Genomic Health (GHDX) 10-K 14 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Feb. 28, 2018	Jun. 30, 2017
Document and Entity Information
Entity Registrant Name	GENOMIC HEALTH INC
Entity Central Index Key	1,131,324
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 646.5
Entity Common Stock, Shares Outstanding		35,324,394
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 45,518	$ 40,404
Short-term marketable securities	84,057	56,585
Accounts receivable (net of allowance for doubtful accounts; 2017—$3,884, 2016—$4,508)	31,161	35,179
Prepaid expenses and other current assets	13,524	13,796
Total current assets	174,260	145,964
Property and equipment, net	46,440	45,688
Other assets	10,917	9,462
Total assets	231,617	201,114
Current liabilities:
Accounts payable	156	2,864
Accrued compensation and employee benefits	24,953	27,900
Accrued expenses and other current liabilities	14,084	10,180
Other current liabilities	323	231
Total current liabilities	39,516	41,175
Other liabilities	3,810	3,834
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.0001 par value, 5,000,000 shares authorized, no shares issued and outstanding
Common stock, $0.0001 par value; 100,000,000 shares authorized, 36,110,767 and 34,893,329 shares issued and 35,049,436 and 33,831,998 shares outstanding at December 31, 2017 and 2016, respectively	3	3
Additional paid-in capital	464,637	427,102
Accumulated other comprehensive (loss) income	(294)	1,198
Accumulated deficit	(245,945)	(242,088)
Treasury stock, at cost , 1,061,331 shares at December 31, 2017 and 2016	(30,110)	(30,110)
Total stockholders' equity	188,291	156,105
Total liabilities and stockholders' equity	$ 231,617	$ 201,114

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Consolidated Balance Sheets
Accounts receivable, allowance for doubtful accounts	$ 3,884	$ 4,508
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	36,110,767	34,893,329
Common stock, shares outstanding	35,049,436	33,831,998
Treasury stock, shares	1,061,331	1,061,331

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Product revenues	$ 340,451	$ 326,918	$ 287,458
Contract revenue	299	950
Total revenues	340,750	327,868	287,458
Operating expenses:
Cost of product revenues	54,718	58,828	55,135
Research and development	62,811	60,158	58,445
Selling and marketing	157,001	151,042	143,557
General and administrative	72,670	73,272	64,348
Total operating expenses	347,200	343,300	321,485
Loss from operations	(6,450)	(15,432)	(34,027)
Interest income	934	418	221
Gain on sale of equity securities	2,807	3,208
Other income (expense), net	356	(732)	(498)
Loss before income taxes	(2,353)	(12,538)	(34,304)
Income tax expense (benefit)	1,504	1,381	(996)
Net loss	$ (3,857)	$ (13,919)	$ (33,308)
Basic and diluted net loss per share (in dollars per share)	$ (0.11)	$ (0.42)	$ (1.03)
Shares used in computing basic and diluted net loss per share (in shares)	34,495	33,264	32,382

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated Statements of Comprehensive Income (Loss)
Net Loss	$ (3,857)	$ (13,919)	$ (33,308)
Other comprehensive Loss:
Unrealized gain (loss), net, on available-for-sale marketable securities, net of tax of $0, $0, and $1,548 for the years ended December 31, 2017, 2016 and 2015 respectively.	(366)	300	2,767
Reclassification adjustment for net gain on sale of investments, net of tax	(1,126)	(1,854)
Comprehensive loss	$ (5,349)	$ (15,473)	$ (30,541)

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated Statements of Comprehensive Income (Loss)
Unrealized gain on available-for-sale marketable securities, tax	$ 0	$ 0	$ 1,548

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Treasury Stock at Cost	Total
Balance at Dec. 31, 2014	$ 3	$ 370,496	$ (15)	$ (194,861)	$ (30,110)	$ 145,513
Balance (in shares) at Dec. 31, 2014	31,911,000
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of stock options for cash and vesting of restricted stock units		3,664				3,664
Issuance of common stock upon exercise of stock options for cash and vesting of restricted stock units (in shares)	678,000
Issuance of common stock upon settlement of employee stock purchase plan		4,694				4,694
Issuance of common stock upon settlement of employee stock purchase plan (in shares)	204,000
Issuance of restricted stock to directors in lieu of fees		200				200
Issuance of restricted stock to directors in lieu of fees (in shares)	7,000
Stock-based compensation expense related to employee stock options, restricted stock units and employee stock purchase plan		16,005				16,005
Net Loss				(33,308)		(33,308)
Unrealized gain (loss) on investments, net of tax			2,767			2,767
Balance at Dec. 31, 2015	$ 3	395,059	2,752	(228,169)	(30,110)	139,535
Balance (in shares) at Dec. 31, 2015	32,800,000
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of stock options for cash and vesting of restricted stock units		8,385				8,385
Issuance of common stock upon exercise of stock options for cash and vesting of restricted stock units (in shares)	799,000
Issuance of common stock upon settlement of employee stock purchase plan		5,155				5,155
Issuance of common stock upon settlement of employee stock purchase plan (in shares)	226,000
Issuance of restricted stock to directors in lieu of fees		200				200
Issuance of restricted stock to directors in lieu of fees (in shares)	7,000
Stock-based compensation expense related to employee stock options, restricted stock units and employee stock purchase plan		18,303				18,303
Net Loss				(13,919)		(13,919)
Unrealized gain (loss) on investments, net of tax			300			300
Reclassification adjustment for net gain on sale of investments, net of tax			(1,854)			(1,854)
Balance at Dec. 31, 2016	$ 3	427,102	1,198	(242,088)	(30,110)	$ 156,105
Balance (in shares) at Dec. 31, 2016	33,832,000					33,831,998
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of stock options for cash and vesting of restricted stock units		11,636				$ 11,636
Issuance of common stock upon exercise of stock options for cash and vesting of restricted stock units (in shares)	1,000,000
Issuance of common stock upon settlement of employee stock purchase plan		5,443				5,443
Issuance of common stock upon settlement of employee stock purchase plan (in shares)	211,000
Issuance of restricted stock to directors in lieu of fees		200				200
Issuance of restricted stock to directors in lieu of fees (in shares)	6,000
Stock-based compensation expense related to employee stock options, restricted stock units and employee stock purchase plan		20,256				20,256
Net Loss				(3,857)		(3,857)
Unrealized gain (loss) on investments, net of tax			(366)			(366)
Reclassification adjustment for net gain on sale of investments, net of tax			(1,126)			(1,126)
Balance at Dec. 31, 2017	$ 3	$ 464,637	$ (294)	$ (245,945)	$ (30,110)	$ 188,291
Balance (in shares) at Dec. 31, 2017	35,049,000					35,049,436

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating activities
Net loss	$ (3,857)	$ (13,919)	$ (33,308)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	11,759	8,933	7,069
Employee stock-based compensation	20,256	18,303	16,005
Write-off of previously capitalized software costs	76	2,600	635
Impairment of assets held for sale and long-lived assets	22	56	123
Gain (loss) on disposal of property and equipment	35	33	(80)
Outside director restricted stock awarded in lieu of fees	200	200	200
Gain on sale of equity securities	(2,807)	(3,208)
Discount on convertible promissory note	671
Discount on equity investment	322
Unrealized gain on revaluation of equity investment	(7)
Deferred tax benefit from unrealized gain on available-for-sale marketable securities, net	820	727	(1,548)
Changes in assets and liabilities:
Accounts receivable	4,018	1,985	(2,248)
Prepaid expenses and other assets	55	(4,550)	(1,292)
Accounts payable	(2,308)	(4,579)	949
Accrued compensation and employee benefits	(2,947)	5,661	4,531
Accrued expenses and other liabilities	4,164	1,645	(2,963)
Deferred revenues	121	(431)	96
Net cash provided by (used in) operating activities	30,593	13,456	(11,831)
Investing activities
Purchases of property and equipment	(13,276)	(19,786)	(23,483)
Proceeds from sale of property and equipment	10	8	70
Purchases of marketable securities	(109,249)	(69,722)	(76,743)
Maturities of marketable securities	71,802	66,757	106,439
Proceeds from sales of marketable securities	10,155	9,717
Other investments	(2,000)	(6,100)
Net cash (used) in provided by investing activities	(42,558)	(19,126)	6,283
Financing activities
Proceeds from issuance of common stock under stock plans	21,776	17,010	12,197
Withholding taxes related to restricted stock units net share settlement	(4,697)	(3,469)	(3,842)
Net cash provided by financing activities	17,079	13,541	8,355
Net increase in cash and cash equivalents	5,114	7,871	2,807
Cash and cash equivalents at the beginning of period	40,404	32,533	29,726
Cash and cash equivalents at the end of period	45,518	40,404	32,533
Supplemental disclosure of cash flow information
Cash paid for income taxes	1,093	428	459
Non-cash investing and financing activities
Accrued purchases of property and equipment	717	1,452	3,847
Change in fair value of equity investment	$ (495)	$ (316)	$ 4,269

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Organization and Summary of Significant Accounting Policies
Organization and Summary of Significant Accounting Policies	Not 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. The tests for invasive breast and colon cancers result in a quantitative score referred to as a Recurrence Score. In December 2011, the Company made Oncotype DX 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, which provides a Genomic Prostate Score, or GPS, to predict disease aggressiveness in men with low risk prostate cancer and to improve treatment decisions for prostate cancer patients in conjunction with the Gleason score, or tumor grading. In July 2017, the Oncotype DX AR-V7 Nucleus Detect test, for men with metastatic castration-resistant prostate cancer, or mCRPC, became commercially available as part of a clinical utility program. Principles of Consolidation These consolidated financial statements include all the accounts of the Company and its wholly‑owned subsidiaries. The Company had two wholly-owned subsidiaries at December 31, 2017: Genomic Health International Holdings, LLC, which was established in Delaware in 2010 and supports the Company’s international sales and marketing efforts; and Oncotype Laboratories, Inc., which was established in 2012, and is inactive. Genomic Health International Holdings, LLC has nine wholly-owned subsidiaries. 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 consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The preparation of financial statements in conformity with GAAP requires management to make judgments, assumptions and estimates that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosures in the Company’s consolidated financial statements and accompanying notes. Actual results could differ materially from those estimates. There have been no material changes in the Company’s significant accounting policies, other than the adoption of Accounting Standards Update ("ASU") 2016-09 described below, as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016. Certain reclassifications have been made to prior period amounts to conform to the current year presentation. For the years ended December 31, 2016 and 2015, a reclassification of certain expenses from research and development to cost of product revenue was made in the consolidated statements of operations to conform to the current-year presentation. Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents. Marketable Securities The Company invests in marketable securities, primarily money market funds, obligations of U.S. Government agencies and government‑sponsored entities, corporate bonds, commercial paper and equity securities. The Company considers all investments with a maturity date of less than one year as of the balance sheet date to be short‑term investments. Those investments with a maturity date greater than one year as of the balance sheet date are considered to be long‑term investments. In December 2017, the Company invested €3.4 million or $4.0 million in 270,000 shares of the common stock of Biocartis N.V. (“Biocartis”), a public company listed on the Euronext exchange. This investment was accounted for as an available-for-sale marketable security and valued at €3.0 million or $3.5 million at December 31, 2017. Unrealized gains or losses resulting from changes in the fair value of this investment will be recognized in other comprehensive income until the securities are sold. During the year ended December 31, 2017, $180,000 of unrealized losses relating to changes in the fair value of this investment were recorded in other comprehensive income. These securities are subject to a lock-up agreement which expires in December 2018. During the year ended December 31, 2017, a discount of $322,000 relating to the lock-up agreement was recognized in research and development expense, and a foreign currency revaluation gain of $7,000 was recorded in other income. Beginning in 2011, the Company made investments in various tranches of the preferred stock of Invitae Corporation (“Invitae”), which at the time was a privately-held company, such that the carrying value of this investment was $13.9 million at December 31, 2014. On February 18, 2015, Invitae completed an initial public offering of its common stock and the Company’s preferred stock investment automatically converted into 2,207,793 shares of Invitae common stock. This investment was accounted for on the cost method as an available-for-sale marketable security and valued at $18.1 million at December 31, 2015. During the year ended December 31, 2017, the Company sold its remaining shares of the common stock of Invitae for net proceeds of $10.2 million based on a cost of $6.28 per share, resulting in a realized gain of $2.8 million. During the year ended December 31, 2016, the Company sold a portion of its shares of the common stock of Invitae for proceeds of $9.7 million based on a cost of $6.28 per share, resulting in a realized gain of $3.2 million. There were no shares sold during the year ended December 31, 2015. The fair value of the remaining investment was $9.3 million at December 31, 2016. This investment, which is accounted for under the cost method, was valued at $7.3 million at December 31, 2016. Unrealized gains or losses resulting from changes in the fair value of this investment were recognized in other comprehensive income until the securities were sold. During the years ended December 31, 2017 and 2016, $1.1 million of unrealized gains, net of tax of $820,000, and $1.9 million of unrealized gains, net of tax of $727,000, respectively, related to the shares sold were reclassified out of accumulated other comprehensive income into earnings. There was no unrealized gain reclassified out of accumulated other comprehensive income into earnings during the year ended December 31, 2015. As of December 31, 2017, and 2016, respectively, all investments in marketable securities were classified as available for sale. These securities are carried at estimated fair value with unrealized gains and losses included in stockholders’ equity. Realized gains and losses and declines in value, if any, judged to be other than temporary on available‑for‑sale securities are reported in other income or expense. When securities are sold, any associated unrealized gain or loss initially recorded as a separate component of stockholders’ equity is reclassified out of stockholders’ equity on a specific‑identification basis and recorded in earnings for the period. The cost of securities sold is determined using specific identification. Fair Value of Financial Instruments The Company’s financial instruments consist principally of cash and cash equivalents, marketable securities, trade receivables and accounts payable. The carrying amounts of certain of these financial instruments, including cash and cash equivalents, trade receivables, note receivables and accounts payable, approximate fair value due to their short maturities. See Note 3, “ Fair Value Measurements ” for further information on the fair value of the Company’s financial instruments. Concentration of Risk Cash equivalents, marketable securities and trade accounts receivable are financial instruments which potentially subject the Company to concentrations of credit risk. Through December 31, 2017, no material losses had been incurred related to such credit risk. The Company is subject to credit risk from its portfolio of cash equivalents and marketable securities. The Company invests in money market funds through a major U.S. bank and is exposed to credit risk in the event of default by the financial institution to the extent of amounts recorded on the consolidated balance sheets. The Company invests in short‑term, investment‑grade debt instruments and by policy limits the amount in any one type of investment, except for securities issued or guaranteed by the U.S. government. Under its investment policy, the Company limits amounts invested in such securities by credit rating, maturity, industry group, investment type and issuer, except for securities issued by the U.S. government. The Company is not exposed to any significant concentrations of credit risk from these financial instruments. The goals of the Company’s investment policy, in order of priority, are as follows: safety and preservation of principal and diversification of risk; liquidity of investments sufficient to meet cash flow requirements; and a competitive after‑tax rate of return. The Company is also subject to credit risk from its accounts receivable related to its product sales. The Company performs evaluations of customers’ financial condition and generally does not require collateral. The majority of the Company’s accounts receivable arise from product sales in the United States. As of December 31, 2017, the substantial majority of the Company’s product revenues have been derived from sales of one product, the Oncotype DX breast cancer test. The majority of the Company’s tests to date have been delivered to physicians in the United States. All tissue-based Oncotype DX tests are processed in the Company’s clinical reference laboratory facility in Redwood City, California. Medicare accounted for 22%, 21% and 20% of the Company’s product revenues for the years ended December 31, 2017, 2016 and 2015, respectively, and represented 23% and 24% of the Company’s total accounts receivable balance as of December 31, 2017 and 2016, respectively. No other third‑party payor represented more than 10% of the Company’s product revenues or accounts receivable balances for these periods. 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 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 December 31, 2017 and 2016 was $3.9 million and $4.5 million, respectively. Write‑offs for doubtful accounts of $7.2 million and $7.1 million were recorded against the allowance during the years ended December 31, 2017 and 2016, respectively. Bad debt expense was $6.8 million, $7.9 million, and $6.0 million for the years ended December 31, 2017, 2016 and 2015, respectively. Property and Equipment Property and equipment, including purchased software, are stated at cost. Depreciation is calculated using the straight‑line method over the estimated useful lives of the assets, which generally range from three to seven years. Leasehold improvements are amortized using the straight‑line method over the estimated useful lives of the assets or the remaining term of the lease, whichever is shorter. Internal-use Software Costs incurred to develop software for internal use are capitalized and amortized over the estimated useful life of the software. Costs related to maintenance of internal-use software are expensed as incurred. For the years ended December 31, 2017, 2016 and 2015, the Company capitalized $5.1 million (including $2.7 million of personnel-related expenses), $3.4 million (including $1.2 million of personnel-related expenses), and $15.1 million (including $5.9 million of personnel-related expenses), respectively, of costs associated with internal-use software development. Amortization of previously capitalized amounts was $3.2 million, $2.5 million, and $380,000 for the years ended December 31, 2017, 2016, and 2015, respectively. Intangible Assets Intangible assets with finite useful lives are recorded at cost, less accumulated amortization. Amortization is recognized over the estimated useful lives of the assets. The Company’s intangible assets with finite lives, which are related to patent licenses, are not material and are included in non‑current other assets on the Company’s consolidated balance sheets. Investments in Privately Held 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 the applicable accounting guidance for such investments. During the years ended December 31, 2017 and 2016, the Company invested $1.4 million and $6.1 million, respectively, in the subordinated convertible promissory notes of a private company. See Note 6, “Collaboration and Commercial Technology Licensing Agreements” for additional information regarding the terms of this investment. On March 8, 2017, the subordinated convertible promissory notes were converted into preferred stock of the private company representing approximately 9% of the private entity’s voting interests, at which time the Company estimated the fair value of the subordinated convertible promissory notes to be approximately $7.1 million. The preferred stock represents a variable interest in the investee. The Company has concluded it is not the primary beneficiary and thus has not consolidated the investee pursuant to the requirements of Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 810. The Company determined that the Company does not have the power to direct activities of the private company that most significantly impact the private company’s economic performance. The Company will continue to assess its investment and future commitments to the investee and to the extent its relationship with the investee changes, may be required to consolidate the investee in future periods. The equity investments are accounted for using the cost method of accounting and recorded in other assets on the Company’s consolidated balance sheets. During the year ended December 31, 2017, the Company invested $2.0 million in the convertible promissory note of a private company. See Note 6, “Collaboration and Commercial Technology Licensing Agreements” for additional information regarding the terms of this investment. The Company estimated the fair value of the convertible promissory note to be approximately $1.3 million. The investment in the convertible promissory note represents a variable interest in the investee. The Company has concluded it is not the primary beneficiary and thus has not consolidated the investee pursuant to the requirements of FASB ASC 810. The Company determined that it does not have the ability to exercise significant influence over the investee company. The Company will continue to assess its investment and future commitments to the investee and to the extent its relationship with the investee changes, may be required to consolidate the investee in future periods. The convertible promissory note is accounted for as available-for-sale debt security and recorded in other assets on the Company’s consolidated balance sheets. Derivative Financial Instruments The Company hedges a portion of its foreign currency exposures related to outstanding monetary assets and liabilities using foreign currency forward contracts. The foreign currency forward contracts the Company uses to hedge the exposure are not designated as hedges, and as a result, changes in their fair value are recorded in other income (expense). As of December 31, 2017, the Company had open foreign currency forward contracts with notional amounts of $16.1 million. There were no open foreign currency forward contracts at December 31, 2016. Impairment of Long‑lived Assets The Company reviews long‑lived assets, which include property and equipment, intangible assets and 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 property and equipment and intangible assets, an impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of the asset and its eventual disposition are less than its carrying amount. Impairment, if any, is assessed using undiscounted cash flows. For investments in non‑marketable equity securities, 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. 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 11, “Income Taxes” for additional information regarding unrecognized tax benefits. Revenue Recognition The Company derives its revenues from product sales and, to a lesser extent from contracts with biopharmaceutical and pharmaceutical companies. The majority of the Company’s historical product revenues have been derived from the sale of the Oncotype DX invasive 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 generally 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 medical 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) collectability 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. When evaluating whether the fee is fixed or determinable and collectible, the Company considers whether it has sufficient history to reliably estimate the total fee that will be received from a payor and a payor’s individual payment patterns. Determination 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 collectability of those fees under any contract or arrangement. 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 arrangement or contracted payment amount. The estimated accrual amounts per test, recorded upon delivery of a patient report, are calculated for each accrual payor and are based on the arrangement or contracted price adjusted for individual payment patterns resulting from co-payment amounts and excluded services in healthcare plans. The Company also reduces revenue for an estimate of amounts that qualify as patient assistance and related deductions that do not qualify for revenue recognition. When a payment received for an individual test is higher or lower than the estimated accrual amount, the Company recognizes the difference as either cash revenue, in the case of higher payments, or in the case of lower payments, a charge against either the patient assistance program and related deductions reserve or the allowance for doubtful accounts, as applicable. 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 distributors covering more than 90 countries outside of the United States. 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 requests for refunds of payments, generally due to overpayments made by third party‑payors. Upon becoming aware of a refund request, the Company establishes an accrued liability for tests covered by the refund request until such time as the Company determines whether or not a refund is due. Accrued refunds were $87,000 and $487,000 at December 31, 2017 and 2016, respectively. 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 typically 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. Cost of Product Revenues Cost of product revenues includes the cost of materials, direct labor, equipment and infrastructure expenses associated with processing tissue samples (including sample accessioning, histopathology, anatomical pathology, paraffin extraction, reverse transcription polymerase chain reaction (“RT‑PCR”), quality control analyses and shipping charges to transport tissue samples) and license fees. Infrastructure expenses include allocated facility occupancy and information technology costs. Costs associated with performing the Company’s tests are recorded as tests are processed. Costs recorded for tissue sample processing and shipping charges represent the cost of all the tests processed during the period regardless of whether revenue was recognized with respect to that test. Royalties for licensed technology calculated as a percentage of product revenues and fixed annual payments relating to the launch and commercialization of the Company’s tests are recorded as license fees in cost of product revenues at the time product revenues are recognized or in accordance with other contractual obligations. 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 these costs 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. Stock‑based Compensation The Company uses the Black‑Scholes option valuation model, single‑option approach, which requires the use of estimates such as stock price volatility and expected option lives, as well as expected option forfeiture rates, to value employee stock‑based compensation at the date of grant, and recognizes stock‑ based compensation expense ratably over the requisite service period. Equity instruments granted to non‑employees are also valued using the Black‑Scholes option valuation model and are subject to periodic revaluation over their vesting terms. The Company did not grant any stock options to non‑employee consultants during any of the years presented. 401(k) Plan Substantially all of the Company’s employees are eligible to participate in its defined contribution plan qualified under Section 401(k) of the Internal Revenue Code. The Company contributed dollar for dollar matching of employee contributions up to a maximum of $4,000, $4,000, and $3,000 for the years ended December 31, 2017, 2016 and 2015, respectively, for each employee per year based on a full calendar year of service. The match is funded concurrently with a participant’s semi‑monthly contributions to the 401(k) Plan. The Company recorded expense for its contributions under the 401(k) Plan of $2.9 million, $3.5 million and $2.8 million for the years ended December 31, 2017, 2016 and 2015, respectively. Foreign Currency Transactions Net foreign currency transaction gains or losses are included in other income (expense), net on the Company’s consolidated statements of operations. Net foreign currency transaction gains (losses) totaled $317,000, $(782,000) and $(551,000) for the years ended December 31, 2017, 2016 and 2015, respectively. Comprehensive Gain or Loss Other comprehensive gain or loss consists of unrealized gains and losses on available‑for‑sale securities. Leases The Company enters into lease agreements for its laboratory and office facilities. These leases are classified as operating leases. Rent expense is recognized on a straight‑line basis over the term of the lease. Incentives granted under the Company’s facilities leases, including allowances to fund leasehold improvements and rent holidays, are capitalized and are recognized as reductions to rental expense on a straight‑line basis over the term of the lease. Guarantees and Indemnifications The Company, as permitted under Delaware law and in accordance with its bylaws, indemnifies its officers and directors for certain events or occurrences, subject to certain limits, while the officer or director is or was serving at the Company’s request in such capacity. The term of the indemnification period is for the officer’s or director’s lifetime. The maximum amount of potential future indemnification is unlimited; however, the Company has a directors and officers insurance policy that limits its exposure and may enable it to recover a portion of any future amounts paid. The Company believes the fair value of these indemnification agreements is minimal. Accordingly, the Company has not recorded any liabilities for these agreements as of December 31, 2017 and 2016. Recently Issued Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606) . Topic 606 supersedes the revenue recognition requirements in Accounting Standards Codification Topic 605, Revenue Recognition , and requires entities to rec

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2017
Net Loss Per Share
Net Loss Per Share	Note 2. Net Loss Per Share Basic net loss per share is calculated by dividing net loss for the period by the weighted-average number of common shares outstanding for the period without consideration of potential common shares. Diluted net loss per share is calculated by dividing net 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 (“RSU”) 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. The following potentially dilutive common shares were excluded from the computation of diluted net loss per share for the periods presented because they would have been anti-dilutive: Year Ended December 31, 2017 2016 2015 (In thousands) Stock awards excluded from the computation 800 828 945

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
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. 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 and Recorded at Fair Value on a Recurring Basis 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 December 31, 2017 and 2016, respectively. The following tables set forth the Company’s financial instruments that were measured at fair value on a recurring basis at December 31, 2017 and 2016 by level within the fair value hierarchy: Actively Quoted Significant Markets for Other Significant Identical Observable Unobservable Balance at Assets Inputs Inputs December 31, Level 1 Level 2 Level 3 2017 (In thousands) As of December 31, 2017: Assets Money market deposits $ 10,215 $ — $ — $ 10,215 Commercial paper — 30,272 — 30,272 Corporate debt securities — 50,260 — 50,260 Corporate equity securities — 3,525 — 3,525 Total $ 10,215 $ 84,057 $ — $ 94,272 Actively Quoted Significant Markets for Other Significant Identical Observable Unobservable Balance at Assets Inputs Inputs December 31, Level 1 Level 2 Level 3 2016 (In thousands) As of December 31, 2016: Assets Money market deposits $ 13,198 $ — $ — $ 13,198 Commercial paper — 32,421 — 32,421 Corporate debt securities — 14,869 — 14,869 Corporate equity securities — 9,295 — 9,295 Total $ 13,198 $ 56,585 $ — $ 69,783 The Company’s 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 and industry and economic events are monitored and may serve as a trigger to acquire further corroborating market data. The Company’s corporate equity securities are classified as Level 2 while subject to certain restrictions on sale. There were no transfers between Level 1 and Level 2 categories during the years ended December 31, 2017 and 2016, respectively. All of the Company’s marketable securities are classified as available-for-sale. The following tables summarize the Company’s available‑for‑sale marketable securities as of the dates indicated: December 31, 2017 Cost or Gross Gross Total Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value (In thousands) Commercial paper $ 30,315 $ — $ (43) $ 30,272 Corporate debt securities 50,331 2 (73) 50,260 Corporate equity securities 4,020 — (495) 3,525 Total $ 84,666 $ 2 $ (611) $ 84,057 December 31, 2016 Cost or Gross Gross Total Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value (In thousands) Commercial paper $ 32,350 $ 71 $ — $ 32,421 Corporate debt securities 14,868 3 (2) 14,869 Corporate equity securities 7,348 1,947 — 9,295 Total $ 54,566 $ 2,021 $ (2) $ 56,585 The Company had realized gains of $2.8 million, $3.2 million and $0 for the years ended December 31, 2017, 2016 and 2015, respectively, on its available‑for‑sale marketable securities. The following table provides the breakdown of the available‑for‑sale marketable securities with unrealized losses as of the date indicated: In a Loss Position for Less Than 12 Months Gross Unrealized Estimated As of December 31, 2017: Losses Fair Value (In thousands) Commercial paper $ (43) $ 30,272 Corporate debt securities (73) 45,110 Corporate equity securities (495) $ 3,525 Total $ (611) $ 78,907 All of the Company’s available‑for‑sale marketable securities had contractual maturities of one year or less as of December 31, 2017 and 2016. Assets Measured and Recorded at Fair Value on a Nonrecurring Basis The Company reviews the fair value of long-lived assets, which include property and equipment, intangible assets and investments in privately held companies, for impairment whenever events or changes in circumstances indicate that the carrying amounts of the assets may not be fully recoverable. During the year ended December 31, 2017 the Company wrote off $98,000 of previously capitalized equipment and software development costs. During the year ended December 31, 2016, the Company wrote off $2.6 million of previously capitalized software development costs related to a project for enhanced report delivery due to scope change. The impairment charge related to the write off is included in the selling and marketing expenses in the accompanying consolidated statements of operations. In addition, during the year ended December 31, 2016, the Company recorded impairment losses of $56,000 for equipment classified as held for sale. During the year ended December 31, 2015, the Company wrote off $635,000 of previously capitalized software costs and recorded impairment losses of $123,000 for equipment classified as held for sale. During the year ended December 31, 2017, the Company invested $2.0 million in a convertible promissory note of Cleveland Diagnostics, Inc. (“Cleveland Diagnostics”). See Note 6, “Collaboration and Commercial Technology Licensing Agreements” for additional information regarding the terms of this investment. The Company estimated the fair value of the convertible promissory note to be approximately $1.3 million. The convertible promissory note is classified as Level 3 as it is valued using unobservable inputs that are primarily based on the Company’s estimate of the fair value of the underlying preferred stock into which the notes are convertible. During the years ended December 31, 2017 and 2016, the Company invested $1.4 million and $6.1 million, respectively, in subordinated convertible promissory notes of Epic Sciences, Inc. (“Epic Sciences”). See Note 6, “Collaboration and Commercial Technology Licensing Agreements” for additional information regarding the terms of this investment. In March 2017, the subordinated convertible promissory notes were converted into preferred stock of Epic Sciences, Inc., with an estimated fair value of $7.1 million. The Company accounted for such preferred stock using the cost method of accounting and accordingly recorded such preferred stock in other assets. There were no identified events or changes in circumstances that may have a significant adverse effect on the fair value of the preferred stock during the remainder of the year ended December 31, 2017. As of December 31, 2016, the Company estimated the fair value of the subordinated convertible promissory notes to be approximately $5.8 million which was recorded in other assets. As of December 31, 2016, the subordinated convertible promissory notes are classified as Level 3 as they are valued using unobservable inputs that are primarily based on the Company’s estimate of the fair value of the underlying preferred stock into which the notes are convertible.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2017
Property and Equipment
Property and Equipment	Note 4. Property and Equipment The following table summarizes the Company’s property and equipment as of the dates indicated: December 31, 2017 2016 (In thousands) Laboratory equipment $ 37,560 $ 29,992 Computer equipment 10,498 9,605 Computer software—internal use 26,483 23,790 Furniture and fixtures 4,749 4,055 Leasehold improvements 29,126 20,756 Work in progress 3,698 14,206 112,114 102,404 Less accumulated depreciation and amortization (65,674) (56,716) Total $ 46,440 $ 45,688 For the years ended December 31, 2017, 2016 and 2015, the Company recognized property and equipment depreciation and amortization expense of $11.6 million, $8.8 million and $6.9 million, respectively.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2017
Accrued Expenses and Other Current Liabilities
Accrued Expenses and Other Current Liabilities	Note 5. Accrued Expenses and Other Current Liabilities The following table summarizes the Company’s accrued expenses and other current liabilities as of the dates indicated: December 31, 2017 2016 (In thousands) Accrued expenses $ 7,197 $ 3,984 Accrued professional and other service fees 3,114 1,902 Accrued refunds 87 487 Accrued rebate 407 588 Accrued collaboration expense 2,532 2,418 Accrued taxes payable 746 800 Other current liabilities 1 1 Total $ 14,084 $ 10,180 Accrued professional and other service fees include third‑party billing and collections costs, legal expenses, accounting and audit fees and investor relations expenses. Accrued refunds include overpayments due to third‑party payors.

Collaboration and Commercial Te

Collaboration and Commercial Technology Licensing Agreements	12 Months Ended
	Dec. 31, 2017
Collaboration and Commercial Technology Licensing Agreements
Collaboration and Commercial Technology Licensing Agreements	Note 6. 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 $7.3 million, $4.6 million and $11.1 million for the years ended December 31, 2017, 2016 and 2015, respectively, relating to services provided by the collaborators in connection with these agreements. In addition to these expenses, some of these 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 these collaborations. In January 2014, the Company entered into a collaboration agreement to conduct a prostate study with a goal to determine the association between the GPS provided by the Company’s assay and the likelihood of experiencing disease progression while on active surveillance. In July 2014, the Company entered into a collaboration agreement to conduct a prostate observational study in men who choose active surveillance at one and two years after receiving the Oncotype DX prostate cancer GPS. In August 2014, the Company entered into an agreement to provide support to conduct the main phase of a prospective study dealing with individualization of adjuvant decision-making in early-stage breast cancer. In November 2017, the Company entered into a collaboration agreement to provide support to conduct a data sweep and analysis for a mid-range recurrence score group for a prospective study which was designed to explore breast cancer recurrences in patients with early stage breast cancer. As of December 31, 2017, the estimated total remaining obligations for these agreements, including certain milestone payments, is approximately $1.3 million. All future milestone payments are contingent on certain accomplishments, and therefore the timing for any related payments cannot be estimated. In June 2016, the Company entered into a collaboration agreement with Epic Sciences, Inc., under which the Company was granted exclusive distribution rights to commercialize Epic Sciences’ AR-V7 Nucleus Detect test in the United States, which is marketed as Oncotype DX AR-V7 Nucleus Detect. The Company has primary responsibility, in accordance with applicable laws and regulations, for marketing and promoting the test, order fulfillment, billing and collections of receivables, claims appeals, customer support, and providing and maintaining order management systems for the test. Epic Sciences is responsible for performing all tests, performing studies including analytic and clinical validation studies, and seeking Medicare coverage and a Medicare payment rate from the Centers for Medicare and Medicaid Services (“CMS”) for the test. Future revenues generated from the test will be shared by the Company and Epic Sciences in accordance with the terms of the agreement. During 2016 and 2017 the Company invested $7.5 million in subordinated promissory notes of Epic Sciences that converted into shares of Epic Sciences preferred stock in March 2017. The subordinated promissory notes had been recognized at fair value which the Company believed was approximately $7.1 million In November 2013, the Company entered into an exclusive license agreement to develop and commercialize a test to predict benefit from DNA damage-based chemotherapy drugs, such as anthracycline-based regimens, in high risk breast cancer. The Company made an up‑front payment of $9.0 million, which was recognized in research and development expense in the fourth quarter of 2013, and milestone payments would have been required if certain clinical and commercial endpoints were achieved in the future. With successful commercialization of a test, the Company would have been obligated to pay royalties. During the quarter ended March 31, 2015, the Company accrued $5.5 million in anticipation of the wind-down of this license agreement and development program, which was recognized as research and development expense in the accompanying consolidated statements of operations. The license agreement was terminated in May 2015 and, as a result, the Company has no future obligations under this agreement. 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 under these agreements totaling $314,000, $5.3 million and $9.2 million for the years ended December 31, 2017, 2016 and 2015, respectively, which were included in cost of product revenues. The decrease in costs for these agreements for the year ended December 31, 2017 compared to the years ended December 31, 2016 and 2015, was primarily due to the satisfaction of certain royalty payment obligations. On October 28, 2016, the Company provided notice of termination of a license agreement with Roche Molecular Systems, Inc. (“Roche”), whereby the Company non-exclusively licensed from Roche a number of U.S. patents claiming nucleic acid amplification processes known as PCR, homogeneous polymerase chain reaction, and RT PCR. The effective date of the termination was November 27, 2016. The Company believes it has satisfied all obligations to make royalty payments to Roche. In September 2017, the Company entered into an exclusive license and development agreement with Biocartis, a molecular diagnostics company based in Belgium, to develop and commercialize an in vitro diagnostic (“IVD”) version of the Oncotype DX breast cancer test on Biocartis’ Idylla platform that can be performed locally by laboratory partners and in hospitals around the world. Under the terms of the license and development agreement, the Company has an exclusive, worldwide, royalty-bearing license to develop and commercialize an IVD version of the Oncotype DX breast cancer tests on Biocartis Idylla platform, and an option to expand the collaboration to include additional tests in oncology and urology. The Company has primary responsibility for developing, validating and obtaining regulatory authorizations and registrations for IVD Oncotype DX tests to be performed on the Idylla platform. The Company is also responsible for manufacturing and commercialization activities with respect to such tests. Pursuant to the license and development agreement, the Company recorded a one-time upfront license fee of €2.8 million or $3.2 million, which is included in research and development expenses for the year ended December 31, 2017. In December 2017, the Company purchased 270,000 ordinary shares of Biocartis at the market price of €12.50 for a total cost of €3.4 million or $4.0 million. This investment is accounted for as an available-for-sale marketable security and is subject to a lock-up agreement that expires in December 2018. The investment has been recognized at fair value, which the Company believes to be $3.5 million with the difference attributable to a $322,000 discount resulting from the lock up period and a $180,000 decrease in the market value of the Biocartis shares. Additional terms of the license and development agreement include the Company’s obligation to pay Biocartis an aggregate of €6.5 million in cash upon achievement of certain milestones, and royalties based primarily on the future sales volumes of the Company’s test performed on the Idylla platform. In November 2017, the Company entered into an exclusive licensing agreement with Cleveland Diagnostics to develop and commercialize new prostate cancer tests based on Cleveland Diagnostics' IsoPSA reagents and technology. Initial efforts under this agreement will focus on the Company’s development of a high-PSA (prostate specific antigen) reflex test to accurately predict the presence of high-grade cancer (Gleason score > 7) prior to prostate biopsy. During the year ended December 31, 2017, the Company invested $2.0 million in a convertible promissory note of Cleveland Diagnostics. The convertible promissory note has been recognized at fair value, which the Company believes is approximately $1.3 million Contract Research Arrangements In November 2017, the Company entered into a multi-year research collaboration agreement with Janssen Pharmaceuticals (“Janssen”) to evaluate the Oncotype DX GPS test for its prostate cancer drug pipeline. As part of the agreement, the Company will test samples from Janssen studies to examine the association of GPS results with clinical outcomes. The Company expects the total payment to be $1.8 million. During the year ended December 31, 2017, the Company recognized $299,000 as contract revenue using a performance-based model following delivery of effort as compared to an estimate of total expected effort.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies
Commitments and Contingencies	Note 7. Commitments and Contingencies Lease Obligations The Company leases approximately 180,700 square feet of office and laboratory space under five non-cancelable operating leases, with terms that expire between 2021 and 2023 in Redwood City, California, and 7,500 square feet of office space for the Company’s European subsidiary under a non-cancelable operating lease that expires in 2021 in Geneva, Switzerland. The Company’s Redwood City, California leases each contain options to extend the terms of such leases for an additional five years as well as tenant improvement allowances that could total as much as $2.3 million to the extent utilized by November 2018. Rent expense under operating leases amounted to $6.3 million, $5.7 million and $4.1 million for the years ended December 31, 2017, 2016 and 2015, respectively. Future non‑cancelable commitments under these operating leases at December 31, 2017 were as follows: Annual Payments (In thousands) Years Ending December 31, 2018 $ 5,958 2019 6,746 2020 7,075 2021 4,822 2022 4,082 2023 and thereafter 1,035 Total minimum payments $ 29,718 Contingencies From time to time, the Company may be subject to various legal proceedings and claims arising in the ordinary course of business. The Company assesses contingencies to determine the degree of probability and range of possible loss for potential accrual in its consolidated financial statements. An estimated loss contingency is accrued in the consolidated financial statements if it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Any such accruals were not material at either December 31, 2017 or 2016.

Capital Stock

Capital Stock	12 Months Ended
	Dec. 31, 2017
Capital Stock
Capital Stock	Note 8. Capital Stock Common Stock As of December 31, 2017, the Company had 35,049,436 shares of common stock outstanding. Shares of common stock reserved for future issuance as of December 31, 2017 were as follows: Number of Shares (In thousands) Shares to be issued upon exercise of outstanding stock options and vesting of RSUs 4,424 Shares available for future stock option and RSU grants, settlement of employee stock purchase plan (ESPP) and restricted stock to be issued to outside directors in lieu of director fees 4,403 Shares of common stock reserved for future issuance 8,827 Treasury Stock In December 2012, the Company entered into an accelerated share repurchase agreement with a financial institution to repurchase $30.0 million of its common stock on an accelerated basis. The shares of common stock repurchased under the agreement were 984,074 and 77,257 during the year ended December 31, 2012 and 2013, respectively. The average purchase price of the Company’s common stock from the accelerated share repurchase program was $28.27 per share.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2017
Stock-Based Compensation
Stock-Based Compensation	Note 9. Stock‑based Compensation 2005 Stock Incentive Plan On September 8, 2005, the Board of Directors approved the 2005 Stock Incentive Plan (the “2005 Plan”), which was later approved by the Company’s stockholders. Pursuant to the 2005 Plan, stock options, restricted shares, stock units, including RSUs, and stock appreciation rights may be granted to employees, consultants, and outside directors of the Company. Options granted may be either incentive stock options or nonstatutory stock options. The Company initially reserved 5,000,000 shares of the Company’s common stock for issuance under the 2005 Plan, effective upon the closing of the Company’s initial public offering on October 4, 2005. On June 8, 2009, the Company’s stockholders approved an amendment to the 2005 Plan to increase the shares reserved for issuance under the 2005 Plan by 3,980,000 shares. The amended and restated plan also extends the term under which awards may be granted under the 2005 Plan until January 27, 2019. On June 11, 2015, the Company’s stockholders approved an amendment to the amended and restated 2005 Plan to increase the shares reserved for issuance under the 2005 Plan by 1,500,000 shares. On June 9, 2016, the Company’s stockholders approved an amendment to the amended and restated 2005 Plan to increase the shares reserved for issuance under the 2005 Plan by 1,500,000 shares. On June 15, 2017 the Company’s stockholders approved an amended and restated 2005 Plan to increase the shares reserved for issuance under the 2005 Plan by 1,500,000 sharers. As of December 31, 2017, a total of 3,034,000 shares remain available for future grant under the 2005 Plan. Stock Option Activity Stock options are governed by stock option agreements between the Company and recipients of stock options. Incentive stock options may be granted under the 2005 Plan at an exercise price of not less than 100% of the fair market value of the common stock on the date of grant, determined by the Compensation Committee of the Board of Directors. Nonstatutory stock options may be granted under the 2005 Plan at an exercise price of not less than 80% of the fair market value of the common stock on the date of grant, determined by the Compensation Committee of the Board of Directors. Options become exercisable and expire as determined by the Compensation Committee, provided that the term of incentive stock options may not exceed 10 years from the date of grant. Stock option agreements may provide for accelerated exercisability in the event of an optionee’s death, disability, or retirement or other events. Under the 2005 Plan, each outside director who joins the board after the effective date of the 2005 Plan will receive an automatic nonstatutory stock option grant that vests at a rate of 25% at the end of the first year, with the remaining balance vesting monthly over the next three years. On the first business day following the annual meeting of the Company’s stockholders, each outside director who is continuing board service and who was not initially elected to the board at the annual meeting will receive an additional nonstatutory stock option grant, which will vest in full on the first anniversary of the date of grant or, if earlier, immediately prior to the next annual meeting of the Company’s stockholders. Nonstatutory stock options granted to outside directors must have an exercise price equal to 100% of the fair market value of the common stock on the date of grant. Nonstatutory stock options terminate on the earlier of the day before the tenth anniversary of the date of grant or the date twelve months after termination of the outside director’s service as a member of the Board of Directors. The following table summarizes option activity for the year ended December 31, 2017: Weighted-Average Outstanding Options Remaining Aggregate Number of Weighted-Average Contractual Intrinsic Shares Exercise Price Life Value (In thousands) (In years) (In thousands) Balance at December 31, 2016 3,606 $ 25.07 Options granted 741 $ 28.12 Options exercised (765) $ 21.34 Options forfeited (87) $ 28.22 Options expired (35) $ 29.80 Balance at December 31, 2017 3,460 $ 26.42 6.0 $ 27,023 Exercisable at December 31, 2017 2,324 $ 25.61 4.7 $ 20,062 Vested and expected to vest at December 31, 2017 3,388 $ 26.39 6.0 $ 26,572 The total intrinsic value of stock options exercised during the years ended December 31, 2017, 2016 and 2015 was $8.0 million, $5.6 million and $6.6 million, respectively. The total fair value of stock options vested during the years ended December 31, 2017, 2016 and 2015 was $6.2 million, $5.3 million and $4.2 million, respectively. Performance-Based Vesting Stock Options Under the 2005 Plan, the Company grants performance-based vesting stock options (“PV stock options”) which vest upon achievement of specified performance goals. The Company recognizes the fair value of these awards to the extent the achievement of the related performance criteria is estimated to be probable. If a performance criterion is subsequently determined to not be probable of achievement, any related expense is reversed in the period such determination is made. Conversely, if a performance criterion is not currently expected to be achieved but is later determined to be probable of achievement, a “catch-up” entry is recorded in the period such determination is made for the expense that would have been recognized had the performance criterion been probable of achievement since the grant of the award. In April 2016, the Company granted PV stock options to purchase 75,531 shares of common stock with an exercise price of $31.12 per share. The number of shares potentially issuable under PV stock options were subject to the attainment of a pre-established, corporate-level objective performance goal for the year ended December 31, 2016. In addition, the awards had a service-vesting criteria following the achievement of performance criteria through February 2019. As of December 31, 2016, the achievement of the performance criteria was estimated to be remote and the award was cancelled. Restricted Stock Unit Activity The Company began granting RSUs in 2011. The RSUs generally vest in three equal annual installments. As of April 2011, outside directors were given the option to elect to receive some or all of their retainers (other than retainers for serving as committee chair) in the form of fully‑vested restricted stock. Restricted shares, stock units and stock appreciation rights granted under the 2005 Plan are governed by agreements between the Company and recipients of the awards. Terms of the agreements are determined by the Compensation Committee. A following table summarizes RSU activity for the year ended December 31, 2017: Weighted-Average Number of Grant Date Fair Shares Value (In thousands) Balance at December 31, 2016 871 $ 28.42 RSUs granted 593 $ 28.35 RSUs vested (388) $ 28.75 RSUs cancelled (112) $ 28.35 Balance at December 31, 2017 964 $ 28.25 The weighted-average per share grant date fair values of RSUs were $28.35, $27.50 and $30.65 during the years ended December 31, 2017, 2016 and 2015, respectively. The fair value of RSUs vested were $12.0 million, $8.6 million $9.4 million for the year ended December 31, 2017, 2016 and 2015, respectively. Performance-Based Restricted Stock Unit Activity Under the 2005 Plan, the Company grants performance-based restricted stock units (“PVRSUs”) which vest upon achievement of specified performance goals. The fair value of each PVRSU is estimated at the date of grant or when performance objectives are defined for the grants. The Company recognizes the fair value of these awards to the extent the achievement of the related performance criteria is estimated to be probable. If a performance criteria is subsequently determined to not be probable of achievement, any related expense is reversed in the period such determination is made. Conversely, if a performance criteria is not currently expected to be achieved but is later determined to be probable of achievement, a “catch-up” entry is recorded in the period such determination is made for the expense that would have been recognized had the performance criteria been probable of achievement since the grant of the award. There were no PVRSU activities during the year ended December 31, 2017. The weighted-average per share grant date fair values of PVRSUs were $0, $28.09 and $31.12 during the years ended December 31, 2017, 2016 and 2015, respectively. The fair value of PVRSUs vested was $0, $163,000 and $211,000 during the years ended December 31, 2017, 2016 and 2015 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 years ended December 31, 2017, 2016 and 2015, the Company issued 6,375, 6,970, and 7,365 shares of restricted stock, respectively, to outside directors, with vesting date fair values of $200,000 for each of the years, and a weighted‑average grant date fair value of $31.33, $28.65, and $27.10 per share, respectively. Employee Stock Purchase Plan In June 2011, the Company’s stockholders approved the Company’s Employee Stock Purchase Plan (“ESPP”). The ESPP provides eligible employees with an opportunity to purchase common stock from the Company and to pay for their purchases through payroll deductions. The ESPP is implemented through a series of offerings of purchase rights to eligible employees beginning December 1, 2011. Under the ESPP, the Compensation Committee of the Company’s Board of Directors may specify offerings with a duration of not more than 27 months, and may specify shorter purchase periods within each offering. During each purchase period, payroll deductions accumulate without interest. On the last day of the purchase period, accumulated payroll deductions are used to purchase common stock for employees participating in the offering. The purchase price is specified pursuant to the offering, but cannot, under the terms of the ESPP, be less than 85% of the fair market value per share of the Company’s common stock on either the last trading day preceding the offering date or on the purchase date, whichever is less. The Company’s Board of Directors has determined that the purchase periods initially shall have a duration of six months and that the purchase price will be 85% of the fair market value per share of the Company’s common stock on either the last trading day preceding the offering date or the purchase date, whichever is less. The length of the purchase period applicable to U.S. employees and the purchase price may not be changed without the approval of the independent members of the Company’s Board of Directors. A total of 1,250,000 shares of common stock were initially reserved for issuance under the ESPP. On June 15, 2017 the Company’s stockholders approved an amendment to the ESPP to increase the shares reserved for issuance under the ESPP by 1,250,000 shares. As of December 31, 2017, a total of 1,368,713 shares were available for issuance under the ESPP. During 2017, 2016 and 2015, 210,880, 226,303 and 203,842 shares were issued under the ESPP, respectively. As of December 31, 2017, there was $587,000 of unrecognized compensation expense related to the ESPP, which is expected to be recognized over a period of five months. Employee Stock‑Based Compensation Expense Stock-based compensation is recognized as expense over the requisite service periods in the consolidated statements of operations using the straight-line expense attribution approach for stock options and RSUs, and using a graded vesting expense attribution approach for PV stock options and PVRSUs. The Company recognized employee stock‑based compensation expense of $20.3 million, $18.3 million and $16.0 million for the years ended December 31, 2017, 2016 and 2015, respectively. Employee stock‑based compensation expense was calculated based on awards 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. Employee stock‑based compensation expense includes expense related to stock options granted to outside directors of the Company as well as stock purchased under the ESPP. The following table presents the impact of employee stock‑based compensation expense on selected statement of operations line items for the periods indicated: Year Ended December 31, 2017 2016 2015 (In thousands) Cost of product revenues $ 741 $ 664 $ 584 Research and development 5,469 4,860 4,169 Selling and marketing 5,730 5,551 4,526 General and administrative 8,316 7,228 6,726 Total $ 20,256 $ 18,303 $ 16,005 As of December 31, 2017, unrecognized compensation expense related to unvested stock options and RSUs net of estimated forfeitures was $10.0 million and $16.3 million, respectively. The Company expects to recognize these expenses over a weighted‑average period of 2.6 years and 1.8 years, respectively. There was no unrecognized compensation expense related to unvested PV stock options and PVRSUs. Valuation Assumptions Fair values of awards granted under the 2005 Plan and ESPP were estimated at grant or purchase dates using a 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 fiscal year are as follows: Year Ended December 31, 2017 2016 2015 Expected volatility: Stock options 40 % 44 % 44 % ESPP 33 % 44 % 35 % Risk-free interest rate: Stock options 2.01 % 1.36 % 1.66 % ESPP 0.91 % 0.47 % 0.10 % Expected life in years: Stock options 6.22 6.10 5.94 ESPP 0.50 0.50 0.50 Weighted-average fair value: Stock options $ 11.83 $ 11.73 $ 13.37 ESPP $ 7.16 $ 7.35 $ 6.99

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2017
Segment Information
Segment Information	Note 10. 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, allowing physicians and patients to make individualized treatment decisions. The Company’s Oncotype DX breast, colon and prostate cancer tests have similar economic and other characteristics, including the nature of the products and production processes, type of customers, distribution methods and regulatory environment. As of December 31, 2017, the majority of the Company’s product revenues have been derived from sales of one product, the Oncotype DX breast cancer test. As of December 31, 2017, the majority of the Company’s tests have been delivered to physicians in the United States. All tissue-based Oncotype DX tests are processed in the Company’s clinical reference laboratory facility in Redwood City, California. The following table summarizes total revenues from customers, payors and collaboration partners by geographic region (in thousands). 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. Year Ended December 31, 2017 2016 2015 (In thousands) United States $ 287,662 $ 281,077 $ 246,008 Outside of the United States 53,088 46,791 41,450 Total revenues $ 340,750 $ 327,868 $ 287,458

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Taxes
Income Taxes	Note 11. Income Taxes The components of the Company’s loss before income taxes were as follows: Year Ended December 31, 2017 2016 2015 (In thousands) Domestic $ (5,404) $ (14,676) $ (34,276) Foreign 3,051 2,138 (28) Total loss before income taxes $ (2,353) $ (12,538) $ (34,304) The components of the Company’s income tax expense (benefit) were as follows: Year Ended December 31, 2017 2016 2015 (In thousands) Current expense (benefit): Federal $ (140) $ 18 $ — State 31 67 (15) Foreign 792 569 566 Deferred tax expense (benefit): Federal 792 702 (1,494) State 29 25 (53) Foreign — — — Total income tax expense (benefit) $ 1,504 $ 1,381 $ (996) The income tax expense (benefit) differs from the amount computed by applying the statutory federal income tax rate as follows: Year Ended December 31, 2017 2016 2015 (In thousands) Federal tax at statutory rate $ (824) $ (4,388) $ (12,006) Stock-based compensation (687) 867 782 Non-deductible meals and entertainment 534 530 558 Net operating losses not used 1,846 3,705 10,499 Tax effect on available-for-sale securities 792 702 (1,494) Subpart F 185 — — Foreign tax (279) (179) 576 Federal AMT refundable credit (122) — — State tax, net of federal benefit 39 68 (63) Other 20 76 152 Total income tax expense (benefit) $ 1,504 $ 1,381 $ (996) Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of deferred tax assets and liabilities are as follows: December 31, 2017 2016 (In thousands) Deferred tax assets: Net operating loss carryforwards $ 34,450 $ 42,550 Stock-based compensation 8,120 12,290 Research tax credits 21,710 17,620 Fixed assets 690 1,960 Accrued compensation 3,070 6,080 Other 7,150 7,490 Total deferred tax assets 75,190 87,990 Valuation allowance (75,190) (87,990) Net deferred tax assets $ — $ — Based on all available objective evidence, the Company believes that it is more likely than not that the net deferred tax assets will not be fully realizable. Accordingly, the Company recorded a valuation allowance against all of its net deferred tax assets as of both December 31, 2017 and 2016. The Company will continue to maintain a full valuation allowance on its net deferred tax assets until there is sufficient evidence to support the reversal of all or some portion of this allowance. The net valuation allowance increased (decreased) by $(12.8) million, $6.1 million and $10.1 million during the years ended December 31, 2017, 2016 and 2015, respectively. As of December 31, 2017, the Company had federal and state net operating loss carryforwards of approximately $156.0 million and $93.3 million, respectively, and federal and state research and development tax credit carryforwards of approximately $13.4 million and $13.3 million, respectively. The federal net operating loss and federal tax credit carryforwards will expire at various dates beginning in 2021. The state net operating loss carryforwards begin to expire in 2018 if not utilized. The state tax credit carryforwards have no expiration date. None of the net operating loss and tax credit carryforwards are subject to the limitations imposed by Sections 382 and 383 of the Internal Revenue Code. The Company had $2.4 million, $2.1 million and $2.8 million of unrecognized tax benefits as of December 31, 2017, 2016 and 2015, respectively. The unrecognized tax benefits are primarily research tax credits for all years. The following table summarizes the activity related to unrecognized tax benefits: Year Ended December 31, 2017 2016 2015 (In thousands) Balance at January 1 $ 2,078 $ 2,847 $ 1,600 Increase (decrease) related to prior year tax positions — (1,076) 927 Increase related to current year tax positions 331 307 320 Balance at December 31 $ 2,409 $ 2,078 $ 2,847 Unrecognized tax benefits may change during the next twelve months for items that arise in the ordinary course of business. The Company does not anticipate a material change to its unrecognized tax benefits over the next twelve months that would affect the Company’s effective tax rate. Accrued interest and penalties related to unrecognized tax benefits are recognized as part of the Company’s income tax provision in its consolidated statements of operations. For the year ended December 31, 2017, 2016 and 2015, the Company recognized $8,800, $8,000 and $7,200 in interest and penalties, respectively, related to unrecognized tax benefits. The Company files federal, state and foreign income tax returns in many jurisdictions in the United States and abroad. The statute of limitations remains open for the years 2001 through 2017 in U.S. federal and state jurisdictions, and for the years 2012 through 2017 in foreign jurisdictions. Fiscal years outside the normal statute of limitations remain open to audit by tax authorities due to tax attributes generated in early years which have been carried forward and may be audited in subsequent years when utilized. On December 22, 2017 the 2017 Tax Cut and Jobs Act (the Act) was enacted into law and the new legislation contains several key tax provisions, including a one-time mandatory transition tax on accumulated foreign earnings and a reduction of the corporate income tax rate to 21% effective January 1, 2018, among others. The Company is required to recognize the effect of the tax law changes in the period of enactment, such as determining the estimated transition tax, re-measuring our U.S. deferred tax assets and liabilities at a 21% rate as well as reassessing the net realizability of its deferred tax assets and liabilities. The one-time transition tax does not generate a tax liability as the deemed distribution is offset by tax attributes. The provisional amount related to the re-measurement of the Company’s deferred tax balance is a reduction of approximately $31.4 million. Due to the corresponding valuation allowance fully offsetting deferred taxes, there is no income statement impact. In December 2017, the SEC staff issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118) which allows companies to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. Since the Act was passed late in the fourth quarter of 2017, and ongoing guidance and accounting interpretation are expected over the next 12 months, the Company considers the accounting of the transition tax and deferred tax re-measurements to be incomplete. Additional work will be necessary for a more detailed analysis of the Company’s deferred tax assets and liabilities and its historical foreign earnings as well as potential correlative adjustments. The Company expects to complete its analysis within the measurement period in accordance with SAB 118. The Company does not expect any material subsequent adjustment to these amounts. Adjustment if any will have no impact to the income statement due to the Company’s loss position and valuation allowance.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2017
Selected Quarterly Financial Data (Unaudited)
Selected Quarterly Financial Data (Unaudited)	Note 12. Selected Quarterly Financial Data (Unaudited) The following table contains selected unaudited consolidated statement of operations information for each of the quarters in 2017 and 2016. The Company believes that the following information reflects all adjustments, consisting of only normal recurring adjustments, necessary for a fair presentation of the information for the periods presented. The operating results for any quarter are not necessarily indicative of results for any future period. Quarter Ended March 31, June 30, September 30, December 31, (In thousands, except per share data) 2017: Total revenues $ 83,979 $ 85,487 $ 83,821 $ 87,463 Product revenues 83,979 85,487 83,821 87,164 Cost of product revenues 13,672 13,798 13,433 13,814 Net income (loss) (806) (2,739) (2,191) 1,879 Basic net income (loss) per common share $ (0.02) $ (0.08) $ (0.06) $ 0.05 Diluted net income (loss) per common share $ (0.02) $ (0.08) $ (0.06) $ 0.05 2016: Total revenues $ 80,894 $ 81,974 $ 82,258 $ 82,742 Product revenues 80,894 81,886 82,136 82,002 Cost of product revenues 16,153 15,598 13,425 13,652 Net income (loss) (6,351) (6,100) (2,820) 1,352 Basic net income (loss) per common share $ (0.19) $ (0.18) $ (0.08) $ 0.04 Diluted net income (loss) per common share $ (0.19) $ (0.18) $ (0.08) $ 0.04 The quarterly increases in product revenues during 2017 and 2016 were primarily attributable to increased adoption of the Oncotype DX breast and Oncotype DX prostate cancer tests by physicians, international expansion, increased revenues recorded on an accrual basis, and increased reimbursement for these tests by third‑party payors. Per share amounts for the quarters and full year have been calculated separately. Accordingly, quarterly amounts may not add up to the annual amount because of differences in the weighted‑average common shares outstanding during each period, due primarily to the effect of the Company’s issuing shares of its common stock during the year. For all of the quarters presented, except for the quarters ended December 31, 2016, and December 31, 2017, basic and diluted net loss per common share were identical as potential common shares were excluded from the calculation because their effects were anti‑dilutive.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events
Subsequent Events	Note 13. Subsequent Events On March 8, 2018 the Company announced its decision to no longer provide its commercial offering of Oncotype SEQ Liquid Select or any further investment in next generation sequencing (NGS) panels due to a decision to focus the Company’s efforts to develop in vitro diagnostic test solutions and other tests with more predictable reimbursement, higher proprietary value and better prospects for global adoption. With this shift in strategic direction, the Company announced a reduction of its workforce resources of approximately 10%. The Company will take a charge of approximately $10 million in the first quarter of 2018 for costs associated with personnel reductions and a write-off of certain assets associated with NGS-based panels.

SCHEDULE II VALUATION AND QUALI

SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
	Dec. 31, 2017
SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS
SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS	Schedule II—Valuation and Qualifying Accounts for the years ended December 31, 2017, 2016, and 2015. SCHEDULE II GENOMIC HEALTH, INC. VALUATION AND QUALIFYING ACCOUNTS Years Ended December 31, 2017, 2016 and 2015 Balance at Balance at Beginning of End of Period Expenses Deductions Period (In thousands) Allowance for Doubtful Accounts: Year ended December 31, 2017 $ 4,508 $ 6,554 $ 7,178 $ 3,884 Year ended December 31, 2016 $ 3,988 $ 7,654 $ 7,134 $ 4,508 Year ended December 31, 2015 $ 3,628 $ 5,542 $ 5,182 $ 3,988

Organization and Summary of S23

Organization and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Organization and Summary of Significant Accounting Policies
Principles of Consolidation	Principles of Consolidation These consolidated financial statements include all the accounts of the Company and its wholly‑owned subsidiaries. The Company had two wholly-owned subsidiaries at December 31, 2017: Genomic Health International Holdings, LLC, which was established in Delaware in 2010 and supports the Company’s international sales and marketing efforts; and Oncotype Laboratories, Inc., which was established in 2012, and is inactive. Genomic Health International Holdings, LLC has nine wholly-owned subsidiaries. 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 consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The preparation of financial statements in conformity with GAAP requires management to make judgments, assumptions and estimates that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosures in the Company’s consolidated financial statements and accompanying notes. Actual results could differ materially from those estimates. There have been no material changes in the Company’s significant accounting policies, other than the adoption of Accounting Standards Update ("ASU") 2016-09 described below, as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016. Certain reclassifications have been made to prior period amounts to conform to the current year presentation. For the years ended December 31, 2016 and 2015, a reclassification of certain expenses from research and development to cost of product revenue was made in the consolidated statements of operations to conform to the current-year presentation.
Cash Equivalents	Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents.
Marketable Securities	Marketable Securities The Company invests in marketable securities, primarily money market funds, obligations of U.S. Government agencies and government‑sponsored entities, corporate bonds, commercial paper and equity securities. The Company considers all investments with a maturity date of less than one year as of the balance sheet date to be short‑term investments. Those investments with a maturity date greater than one year as of the balance sheet date are considered to be long‑term investments. In December 2017, the Company invested €3.4 million or $4.0 million in 270,000 shares of the common stock of Biocartis N.V. (“Biocartis”), a public company listed on the Euronext exchange. This investment was accounted for as an available-for-sale marketable security and valued at €3.0 million or $3.5 million at December 31, 2017. Unrealized gains or losses resulting from changes in the fair value of this investment will be recognized in other comprehensive income until the securities are sold. During the year ended December 31, 2017, $180,000 of unrealized losses relating to changes in the fair value of this investment were recorded in other comprehensive income. These securities are subject to a lock-up agreement which expires in December 2018. During the year ended December 31, 2017, a discount of $322,000 relating to the lock-up agreement was recognized in research and development expense, and a foreign currency revaluation gain of $7,000 was recorded in other income. Beginning in 2011, the Company made investments in various tranches of the preferred stock of Invitae Corporation (“Invitae”), which at the time was a privately-held company, such that the carrying value of this investment was $13.9 million at December 31, 2014. On February 18, 2015, Invitae completed an initial public offering of its common stock and the Company’s preferred stock investment automatically converted into 2,207,793 shares of Invitae common stock. This investment was accounted for on the cost method as an available-for-sale marketable security and valued at $18.1 million at December 31, 2015. During the year ended December 31, 2017, the Company sold its remaining shares of the common stock of Invitae for net proceeds of $10.2 million based on a cost of $6.28 per share, resulting in a realized gain of $2.8 million. During the year ended December 31, 2016, the Company sold a portion of its shares of the common stock of Invitae for proceeds of $9.7 million based on a cost of $6.28 per share, resulting in a realized gain of $3.2 million. There were no shares sold during the year ended December 31, 2015. The fair value of the remaining investment was $9.3 million at December 31, 2016. This investment, which is accounted for under the cost method, was valued at $7.3 million at December 31, 2016. Unrealized gains or losses resulting from changes in the fair value of this investment were recognized in other comprehensive income until the securities were sold. During the years ended December 31, 2017 and 2016, $1.1 million of unrealized gains, net of tax of $820,000, and $1.9 million of unrealized gains, net of tax of $727,000, respectively, related to the shares sold were reclassified out of accumulated other comprehensive income into earnings. There was no unrealized gain reclassified out of accumulated other comprehensive income into earnings during the year ended December 31, 2015. As of December 31, 2017, and 2016, respectively, all investments in marketable securities were classified as available for sale. These securities are carried at estimated fair value with unrealized gains and losses included in stockholders’ equity. Realized gains and losses and declines in value, if any, judged to be other than temporary on available‑for‑sale securities are reported in other income or expense. When securities are sold, any associated unrealized gain or loss initially recorded as a separate component of stockholders’ equity is reclassified out of stockholders’ equity on a specific‑identification basis and recorded in earnings for the period. The cost of securities sold is determined using specific identification.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company’s financial instruments consist principally of cash and cash equivalents, marketable securities, trade receivables and accounts payable. The carrying amounts of certain of these financial instruments, including cash and cash equivalents, trade receivables, note receivables and accounts payable, approximate fair value due to their short maturities. See Note 3, “ Fair Value Measurements ” for further information on the fair value of the Company’s financial instruments.
Concentration of Risk	Concentration of Risk Cash equivalents, marketable securities and trade accounts receivable are financial instruments which potentially subject the Company to concentrations of credit risk. Through December 31, 2017, no material losses had been incurred related to such credit risk. The Company is subject to credit risk from its portfolio of cash equivalents and marketable securities. The Company invests in money market funds through a major U.S. bank and is exposed to credit risk in the event of default by the financial institution to the extent of amounts recorded on the consolidated balance sheets. The Company invests in short‑term, investment‑grade debt instruments and by policy limits the amount in any one type of investment, except for securities issued or guaranteed by the U.S. government. Under its investment policy, the Company limits amounts invested in such securities by credit rating, maturity, industry group, investment type and issuer, except for securities issued by the U.S. government. The Company is not exposed to any significant concentrations of credit risk from these financial instruments. The goals of the Company’s investment policy, in order of priority, are as follows: safety and preservation of principal and diversification of risk; liquidity of investments sufficient to meet cash flow requirements; and a competitive after‑tax rate of return. The Company is also subject to credit risk from its accounts receivable related to its product sales. The Company performs evaluations of customers’ financial condition and generally does not require collateral. The majority of the Company’s accounts receivable arise from product sales in the United States. As of December 31, 2017, the substantial majority of the Company’s product revenues have been derived from sales of one product, the Oncotype DX breast cancer test. The majority of the Company’s tests to date have been delivered to physicians in the United States. All tissue-based Oncotype DX tests are processed in the Company’s clinical reference laboratory facility in Redwood City, California. Medicare accounted for 22%, 21% and 20% of the Company’s product revenues for the years ended December 31, 2017, 2016 and 2015, respectively, and represented 23% and 24% of the Company’s total accounts receivable balance as of December 31, 2017 and 2016, respectively. No other third‑party payor represented more than 10% of the Company’s product revenues or accounts receivable balances for these periods.
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 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 December 31, 2017 and 2016 was $3.9 million and $4.5 million, respectively. Write‑offs for doubtful accounts of $7.2 million and $7.1 million were recorded against the allowance during the years ended December 31, 2017 and 2016, respectively. Bad debt expense was $6.8 million, $7.9 million, and $6.0 million for the years ended December 31, 2017, 2016 and 2015, respectively.
Property and Equipment	Property and Equipment Property and equipment, including purchased software, are stated at cost. Depreciation is calculated using the straight‑line method over the estimated useful lives of the assets, which generally range from three to seven years. Leasehold improvements are amortized using the straight‑line method over the estimated useful lives of the assets or the remaining term of the lease, whichever is shorter.
Internal-use Software	Internal-use Software Costs incurred to develop software for internal use are capitalized and amortized over the estimated useful life of the software. Costs related to maintenance of internal-use software are expensed as incurred. For the years ended December 31, 2017, 2016 and 2015, the Company capitalized $5.1 million (including $2.7 million of personnel-related expenses), $3.4 million (including $1.2 million of personnel-related expenses), and $15.1 million (including $5.9 million of personnel-related expenses), respectively, of costs associated with internal-use software development. Amortization of previously capitalized amounts was $3.2 million, $2.5 million, and $380,000 for the years ended December 31, 2017, 2016, and 2015, respectively.
Intangible Assets	Intangible Assets Intangible assets with finite useful lives are recorded at cost, less accumulated amortization. Amortization is recognized over the estimated useful lives of the assets. The Company’s intangible assets with finite lives, which are related to patent licenses, are not material and are included in non‑current other assets on the Company’s consolidated balance sheets.
Investments in Privately Held Companies	Investments in Privately Held 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 the applicable accounting guidance for such investments. During the years ended December 31, 2017 and 2016, the Company invested $1.4 million and $6.1 million, respectively, in the subordinated convertible promissory notes of a private company. See Note 6, “Collaboration and Commercial Technology Licensing Agreements” for additional information regarding the terms of this investment. On March 8, 2017, the subordinated convertible promissory notes were converted into preferred stock of the private company representing approximately 9% of the private entity’s voting interests, at which time the Company estimated the fair value of the subordinated convertible promissory notes to be approximately $7.1 million. The preferred stock represents a variable interest in the investee. The Company has concluded it is not the primary beneficiary and thus has not consolidated the investee pursuant to the requirements of Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 810. The Company determined that the Company does not have the power to direct activities of the private company that most significantly impact the private company’s economic performance. The Company will continue to assess its investment and future commitments to the investee and to the extent its relationship with the investee changes, may be required to consolidate the investee in future periods. The equity investments are accounted for using the cost method of accounting and recorded in other assets on the Company’s consolidated balance sheets. During the year ended December 31, 2017, the Company invested $2.0 million in the convertible promissory note of a private company. See Note 6, “Collaboration and Commercial Technology Licensing Agreements” for additional information regarding the terms of this investment. The Company estimated the fair value of the convertible promissory note to be approximately $1.3 million. The investment in the convertible promissory note represents a variable interest in the investee. The Company has concluded it is not the primary beneficiary and thus has not consolidated the investee pursuant to the requirements of FASB ASC 810. The Company determined that it does not have the ability to exercise significant influence over the investee company. The Company will continue to assess its investment and future commitments to the investee and to the extent its relationship with the investee changes, may be required to consolidate the investee in future periods. The convertible promissory note is accounted for as available-for-sale debt security and recorded in other assets on the Company’s consolidated balance sheets.
Derivative Financial Instruments	Derivative Financial Instruments The Company hedges a portion of its foreign currency exposures related to outstanding monetary assets and liabilities using foreign currency forward contracts. The foreign currency forward contracts the Company uses to hedge the exposure are not designated as hedges, and as a result, changes in their fair value are recorded in other income (expense). As of December 31, 2017, the Company had open foreign currency forward contracts with notional amounts of $16.1 million. There were no open foreign currency forward contracts at December 31, 2016.
Impairment of Long-lived Assets	Impairment of Long‑lived Assets The Company reviews long‑lived assets, which include property and equipment, intangible assets and 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 property and equipment and intangible assets, an impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of the asset and its eventual disposition are less than its carrying amount. Impairment, if any, is assessed using undiscounted cash flows. For investments in non‑marketable equity securities, 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.
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 11, “Income Taxes” for additional information regarding unrecognized tax benefits.
Revenue Recognition	Revenue Recognition The Company derives its revenues from product sales and, to a lesser extent from contracts with biopharmaceutical and pharmaceutical companies. The majority of the Company’s historical product revenues have been derived from the sale of the Oncotype DX invasive 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 generally 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 medical 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) collectability 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. When evaluating whether the fee is fixed or determinable and collectible, the Company considers whether it has sufficient history to reliably estimate the total fee that will be received from a payor and a payor’s individual payment patterns. Determination 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 collectability of those fees under any contract or arrangement. 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 arrangement or contracted payment amount. The estimated accrual amounts per test, recorded upon delivery of a patient report, are calculated for each accrual payor and are based on the arrangement or contracted price adjusted for individual payment patterns resulting from co-payment amounts and excluded services in healthcare plans. The Company also reduces revenue for an estimate of amounts that qualify as patient assistance and related deductions that do not qualify for revenue recognition. When a payment received for an individual test is higher or lower than the estimated accrual amount, the Company recognizes the difference as either cash revenue, in the case of higher payments, or in the case of lower payments, a charge against either the patient assistance program and related deductions reserve or the allowance for doubtful accounts, as applicable. 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 distributors covering more than 90 countries outside of the United States. 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 requests for refunds of payments, generally due to overpayments made by third party‑payors. Upon becoming aware of a refund request, the Company establishes an accrued liability for tests covered by the refund request until such time as the Company determines whether or not a refund is due. Accrued refunds were $87,000 and $487,000 at December 31, 2017 and 2016, respectively. 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 typically 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.
Cost of Product Revenues	Cost of Product Revenues Cost of product revenues includes the cost of materials, direct labor, equipment and infrastructure expenses associated with processing tissue samples (including sample accessioning, histopathology, anatomical pathology, paraffin extraction, reverse transcription polymerase chain reaction (“RT‑PCR”), quality control analyses and shipping charges to transport tissue samples) and license fees. Infrastructure expenses include allocated facility occupancy and information technology costs. Costs associated with performing the Company’s tests are recorded as tests are processed. Costs recorded for tissue sample processing and shipping charges represent the cost of all the tests processed during the period regardless of whether revenue was recognized with respect to that test. Royalties for licensed technology calculated as a percentage of product revenues and fixed annual payments relating to the launch and commercialization of the Company’s tests are recorded as license fees in cost of product revenues at the time product revenues are recognized or in accordance with other contractual obligations.
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 these costs 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.
Share-based Compensation	Stock‑based Compensation The Company uses the Black‑Scholes option valuation model, single‑option approach, which requires the use of estimates such as stock price volatility and expected option lives, as well as expected option forfeiture rates, to value employee stock‑based compensation at the date of grant, and recognizes stock‑ based compensation expense ratably over the requisite service period. Equity instruments granted to non‑employees are also valued using the Black‑Scholes option valuation model and are subject to periodic revaluation over their vesting terms. The Company did not grant any stock options to non‑employee consultants during any of the years presented.
401(k) Plan	401(k) Plan Substantially all of the Company’s employees are eligible to participate in its defined contribution plan qualified under Section 401(k) of the Internal Revenue Code. The Company contributed dollar for dollar matching of employee contributions up to a maximum of $4,000, $4,000, and $3,000 for the years ended December 31, 2017, 2016 and 2015, respectively, for each employee per year based on a full calendar year of service. The match is funded concurrently with a participant’s semi‑monthly contributions to the 401(k) Plan. The Company recorded expense for its contributions under the 401(k) Plan of $2.9 million, $3.5 million and $2.8 million for the years ended December 31, 2017, 2016 and 2015, respectively.
Foreign Currency Transactions	Foreign Currency Transactions Net foreign currency transaction gains or losses are included in other income (expense), net on the Company’s consolidated statements of operations. Net foreign currency transaction gains (losses) totaled $317,000, $(782,000) and $(551,000) for the years ended December 31, 2017, 2016 and 2015, respectively.
Comprehensive Gain or Loss	Comprehensive Gain or Loss Other comprehensive gain or loss consists of unrealized gains and losses on available‑for‑sale securities.
Leases	Leases The Company enters into lease agreements for its laboratory and office facilities. These leases are classified as operating leases. Rent expense is recognized on a straight‑line basis over the term of the lease. Incentives granted under the Company’s facilities leases, including allowances to fund leasehold improvements and rent holidays, are capitalized and are recognized as reductions to rental expense on a straight‑line basis over the term of the lease.
Guarantees and Indemnifications	Guarantees and Indemnifications The Company, as permitted under Delaware law and in accordance with its bylaws, indemnifies its officers and directors for certain events or occurrences, subject to certain limits, while the officer or director is or was serving at the Company’s request in such capacity. The term of the indemnification period is for the officer’s or director’s lifetime. The maximum amount of potential future indemnification is unlimited; however, the Company has a directors and officers insurance policy that limits its exposure and may enable it to recover a portion of any future amounts paid. The Company believes the fair value of these indemnification agreements is minimal. Accordingly, the Company has not recorded any liabilities for these agreements as of December 31, 2017 and 2016.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606) . Topic 606 supersedes the revenue recognition requirements in Accounting Standards Codification Topic 605, Revenue Recognition , and requires entities to recognize revenue when they transfer control of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. In addition, Topic 606 requires more detailed disclosures to enable users of financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. Topic 606 will be effective for the Company in the first quarter of 2018. The Company will adopt Topic 606 effective January 1, 2018, using the modified retrospective transition method. The Company will also elect the practical expedient of applying the new guidance only to contracts that are not completed as of the date of initial application. Upon adoption, the Company will recognize the cumulative effect of adopting this guidance as an adjustment to its opening accumulated deficit balance. The Company expects this adjustment to be approximately $14 million. Prior periods will not be retrospectively adjusted. The Company has completed its assessment of the impact Topic 606 will have on its consolidated financial statements and related disclosures. The assessment included the analysis of the Company’s current portfolio of customer contracts, including a review of historical accounting policies and practices to identify potential differences in applying Topic 606. Based on the assessment, the Company expects changes to the timing of its revenue recognition from certain payors who are not currently accrual payors to be accelerated. In addition, certain amounts that were historically classified as bad debt expense will be considered an implicit price concession in determining the transaction price and therefore as a reduction in net revenues when historically these amounts were classified as bad debt expenses within general and administrative expenses. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. This ASU changes accounting for equity investments, financial liabilities under the fair value option and the presentation and disclosure requirements for financial instruments. In addition, it clarified guidance related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale debt securities. The new guidance could result to volatility of other income (expense), net, in future periods as a result of the remeasurement of the equity securities through earnings upon the occurrence of future observable price changes. The guidance will become effective for the Company beginning in the first quarter of 2018 and must be adopted using a modified retrospective approach, with certain exceptions. The Company adopted this new guidance effective January 1, 2018. The Company expects an impact related to the recognition and measurement of its equity investment in Biocartis. The Company will reclassify the unrealized loss from accumulated other comprehensive income (loss) to accumulated deficit as of the date of the adoption, which was $180,000 of unrealized loss based on the fair value of the equity investment in Biocartis as of December 31, 2017. In February 2016, the FASB issued ASU No. 2016-2, Leases (Topic 842). Topic 842 generally requires entities to recognize operating and financing lease liabilities and corresponding right-of-use assets on the balance sheet. Topic 842 is effective for the Company’s interim and annual reporting periods during the year ending December 31, 2019, and all annual and interim reporting periods thereafter. Early adoption is permitted. Entities are required to use a modified retrospective approach for leases that exist or are entered into after the beginning of the earliest comparative period in the financial statements, and there are certain optional practical expedients that an entity may elect to apply. Full retrospective application is prohibited and early adoption by public entities is permitted. The Company is currently evaluating the impact that the adoption of Topic 842 will have on its consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting, which simplifies several aspects of the accounting for share-based payments, including immediate recognition of all excess tax benefits and deficiencies in the income statement, changing the threshold to qualify for equity classification up to the employees' maximum statutory tax rates, allowing an entity-wide accounting policy election to either estimate the number of awards that are expected to vest or account for forfeitures as they occur, and clarifying the classification on the statement of cash flows for the excess tax benefit and employee taxes paid when an employer withholds shares for tax-withholding purposes. The standard is effective for interim and annual reporting periods beginning after December 15, 2016, although early adoption is permitted. The Company adopted this ASU in the first quarter of 2017 and elected to continue to estimate forfeitures expected to occur to estimate the amount of compensation cost to be recognized in each period. As a result, in the first quarter of 2017, the Company recorded a $11.6 million cumulative-effect adjustment decrease in accumulated deficit and an offsetting increase in deferred tax assets for previously unrecognized excess tax benefits that existed as of December 31, 2016. However, as all of the Company’s deferred tax assets, net of deferred tax liabilities, are subject to a valuation allowance and the realization of these assets is not more likely than not to be achieved, the Company recorded an $11.6 million valuation allowance against these deferred tax assets with an offsetting increase in accumulated deficit. The presentation requirement for cash flows related to employee taxes paid for withheld shares will not impact the statements of cash flows since such amounts have historically been presented as a financing activity. The adoption was on a prospective basis and therefore had no impact on prior periods.

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Net Loss Per Share
Schedule of potentially dilutive common shares excluded from computation of diluted net loss per share	Year Ended December 31, 2017 2016 2015 (In thousands) Stock awards excluded from the computation 800 828 945

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Measurements
Schedule of financial instruments measured at fair value on recurring basis	Actively Quoted Significant Markets for Other Significant Identical Observable Unobservable Balance at Assets Inputs Inputs December 31, Level 1 Level 2 Level 3 2017 (In thousands) As of December 31, 2017: Assets Money market deposits $ 10,215 $ — $ — $ 10,215 Commercial paper — 30,272 — 30,272 Corporate debt securities — 50,260 — 50,260 Corporate equity securities — 3,525 — 3,525 Total $ 10,215 $ 84,057 $ — $ 94,272 Actively Quoted Significant Markets for Other Significant Identical Observable Unobservable Balance at Assets Inputs Inputs December 31, Level 1 Level 2 Level 3 2016 (In thousands) As of December 31, 2016: Assets Money market deposits $ 13,198 $ — $ — $ 13,198 Commercial paper — 32,421 — 32,421 Corporate debt securities — 14,869 — 14,869 Corporate equity securities — 9,295 — 9,295 Total $ 13,198 $ 56,585 $ — $ 69,783
Summary of available-for-sale marketable securities	December 31, 2017 Cost or Gross Gross Total Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value (In thousands) Commercial paper $ 30,315 $ — $ (43) $ 30,272 Corporate debt securities 50,331 2 (73) 50,260 Corporate equity securities 4,020 — (495) 3,525 Total $ 84,666 $ 2 $ (611) $ 84,057 December 31, 2016 Cost or Gross Gross Total Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value (In thousands) Commercial paper $ 32,350 $ 71 $ — $ 32,421 Corporate debt securities 14,868 3 (2) 14,869 Corporate equity securities 7,348 1,947 — 9,295 Total $ 54,566 $ 2,021 $ (2) $ 56,585
Schedule of the breakdown of available-for-sale marketable securities with unrealized losses	In a Loss Position for Less Than 12 Months Gross Unrealized Estimated As of December 31, 2017: Losses Fair Value (In thousands) Commercial paper $ (43) $ 30,272 Corporate debt securities (73) 45,110 Corporate equity securities (495) $ 3,525 Total $ (611) $ 78,907

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property and Equipment
Summary of the Company's property and equipment	December 31, 2017 2016 (In thousands) Laboratory equipment $ 37,560 $ 29,992 Computer equipment 10,498 9,605 Computer software—internal use 26,483 23,790 Furniture and fixtures 4,749 4,055 Leasehold improvements 29,126 20,756 Work in progress 3,698 14,206 112,114 102,404 Less accumulated depreciation and amortization (65,674) (56,716) Total $ 46,440 $ 45,688

Accrued Expenses and Other Cu27

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Accrued Expenses and Other Current Liabilities
Summary of the Company's accrued expenses and other current liabilities	December 31, 2017 2016 (In thousands) Accrued expenses $ 7,197 $ 3,984 Accrued professional and other service fees 3,114 1,902 Accrued refunds 87 487 Accrued rebate 407 588 Accrued collaboration expense 2,532 2,418 Accrued taxes payable 746 800 Other current liabilities 1 1 Total $ 14,084 $ 10,180

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies
Schedule of future non-cancelable commitments under operating leases	Annual Payments (In thousands) Years Ending December 31, 2018 $ 5,958 2019 6,746 2020 7,075 2021 4,822 2022 4,082 2023 and thereafter 1,035 Total minimum payments $ 29,718

Capital Stock (Tables)

Capital Stock (Tables)	12 Months Ended
	Dec. 31, 2017
Capital Stock
Schedule of shares of common stock reserved for future issuance	Number of Shares (In thousands) Shares to be issued upon exercise of outstanding stock options and vesting of RSUs 4,424 Shares available for future stock option and RSU grants, settlement of employee stock purchase plan (ESPP) and restricted stock to be issued to outside directors in lieu of director fees 4,403 Shares of common stock reserved for future issuance 8,827

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Stock-Based Compensation
Summary of option activity	Weighted-Average Outstanding Options Remaining Aggregate Number of Weighted-Average Contractual Intrinsic Shares Exercise Price Life Value (In thousands) (In years) (In thousands) Balance at December 31, 2016 3,606 $ 25.07 Options granted 741 $ 28.12 Options exercised (765) $ 21.34 Options forfeited (87) $ 28.22 Options expired (35) $ 29.80 Balance at December 31, 2017 3,460 $ 26.42 6.0 $ 27,023 Exercisable at December 31, 2017 2,324 $ 25.61 4.7 $ 20,062 Vested and expected to vest at December 31, 2017 3,388 $ 26.39 6.0 $ 26,572
Summary of RSU activity	Weighted-Average Number of Grant Date Fair Shares Value (In thousands) Balance at December 31, 2016 871 $ 28.42 RSUs granted 593 $ 28.35 RSUs vested (388) $ 28.75 RSUs cancelled (112) $ 28.35 Balance at December 31, 2017 964 $ 28.25
Schedule of share-based compensation expense	Year Ended December 31, 2017 2016 2015 (In thousands) Cost of product revenues $ 741 $ 664 $ 584 Research and development 5,469 4,860 4,169 Selling and marketing 5,730 5,551 4,526 General and administrative 8,316 7,228 6,726 Total $ 20,256 $ 18,303 $ 16,005
Schedule of weighted-average fair values and assumptions used in calculation of fair value of stock options and employee stock purchase plan	Year Ended December 31, 2017 2016 2015 Expected volatility: Stock options 40 % 44 % 44 % ESPP 33 % 44 % 35 % Risk-free interest rate: Stock options 2.01 % 1.36 % 1.66 % ESPP 0.91 % 0.47 % 0.10 % Expected life in years: Stock options 6.22 6.10 5.94 ESPP 0.50 0.50 0.50 Weighted-average fair value: Stock options $ 11.83 $ 11.73 $ 13.37 ESPP $ 7.16 $ 7.35 $ 6.99

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Information
Summary of total revenue from customers by geographic region	Year Ended December 31, 2017 2016 2015 (In thousands) United States $ 287,662 $ 281,077 $ 246,008 Outside of the United States 53,088 46,791 41,450 Total revenues $ 340,750 $ 327,868 $ 287,458

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Taxes
Schedule of components of the Company's loss before income taxes	Year Ended December 31, 2017 2016 2015 (In thousands) Domestic $ (5,404) $ (14,676) $ (34,276) Foreign 3,051 2,138 (28) Total loss before income taxes $ (2,353) $ (12,538) $ (34,304)
Schedule of components of the Company's income tax expense (benefit)	Year Ended December 31, 2017 2016 2015 (In thousands) Current expense (benefit): Federal $ (140) $ 18 $ — State 31 67 (15) Foreign 792 569 566 Deferred tax expense (benefit): Federal 792 702 (1,494) State 29 25 (53) Foreign — — — Total income tax expense (benefit) $ 1,504 $ 1,381 $ (996)
Schedule of reconciliation of income tax expense (benefit) and the amount computed by applying the statutory federal income tax rate	Year Ended December 31, 2017 2016 2015 (In thousands) Federal tax at statutory rate $ (824) $ (4,388) $ (12,006) Stock-based compensation (687) 867 782 Non-deductible meals and entertainment 534 530 558 Net operating losses not used 1,846 3,705 10,499 Tax effect on available-for-sale securities 792 702 (1,494) Subpart F 185 — — Foreign tax (279) (179) 576 Federal AMT refundable credit (122) — — State tax, net of federal benefit 39 68 (63) Other 20 76 152 Total income tax expense (benefit) $ 1,504 $ 1,381 $ (996)
Schedule of significant components of deferred tax assets and liabilities	December 31, 2017 2016 (In thousands) Deferred tax assets: Net operating loss carryforwards $ 34,450 $ 42,550 Stock-based compensation 8,120 12,290 Research tax credits 21,710 17,620 Fixed assets 690 1,960 Accrued compensation 3,070 6,080 Other 7,150 7,490 Total deferred tax assets 75,190 87,990 Valuation allowance (75,190) (87,990) Net deferred tax assets $ — $ —
Summary of the activity related to unrecognized tax benefits	Year Ended December 31, 2017 2016 2015 (In thousands) Balance at January 1 $ 2,078 $ 2,847 $ 1,600 Increase (decrease) related to prior year tax positions — (1,076) 927 Increase related to current year tax positions 331 307 320 Balance at December 31 $ 2,409 $ 2,078 $ 2,847

Selected Quarterly Financial 33

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Selected Quarterly Financial Data (Unaudited)
Schedule of selected quarterly unaudited consolidated statement of operations information	Quarter Ended March 31, June 30, September 30, December 31, (In thousands, except per share data) 2017: Total revenues $ 83,979 $ 85,487 $ 83,821 $ 87,463 Product revenues 83,979 85,487 83,821 87,164 Cost of product revenues 13,672 13,798 13,433 13,814 Net income (loss) (806) (2,739) (2,191) 1,879 Basic net income (loss) per common share $ (0.02) $ (0.08) $ (0.06) $ 0.05 Diluted net income (loss) per common share $ (0.02) $ (0.08) $ (0.06) $ 0.05 2016: Total revenues $ 80,894 $ 81,974 $ 82,258 $ 82,742 Product revenues 80,894 81,886 82,136 82,002 Cost of product revenues 16,153 15,598 13,425 13,652 Net income (loss) (6,351) (6,100) (2,820) 1,352 Basic net income (loss) per common share $ (0.19) $ (0.18) $ (0.08) $ 0.04 Diluted net income (loss) per common share $ (0.19) $ (0.18) $ (0.08) $ 0.04

Organization and Summary of S34

Organization and Summary of Significant Accounting Policies (Principles of Consolidation) (Details)	12 Months Ended
	Dec. 31, 2017subsidiary
Principles of Consolidation
Number of wholly-owned subsidiaries	2
Genomic Health International Holdings, LLC
Principles of Consolidation
Number of wholly-owned subsidiaries	9

Organization and Summary of S35

Organization and Summary of Significant Accounting Policies (Marketable Securities) (Details) € in Millions	Feb. 18, 2015shares	Dec. 31, 2017EUR (€)shares	Dec. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2017USD ($)shares	Dec. 31, 2014USD ($)
Investments in Privately Held Companies
Amount invested in shares of common stock				$ 109,249,000	$ 69,722,000	$ 76,743,000
Net foreign currency gains (losses)				317,000	(782,000)	(551,000)
Biocartis N.V.
Investments in Privately Held Companies
Amount invested in shares of common stock		€ 3.4	$ 4,000,000
Estimated fair value, equity securities		€ 3					$ 3,500,000
Unrealized losses recorded in other comprehensive income				180,000
Biocartis N.V. | Research and development
Investments in Privately Held Companies
Discount relating to lock-up agreement				322,000
Biocartis N.V. | Other income (expense)
Investments in Privately Held Companies
Net foreign currency gains (losses)				$ 7,000
Invitae
Investments in Privately Held Companies
Estimated fair value, equity securities					9,300,000	$ 18,100,000
Carrying value					$ 7,300,000			$ 13,900,000
Common Stock | Biocartis N.V.
Investments in Privately Held Companies
Number of shares purchased | shares		270,000					270,000
Common Stock | Invitae
Investments in Privately Held Companies
Number of shares of common stock issued from conversion | shares	2,207,793

Organization and Summary of S36

Organization and Summary of Significant Accounting Policies (Marketable Securities Sold) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Investments in Privately Held Companies
Proceeds from sales of marketable securities	$ 10,155,000	$ 9,717,000
Realized gains on available-for-sale marketable securities	2,807,000	3,208,000
Amount reclassified out of accumulated other comprehensive income	1,126,000	1,854,000
Exclusive license and development agreement with Biocartis NV
Investments in Privately Held Companies
Estimated fair value, equity securities	3,500,000
Invitae
Investments in Privately Held Companies
Estimated fair value, equity securities		9,300,000	$ 18,100,000
Carrying value		7,300,000		$ 13,900,000
Common Stock | Sale | Invitae
Investments in Privately Held Companies
Proceeds from sales of marketable securities	$ 10,200,000	$ 9,700,000
Cost per share (in dollars per share)	$ 6.28	$ 6.28
Realized gains on available-for-sale marketable securities	$ 2,800,000	$ 3,200,000
Number of shares of cost method investment sold by entity			0
Amount reclassified out of accumulated other comprehensive income	1,100,000	1,900,000	$ 0
Amount reclassified out of accumulated other comprehensive income, tax portion	$ 820,000	$ 727,000

Organization and Summary of S37

Organization and Summary of Significant Accounting Policies Concentration of Risk (Details) - product	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Concentration of Risk
Number of products from which the majority of the entity's product revenues have been derived	1
Product line | Product
Concentration of Risk
Number of products from which the majority of the entity's product revenues have been derived	1
Product revenues | Customer | Medicare
Concentration of Risk
Concentration risk percentage	22.00%	21.00%	20.00%
Net accounts receivable | Credit | Medicare
Concentration of Risk
Concentration risk percentage	23.00%	24.00%

Organization and Summary of S38

Organization and Summary of Significant Accounting Policies (Other) (Details)	Mar. 08, 2017USD ($)	Dec. 31, 2017USD ($)Testcountry	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Allowance for Doubtful Accounts
Allowance for doubtful accounts		$ 3,884,000	$ 4,508,000
Write-offs for doubtful accounts recorded against allowance		7,200,000	7,100,000
Bad debt expense		$ 6,800,000	7,900,000	$ 6,000,000
Revenue Recognition
Minimum number of Oncotype tests by exclusive distribution agreements | Test		1
Minimum number of countries covered for distribution agreements establishment | country		90
Accrued refunds		$ 87,000	487,000
401(k) Plan
Maximum amount of matching employer contribution for each employee per year		4,000	4,000	3,000
Contributions expensed		2,900,000	3,500,000	2,800,000
Foreign Currency Transactions
Net foreign currency gains (losses)		317,000	(782,000)	(551,000)
Foreign exchange forward contract
Derivative Financial Instruments
Notional amount		16,100,000	0
Epic Sciences, Inc. | Subordinated convertible promissory notes
Investments in Privately Held Companies
Amount invested in convertible promissory notes		1,400,000	6,100,000
Percentage of ownership interest in private company	9.00%
Epic Sciences, Inc. | Subordinated convertible promissory notes | Other Assets
Investments in Privately Held Companies
Estimated fair value, debt securities	$ 7,100,000
Cleveland Diagnostics, Inc. | Convertible promissory notes
Investments in Privately Held Companies
Amount invested in convertible promissory notes		2,000,000
Cleveland Diagnostics, Inc. | Convertible promissory notes | Other Assets
Investments in Privately Held Companies
Estimated fair value, debt securities		$ 1,300,000
Property and equipment | Minimum
Property and Equipment
Estimated useful lives of the assets		3 years
Property and equipment | Maximum
Property and Equipment
Estimated useful lives of the assets		7 years
Computer software—internal use
Internal-use Software
Costs to develop internal-use software capitalized		$ 5,100,000	3,400,000	15,100,000
Personnel-related expenses		2,700,000	1,200,000	5,900,000
Amortization		$ 3,200,000	$ 2,500,000	$ 380,000

Organization and Summary of S39

Organization and Summary of Significant Accounting Policies (Recently Issued Accounting Pronouncements) (Details) - USD ($)	Jan. 01, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Recently Issued Accounting Pronouncements
Deferred tax assets			$ 75,190,000	$ 87,990,000
Deferred tax assets valuation allowance			75,190,000	87,990,000
Accumulated deficit			245,945,000	$ 242,088,000
ASU 2014-09
Recently Issued Accounting Pronouncements
Cumulative effect before tax	$ 14,000,000
ASU 2016-09
Recently Issued Accounting Pronouncements
Cumulative-effect adjustment		$ 11,600,000
Deferred tax assets		11,600,000
Deferred tax assets valuation allowance		11,600,000
Accumulated deficit		$ 11,600,000
Biocartis N.V.
Recently Issued Accounting Pronouncements
Unrealized losses recorded in other comprehensive income			$ 180,000

Net Loss Per Share (Details)

Net Loss Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net Loss Per Share
Stock awards excluded from the computation (in shares)	800	828	945

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets measured at fair value on a recurring basis:
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
Recurring basis
Assets measured at fair value on a recurring basis:
Total assets at fair value	94,272	69,783
Recurring basis | Money market deposits
Assets measured at fair value on a recurring basis:
Total assets at fair value	10,215	13,198
Recurring basis | Commercial paper
Assets measured at fair value on a recurring basis:
Total assets at fair value	30,272	32,421
Recurring basis | Corporate debt securities
Assets measured at fair value on a recurring basis:
Total assets at fair value	50,260	14,869
Recurring basis | Corporate equity securities
Assets measured at fair value on a recurring basis:
Total assets at fair value	3,525	9,295
Recurring basis | Actively Quoted Markets for Identical Assets Level 1
Assets measured at fair value on a recurring basis:
Total assets at fair value	10,215	13,198
Recurring basis | Actively Quoted Markets for Identical Assets Level 1 | Money market deposits
Assets measured at fair value on a recurring basis:
Total assets at fair value	10,215	13,198
Recurring basis | Significant Other Observable Inputs Level 2
Assets measured at fair value on a recurring basis:
Total assets at fair value	84,057	56,585
Recurring basis | Significant Other Observable Inputs Level 2 | Commercial paper
Assets measured at fair value on a recurring basis:
Total assets at fair value	30,272	32,421
Recurring basis | Significant Other Observable Inputs Level 2 | Corporate debt securities
Assets measured at fair value on a recurring basis:
Total assets at fair value	50,260	14,869
Recurring basis | Significant Other Observable Inputs Level 2 | Corporate equity securities
Assets measured at fair value on a recurring basis:
Total assets at fair value	$ 3,525	$ 9,295

Fair Value Measurements (Availa

Fair Value Measurements (Available-For-Sale Marketable Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Marketable securities classified as available-for-sale
Cost or Amortized Cost	$ 84,666	$ 54,566
Gross Unrealized Gains	2	2,021
Gross Unrealized Losses	(611)	(2)
Total Estimated Fair Value	84,057	56,585
Commercial paper
Marketable securities classified as available-for-sale
Cost or Amortized Cost	30,315	32,350
Gross Unrealized Gains		71
Gross Unrealized Losses	(43)
Total Estimated Fair Value	30,272	32,421
Corporate debt securities
Marketable securities classified as available-for-sale
Cost or Amortized Cost	50,331	14,868
Gross Unrealized Gains	2	3
Gross Unrealized Losses	(73)	(2)
Total Estimated Fair Value	50,260	14,869
Corporate equity securities
Marketable securities classified as available-for-sale
Cost or Amortized Cost	4,020	7,348
Gross Unrealized Gains		1,947
Gross Unrealized Losses	(495)
Total Estimated Fair Value	$ 3,525	$ 9,295

Fair Value Measurements (Avai43

Fair Value Measurements (Available-For-Sale Marketable Securities with Unrealized Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Measurements
Realized gains on available-for-sale marketable securities	$ 2,807	$ 3,208
In a Loss Position for Less Than 12 Months, Gross Unrealized Losses	(611)
In a Loss Position for Less Than 12 Months, Estimated Fair Value	$ 78,907
Maximum contractual maturities of Company's available-for-sale marketable securities	1 year	1 year
Commercial paper
Fair Value Measurements
In a Loss Position for Less Than 12 Months, Gross Unrealized Losses	$ (43)
In a Loss Position for Less Than 12 Months, Estimated Fair Value	30,272
Corporate debt securities
Fair Value Measurements
In a Loss Position for Less Than 12 Months, Gross Unrealized Losses	(73)
In a Loss Position for Less Than 12 Months, Estimated Fair Value	45,110
Corporate equity securities
Fair Value Measurements
In a Loss Position for Less Than 12 Months, Gross Unrealized Losses	(495)
In a Loss Position for Less Than 12 Months, Estimated Fair Value	$ 3,525

Fair Value Measurements (Impair

Fair Value Measurements (Impairment) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Capitalized Computer Software, Impairments	$ 76,000	$ 2,600,000	$ 635,000
Previously Capitalized Software | Held for sale | Selling and marketing
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Capitalized Computer Software, Impairments	$ 98,000	2,600,000	635,000
Equipment | Held for sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of assets held for use		$ 56,000	$ 123,000

Fair Value Measurements (Conver

Fair Value Measurements (Convertible Note) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Mar. 08, 2017
Convertible promissory notes | Cleveland Diagnostics, Inc.
Investment fair value
Amount invested in convertible promissory notes	$ 2
Convertible promissory notes | Cleveland Diagnostics, Inc. | Other Assets
Investment fair value
Estimated fair value, debt securities	1.3
Subordinated convertible promissory notes | Epic Sciences, Inc.
Investment fair value
Amount invested in convertible promissory notes	1.4	$ 6.1
Subordinated convertible promissory notes | Epic Sciences, Inc. | Other Assets
Investment fair value
Estimated fair value, debt securities			$ 7.1
Significant Unobservable Inputs Level 3 | Convertible promissory notes | Cleveland Diagnostics, Inc.
Investment fair value
Estimated fair value, debt securities	$ 1.3
Significant Unobservable Inputs Level 3 | Subordinated convertible promissory notes | Epic Sciences, Inc. | Other Assets
Investment fair value
Estimated fair value, debt securities		$ 5.8	$ 7.1

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property and Equipment
Property and equipment, gross	$ 112,114	$ 102,404
Less accumulated depreciation and amortization	(65,674)	(56,716)
Total	46,440	45,688
Depreciation and amortization expense	11,600	8,800	$ 6,900
Laboratory equipment
Property and Equipment
Property and equipment, gross	37,560	29,992
Computer equipment
Property and Equipment
Property and equipment, gross	10,498	9,605
Computer software—internal use
Property and Equipment
Property and equipment, gross	26,483	23,790
Furniture and fixtures
Property and Equipment
Property and equipment, gross	4,749	4,055
Leasehold improvements
Property and Equipment
Property and equipment, gross	29,126	20,756
Work in progress
Property and Equipment
Property and equipment, gross	$ 3,698	$ 14,206

Accrued Expenses and Other Cu47

Accrued Expenses and Other Current Liabilities (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Accrued Expenses and Other Current Liabilities
Accrued expenses	$ 7,197,000	$ 3,984,000
Accrued professional and other service fees	3,114,000	1,902,000
Accrued refunds	87,000	487,000
Accrued rebate	407,000	588,000
Accrued collaboration expense	2,532,000	2,418,000
Accrued taxes payable	746,000	800,000
Other current liabilities	1,000	1,000
Total	$ 14,084,000	$ 10,180,000

Collaboration and Commercial 48

Collaboration and Commercial Technology Licensing Agreements (Details) € / shares in Units, € in Millions

1 Months Ended

3 Months Ended

12 Months Ended

Dec. 31, 2017EUR (€)€ / shares

Dec. 31, 2017USD ($)

Nov. 30, 2017USD ($)

Jun. 30, 2016USD ($)item

Jul. 31, 2014

Mar. 31, 2015USD ($)

Dec. 31, 2013USD ($)

Dec. 31, 2017EUR (€)€ / shares

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)

Dec. 31, 2015USD ($)

Dec. 31, 2017USD ($)shares

Sep. 30, 2017EUR (€)

Collaboration payments and costs

Amount invested in shares of common stock

$ 109,249,000

$ 69,722,000

$ 76,743,000

Contract revenue

299,000

950,000

Collaboration and specimen transfer agreements

Collaboration payments and costs

Collaboration expense

7,300,000

4,600,000

11,100,000

Oncotype DX GPS

Collaboration payments and costs

Estimated total remaining obligation, including milestone payments

1,300,000

Oncotype DX GPS | Minimum

Collaboration payments and costs

Number of years of active surveillance

1 year

Oncotype DX GPS | Maximum

Collaboration payments and costs

Number of years of active surveillance

2 years

Exclusive distribution rights Epic's AR-V7 Nucleus Detect

Collaboration payments and costs

Investment in subordinated convertible promissory notes per agreement

7,500,000

$ 7,500,000

Fair value of convertible promissory notes

7,100,000

Deferred cost

$ 375,000

Obligation upon achievement of certain milestones

$ 4,000,000

Number of milestones needed to be achieved for conversion into preferred stock | item

1

Investment in preferred stock per collaboration agreement

$ 2,500,000

Term of agreement

10 years

Exclusive license agreement

Collaboration payments and costs

Estimated total remaining obligation, including milestone payments

0

Exclusive license agreement | Research and development

Collaboration payments and costs

Up-front payment

$ 9,000,000

Amount accrued in anticipation of the wind-down of license

$ 5,500,000

Technology license agreements | Cost of product revenues

Collaboration payments and costs

Costs recorded under collaborative arrangements

314,000

$ 5,300,000

$ 9,200,000

Exclusive license and development agreement with Biocartis NV

Collaboration payments and costs

Shares purchased | shares

270,000

Market price | € / shares

€ 12.50

€ 12.50

Amount invested in shares of common stock

€ 3.4

$ 4,000,000

Estimated fair value, equity securities

$ 3,500,000

Discount relating to lock-up agreement

322,000

Unrealized losses recorded in other comprehensive income

180,000

Cash obligation upon achievement of certain milestones | €

€ 6.5

Exclusive license and development agreement with Biocartis NV | Research and development

Collaboration payments and costs

Upfront license and option fee payment

€ 2.8

3,200,000

Exclusive licensing agreement with Cleveland Diagnostics | Convertible promissory notes

Collaboration payments and costs

Convertible promissory note

2,000,000

Estimated fair value, debt securities

1,300,000

Additional cost of the license

671,000

Exclusive licensing agreement with Cleveland Diagnostics | Future plan | Convertible promissory notes

Collaboration payments and costs

Convertible promissory note

$ 3,000,000

Exclusive licensing agreement with Cleveland Diagnostics | Maximum | Convertible promissory notes

Collaboration payments and costs

Cash obligation upon achievement of certain milestones

$ 18,500,000

Contract research arrangement with Janssen Pharmaceuticals

Collaboration payments and costs

Total expected payment to be received

$ 1,800,000

Contract revenue

$ 299,000

Commitments and Contingencies49

Commitments and Contingencies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)ft²item	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Lease Obligations
Rent expense	$ 6,300	$ 5,700	$ 4,100
Non-cancelable commitments under operating leases
2,018	5,958
2,019	6,746
2,020	7,075
2,021	4,822
2,022	4,082
2023 and thereafter	1,035
Total minimum payments	$ 29,718
Leased laboratory and office space located in Redwood City, California
Lease Obligations
Area leased under non-cancelable operating lease agreement (in square feet) | ft²	180,700
Number of non-cancelable operating leases | item	5
Period of time for which entity has an option to extend lease term	5 years
Allowance for certain tenant improvements	$ 2,300
Leased office space located in Geneva, Switzerland
Lease Obligations
Area leased under non-cancelable operating lease agreement (in square feet) | ft²	7,500

Capital Stock (Details)

Capital Stock (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended	13 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2017	Dec. 31, 2016
Capital Stock
Common stock outstanding (in shares)				35,049,436	33,831,998
Shares of common stock reserved for future issuance				8,827,000
Treasury Stock
Amount of common stock to be repurchased on an accelerated basis under accelerated share repurchase agreement	$ 30
Number of common shares received under accelerated share repurchase agreement	984,074	77,257
Average purchase price of common stock from the accelerated share repurchase program (in dollars per share)			$ 28.27
Exercise of outstanding stock options and vesting of RSUs
Capital Stock
Shares of common stock reserved for future issuance				4,424,000
Stock option and restricted stock unit grants, settlement of employee stock purchase plan (ESPP) and restricted stock to be issued to outside directors in lieu of director fees
Capital Stock
Shares of common stock reserved for future issuance				4,403,000

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - 2005 Stock Incentive Plan - shares	Jun. 15, 2017	Jun. 09, 2016	Jun. 11, 2015	Jun. 08, 2009	Dec. 31, 2017	Sep. 08, 2005
Stock awards other than options
Shares of common stock reserved for issuance						5,000,000
Increase in shares reserved for issuance	1,500,000	1,500,000	1,500,000	3,980,000
Shares of common stock available for future grant					3,034,000

Stock-Based Compensation (Stock

Stock-Based Compensation (Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Apr. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stock Options
Number of Shares
Options outstanding at the beginning of the period (in shares)		3,606,000
Options granted (in shares)		741,000
Options exercised (in shares)		(765,000)
Options forfeited (in shares)		(87,000)
Options expired (in shares)		(35,000)
Options outstanding at the end of the period (in shares)		3,460,000	3,606,000
Exercisable at the end of the period (in shares)		2,324,000
Vested and expected to vest at the end of the period (in shares)		3,388,000
Weighted-Average Exercise Price
Options outstanding at the beginning of the period (in dollars per share)		$ 25.07
Options granted (in dollars per share)		28.12
Options exercised (in dollars per share)		21.34
Options forfeited (in dollars per share)		28.22
Options expired (in dollars per share)		29.80
Options outstanding at the end of the period (in dollars per share)		26.42	$ 25.07
Exercisable at the end of the period (in dollars per share)		25.61
Vested and expected to vest at the end of the period (in dollars per share)		$ 26.39
Weighted-Average Remaining Contractual Life
Options outstanding at the end of the period		6 years
Exercisable at the end of the period		4 years 8 months 12 days
Vested and expected to vest at the end of the period		6 years
Aggregate Intrinsic Value
Options outstanding at the end of the period (in dollars)		$ 27,023
Exercisable at the end of the period (in dollars)		20,062
Vested and expected to vest at the end of the period (in dollars)		26,572
Intrinsic value (in dollars)		8,000	$ 5,600	$ 6,600
Fair value of shares vested (in dollars)		$ 6,200	$ 5,300	$ 4,200
Stock Options | Performance-Based Vesting
Number of Shares
Options granted (in shares)	75,531
Weighted-Average Exercise Price
Options exercised (in dollars per share)	$ 31.12
Nonstatutory Stock Options | Outside directors
Additional disclosure related to options
Exercise price as a percentage of the fair market value of the company's stock		100.00%
Minimum | Incentive Stock Options
Additional disclosure related to options
Exercise price as a percentage of the fair market value of the company's stock		100.00%
Minimum | Nonstatutory Stock Options
Additional disclosure related to options
Exercise price as a percentage of the fair market value of the company's stock		80.00%
Maximum | Incentive Stock Options
Additional disclosure related to options
Term of incentive stock options from the date of grant		10 years
Maximum | Nonstatutory Stock Options | Outside directors
Additional disclosure related to options
Term of stock options after termination of the outside directors' service		12 months
End of first year | Nonstatutory Stock Options | Outside directors
Additional disclosure related to options
Vesting percentage		25.00%
Vesting period, after the first anniversary, in which the options vest monthly		3 years

Stock-Based Compensation (RSU A

Stock-Based Compensation (RSU Activity) (Details)	12 Months Ended
	Dec. 31, 2017USD ($)installment$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares
RSUs
Stock based compensation
Number of equal annual installments | installment	3
Number of Shares
Balance at the beginning of the period (in shares) | shares	871,000
Granted (in shares) | shares	593,000
Vested (in shares) | shares	(388,000)
Cancelled (in shares) | shares	(112,000)
Balance at the end of the period (in shares) | shares	964,000	871,000
Weighted-Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share)	$ 28.42
Granted (in dollars per share)	28.35	$ 27.50	$ 30.65
Vested (in dollars per share)	28.75
Cancelled (in dollars per share)	28.35
Balance at the end of the period (in dollars per share)	$ 28.25	$ 28.42
Additional Disclosure
Fair value (in dollars) | $	$ 12,000,000	$ 8,600,000	$ 9,400,000
RSUs | Performance-Based Vesting
Weighted-Average Grant Date Fair Value
Granted (in dollars per share)	$ 0	$ 28.09	$ 31.12
Additional Disclosure
Fair value (in dollars) | $	$ 0	$ 163,000	$ 211,000
Restricted Stock | Outside directors
Number of Shares
Granted (in shares) | shares	6,375	6,970	7,365
Weighted-Average Grant Date Fair Value
Granted (in dollars per share)	$ 31.33	$ 28.65	$ 27.10
Additional Disclosure
Fair value (in dollars) | $	$ 200,000	$ 200,000	$ 200,000

Stock-Based Compensation (Emplo

Stock-Based Compensation (Employee Stock Purchase Plan) (Details) - Employee Stock Purchase Plan - USD ($)	Jun. 15, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Stock Purchase Plan
Maximum period for offerings under ESPP		27 months
Exercise price as a percentage of the fair market value of the company's stock		85.00%
Length of purchase period under ESPP		6 months
Shares of common stock reserved for issuance		1,250,000
Increase in shares reserved for issuance	1,250,000
Shares of common stock available for future grant		1,368,713
Number of shares issued		210,880	226,303	203,842
Unrecognized compensation expense (in dollars)		$ 587,000
Weighted-average period of recognition of unrecognized stock-based compensation expense		5 months
Maximum
Employee Stock Purchase Plan
Exercise price as a percentage of the fair market value of the company's stock		85.00%

Stock-Based Compensation (Emp55

Stock-Based Compensation (Employee Stock-Based Compensation Expense) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	$ 20,256,000	$ 18,303,000	$ 16,005,000
Stock Options | Unvested Stock Options
Employee Stock Based Compensation Expense
Unrecognized compensation expense (in dollars)	$ 10,000,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 7 months 6 days
Stock Options | Performance-Based Vesting
Employee Stock Based Compensation Expense
Unrecognized compensation expense (in dollars)	$ 0
RSUs
Employee Stock Based Compensation Expense
Unrecognized compensation expense (in dollars)	$ 16,300,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 year 9 months 18 days
Cost of product revenues
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	$ 741,000	664,000	584,000
Research and development
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	5,469,000	4,860,000	4,169,000
Selling and marketing
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	5,730,000	5,551,000	4,526,000
General and administrative
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	$ 8,316,000	$ 7,228,000	$ 6,726,000

Stock-Based Compensation (Valua

Stock-Based Compensation (Valuation Assumptions) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Weighted-average fair values and assumptions used in calculation of fair value
Dividend yield (as a percent)	0.00%
Employee Stock Purchase Plan
Weighted-average fair values and assumptions used in calculation of fair value
Expected volatility (as a percent)	33.00%	44.00%	35.00%
Risk-free interest rate (as a percent)	0.91%	0.47%	0.10%
Expected life	6 months	6 months	6 months
Weighted-average fair value (in dollars per share)	$ 7.16	$ 7.35	$ 6.99
Stock Options
Weighted-average fair values and assumptions used in calculation of fair value
Expected volatility (as a percent)	40.00%	44.00%	44.00%
Risk-free interest rate (as a percent)	2.01%	1.36%	1.66%
Expected life	6 years 2 months 19 days	6 years 1 month 6 days	5 years 11 months 9 days
Weighted-average fair value (in dollars per share)	$ 11.83	$ 11.73	$ 13.37

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017USD ($)product	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)segmentproduct	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Segment information
Number of business segments in which the entity operates | segment									1
Number of products from which the majority of the entity's product revenues have been derived | product	1								1
Total revenues	$ 87,463	$ 83,821	$ 85,487	$ 83,979	$ 82,742	$ 82,258	$ 81,974	$ 80,894	$ 340,750	$ 327,868	$ 287,458
United States
Segment information
Total revenues									287,662	281,077	246,008
Outside of the United States
Segment information
Total revenues									$ 53,088	$ 46,791	$ 41,450

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of income (loss) before income taxes
Domestic	$ (5,404)	$ (14,676)	$ (34,276)
Foreign	3,051	2,138	(28)
Loss before income taxes	(2,353)	(12,538)	(34,304)
Current expense (benefit):
Federal	(140)	18
State	31	67	(15)
Foreign	792	569	566
Deferred tax expense (benefit):
Federal	792	702	(1,494)
State	29	25	(53)
Total income tax expense (benefit)	1,504	1,381	(996)
Reconciliation of income tax expense (benefit) and the amount computed by applying the statutory federal income tax rate
Federal tax at statutory rate	(824)	(4,388)	(12,006)
Stock-based compensation	(687)	867	782
Non-deductible meals and entertainment	534	530	558
Net operating losses not used	1,846	3,705	10,499
Tax effect on available-for-sale securities	792	702	(1,494)
Subpart F	185
Foreign tax	(279)	(179)	576
Federal AMT refundable credit	(122)
State tax, net of federal benefit	39	68	(63)
Other	20	76	152
Total income tax expense (benefit)	1,504	1,381	(996)
Deferred tax assets:
Net operating loss carryforwards	34,450	42,550
Stock-based compensation	8,120	12,290
Research tax credits	21,710	17,620
Fixed assets	690	1,960
Accrued compensation	3,070	6,080
Other	7,150	7,490
Total deferred tax assets	75,190	87,990
Valuation allowance	(75,190)	(87,990)
Increase (decrease) in net valuation allowance	$ (12,800)	$ 6,100	$ 10,100

Income Taxes (Net Operating Los

Income Taxes (Net Operating Loss Carryforwards) (Details) $ in Millions	Dec. 31, 2017USD ($)
Federal
Net operating loss carryforwards
Net operating loss carryforwards	$ 156
State
Net operating loss carryforwards
Net operating loss carryforwards	$ 93.3

Income Taxes (Tax Credit Carryf

Income Taxes (Tax Credit Carryforwards) (Details) - Research and development. $ in Millions	Dec. 31, 2017USD ($)
Federal
Tax credit carryforwards
Research and development tax credit carryforwards	$ 13.4
State
Tax credit carryforwards
Research and development tax credit carryforwards	$ 13.3

Income Taxes (Activity Related

Income Taxes (Activity Related to Unrecognized Tax Benefits) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Activity related to unrecognized tax benefits
Balance at the beginning of the period	$ 2,078,000	$ 2,847,000	$ 1,600,000
Increase related to prior year tax positions			927,000
(Decrease) related to prior year tax positions		(1,076,000)
Increase related to current year tax positions	331,000	307,000	320,000
Balance at the end of the period	2,409,000	2,078,000	2,847,000
Unrecognized tax benefits
Interest and penalties	$ 8,800	$ 8,000	$ 7,200

Income Taxes (Tax Cuts and Jobs

Income Taxes (Tax Cuts and Jobs Acts) (Details) - USD ($) $ in Millions	Dec. 22, 2017	Dec. 31, 2018
Income taxes
Remeasurement of deferred tax balance	$ 31.4
Forecast
Income taxes
Corporate tax rate		21.00%

Selected Quarterly Financial 63

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Selected Quarterly Financial Data (Unaudited)
Total revenues	$ 87,463	$ 83,821	$ 85,487	$ 83,979	$ 82,742	$ 82,258	$ 81,974	$ 80,894	$ 340,750	$ 327,868	$ 287,458
Product revenues	87,164	83,821	85,487	83,979	82,002	82,136	81,886	80,894	340,451	326,918	287,458
Cost of product revenues	13,814	13,433	13,798	13,672	13,652	13,425	15,598	16,153	54,718	58,828	55,135
Net income (loss)	$ 1,879	$ (2,191)	$ (2,739)	$ (806)	$ 1,352	$ (2,820)	$ (6,100)	$ (6,351)	$ (3,857)	$ (13,919)	$ (33,308)
Basic net income (loss) per share (in dollars per share)	$ 0.05	$ (0.06)	$ (0.08)	$ (0.02)	$ 0.04	$ (0.08)	$ (0.18)	$ (0.19)
Diluted net income (loss) per share (in dollars per share)	$ 0.05	$ (0.06)	$ (0.08)	$ (0.02)	$ 0.04	$ (0.08)	$ (0.18)	$ (0.19)

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event - USD ($) $ in Millions	Mar. 08, 2018	Mar. 31, 2018
Percentage reduction of workforce (as a percent)	10.00%
Restructuring charges		$ 10

SCHEDULE II VALUATION AND QUA65

SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS (Details) - Allowance for Doubtful Accounts: - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Movement in valuation and qualifying accounts
Balance at Beginning of Period	$ 4,508	$ 3,988	$ 3,628
Expenses	6,554	7,654	5,542
Deductions	7,178	7,134	5,182
Balance at End of Period	$ 3,884	$ 4,508	$ 3,988