposits	$	7,403	$	—	$	—		$	7,403
	U.S. Treasury securities	1,276		—		—			1,276
	Debt securities of U.S. government-sponsored entities	—		761		—			761
	Commercial paper	—		33,888		—			33,888
	Corporate debt securities	—		52,102		—			52,102
	Total	$	8,679	$	86,751	$	—		$	95,430
Summary of available-for-sale marketable securities	'
		September 30, 2013
		Amortized		Unrealized		Unrealized			Estimated
		Cost		Gains		Losses			Fair Value
		(In thousands)
	U.S. Treasury securities	$	751	$	—	$	—		$	751
	Debt securities of U.S. government-sponsored entities	1,106		1		—			1,107
	Commercial paper	42,875		24		—			42,899
	Corporate debt securities	29,515		4		(11		)	29,508
	Total	$	74,247	$	29	$	(11	)	$	74,265
		December 31, 2012
		Amortized		Unrealized		Unrealized			Estimated
		Cost		Gains		Losses			Fair Value
		(In thousands)
	U.S. Treasury securities	$	1,275	$	1	$	—		$	1,276
	Debt securities of U.S. government-sponsored entities	761		—		—			761
	Commercial paper	28,854		35		—			28,889
	Corporate debt securities	50,155		2		(23		)	50,134
	Total	$	81,045	$	38	$	(23	)	$	81,060

Collaboration_and_Commercial_T1

Collaboration and Commercial Technology Licensing Agreements (Tables)	9 Months Ended
	Sep. 30, 2013
Collaboration and Commercial Technology Licensing Agreements	'
Schedule of fixed future annual payments, exclusive of royalty payments	'
		Fixed Future
		Annual Payments
		(In thousands)
	Payment Due:
	2014	$	550
	2015	550
	Total	$	1,100

Commitments_Tables

Commitments (Tables)	9 Months Ended
	Sep. 30, 2013
Commitments	'
Schedule of future non-cancelable commitments under operating leases	'
		Annual
		Payments
		(In thousands)
	Years Ending December 31,
	2013 (remainder of year)	$	771
	2014	3,603
	2015	3,539
	2016	3,597
	2017	3,706
	2018 and thereafter	2,771
	Total minimum payments	$	17,987

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2013
Stock-Based Compensation	'
Schedule of weighted-average fair values and assumptions used in calculation of fair value of stock options and employee stock purchase plan	'
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Expected volatility:
	Stock options	45		%	45		%	46		%	46		%
	ESPP	29		%	38		%	41		%	43		%
	Risk-free interest rate:
	Stock options	1.9		%	1.43		%	1.4		%	1.23		%
	ESPP	0.08		%	0.12		%	0.11		%	0.08		%
	Expected life in years:
	Stock options	6.59			6.68			6.64			6.98
	ESPP	0.5			0.5			0.5			0.5
	Weighted-average fair value:
	Stock options	$	15.83		$	18.4		$	14.11		$	14.51
	ESPP	$	8.04		$	8.12		$	7.74		$	7.59

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Information	'
Summary of total revenues from customers and collaboration partners by geographic region	'
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
		(in thousands)
	United States	$	55,890	$	50,564	$	164,973	$	155,798
	Outside of the United States	10,100		8,084		27,803		18,948
	Total revenues	$	65,990	$	58,648	$	192,776	$	174,746

Organization_and_Summary_of_Si2

Organization and Summary of Significant Accounting Policies (Details) (USD $)

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Jun. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Oct. 31, 2012

Aug. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Mar. 31, 2011

Dec. 31, 2010

Sep. 30, 2013

country

Private company 1, Cost Method Investment

Private company 1, Cost Method Investment

Private company 1, Cost Method Investment

Private company 2

Private company 2

Private company 2

Private company 2

Private company 2

Private company 1, Equity Method Investment

Genomic Health International Holdings, LLC

subsidiary

subsidiary

test

distributor

Organization and summary of significant accounting policies

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of wholly-owned subsidiaries

'

'

3

'

'

'

'

'

'

'

'

'

'

'

5

Revenue Recognition

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Minimum number of Oncotype DX tests by exclusive distribution agreements

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

Approximate number of distributors with exclusive distribution agreements

'

'

20

'

'

'

'

'

'

'

'

'

'

'

'

Minimum number of countries covered for distribution agreements establishment

'

'

80

'

'

'

'

'

'

'

'

'

'

'

'

Accrued refunds

$946,000

'

$946,000

'

$664,000

'

'

'

'

'

'

'

'

'

'

Allowance for Doubtful Accounts

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Allowance for doubtful accounts

1,847,000

'

1,847,000

'

1,133,000

'

'

'

'

'

'

'

'

'

'

Write-offs for doubtful accounts recorded against allowance

1,700,000

972,000

4,100,000

2,600,000

'

'

'

'

'

'

'

'

'

'

'

Bad debt expense

1,800,000

998,000

4,800,000

2,600,000

'

'

'

'

'

'

'

'

'

'

'

Investments in Privately Held Companies

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount invested in preferred stock of a private company

'

'

'

'

'

'

'

'

'

'

'

'

'

500,000

'

Percentage of ownership interest in private company

'

'

'

'

'

'

'

'

'

'

'

'

'

21.00%

'

Additional investment made in preferred stock of a private company

'

'

'

'

'

400,000

'

'

3,600,000

1,000,000

'

'

'

'

'

Percentage of ownership interest in private company accounted for under the cost method of accounting

'

'

'

'

'

16.00%

'

'

18.00%

19.00%

13.00%

'

'

'

'

Investment in redeemable preferred stock

'

'

'

'

'

'

'

'

'

'

'

'

2,300,000

'

'

Investment in the redeemable preferred stock of a private company, percent of the entity's outstanding voting shares

'

'

'

'

'

'

'

'

'

'

'

'

21.00%

'

'

Carrying value of investments in privately held companies

7,500,000

'

7,500,000

'

7,500,000

'

643,000

643,000

'

'

6,900,000

6,900,000

'

'

'

Impairment recognized

'

'

'

'

'

'

$0

'

'

'

$0

'

'

'

'

Net_Income_Loss_Per_Share_Deta

Net Income (Loss) Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Numerator:	'	'	'	'
Net income (loss) (in dollars)	$488	$3,712	($3,388)	$6,290
Denominator:	'	'	'	'
Weighted-average shares of common stock outstanding used in the calculation of basic net income (loss) per share	30,661,000	30,580,000	30,368,000	30,233,000
Effect of dilutive securities:	'	'	'	'
Effect of dilutive securities (in shares)	1,663,000	1,998,000	'	1,862,000
Weighted-average shares of common stock outstanding used in the calculation of diluted net income (loss) per share	32,324,000	32,578,000	30,368,000	32,095,000
Basic net income (loss) per share (in dollars per share)	$0.02	$0.12	($0.11)	$0.21
Diluted net income (loss) per share (in dollars per share)	$0.02	$0.11	($0.11)	$0.20
Options to purchase common stock	'	'	'	'
Effect of dilutive securities:	'	'	'	'
Effect of dilutive securities (in shares)	1,486,000	1,844,000	'	1,758,000
Outstanding options to purchase shares of common stock not included in the computation of diluted net loss per share (in shares)	829,000	556,000	834,000	486,000
Restricted stock units	'	'	'	'
Effect of dilutive securities:	'	'	'	'
Effect of dilutive securities (in shares)	177,000	154,000	'	104,000

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

In Thousands, unless otherwise specified

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

Actively Quoted Markets for Identical Assets Level 1

Actively Quoted Markets for Identical Assets Level 1

Actively Quoted Markets for Identical Assets Level 1

Actively Quoted Markets for Identical Assets Level 1

Actively Quoted Markets for Identical Assets Level 1

Actively Quoted 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

Fair value

Fair value

Fair value

Fair value

Fair value

Fair value

Fair value

Fair value

Fair value

Fair value

Fair value

Fair value

Money market deposits

Money market deposits

U.S. Treasury securities

U.S. Treasury securities

Debt securities of U.S. government-sponsored entities

Debt securities of U.S. government-sponsored entities

Commercial paper

Commercial paper

Corporate debt securities

Corporate debt securities

Money market deposits

Money market deposits

U.S. Treasury securities

U.S. Treasury securities

Debt securities of U.S. government-sponsored entities

Debt securities of U.S. government-sponsored entities

Commercial paper

Commercial paper

Corporate debt securities

Corporate debt securities

Assets measured at fair value on a recurring basis:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total assets at fair value

'

'

$10,108

$8,679

$9,357

$7,403

$751

$1,276

$78,614

$86,751

$1,107

$761

$47,149

$33,888

$30,358

$52,102

$88,722

$95,430

$9,357

$7,403

$751

$1,276

$1,107

$761

$47,149

$33,888

$30,358

$52,102

Transfer of assets from level 1 to level 2

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Transfer of assets from level 2 to level 1

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Transfer of liabilities from level 1 to level 2

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Transfer of liabilities from level 2 to level 1

$0

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Marketable securities classified as available-for-sale	'	'	'	'	'
Amortized Cost	$74,247	'	$74,247	'	$81,045
Unrealized Gains	29	'	29	'	38
Unrealized Losses	-11	'	-11	'	-23
Estimated Fair Value	74,265	'	74,265	'	81,060
Realized gains on available-for-sale marketable securities	0	0	0	0	'
Realized losses on available-for-sale marketable securities	0	0	0	0	'
Maximum contractual maturities of Company's available-for-sale marketable securities	'	'	'1 year	'	'1 year
U.S. Treasury securities	'	'	'	'	'
Marketable securities classified as available-for-sale	'	'	'	'	'
Amortized Cost	751	'	751	'	1,275
Unrealized Gains	'	'	'	'	1
Estimated Fair Value	751	'	751	'	1,276
Debt securities of U.S. government-sponsored entities	'	'	'	'	'
Marketable securities classified as available-for-sale	'	'	'	'	'
Amortized Cost	1,106	'	1,106	'	761
Unrealized Gains	1	'	1	'	'
Estimated Fair Value	1,107	'	1,107	'	761
Commercial paper	'	'	'	'	'
Marketable securities classified as available-for-sale	'	'	'	'	'
Amortized Cost	42,875	'	42,875	'	28,854
Unrealized Gains	24	'	24	'	35
Estimated Fair Value	42,899	'	42,899	'	28,889
Corporate debt securities	'	'	'	'	'
Marketable securities classified as available-for-sale	'	'	'	'	'
Amortized Cost	29,515	'	29,515	'	50,155
Unrealized Gains	4	'	4	'	2
Unrealized Losses	-11	'	-11	'	-23
Estimated Fair Value	$29,508	'	$29,508	'	$50,134

Collaboration_and_Commercial_T2

Collaboration and Commercial Technology Licensing Agreements (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Specimen transfer agreements	'	'	'	'
Collaboration and Commercial Technology Licensing Agreements	'	'	'	'
Collaboration expense	$1,000,000	$370,000	$2,100,000	$1,400,000
Oncotype DX DCIS score	'	'	'	'
Collaboration and Commercial Technology Licensing Agreements	'	'	'	'
Milestone payment	392,000	'	392,000	'
Technology license agreements	'	'	'	'
Collaboration and Commercial Technology Licensing Agreements	'	'	'	'
Costs recorded under collaborative arrangements	2,200,000	2,000,000	6,700,000	6,000,000
Oncotype DX colon cancer test and Oncotype DX prostate cancer test	'	'	'	'
Fixed future annual payments, exclusive of royalty payments	'	'	'	'
2014	550,000	'	550,000	'
2015	550,000	'	550,000	'
Total	$1,100,000	'	$1,100,000	'

Collaboration_and_Commercial_T3

Collaboration and Commercial Technology Licensing Agreements (Details 2) (Collaborative Diagnostic Development Agreement with Pfizer Inc., USD $)	1 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2007
Collaborative Diagnostic Development Agreement with Pfizer Inc.	'
Contract research arrangements	'
Initial payment received upon joint agreement	$1.50
Payment receivable upon joint agreement on gene identification plan	2.2
Additional payments receivable to conduct next phase of development	5
Final payment receivable upon completion of clinical validation	$1.50

Commitments_Details

Commitments (Details) (USD $)	Sep. 30, 2013	Nov. 30, 2010	Sep. 30, 2005	Nov. 30, 2010	Jan. 31, 2007	Oct. 31, 2009	Aug. 31, 2013	31-May-10
		Leased laboratory and office space located in Redwood City, California	Leased laboratory and office space located in Redwood City, California	Leased laboratory and office space located near the leased facility in Redwood City, California	Leased laboratory and office space located near the leased facility in Redwood City, California	Leased office space located near the leased facility in Redwood City, California	Second leased laboratory and office space located near the leased facility in Redwood City, California	Leased office space located in Geneva, Switzerland
			sqft		sqft	sqft	sqft	European subsidiary
								sqft
Non-cancelable operating leases	'	'	'	'	'	'	'	'
Area covered under non-cancelable operating lease agreement (in square feet)	'	'	48,000	'	48,000	30,500	18,400	2,500
Period of time for which entity has an option to extend lease term	'	'5 years	'	'5 years	'	'5 years	'5 years	'
Additional area that may become available during initial term of lease (in square feet)	'	'	'	'	'	'	5,500	'
Lease incentive obligations	'	'	$834,000	'	$283,000	$307,000	$276,000	'
Non-cancelable commitments under operating leases	'	'	'	'	'	'	'	'
2013 (remainder of year)	771,000	'	'	'	'	'	'	'
2014	3,603,000	'	'	'	'	'	'	'
2015	3,539,000	'	'	'	'	'	'	'
2016	3,597,000	'	'	'	'	'	'	'
2017	3,706,000	'	'	'	'	'	'	'
2018 and thereafter	2,771,000	'	'	'	'	'	'	'
Total minimum payments	$17,987,000	'	'	'	'	'	'	'

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stock-Based Compensation	'	'	'	'
Stock-based compensation expense (in dollars)	$4,400,000	$3,400,000	$12,800,000	$10,800,000
Employee Stock Purchase Plan	'	'	'	'
Employee Stock Purchase Plan	'	'	'	'
Number of shares issued	0	'	86,683	'
Shares of common stock reserved for issuance under the ESPP	1,250,000	'	1,250,000	'
Shares available for issuance	1,017,254	'	1,017,254	'
Unrecognized compensation expense (in dollars)	171,000	'	171,000	'
Weighted-average period of recognition of unrecognized stock-based compensation expense	'	'	'2 months	'
Weighted-average fair values and assumptions used in calculation of fair value	'	'	'	'
Expected volatility (as a percent)	29.00%	38.00%	41.00%	43.00%
Risk-free interest rate (as a percent)	0.08%	0.12%	0.11%	0.08%
Expected life	'6 months	'6 months	'6 months	'6 months
Weighted-average fair value (in dollars per share)	$8.04	$8.12	$7.74	$7.59
Stock Options	'	'	'	'
Stock Option Grants	'	'	'	'
Common stock issued in connection with the exercise of stock options (in shares)	123,796	303,577	631,114	835,865
Weighted-average exercise price of common stock issued (in dollars per share)	$15.37	$17.96	$16.44	$16.53
Weighted-average fair values and assumptions used in calculation of fair value	'	'	'	'
Dividend yield (as a percent)	0.00%	0.00%	0.00%	0.00%
Expected volatility (as a percent)	45.00%	45.00%	46.00%	46.00%
Risk-free interest rate (as a percent)	1.90%	1.43%	1.40%	1.23%
Expected life	'6 years 7 months 2 days	'6 years 8 months 5 days	'6 years 7 months 20 days	'6 years 11 months 23 days
Weighted-average fair value (in dollars per share)	$15.83	$18.40	$14.11	$14.51
Employee Stock Options	'	'	'	'
Stock Option Grants	'	'	'	'
Options granted to purchase shares of common stock to employees (in shares)	83,105	41,500	458,355	608,000
Restricted Stock Units	'	'	'	'
Stock awards other than options	'	'	'	'
Stock awards (in shares)	110,635	31,550	379,158	415,566
Grant-date fair value (in dollars)	3,900,000	1,100,000	11,600,000	12,300,000
Number of shares of common stock to be received for each restricted stock unit	'	'	1	'
Shares of common stock issued in connection with the vesting of the stock award	12,328	2,819	223,791	64,909
Weighted-average fair values and assumptions used in calculation of fair value	'	'	'	'
Weighted-average fair value (in dollars per share)	$31.35	$22.80	$26.94	$23.29
Restricted Stock Units | Employees	'	'	'	'
Stock awards other than options	'	'	'	'
Vesting period	'	'	'3 years	'
Restricted Stock Units | Employees | Annual vesting over vesting period	'	'	'	'
Stock awards other than options	'	'	'	'
Vesting percentage	'	'	33.00%	'
Restricted Stock | Outside directors	'	'	'	'
Stock awards other than options	'	'	'	'
Stock awards (in shares)	1,818	1,196	5,795	4,072
Grant-date fair value (in dollars)	$60,000	$40,000	$170,000	$120,000
Weighted-average fair values and assumptions used in calculation of fair value	'	'	'	'
Weighted-average fair value (in dollars per share)	$32.85	$33.40	$29.28	$29.41

Segment_Information_Details

Segment Information (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
	product		segment
	segment		product
Segment Information	'	'	'	'
Number of business segments in which the entity operates	'	'	1	'
Number of products from which the majority of the entity's product revenues have been derived	1	'	1	'
Number of segments in which product tests are included	1	'	1	'
Segment information	'	'	'	'
Total revenues	$65,990	$58,648	$192,776	$174,746
United States	'	'	'	'
Segment information	'	'	'	'
Total revenues	55,890	50,564	164,973	155,798
Outside of the United States	'	'	'	'
Segment information	'	'	'	'
Total revenues	$10,100	$8,084	$27,803	$18,948

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Income Taxes	'	'	'	'	'
Income tax expense	$116,000	$109,000	$223,000	$243,000	'
Unrecognized tax benefits	$967,000	'	$967,000	'	$875,000