Document_and_Entity_Informatio
| Document and Entity Information | 9 Months Ended | |
| Sep. 30, 2014 | Oct. 30, 2014 | |
| Document And Entity Information [Abstract] | ' | ' |
| Document Type | '10-Q | ' |
| Amendment Flag | 'false | ' |
| Document Period End Date | 30-Sep-14 | ' |
| Document Fiscal Year Focus | '2014 | ' |
| Document Fiscal Period Focus | 'Q3 | ' |
| Trading Symbol | 'TNDM | ' |
| Entity Registrant Name | 'TANDEM DIABETES CARE INC | ' |
| Entity Central Index Key | '0001438133 | ' |
| Current Fiscal Year End Date | '--12-31 | ' |
| Entity Filer Category | 'Non-accelerated Filer | ' |
| Entity Common Stock, Shares Outstanding | ' | 23,500,687 |
Condensed_Balance_Sheets
| Condensed Balance Sheets (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| Current assets: | ' | ' |
| Cash and cash equivalents | $35,558,073 | $124,385,137 |
| Restricted cash | 2,000,000 | 2,050,000 |
| Short-term investments | 44,318,806 | 5,095,331 |
| Accounts receivable, net | 5,842,849 | 5,298,502 |
| Inventory | 11,891,586 | 10,330,156 |
| Prepaid and other current assets | 1,438,282 | 1,830,056 |
| Total current assets | 101,049,596 | 148,989,182 |
| Property and equipment, net | 12,344,942 | 9,885,985 |
| Patents, net | 2,459,230 | 2,697,220 |
| Other long term assets | 710,931 | 642,746 |
| Total assets | 116,564,699 | 162,215,133 |
| Current liabilities: | ' | ' |
| Accounts payable | 3,046,800 | 2,352,037 |
| Accrued expense | 1,190,483 | 1,873,565 |
| Employee-related liabilities | 8,367,716 | 5,876,011 |
| Deferred revenue | 638,143 | 411,423 |
| Other current liabilities | 2,412,812 | 4,086,196 |
| Total current liabilities | 15,655,954 | 14,599,232 |
| Notes payable—long-term | 29,415,563 | 29,396,571 |
| Deferred rent—long-term | 2,853,814 | 1,886,508 |
| Other long-term liabilities | 1,156,092 | 795,640 |
| Total liabilities | 49,081,423 | 46,677,951 |
| Commitments and contingencies | ' | ' |
| Stockholders’ equity: | ' | ' |
| Common stock, $0.001 par value; 100,000,000 shares authorized, 23,491,770 and 22,925,614 shares issued and outstanding at September 30, 2014 (unaudited) and December 31, 2013, respectively | 23,492 | 22,926 |
| Additional paid-in capital | 297,689,896 | 284,705,251 |
| Accumulated other comprehensive income | 18,811 | ' |
| Accumulated deficit | -230,248,923 | -169,190,995 |
| Total stockholders’ equity | 67,483,276 | 115,537,182 |
| Total liabilities and stockholders’ equity | $116,564,699 | $162,215,133 |
Condensed_Balance_Sheets_Paren
| Condensed Balance Sheets (Parenthetical) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| Statement Of Financial Position [Abstract] | ' | ' |
| Common stock, par value | $0.00 | $0.00 |
| Common stock, shares authorized | 100,000,000 | 100,000,000 |
| Common stock, shares issued | 23,491,770 | 22,925,614 |
| Common stock, shares outstanding | 23,491,770 | 22,925,614 |
Condensed_Statements_of_Operat
| Condensed Statements of Operations and Comprehensive Loss (Unaudited) (USD $) | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | |
| Income Statement [Abstract] | ' | ' | ' | ' |
| Sales | $13,513,716 | $7,776,150 | $31,833,824 | $18,762,301 |
| Cost of sales | 9,116,570 | 5,243,288 | 23,121,269 | 13,783,155 |
| Gross profit | 4,397,146 | 2,532,862 | 8,712,555 | 4,979,146 |
| Operating expenses: | ' | ' | ' | ' |
| Selling, general and administrative | 18,894,758 | 12,008,799 | 55,003,966 | 30,217,184 |
| Research and development | 4,508,004 | 2,651,580 | 11,869,567 | 7,732,818 |
| Total operating expenses | 23,402,762 | 14,660,379 | 66,873,533 | 37,950,002 |
| Operating loss | -19,005,616 | -12,127,517 | -58,160,978 | -32,970,856 |
| Other income (expense), net | ' | ' | ' | ' |
| Interest and other income | 29,991 | 151 | 79,275 | 611 |
| Interest and other expense | -923,771 | -1,205,697 | -2,976,225 | -3,543,568 |
| Change in fair value of stock warrants | ' | 272,030 | ' | -3,011,574 |
| Total other expense, net | -893,780 | -933,516 | -2,896,950 | -6,554,531 |
| Net loss | -19,899,396 | -13,061,033 | -61,057,928 | -39,525,387 |
| Other comprehensive gain or loss: | ' | ' | ' | ' |
| Unrealized gain on short-term investments | 6,529 | ' | 18,811 | ' |
| Comprehensive loss | ($19,892,867) | ($13,061,033) | ($61,039,117) | ($39,525,387) |
| Net loss per share, basic and diluted | ($0.85) | ($60.96) | ($2.64) | ($187.33) |
| Weighted average shares used to compute basic and diluted net loss per share | 23,472,150 | 214,269 | 23,170,665 | 210,996 |
Condensed_Statements_of_Cash_F
| Condensed Statements of Cash Flows (Unaudited) (USD $) | 9 Months Ended | |
| Sep. 30, 2014 | Sep. 30, 2013 | |
| Operating activities | ' | ' |
| Net loss | ($61,057,928) | ($39,525,387) |
| Adjustments to reconcile net loss to net cash used in operating activities: | ' | ' |
| Depreciation and amortization expense | 3,084,774 | 2,463,022 |
| Provision for allowance for doubtful accounts | 104,726 | 144,050 |
| Provision for inventory reserve | 163,246 | 435,419 |
| Interest expense related to amortization of debt discount and debt issuance costs | 175,808 | 160,565 |
| Change in fair value of common and preferred stock warrants | ' | 3,011,574 |
| Amortization of premium/discount on short-term investments | -32,713 | ' |
| Stock-based compensation expense | 11,047,973 | 1,609,675 |
| Other | ' | 14,132 |
| Changes in operating assets and liabilities: | ' | ' |
| Restricted cash | ' | -177,800 |
| Accounts receivable | -649,073 | -1,899,014 |
| Inventory | -1,772,338 | -4,851,688 |
| Prepaid and other current assets | 391,774 | 812,580 |
| Other long term assets | -150,000 | ' |
| Accounts payable | 615,963 | -157,918 |
| Accrued expense | -683,082 | 849,818 |
| Employee-related liabilities | 2,491,706 | 2,730,448 |
| Deferred revenue | 226,720 | -1,712,159 |
| Other current liabilities | -1,822,330 | 1,315,502 |
| Deferred rent | 1,289,451 | -431,211 |
| Other long term liabilities | 334,483 | 252,597 |
| Payments received on note receivable from employees | ' | 25,000 |
| Net cash used in operating activities | -46,240,840 | -34,930,795 |
| Investing activities | ' | ' |
| Purchase of short-term investments | -61,855,984 | ' |
| Proceeds from sales and maturities of short-term investments | 22,710,000 | ' |
| Purchase of property and equipment | -5,259,831 | -2,530,041 |
| Purchase of patents | -173,200 | -2,000,000 |
| Net cash used in investing activities | -44,579,015 | -4,530,041 |
| Financing activities | ' | ' |
| Issuance of notes payable, net of issuance costs | 29,925,000 | 28,874,504 |
| Restricted cash in connection with notes payable and corporate credit card | 50,000 | -2,000,000 |
| Principal payments on notes payable | -30,000,000 | -4,396,323 |
| Issuance of preferred stock for cash, net of offering costs | ' | 15,990,891 |
| Proceeds from issuance of common stock | 2,017,791 | 14,687 |
| Deferred initial public offering costs | ' | -635,630 |
| Net cash provided by financing activities | 1,992,791 | 37,848,129 |
| Net decrease in cash and cash equivalents | -88,827,064 | -1,612,707 |
| Cash and cash equivalents at beginning of period | 124,385,137 | 17,162,730 |
| Cash and cash equivalents at end of period | 35,558,073 | 15,550,023 |
| Supplemental disclosures of cash flow information | ' | ' |
| Interest paid | 2,800,417 | 3,666,516 |
| Supplemental schedule of noncash investing and financing activities | ' | ' |
| Unrealized gain on short-term investments | 18,811 | ' |
| Property and equipment included in accounts payable | 45,910 | 32,549 |
| Deferred initial public offering costs included in accounts payable | ' | 1,127,856 |
| Common and preferred stock warrants issued, including incremental value of modification of warrants | ' | $437,268 |
Organization_and_Basis_of_Pres
| Organization and Basis of Presentation | 9 Months Ended |
| Sep. 30, 2014 | |
| Accounting Policies [Abstract] | ' |
| Organization and Basis of Presentation | ' |
| 1. Organization and Basis of Presentation | |
| The Company | |
| Tandem Diabetes Care, Inc. is a medical device company focused on the design, development and commercialization of products for people with insulin-dependent diabetes. Unless the context requires otherwise, the terms the “Company” or “Tandem” refer to Tandem Diabetes Care, Inc. | |
| The Company designed and commercialized its flagship product, the t:slim Insulin Delivery System, or t:slim, based on its proprietary technology platform and unique consumer-focused approach. The t:slim Insulin Delivery System is comprised of the t:slim Pump and pump-related supplies that include disposable cartridges and infusion sets. The U.S. Food and Drug Administration (“FDA”) cleared t:slim in November 2011 and the Company commenced commercial sales of t:slim in the United States in the third quarter of 2012. | |
| Tandem was originally incorporated in the state of Colorado on January 27, 2006 under the name Phluid, Inc. On January 7, 2008, the Company was reincorporated in the state of Delaware for the purposes of changing its legal name from Phluid, Inc. to Tandem Diabetes Care, Inc. and changing its state of incorporation from Colorado to Delaware. | |
| Basis of Presentation | |
| The Company has prepared the accompanying unaudited condensed financial statements in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and disclosures required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments which are of a normal and recurring nature, considered necessary for a fair presentation have been included. | |
| Interim financial results are not necessarily indicative of results anticipated for the full year. These unaudited condensed financial statements should be read in conjunction with the Company’s audited financial statements and footnotes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013, from which the balance sheet information herein was derived. | |
| Initial Public Offering | |
| In November 2013, the Company completed its initial public offering of 8,000,000 shares of its common stock at a public offering price of $15.00 per share. Net cash proceeds from the initial public offering were approximately $108.3 million, after deducting underwriting discounts, commissions and estimated offering related transaction costs payable by the Company. In November 2013, the underwriters also exercised their overallotment option and purchased an additional 1,200,000 shares of the Company’s common stock, from which the Company received cash proceeds, net of underwriting discounts and commissions, of approximately $16.7 million. In connection with the closing of the initial public offering, all of the Company’s shares of convertible preferred stock outstanding at the time of the offering were automatically converted into 13,403,747 shares of common stock. In addition, all outstanding preferred stock warrants were automatically converted into warrants to purchase an aggregate of 1,171,352 shares of common stock. | |
| Reverse Stock Splits | |
| In October 2013, the Board of Directors approved a 1-for-1.6756 reverse stock split of the Company’s common stock. All share and per share information included in the accompanying unaudited condensed financial statements and notes to the unaudited condensed financial statements give retroactive effect to this reverse stock split of the common stock. | |
| Voluntary Recall | |
| On January 10, 2014, the Company announced a voluntary recall of select lots of cartridges used with the t:slim that may have been at risk of leaking. The cause of the recall was identified during the Company’s internal product testing. The recall was expanded on January 20, 2014 to include additional lots of affected cartridges used with the t:slim. The Company incurred approximately $1.7 million in direct costs associated with the recall. The Company recorded a cost of sales charge of approximately $1.3 million in the fourth quarter of 2013 and recorded a cost of sales charge for the remainder in the first quarter of 2014 for affected cartridges shipped in 2014. The Company does not currently expect any further direct financial impact of the recall beyond these costs. The total cost of the recall consisted of approximately $0.7 million associated with the return and replacement of affected cartridges in the field and approximately $1.0 million for the write-off of affected cartridges within the Company’s internal inventory. | |
Summary_of_Significant_Account
| Summary of Significant Accounting Policies | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Accounting Policies [Abstract] | ' | |||||||||||||||
| Summary of Significant Accounting Policies | ' | |||||||||||||||
| 2. Summary of Significant Accounting Policies | ||||||||||||||||
| Use of Estimates | ||||||||||||||||
| The preparation of the financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities in the Company’s financial statements and accompanying notes as of the date of the financial statements. Actual results could differ from those estimates and assumptions. | ||||||||||||||||
| Restricted Cash | ||||||||||||||||
| Restricted cash as of September 30, 2014 represents a $2.0 million minimum cash balance requirement in connection with the Capital Royalty Term Loan (see Note 6 “Loan Agreements”). | ||||||||||||||||
| Accounts Receivable | ||||||||||||||||
| The Company grants credit to various customers in the normal course of business. The Company maintains an allowance for doubtful accounts for potential credit losses. Provisions are made, generally, for receivables greater than 120 days past due and based upon a specific review of other outstanding invoices. Accounts are written off against the allowance after appropriate collection efforts have been exhausted and when it is deemed that a balance is uncollectible. | ||||||||||||||||
| Concentration of Credit Risk | ||||||||||||||||
| Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash, cash equivalents, short-term investments and accounts receivable. The Company maintains deposit accounts in federally insured financial institutions in excess of federally insured limits. The Company also maintains investments in money market funds that are not federally insured. Additionally, the Company has established guidelines regarding investment instruments and their maturities, which are designed to preserve principal and maintain liquidity. | ||||||||||||||||
| The following table summarizes customers who accounted for 10% or more of net accounts receivable: | ||||||||||||||||
| September 30, | December 31, | |||||||||||||||
| 2014 | 2013 | |||||||||||||||
| Byram Healthcare | 18.5 | % | N/A | |||||||||||||
| CCS Medical, Inc. | 13.8 | % | 21.4 | % | ||||||||||||
| Edgepark Medical Supplies, Inc. | 13.5 | % | 13.1 | % | ||||||||||||
| The following table summarizes customers who accounted for 10% or more of sales for the periods presented: | ||||||||||||||||
| Three Months Ended | Nine Months Ended | |||||||||||||||
| September 30, | September 30, | |||||||||||||||
| 2014 | 2013 | 2014 | 2013 | |||||||||||||
| Edgepark Medical Supplies, Inc. | 14.6 | % | 17.2 | % | 15.6 | % | 17.1 | % | ||||||||
| Byram Healthcare | 14.3 | % | N/A | N/A | N/A | |||||||||||
| CCS Medical, Inc. | 10.9 | % | 15.8 | % | 13.8 | % | 11.6 | % | ||||||||
| Fair Value of Financial Instruments | ||||||||||||||||
| The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable, accrued expense, and employee-related liabilities are reasonable estimates of their fair value because of the short-term nature of these items. Short-term investments are carried at fair value. Based on the borrowing rates currently available for loans with similar terms, the Company believes that the fair value of its long-term debt approximates its carrying value. | ||||||||||||||||
| Revenue Recognition | ||||||||||||||||
| Revenue is generated in the United States from the sale of the t:slim Pump, disposable cartridges and infusion sets to individual customers and third-party distributors that resell the product to insulin-dependent diabetes customers. Sales to distributors accounted for 72% and 71% of our total sales for the nine months ended September 30, 2014 and 2013, respectively. The Company is paid directly by customers who use the products, distributors and third-party insurance payors. | ||||||||||||||||
| Revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred and title passed, the price is fixed or determinable, and collectability is reasonably assured. These criteria are applied as follows: | ||||||||||||||||
| — | The evidence of an arrangement generally consists of contractual arrangements with distributors, third-party insurance payors or direct customers. | |||||||||||||||
| — | Transfer of title and risk and rewards of ownership are passed upon shipment of the pump to distributors or upon delivery to the customer. | |||||||||||||||
| — | The selling prices are fixed and agreed upon based on the contracts with distributors, the customer and contracted insurance payors, if applicable. For sales to customers associated with insurance providers with whom there is no contract, revenue is recognized upon collection of cash at which time the price is determinable. The Company generally does not offer rebates to its distributors and customers. | |||||||||||||||
| — | The Company considers the overall creditworthiness and payment history of the distributor, customer and the contracted insurance payor in concluding whether collectability is reasonably assured. | |||||||||||||||
| Prior to the first quarter of 2013, t:slim Pump sales were recorded as deferred revenue until the Company’s 30-day right of return expired because the Company did not have sufficient sales history to be able to reasonably estimate returns. At December 31, 2012, $1.9 million was recorded as deferred revenue. Beginning in the first quarter of 2013, the Company began recognizing t:slim Pump revenue when all the revenue recognition criteria above are met, as it established sufficient history in order to reasonably estimate product returns. As a result of this change, a one-time adjustment was recorded during the nine month period ended September 30, 2013, to recognize previously deferred revenue and cost of sales of $1.9 million and $1.1 million, respectively. | ||||||||||||||||
| Revenue Recognition for Arrangements with Multiple Deliverables | ||||||||||||||||
| The Company considers the deliverables in its product offering as separate units of accounting and recognizes deliverables as revenue upon delivery only if (i) the deliverable has standalone value and (ii) if the arrangement includes a general right of return relative to the delivered item(s), delivery or performance of the undelivered item(s) is probable and substantially controlled by the Company. The Company allocates consideration to the separate units of accounting, unless the undelivered elements were deemed perfunctory and inconsequential. The Company uses the relative selling price method, in which allocation of consideration is based on vendor-specific objective evidence (“VSOE”) if available, third-party evidence (“TPE”), or if VSOE and TPE are not available, management’s best estimate of a standalone selling price (“ESP”) for the undelivered elements. | ||||||||||||||||
| In February 2013, the FDA cleared t:connect, the Company’s cloud-based data management application, which is made available upon purchase by t:slim Pump customers. This service is deemed an undelivered element at the time of the t:slim sale. Because the Company has neither VSOE nor TPE for this deliverable, the allocation of revenue is based on the Company’s ESP. The Company establishes its ESP based on estimated cost to provide such services, including consideration of a reasonable profit margin that is corroborated by comparable market data. The Company allocates fair value based on management’s ESP to this element at the time of sale and recognizes the revenue over the four-year hosting period. Deferred revenue for the t:connect hosting services was $0.5 million and $0.2 million at September 30, 2014 and December 31, 2013, respectively. All other undelivered elements at the time of sale are deemed inconsequential or perfunctory. | ||||||||||||||||
| Product Returns | ||||||||||||||||
| The Company offers a 30-day right of return for its t:slim Pump customers from the date of shipment, provided a physician’s confirmation of the medical reason for the return is received. Estimated allowances for sales returns are based on historical returned quantities as compared to t:slim Pump shipments in the same period. The return rate is then applied to the sales of the period to establish a reserve at the end of the period. The return rates used in the reserve are adjusted for known or expected changes in the marketplace when appropriate. The allowance for product returns at September 30, 2014 and December 31, 2013 was $0.2 million, which was included in accounts receivable on the Company’s condensed balance sheets. Actual product returns have not differed materially from estimated amounts reserved. | ||||||||||||||||
| Warranty Reserve | ||||||||||||||||
| The Company generally provides a four-year warranty on its t:slim Pump to end user customers and may replace any pumps that do not function in accordance with the product specifications. Pumps returned to the Company may be refurbished and redeployed. Additionally, the Company offers a six-month warranty on t:slim cartridges and infusion sets. Estimated warranty costs are recorded at the time of shipment. Warranty costs are estimated based on the current product cost considering a mix of new and refurbished costs for the pump, actual experience and expected failure rates from test studies performed in conjunction with the clearance of the Company’s product with the FDA to support the longevity and reliability of its t:slim Pump. The Company evaluates the reserve quarterly and makes adjustments when appropriate. At September 30, 2014 and December 31, 2013, the warranty reserve was $1.3 million and $1.1 million, respectively. Of the $1.1 million warranty reserve at December 31, 2013, $0.3 million was related to potential replacements associated with the voluntary product recall of selected lots of cartridges. The estimated reserve has been fully utilized and the Company does not expect further replacements related to this recall. As such, there was no warranty reserve at September 30, 2014 for such potential replacements. Actual warranty costs have not differed materially from estimated amounts reserved. | ||||||||||||||||
| The following table provides a reconciliation of the change in product warranty liabilities through September 30, 2014 (in thousands): | ||||||||||||||||
| Balance at December 31, 2013 | $ | 1,123 | ||||||||||||||
| Provision for warranties issued during the period | 2,301 | |||||||||||||||
| Settlements made during the period | (2,114 | ) | ||||||||||||||
| Balance at September 30, 2014 | $ | 1,310 | ||||||||||||||
| Current portion recorded in other current liabilities | $ | 360 | ||||||||||||||
| Non-current portion recorded in other long-term liabilities | 950 | |||||||||||||||
| Total | $ | 1,310 | ||||||||||||||
| Stock-Based Compensation | ||||||||||||||||
| The Company estimates the fair value of stock options and shares issued to employees under the Employee Stock Purchase Plan (“ESPP”) using a Black-Scholes option-pricing model on the date of grant. The Black-Scholes option-pricing model requires the use of subjective assumptions including volatility, expected term, risk-free rate, and the fair value of the underlying common stock. For awards that vest based on service conditions, the Company recognizes expense using the straight-line method less estimated forfeitures. Prior to the Company’s initial public offering, the estimated fair value of these awards was determined at the date of grant based upon the estimated fair value of the Company’s common stock. Subsequent to the Company’s initial public offering, the fair value of the common stock is based on observable market prices. As of September 30, 2014, there were no outstanding equity awards with market or performance conditions. | ||||||||||||||||
| The Company also records the expense for stock option grants to non-employees based on the estimated fair value of the stock option using the Black-Scholes option-pricing model. The fair value of non-employee awards is remeasured at each reporting period as the underlying awards vest unless the instruments are fully vested, immediately exercisable and nonforfeitable on the date of grant. | ||||||||||||||||
| Warrant Liabilities | ||||||||||||||||
| The Company issued freestanding warrants to purchase shares of common stock and convertible preferred stock in connection with the issuance of convertible notes payable in 2011 and 2012. The Company accounted for these warrants as a liability in the financial statements because either the Company did not have enough authorized shares to satisfy potential exercise of the common stock warrants and the number of shares to be issued upon their exercise was outside the control of the Company, or because the underlying instrument into which the warrants were exercisable (Series D convertible preferred stock) contained deemed liquidation provisions that were outside of the control of the Company. Upon the closing of the initial public offering, warrants to purchase shares of Series D Preferred Stock automatically converted into warrants to purchase shares of common stock. The Company reclassified the warrant liability to stockholders’ equity as the warrants met the definition of an equity instrument. | ||||||||||||||||
| Prior to the warrants being converted to an equity instrument, the warrants were recorded at fair value using either the Black-Scholes option pricing model or a binomial lattice model, depending on the characteristics of the warrants at the time of the valuation. The fair value of these warrants was remeasured at each financial reporting period with any changes in fair value being recognized as a component of other income (expense) in the accompanying statements of operations and comprehensive loss. For the three and nine months ended September 30, 2013, income of $0.3 million and expense of $3.0 million were recorded as other income and expense from the revaluations, respectively. In connection with the completion of the initial public offering in November 2013, the Company performed the final remeasurement of the warrant liability. | ||||||||||||||||
| Net Loss Per Share | ||||||||||||||||
| Basic net loss per share is calculated by dividing the net loss by the weighted average number of common shares that were outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by dividing the net loss by the sum of the weighted-average number of dilutive common share equivalents outstanding for the period determined using the treasury stock method. Dilutive common share equivalents are comprised of convertible preferred stock, preferred stock warrants, common stock warrants, potential ESPP shares, restricted common stock and options outstanding under the Company’s equity incentive plans. Applicable accounting guidance provides that a contract that is reported as an asset or liability for accounting purposes may require an adjustment to the numerator of the diluted earnings per share calculation for any changes in income or loss that would result if the contract had been reported as an equity instrument during the period. Securities are assumed to be converted at the beginning of the period, and the resulting common shares are included in the denominator of the diluted earnings per share calculation for the entire period presented. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company’s net loss position. | ||||||||||||||||
| Potentially dilutive securities not included in the calculation of diluted net loss per share (because inclusion would be anti-dilutive) are as follows (in common stock equivalent shares): | ||||||||||||||||
| Three Months Ended | Nine Months Ended | |||||||||||||||
| September 30, | September 30, | |||||||||||||||
| 2014 | 2013 | 2014 | 2013 | |||||||||||||
| Convertible preferred stock outstanding | — | 13,148,484 | — | 12,314,967 | ||||||||||||
| Warrants for convertible preferred stock | — | 1,426,704 | — | 1,426,704 | ||||||||||||
| Warrants for common stock | 1,006,577 | 271,834 | 1,006,577 | 256,898 | ||||||||||||
| Common stock options | 2,292,897 | 1,716,845 | 2,279,347 | 967,857 | ||||||||||||
| ESPP | 139,145 | — | 139,145 | — | ||||||||||||
| Restricted common stock subject to repurchase | — | 58,555 | — | 55,633 | ||||||||||||
| 3,438,619 | 16,622,422 | 3,425,069 | 15,022,059 | |||||||||||||
| Recent Accounting Pronouncements | ||||||||||||||||
| In August 2014, the Financial Accounting Standards Board (“FASB”) issued an accounting standards update, which requires management of public and private companies to evaluate whether there are conditions and events that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the financial statements are issued (or available to be issued when applicable) and, if so, disclose that fact. Management will be required to make this evaluation for both annual and interim reporting periods, if applicable. Management is also required to evaluate and disclose whether its plans alleviate that doubt. The standard is effective for annual periods ending after December 15, 2016 and interim periods within annual periods beginning after December 15, 2016. Early adoption is permitted for annual or interim reporting periods for which the financial statements have not previously been issued. The Company does not believe the adoption of this standard will have a material impact on its financial position, results of operations or related financial statement disclosures. | ||||||||||||||||
| In May 2014, the FASB and the International Accounting Standards Board (“IASB”) issued a comprehensive new revenue recognition standard that will supersede existing revenue guidance under U.S. GAAP and International Financial Reporting Standards (“IFRS”). The standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under current guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. The guidance is effective for annual periods beginning after December 15, 2016, including interim periods within that period. The Company is in the process of assessing the future impact of the adoption of the standard on its financial statements. | ||||||||||||||||
| In April 2014, the Financial Accounting Standards Board (“FASB”) issued an accounting standards update, which includes amendments that change the requirements for reporting discontinued operations and require additional disclosures about discontinued operations. Under the new guidance, only disposals representing a strategic shift in operations - that is, a major effect on the organization’s operations and financial results - should be presented as discontinued operations. Examples include a disposal of a major geographic area, a major line of business, or a major equity method investment. Additionally, the update requires expanded disclosures about discontinued operations that will provide financial statement users with more information about the assets, liabilities, income, and expenses of discontinued operations. The guidance is effective prospectively for fiscal years beginning after December 15, 2014 and interim periods within annual periods beginning on or after December 15, 2015. The Company does not believe the adoption of this standard will have a material impact on its financial position, results of operations or related financial statement disclosures. | ||||||||||||||||
ShortTerm_Investments
| Short-Term Investments | 9 Months Ended | |||||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||||
| Investments Debt And Equity Securities [Abstract] | ' | |||||||||||||||||
| Short-Term Investments | ' | |||||||||||||||||
| 3. Short-Term Investments | ||||||||||||||||||
| The Company invests excess cash in investment securities, principally debt instruments of financial institutions, government sponsored enterprise securities and corporations with strong credit ratings. The following represents a summary of the estimated fair value of short-term investments at September 30, 2014 and December 31, 2013 (in thousands): | ||||||||||||||||||
| At September 30, 2014 | Maturity | Amortized | Unrealized | Unrealized | Estimated | |||||||||||||
| (in years) | Cost | Gain | Loss | Fair Value | ||||||||||||||
| Commercial paper | Less than 1 | $ | 40,769 | $ | 19 | $ | — | $ | 40,788 | |||||||||
| Government-sponsored enterprise securities | 1 to 2 | 3,505 | — | — | 3,505 | |||||||||||||
| Trading securities — mutual funds held for nonqualified deferred compensation plan participants | 26 | — | — | 26 | ||||||||||||||
| Total | $ | 44,300 | $ | 19 | $ | — | $ | 44,319 | ||||||||||
| At December 31, 2013 | Maturity | Amortized | Unrealized | Unrealized | Estimated | |||||||||||||
| (in years) | Cost | Gain | Loss | Fair Value | ||||||||||||||
| Commercial paper | Less than 1 | $ | 5,095 | $ | — | $ | — | $ | 5,095 | |||||||||
| Total | $ | 5,095 | $ | — | $ | — | $ | 5,095 | ||||||||||
Inventory
| Inventory | 9 Months Ended | |||||||
| Sep. 30, 2014 | ||||||||
| Inventory Disclosure [Abstract] | ' | |||||||
| Inventory | ' | |||||||
| 4. Inventory | ||||||||
| Inventories, stated at the lower of cost or market, consisted of the following (in thousands): | ||||||||
| September 30, | December 31, | |||||||
| 2014 | 2013 | |||||||
| Raw materials | $ | 6,098 | $ | 6,363 | ||||
| Work in process | 3,832 | 2,169 | ||||||
| Finished goods | 2,191 | 3,535 | ||||||
| 12,121 | 12,067 | |||||||
| Less reserve | (229 | ) | (1,737 | ) | ||||
| Total | $ | 11,892 | $ | 10,330 | ||||
| The inventory reserve at December 31, 2013 included $0.9 million associated with the Company’s voluntary product recall. There was no reserve associated with the product recall at September 30, 2014. | ||||||||
Fair_Value_Measurements
| Fair Value Measurements | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Fair Value Disclosures [Abstract] | ' | |||||||||||||||
| Fair Value Measurements | ' | |||||||||||||||
| 5. Fair Value Measurements | ||||||||||||||||
| Authoritative guidance on fair value measurements defines fair value, establishes a consistent framework for measuring fair value, and expands disclosures for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the authoritative guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: | ||||||||||||||||
| Level 1: Observable inputs such as quoted prices in active markets. | ||||||||||||||||
| Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly. | ||||||||||||||||
| Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. | ||||||||||||||||
| The following table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis as of September 30, 2014 and December 31, 2013, and indicates the fair value hierarchy of the valuation techniques utilized by the Company to determine such fair value (in thousands): | ||||||||||||||||
| Fair Value Measurements at | ||||||||||||||||
| September 30, | 30-Sep-14 | |||||||||||||||
| 2014 | Level 1 | Level 2 | Level 3 | |||||||||||||
| Assets | ||||||||||||||||
| Cash equivalents (1) | $ | 31,801 | $ | 31,801 | $ | — | $ | — | ||||||||
| Restricted cash | 2,000 | 2,000 | — | — | ||||||||||||
| Commercial paper | 40,788 | — | 40,788 | — | ||||||||||||
| Mutual funds held for nonqualified deferred compensation plan participants (2) | 26 | 26 | — | — | ||||||||||||
| Government-sponsored enterprise securities | 3,505 | 3,505 | — | — | ||||||||||||
| Total assets | $ | 78,120 | $ | 37,332 | $ | 40,788 | $ | — | ||||||||
| Liabilities | ||||||||||||||||
| Deferred compensation (2) | $ | 26 | $ | 26 | $ | — | $ | — | ||||||||
| Total liabilities | $ | 26 | $ | 26 | $ | — | $ | — | ||||||||
| -1 | Cash equivalents included money market funds and commercial paper with a maturity of three months or less from the date of purchase. | |||||||||||||||
| -2 | Deferred compensation plans are compensation plans directed by the Company and structured as a Rabbi Trust for certain executives and non-employee directors. The investment assets of the Rabbi Trust are valued using quoted market prices multiplied by the number of shares held in each trust account. The related deferred compensation liability represents the fair value of the investment assets. | |||||||||||||||
| Fair Value Measurements at | ||||||||||||||||
| December 31, | 31-Dec-13 | |||||||||||||||
| 2013 | Level 1 | Level 2 | Level 3 | |||||||||||||
| Assets | ||||||||||||||||
| Money market funds | $ | 115,112 | $ | 115,112 | $ | — | $ | — | ||||||||
| Restricted cash | 2,050 | 2,050 | — | — | ||||||||||||
| Commercial paper | 5,095 | — | 5,095 | — | ||||||||||||
| Total assets | $ | 122,257 | $ | 117,162 | $ | 5,095 | $ | — | ||||||||
| The Company’s Level 2 financial instruments are valued using market prices on less active markets and model-derived valuations with observable valuation inputs such as interest rates and yield curves. The Company obtains the fair value of Level 2 financial instruments from quoted market prices, calculated prices or quotes from third-party pricing services. The Company validates these prices through independent valuation testing and review of portfolio valuations provided by the Company’s investment managers. There were no transfers between Level 1 and Level 2 securities during the nine months ended September 30, 2014. | ||||||||||||||||
Loan_Agreements
| Loan Agreements | 9 Months Ended |
| Sep. 30, 2014 | |
| Debt Disclosure [Abstract] | ' |
| Loan Agreements | ' |
| 6. Loan Agreements | |
| Silicon Valley Bank Loan | |
| In March 2012, the Company entered into a Loan and Security Agreement with Silicon Valley Bank (“SVB”), drawing a bridge loan in the amount of $5.0 million (the “SVB Bridge Loan”). Subsequent to the closing of the Series D financing, the SVB Bridge Loan was converted into a 24-month term loan (the “SVB Term Loan”) in September 2012. The term loan accrued interest at an annual rate of 4%, with principal and accrued interest payments due monthly throughout the 24-month term. The SVB Term Loan also required a final payment of $0.3 million and a fee of $0.2 million if the loan was prepaid in its entirety prior to the end of the term of the loan. | |
| In connection with the SVB Bridge Loan and SVB Term Loan, the Company issued an aggregate of 102,270 warrants to purchase shares of Series D convertible preferred stock at an exercise price of $4.40 per share. In November 2013, in connection with the closing of the initial public offering, all SVB Series D Preferred Stock warrants automatically converted into warrants to purchase 61,033 shares of our Common Stock at a weighted average exercise price of $7.37 per share. | |
| In conjunction with the Capital Royalty Term Loan closing in January 2013, all principal, interest due and prepayment fee amounts due under the SVB Term Loan were paid by the Company. | |
| Silicon Valley Bank Revolving Line of Credit | |
| In January 2013, the Company entered into an amended loan agreement with Silicon Valley Bank, making available a revolving line of credit in an amount up to the lesser of $1.5 million or 75% of eligible accounts receivable, and expiring in January 2015. Interest-only payments at a rate of 6% per annum are payable monthly through the maturity date. Loans drawn under the agreement are secured by eligible accounts receivable and proceeds therefrom. Additionally, the terms of the revolving line of credit contain various affirmative and negative covenants. There were no amounts outstanding under this loan as of September 30, 2014 or December 31, 2013. | |
| Capital Royalty Term Loan | |
| In December 2012, the Company executed a Term Loan Agreement (the “Original Term Loan Agreement”) with Capital Royalty Partners II L.P. (“Capital Royalty Partners”) and Capital Royalty Partners II—Parallel Fund “A” L.P. (“CRPPF,” together with Capital Royalty Partners, the “Lenders”), providing the Company access to up to $45.0 million under the arrangement, of which $30.0 million was available in January 2013. An additional amount up to $15.0 million became available upon achievement of a 2013 revenue-based milestone. In January 2013, $30.0 million was drawn under the Original Term Loan Agreement. The loan under the Original Term Loan Agreement accrued interest at an annual rate of 14%. Interest-only payments were due quarterly at March 31, June 30, September 30 and December 31 of each year through December 31, 2015. Thereafter, in addition to interest accrued during the period, quarterly payments were required to include an amount equal to the outstanding principal at December 31, 2015 divided by the remaining number of quarters prior to the maturity of the loan which is December 31, 2017. The Original Term Loan Agreement stipulated prepayment fees of 5% of the outstanding balance of the loan if the loan was repaid prior to April 1, 2014. The prepayment fee was reduced 1% per year for each subsequent year until maturity. | |
| In connection with the Original Term Loan Agreement, in January 2013, the Company issued warrants to purchase 271,834 shares of the Company’s Common Stock at an exercise price of $0.02 per share. The warrants were immediately exercisable and expire in January 2023. Because the exercise price of these warrants is nominal, the Company used the fair value of the common stock of $1.61 at December 31, 2012 to value these warrants. The Company also paid a $0.4 million financing fee to the Lenders. The warrants’ fair value of approximately $0.4 million and the financing fee of $0.4 million were recorded as a debt discount. Additionally, the Company paid $0.7 million to a third party for sourcing the Capital Royalty Term Loan, which was recorded as debt issuance cost, within other long term assets on the condensed balance sheets. The fees and the value of the warrants are amortized to interest expense over the remaining term using the effective interest method. | |
| In April 2014, the Company entered into an Amended and Restated Term Loan Agreement (the “Amended and Restated Term Loan Agreement”) with the Lenders and other parties affiliated with Capital Royalty Partners. The Amended and Restated Term Loan Agreement primarily amends the terms of the Original Term Loan Agreement to reduce the borrowing limit to $30.0 million, to reduce the applicable interest rate from 14.0% to 11.5%, and to extend the interest only payment period from December 31, 2015 to March 31, 2018. Interest is payable, at the Company’s option, (i) in cash at a rate of 11.5% per annum or (ii) 9.5% of the 11.5% per annum in cash and 2.0% of the 11.5% per annum is added to the principal of the loan and is subject to accruing interest. Interest-only payments are due quarterly on March 31, June 30, September 30 and December 31 of each year of the interest-only payment period. Thereafter, in addition to interest accrued during the period, the quarterly payments shall include an amount equal to the outstanding principal at March 31, 2018 divided by the remaining number of quarters prior to the end of the term of the loan which is March 31, 2020. The Amended and Restated Term Loan Agreement provides for prepayment fees of 3% of the outstanding balance of the loan if the loan is repaid prior to March 31, 2015. The prepayment fee is reduced by 1% per year for each subsequent year until maturity. | |
| Certain affirmative and negative covenants were also amended. The principal financial covenants require that the Company attain minimum annual revenues of $30.0 million in 2014, $50.0 million in 2015, $65.0 million in 2016, $80.0 million in 2017 and $95.0 million thereafter. As of September 30, 2014, the Company had already met the minimum annual revenue threshold for 2014. | |
| Aggregate borrowings outstanding under the Amended and Restated Term Loan Agreement are $30.0 million. Borrowings under the Amended and Restated Term Loan Agreement were used to refinance amounts outstanding under the Original Term Loan Agreement. The present value of the future cash flows under the modified terms described above did not exceed the present value of the future cash flows under the original terms by more than 10%. The Company treated this amendment as a modification and the facility fee of approximately $0.1 million recorded as a discount to the Amended and Restated Term Loan. The facility fee and the remaining balance of debt issuance cost and debt discount of the Original Term Loan are amortized over the remaining term of the Amended and Restated Term Loan using the effective interest method. | |
| Concurrently, the Company also entered into a new Term Loan Agreement (the “New Tranche Term Loan Agreement”) with the Lenders and other parties affiliated with Capital Royalty Partners, under which the Company may borrow up to an additional $30.0 million on or before March 31, 2015 at the same interest rate and on the same key terms as the Amended and Restated Term Loan Agreement. |
Stockholders_Equity
| Stockholders' Equity | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Equity [Abstract] | ' | |||||||||||||||
| Stockholders' Equity | ' | |||||||||||||||
| 7. Stockholders’ Equity | ||||||||||||||||
| Shares Reserved for Future Issuance | ||||||||||||||||
| The following shares of common stock are reserved for future issuance at September 30, 2014: | ||||||||||||||||
| Common stock warrants outstanding | 1,006,577 | |||||||||||||||
| Stock options issued and outstanding | 4,899,528 | |||||||||||||||
| Authorized for future option grants | 2,149,102 | |||||||||||||||
| Employee stock purchase plan | 659,863 | |||||||||||||||
| 8,715,070 | ||||||||||||||||
| The Company issued 106,801 shares of common stock upon the exercise of stock options and warrants during the nine months ended September 30, 2014, and issued 95,007 shares of common stock upon the exercise of stock options and warrants during the year ended December 31, 2013. | ||||||||||||||||
| In October 2013, the Company adopted the 2013 Employee Stock Purchase Plan (“2013 ESPP”). During the nine months ended September 30, 2014, there were 125,393 shares of common stock purchased under the 2013 ESPP. | ||||||||||||||||
| Stock-Based Compensation | ||||||||||||||||
| The assumptions used in the Black-Scholes option-pricing model are as follows: | ||||||||||||||||
| Stock Option | ||||||||||||||||
| Three Months Ended | Nine Months Ended | |||||||||||||||
| September 30, | September 30, | |||||||||||||||
| 2014 | 2013 | 2014 | 2013 | |||||||||||||
| Risk-free interest rate | 1.9 | % | 1.8 | % | 1.9 | % | 1.1 | % | ||||||||
| Expected dividend yield | 0 | % | 0 | % | 0 | % | 0 | % | ||||||||
| Expected volatility | 78.1 | % | 79.4 | % | 78.7 | % | 76.6 | % | ||||||||
| Expected term (in years) | 6.1 | 5.7 | 6.1 | 5.6 | ||||||||||||
| ESPP | ||||||||||||||||
| Nine Months Ended | ||||||||||||||||
| September 30, | ||||||||||||||||
| 2014 | 2013 | |||||||||||||||
| Risk-free interest rate | 0.2 | % | — | |||||||||||||
| Expected dividend yield | 0 | % | — | |||||||||||||
| Expected volatility | 62.9 | % | — | |||||||||||||
| Expected term (in years) | 1.3 | — | ||||||||||||||
| There were no ESPP valuations performed during the three months ended September 30, 2014. | ||||||||||||||||
| The following table summarizes the allocation of stock compensation expense (in thousands): | ||||||||||||||||
| Three Months Ended | Nine Months Ended | |||||||||||||||
| September 30, | September 30, | |||||||||||||||
| 2014 | 2013 | 2014 | 2013 | |||||||||||||
| Cost of sales | $ | 313 | $ | (9 | ) | $ | 940 | $ | 58 | |||||||
| Selling, general & administrative | 2,979 | 861 | 8,798 | 1,370 | ||||||||||||
| Research and development | 454 | 114 | 1,310 | 183 | ||||||||||||
| Total | $ | 3,746 | $ | 966 | $ | 11,048 | $ | 1,611 | ||||||||
| The total stock-based compensation capitalized as part of the cost of inventory was $0.2 million and $0.3 million at September 30, 2014 and December 31, 2013, respectively. | ||||||||||||||||
Collaborations
| Collaborations | 9 Months Ended |
| Sep. 30, 2014 | |
| Organization Consolidation And Presentation Of Financial Statements [Abstract] | ' |
| Collaborations | ' |
| 8. Collaborations | |
| DexCom Development and Commercialization Agreement | |
| In February 2012, the Company entered into a Development and Commercialization Agreement with DexCom, Inc. (the “DexCom Agreement”) for the purpose of collaborating on the development and commercialization of an integrated system which incorporates the t:slim Insulin Delivery System with DexCom’s proprietary continuous glucose monitoring system. Under the DexCom Agreement, the Company paid DexCom $1.0 million in 2012 at the commencement of the collaboration and a $1.0 million milestone payment in July 2014, which related to the Company’s submission of a pre-market approval (“PMA”) application for the t:slim G4, which the Company has previously referenced as t:sensor, to the FDA. The payments were recorded as research and development costs. The Company will make one additional $1.0 million payment upon the achievement of certain milestones. Additionally, the Company will reimburse DexCom up to $1.0 million of its development costs and is solely responsible for its own development costs. As of September 30, 2014, the Company has reimbursed DexCom $0.2 million of its development costs. The Company recognized research and development costs of $32,000 and $78,000 for the nine months ended September 30, 2014 and 2013, respectively. The research and development costs recognized for the three months ended September 30, 2014, and 2013 were not significant. | |
| Upon commercialization of the integrated system, and as compensation for the non-exclusive license rights, the Company will also pay DexCom a royalty of $100 for each integrated system sold. | |
| Juvenile Diabetes Research Foundation Collaboration | |
| In January 2013, the Company entered into a research, development and commercialization agreement (“JDRF Agreement”) with the Juvenile Diabetes Research Foundation (“JDRF”) to develop the t:dual Infusion System, a first-of-its-kind, dual-chamber infusion pump for the management of diabetes. According to the terms of the JDRF Agreement, JDRF will provide research funding of up to $3.0 million based on the achievement of research and development milestones, not to exceed research costs incurred by the Company. The research and development milestones are anticipated to be reached by September 2016. Payments the Company receives to fund the collaboration efforts under the terms of the JDRF Agreement will be recorded as restricted cash and current and long-term liabilities. The liabilities are recognized as an offset of research and development expenses straight-line over the remaining months until anticipated completion of the final milestone, only to the extent that the restricted cash is utilized to fund such development activities. | |
| As of September 30, 2014, milestone payment achievements totaled $0.7 million, and research and development costs were offset cumulatively by $0.3 million. The research and development costs were offset by $37,000 and $146,000 for the three and nine-months ended September 30, 2014, respectively. For the three and nine months ended September 30, 2013, research and development costs were offset by $63,000 and $145,000, respectively. The Company did not have any restricted cash balances related to the JDRF Agreement at September 30, 2014 or December 31, 2013. |
Commitments_and_Contingencies
| Commitments and Contingencies | 9 Months Ended |
| Sep. 30, 2014 | |
| Commitments And Contingencies Disclosure [Abstract] | ' |
| Commitments and Contingencies | ' |
| 9. Commitments and Contingencies | |
| From time to time, the Company may be subject to legal or regulatory proceedings or other matters arising in the ordinary course of business, including proceedings with respect to intellectual property, employment, product liability, and contractual matters. The Company assesses, on a regular basis, the probability of a negative outcome and the range of possible loss based on the developments with respect to these matters. A liability is only recorded in the financial statements if it is believed to be probable that a loss has been incurred and that the amount of the loss can be reasonably estimated. Because of the uncertainties related to the occurrence, amount, and range of loss on any pending proceedings, the Company is currently unable to predict their ultimate outcome, and, with respect to any pending litigation or claim where no liability has been accrued, to make a meaningful estimate of the reasonably possible loss or range of loss that could result from an unfavorable outcome. At September 30, 2014 and December 31, 2013, there were no pending legal or regulatory proceedings for which a negative outcome was considered probable and for which the loss could be reasonably estimated. As a result, no amounts have been accrued with respect to any such proceedings at either date. |
Organization_and_Basis_of_Pres1
| Organization and Basis of Presentation (Policies) | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Accounting Policies [Abstract] | ' | |||||||||||||||
| The Company | ' | |||||||||||||||
| The Company | ||||||||||||||||
| Tandem Diabetes Care, Inc. is a medical device company focused on the design, development and commercialization of products for people with insulin-dependent diabetes. Unless the context requires otherwise, the terms the “Company” or “Tandem” refer to Tandem Diabetes Care, Inc. | ||||||||||||||||
| The Company designed and commercialized its flagship product, the t:slim Insulin Delivery System, or t:slim, based on its proprietary technology platform and unique consumer-focused approach. The t:slim Insulin Delivery System is comprised of the t:slim Pump and pump-related supplies that include disposable cartridges and infusion sets. The U.S. Food and Drug Administration (“FDA”) cleared t:slim in November 2011 and the Company commenced commercial sales of t:slim in the United States in the third quarter of 2012. | ||||||||||||||||
| Tandem was originally incorporated in the state of Colorado on January 27, 2006 under the name Phluid, Inc. On January 7, 2008, the Company was reincorporated in the state of Delaware for the purposes of changing its legal name from Phluid, Inc. to Tandem Diabetes Care, Inc. and changing its state of incorporation from Colorado to Delaware. | ||||||||||||||||
| Basis of Presentation | ' | |||||||||||||||
| Basis of Presentation | ||||||||||||||||
| The Company has prepared the accompanying unaudited condensed financial statements in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and disclosures required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments which are of a normal and recurring nature, considered necessary for a fair presentation have been included. | ||||||||||||||||
| Interim financial results are not necessarily indicative of results anticipated for the full year. These unaudited condensed financial statements should be read in conjunction with the Company’s audited financial statements and footnotes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013, from which the balance sheet information herein was derived. | ||||||||||||||||
| Initial Public Offering | ' | |||||||||||||||
| Initial Public Offering | ||||||||||||||||
| In November 2013, the Company completed its initial public offering of 8,000,000 shares of its common stock at a public offering price of $15.00 per share. Net cash proceeds from the initial public offering were approximately $108.3 million, after deducting underwriting discounts, commissions and estimated offering related transaction costs payable by the Company. In November 2013, the underwriters also exercised their overallotment option and purchased an additional 1,200,000 shares of the Company’s common stock, from which the Company received cash proceeds, net of underwriting discounts and commissions, of approximately $16.7 million. In connection with the closing of the initial public offering, all of the Company’s shares of convertible preferred stock outstanding at the time of the offering were automatically converted into 13,403,747 shares of common stock. In addition, all outstanding preferred stock warrants were automatically converted into warrants to purchase an aggregate of 1,171,352 shares of common stock. | ||||||||||||||||
| Reverse Stock Splits | ' | |||||||||||||||
| Reverse Stock Splits | ||||||||||||||||
| In October 2013, the Board of Directors approved a 1-for-1.6756 reverse stock split of the Company’s common stock. All share and per share information included in the accompanying unaudited condensed financial statements and notes to the unaudited condensed financial statements give retroactive effect to this reverse stock split of the common stock. | ||||||||||||||||
| Voluntary Recall | ' | |||||||||||||||
| Voluntary Recall | ||||||||||||||||
| On January 10, 2014, the Company announced a voluntary recall of select lots of cartridges used with the t:slim that may have been at risk of leaking. The cause of the recall was identified during the Company’s internal product testing. The recall was expanded on January 20, 2014 to include additional lots of affected cartridges used with the t:slim. The Company incurred approximately $1.7 million in direct costs associated with the recall. The Company recorded a cost of sales charge of approximately $1.3 million in the fourth quarter of 2013 and recorded a cost of sales charge for the remainder in the first quarter of 2014 for affected cartridges shipped in 2014. The Company does not currently expect any further direct financial impact of the recall beyond these costs. The total cost of the recall consisted of approximately $0.7 million associated with the return and replacement of affected cartridges in the field and approximately $1.0 million for the write-off of affected cartridges within the Company’s internal inventory. | ||||||||||||||||
| Use of Estimates | ' | |||||||||||||||
| Use of Estimates | ||||||||||||||||
| The preparation of the financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities in the Company’s financial statements and accompanying notes as of the date of the financial statements. Actual results could differ from those estimates and assumptions. | ||||||||||||||||
| Restricted Cash | ' | |||||||||||||||
| Restricted Cash | ||||||||||||||||
| Restricted cash as of September 30, 2014 represents a $2.0 million minimum cash balance requirement in connection with the Capital Royalty Term Loan (see Note 6 “Loan Agreements”). | ||||||||||||||||
| Accounts Receivable | ' | |||||||||||||||
| Accounts Receivable | ||||||||||||||||
| The Company grants credit to various customers in the normal course of business. The Company maintains an allowance for doubtful accounts for potential credit losses. Provisions are made, generally, for receivables greater than 120 days past due and based upon a specific review of other outstanding invoices. Accounts are written off against the allowance after appropriate collection efforts have been exhausted and when it is deemed that a balance is uncollectible. | ||||||||||||||||
| Concentration of Credit Risk | ' | |||||||||||||||
| Concentration of Credit Risk | ||||||||||||||||
| Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash, cash equivalents, short-term investments and accounts receivable. The Company maintains deposit accounts in federally insured financial institutions in excess of federally insured limits. The Company also maintains investments in money market funds that are not federally insured. Additionally, the Company has established guidelines regarding investment instruments and their maturities, which are designed to preserve principal and maintain liquidity. | ||||||||||||||||
| The following table summarizes customers who accounted for 10% or more of net accounts receivable: | ||||||||||||||||
| September 30, | December 31, | |||||||||||||||
| 2014 | 2013 | |||||||||||||||
| Byram Healthcare | 18.5 | % | N/A | |||||||||||||
| CCS Medical, Inc. | 13.8 | % | 21.4 | % | ||||||||||||
| Edgepark Medical Supplies, Inc. | 13.5 | % | 13.1 | % | ||||||||||||
| The following table summarizes customers who accounted for 10% or more of sales for the periods presented: | ||||||||||||||||
| Three Months Ended | Nine Months Ended | |||||||||||||||
| September 30, | September 30, | |||||||||||||||
| 2014 | 2013 | 2014 | 2013 | |||||||||||||
| Edgepark Medical Supplies, Inc. | 14.6 | % | 17.2 | % | 15.6 | % | 17.1 | % | ||||||||
| Byram Healthcare | 14.3 | % | N/A | N/A | N/A | |||||||||||
| CCS Medical, Inc. | 10.9 | % | 15.8 | % | 13.8 | % | 11.6 | % | ||||||||
| Fair Value of Financial Instruments | ' | |||||||||||||||
| Fair Value of Financial Instruments | ||||||||||||||||
| The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable, accrued expense, and employee-related liabilities are reasonable estimates of their fair value because of the short-term nature of these items. Short-term investments are carried at fair value. Based on the borrowing rates currently available for loans with similar terms, the Company believes that the fair value of its long-term debt approximates its carrying value. | ||||||||||||||||
| Revenue Recognition | ' | |||||||||||||||
| Revenue Recognition | ||||||||||||||||
| Revenue is generated in the United States from the sale of the t:slim Pump, disposable cartridges and infusion sets to individual customers and third-party distributors that resell the product to insulin-dependent diabetes customers. Sales to distributors accounted for 72% and 71% of our total sales for the nine months ended September 30, 2014 and 2013, respectively. The Company is paid directly by customers who use the products, distributors and third-party insurance payors. | ||||||||||||||||
| Revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred and title passed, the price is fixed or determinable, and collectability is reasonably assured. These criteria are applied as follows: | ||||||||||||||||
| — | The evidence of an arrangement generally consists of contractual arrangements with distributors, third-party insurance payors or direct customers. | |||||||||||||||
| — | Transfer of title and risk and rewards of ownership are passed upon shipment of the pump to distributors or upon delivery to the customer. | |||||||||||||||
| — | The selling prices are fixed and agreed upon based on the contracts with distributors, the customer and contracted insurance payors, if applicable. For sales to customers associated with insurance providers with whom there is no contract, revenue is recognized upon collection of cash at which time the price is determinable. The Company generally does not offer rebates to its distributors and customers. | |||||||||||||||
| — | The Company considers the overall creditworthiness and payment history of the distributor, customer and the contracted insurance payor in concluding whether collectability is reasonably assured. | |||||||||||||||
| Prior to the first quarter of 2013, t:slim Pump sales were recorded as deferred revenue until the Company’s 30-day right of return expired because the Company did not have sufficient sales history to be able to reasonably estimate returns. At December 31, 2012, $1.9 million was recorded as deferred revenue. Beginning in the first quarter of 2013, the Company began recognizing t:slim Pump revenue when all the revenue recognition criteria above are met, as it established sufficient history in order to reasonably estimate product returns. As a result of this change, a one-time adjustment was recorded during the nine month period ended September 30, 2013, to recognize previously deferred revenue and cost of sales of $1.9 million and $1.1 million, respectively. | ||||||||||||||||
| Revenue Recognition for Arrangements with Multiple Deliverables | ||||||||||||||||
| The Company considers the deliverables in its product offering as separate units of accounting and recognizes deliverables as revenue upon delivery only if (i) the deliverable has standalone value and (ii) if the arrangement includes a general right of return relative to the delivered item(s), delivery or performance of the undelivered item(s) is probable and substantially controlled by the Company. The Company allocates consideration to the separate units of accounting, unless the undelivered elements were deemed perfunctory and inconsequential. The Company uses the relative selling price method, in which allocation of consideration is based on vendor-specific objective evidence (“VSOE”) if available, third-party evidence (“TPE”), or if VSOE and TPE are not available, management’s best estimate of a standalone selling price (“ESP”) for the undelivered elements. | ||||||||||||||||
| In February 2013, the FDA cleared t:connect, the Company’s cloud-based data management application, which is made available upon purchase by t:slim Pump customers. This service is deemed an undelivered element at the time of the t:slim sale. Because the Company has neither VSOE nor TPE for this deliverable, the allocation of revenue is based on the Company’s ESP. The Company establishes its ESP based on estimated cost to provide such services, including consideration of a reasonable profit margin that is corroborated by comparable market data. The Company allocates fair value based on management’s ESP to this element at the time of sale and recognizes the revenue over the four-year hosting period. Deferred revenue for the t:connect hosting services was $0.5 million and $0.2 million at September 30, 2014 and December 31, 2013, respectively. All other undelivered elements at the time of sale are deemed inconsequential or perfunctory. | ||||||||||||||||
| Product Returns | ||||||||||||||||
| The Company offers a 30-day right of return for its t:slim Pump customers from the date of shipment, provided a physician’s confirmation of the medical reason for the return is received. Estimated allowances for sales returns are based on historical returned quantities as compared to t:slim Pump shipments in the same period. The return rate is then applied to the sales of the period to establish a reserve at the end of the period. The return rates used in the reserve are adjusted for known or expected changes in the marketplace when appropriate. The allowance for product returns at September 30, 2014 and December 31, 2013 was $0.2 million, which was included in accounts receivable on the Company’s condensed balance sheets. Actual product returns have not differed materially from estimated amounts reserved. | ||||||||||||||||
| Warranty Reserve | ' | |||||||||||||||
| Warranty Reserve | ||||||||||||||||
| The Company generally provides a four-year warranty on its t:slim Pump to end user customers and may replace any pumps that do not function in accordance with the product specifications. Pumps returned to the Company may be refurbished and redeployed. Additionally, the Company offers a six-month warranty on t:slim cartridges and infusion sets. Estimated warranty costs are recorded at the time of shipment. Warranty costs are estimated based on the current product cost considering a mix of new and refurbished costs for the pump, actual experience and expected failure rates from test studies performed in conjunction with the clearance of the Company’s product with the FDA to support the longevity and reliability of its t:slim Pump. The Company evaluates the reserve quarterly and makes adjustments when appropriate. At September 30, 2014 and December 31, 2013, the warranty reserve was $1.3 million and $1.1 million, respectively. Of the $1.1 million warranty reserve at December 31, 2013, $0.3 million was related to potential replacements associated with the voluntary product recall of selected lots of cartridges. The estimated reserve has been fully utilized and the Company does not expect further replacements related to this recall. As such, there was no warranty reserve at September 30, 2014 for such potential replacements. Actual warranty costs have not differed materially from estimated amounts reserved. | ||||||||||||||||
| The following table provides a reconciliation of the change in product warranty liabilities through September 30, 2014 (in thousands): | ||||||||||||||||
| Balance at December 31, 2013 | $ | 1,123 | ||||||||||||||
| Provision for warranties issued during the period | 2,301 | |||||||||||||||
| Settlements made during the period | (2,114 | ) | ||||||||||||||
| Balance at September 30, 2014 | $ | 1,310 | ||||||||||||||
| Current portion recorded in other current liabilities | $ | 360 | ||||||||||||||
| Non-current portion recorded in other long-term liabilities | 950 | |||||||||||||||
| Total | $ | 1,310 | ||||||||||||||
| Stock-Based Compensation | ' | |||||||||||||||
| Stock-Based Compensation | ||||||||||||||||
| The Company estimates the fair value of stock options and shares issued to employees under the Employee Stock Purchase Plan (“ESPP”) using a Black-Scholes option-pricing model on the date of grant. The Black-Scholes option-pricing model requires the use of subjective assumptions including volatility, expected term, risk-free rate, and the fair value of the underlying common stock. For awards that vest based on service conditions, the Company recognizes expense using the straight-line method less estimated forfeitures. Prior to the Company’s initial public offering, the estimated fair value of these awards was determined at the date of grant based upon the estimated fair value of the Company’s common stock. Subsequent to the Company’s initial public offering, the fair value of the common stock is based on observable market prices. As of September 30, 2014, there were no outstanding equity awards with market or performance conditions. | ||||||||||||||||
| The Company also records the expense for stock option grants to non-employees based on the estimated fair value of the stock option using the Black-Scholes option-pricing model. The fair value of non-employee awards is remeasured at each reporting period as the underlying awards vest unless the instruments are fully vested, immediately exercisable and nonforfeitable on the date of grant. | ||||||||||||||||
| Warrant Liabilities | ' | |||||||||||||||
| Warrant Liabilities | ||||||||||||||||
| The Company issued freestanding warrants to purchase shares of common stock and convertible preferred stock in connection with the issuance of convertible notes payable in 2011 and 2012. The Company accounted for these warrants as a liability in the financial statements because either the Company did not have enough authorized shares to satisfy potential exercise of the common stock warrants and the number of shares to be issued upon their exercise was outside the control of the Company, or because the underlying instrument into which the warrants were exercisable (Series D convertible preferred stock) contained deemed liquidation provisions that were outside of the control of the Company. Upon the closing of the initial public offering, warrants to purchase shares of Series D Preferred Stock automatically converted into warrants to purchase shares of common stock. The Company reclassified the warrant liability to stockholders’ equity as the warrants met the definition of an equity instrument. | ||||||||||||||||
| Prior to the warrants being converted to an equity instrument, the warrants were recorded at fair value using either the Black-Scholes option pricing model or a binomial lattice model, depending on the characteristics of the warrants at the time of the valuation. The fair value of these warrants was remeasured at each financial reporting period with any changes in fair value being recognized as a component of other income (expense) in the accompanying statements of operations and comprehensive loss. For the three and nine months ended September 30, 2013, income of $0.3 million and expense of $3.0 million were recorded as other income and expense from the revaluations, respectively. In connection with the completion of the initial public offering in November 2013, the Company performed the final remeasurement of the warrant liability. | ||||||||||||||||
| Net Loss Per Share | ' | |||||||||||||||
| Net Loss Per Share | ||||||||||||||||
| Basic net loss per share is calculated by dividing the net loss by the weighted average number of common shares that were outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by dividing the net loss by the sum of the weighted-average number of dilutive common share equivalents outstanding for the period determined using the treasury stock method. Dilutive common share equivalents are comprised of convertible preferred stock, preferred stock warrants, common stock warrants, potential ESPP shares, restricted common stock and options outstanding under the Company’s equity incentive plans. Applicable accounting guidance provides that a contract that is reported as an asset or liability for accounting purposes may require an adjustment to the numerator of the diluted earnings per share calculation for any changes in income or loss that would result if the contract had been reported as an equity instrument during the period. Securities are assumed to be converted at the beginning of the period, and the resulting common shares are included in the denominator of the diluted earnings per share calculation for the entire period presented. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company’s net loss position. | ||||||||||||||||
| Potentially dilutive securities not included in the calculation of diluted net loss per share (because inclusion would be anti-dilutive) are as follows (in common stock equivalent shares): | ||||||||||||||||
| Three Months Ended | Nine Months Ended | |||||||||||||||
| September 30, | September 30, | |||||||||||||||
| 2014 | 2013 | 2014 | 2013 | |||||||||||||
| Convertible preferred stock outstanding | — | 13,148,484 | — | 12,314,967 | ||||||||||||
| Warrants for convertible preferred stock | — | 1,426,704 | — | 1,426,704 | ||||||||||||
| Warrants for common stock | 1,006,577 | 271,834 | 1,006,577 | 256,898 | ||||||||||||
| Common stock options | 2,292,897 | 1,716,845 | 2,279,347 | 967,857 | ||||||||||||
| ESPP | 139,145 | — | 139,145 | — | ||||||||||||
| Restricted common stock subject to repurchase | — | 58,555 | — | 55,633 | ||||||||||||
| 3,438,619 | 16,622,422 | 3,425,069 | 15,022,059 | |||||||||||||
| Recent Accounting Pronouncements | ' | |||||||||||||||
| Recent Accounting Pronouncements | ||||||||||||||||
| In August 2014, the Financial Accounting Standards Board (“FASB”) issued an accounting standards update, which requires management of public and private companies to evaluate whether there are conditions and events that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the financial statements are issued (or available to be issued when applicable) and, if so, disclose that fact. Management will be required to make this evaluation for both annual and interim reporting periods, if applicable. Management is also required to evaluate and disclose whether its plans alleviate that doubt. The standard is effective for annual periods ending after December 15, 2016 and interim periods within annual periods beginning after December 15, 2016. Early adoption is permitted for annual or interim reporting periods for which the financial statements have not previously been issued. The Company does not believe the adoption of this standard will have a material impact on its financial position, results of operations or related financial statement disclosures. | ||||||||||||||||
| In May 2014, the FASB and the International Accounting Standards Board (“IASB”) issued a comprehensive new revenue recognition standard that will supersede existing revenue guidance under U.S. GAAP and International Financial Reporting Standards (“IFRS”). The standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under current guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. The guidance is effective for annual periods beginning after December 15, 2016, including interim periods within that period. The Company is in the process of assessing the future impact of the adoption of the standard on its financial statements. | ||||||||||||||||
| In April 2014, the Financial Accounting Standards Board (“FASB”) issued an accounting standards update, which includes amendments that change the requirements for reporting discontinued operations and require additional disclosures about discontinued operations. Under the new guidance, only disposals representing a strategic shift in operations - that is, a major effect on the organization’s operations and financial results - should be presented as discontinued operations. Examples include a disposal of a major geographic area, a major line of business, or a major equity method investment. Additionally, the update requires expanded disclosures about discontinued operations that will provide financial statement users with more information about the assets, liabilities, income, and expenses of discontinued operations. The guidance is effective prospectively for fiscal years beginning after December 15, 2014 and interim periods within annual periods beginning on or after December 15, 2015. The Company does not believe the adoption of this standard will have a material impact on its financial position, results of operations or related financial statement disclosures. | ||||||||||||||||
Summary_of_Significant_Account1
| Summary of Significant Accounting Policies (Tables) | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Accounting Policies [Abstract] | ' | |||||||||||||||
| Summary of Customers Accounted for 10% or More | ' | |||||||||||||||
| The following table summarizes customers who accounted for 10% or more of net accounts receivable: | ||||||||||||||||
| September 30, | December 31, | |||||||||||||||
| 2014 | 2013 | |||||||||||||||
| Byram Healthcare | 18.5 | % | N/A | |||||||||||||
| CCS Medical, Inc. | 13.8 | % | 21.4 | % | ||||||||||||
| Edgepark Medical Supplies, Inc. | 13.5 | % | 13.1 | % | ||||||||||||
| The following table summarizes customers who accounted for 10% or more of sales for the periods presented: | ||||||||||||||||
| Three Months Ended | Nine Months Ended | |||||||||||||||
| September 30, | September 30, | |||||||||||||||
| 2014 | 2013 | 2014 | 2013 | |||||||||||||
| Edgepark Medical Supplies, Inc. | 14.6 | % | 17.2 | % | 15.6 | % | 17.1 | % | ||||||||
| Byram Healthcare | 14.3 | % | N/A | N/A | N/A | |||||||||||
| CCS Medical, Inc. | 10.9 | % | 15.8 | % | 13.8 | % | 11.6 | % | ||||||||
| Summary of Reconciliation of Change in Product Warranty Liabilities | ' | |||||||||||||||
| The following table provides a reconciliation of the change in product warranty liabilities through September 30, 2014 (in thousands): | ||||||||||||||||
| Balance at December 31, 2013 | $ | 1,123 | ||||||||||||||
| Provision for warranties issued during the period | 2,301 | |||||||||||||||
| Settlements made during the period | (2,114 | ) | ||||||||||||||
| Balance at September 30, 2014 | $ | 1,310 | ||||||||||||||
| Current portion recorded in other current liabilities | $ | 360 | ||||||||||||||
| Non-current portion recorded in other long-term liabilities | 950 | |||||||||||||||
| Total | $ | 1,310 | ||||||||||||||
| Schedule of Anti-Dilutive Securities | ' | |||||||||||||||
| Potentially dilutive securities not included in the calculation of diluted net loss per share (because inclusion would be anti-dilutive) are as follows (in common stock equivalent shares): | ||||||||||||||||
| Three Months Ended | Nine Months Ended | |||||||||||||||
| September 30, | September 30, | |||||||||||||||
| 2014 | 2013 | 2014 | 2013 | |||||||||||||
| Convertible preferred stock outstanding | — | 13,148,484 | — | 12,314,967 | ||||||||||||
| Warrants for convertible preferred stock | — | 1,426,704 | — | 1,426,704 | ||||||||||||
| Warrants for common stock | 1,006,577 | 271,834 | 1,006,577 | 256,898 | ||||||||||||
| Common stock options | 2,292,897 | 1,716,845 | 2,279,347 | 967,857 | ||||||||||||
| ESPP | 139,145 | — | 139,145 | — | ||||||||||||
| Restricted common stock subject to repurchase | — | 58,555 | — | 55,633 | ||||||||||||
| 3,438,619 | 16,622,422 | 3,425,069 | 15,022,059 | |||||||||||||
ShortTerm_Investments_Tables
| Short-Term Investments (Tables) | 9 Months Ended | |||||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||||
| Investments Debt And Equity Securities [Abstract] | ' | |||||||||||||||||
| Summary of Estimated Fair Value of Short-Term Investments | ' | |||||||||||||||||
| The following represents a summary of the estimated fair value of short-term investments at September 30, 2014 and December 31, 2013 (in thousands): | ||||||||||||||||||
| At September 30, 2014 | Maturity | Amortized | Unrealized | Unrealized | Estimated | |||||||||||||
| (in years) | Cost | Gain | Loss | Fair Value | ||||||||||||||
| Commercial paper | Less than 1 | $ | 40,769 | $ | 19 | $ | — | $ | 40,788 | |||||||||
| Government-sponsored enterprise securities | 1 to 2 | 3,505 | — | — | 3,505 | |||||||||||||
| Trading securities — mutual funds held for nonqualified deferred compensation plan participants | 26 | — | — | 26 | ||||||||||||||
| Total | $ | 44,300 | $ | 19 | $ | — | $ | 44,319 | ||||||||||
| At December 31, 2013 | Maturity | Amortized | Unrealized | Unrealized | Estimated | |||||||||||||
| (in years) | Cost | Gain | Loss | Fair Value | ||||||||||||||
| Commercial paper | Less than 1 | $ | 5,095 | $ | — | $ | — | $ | 5,095 | |||||||||
| Total | $ | 5,095 | $ | — | $ | — | $ | 5,095 | ||||||||||
Inventory_Tables
| Inventory (Tables) | 9 Months Ended | |||||||
| Sep. 30, 2014 | ||||||||
| Inventory Disclosure [Abstract] | ' | |||||||
| Schedule of Inventories | ' | |||||||
| Inventories, stated at the lower of cost or market, consisted of the following (in thousands): | ||||||||
| September 30, | December 31, | |||||||
| 2014 | 2013 | |||||||
| Raw materials | $ | 6,098 | $ | 6,363 | ||||
| Work in process | 3,832 | 2,169 | ||||||
| Finished goods | 2,191 | 3,535 | ||||||
| 12,121 | 12,067 | |||||||
| Less reserve | (229 | ) | (1,737 | ) | ||||
| Total | $ | 11,892 | $ | 10,330 | ||||
Fair_Value_Measurements_Tables
| Fair Value Measurements (Tables) | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Fair Value Disclosures [Abstract] | ' | |||||||||||||||
| Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis | ' | |||||||||||||||
| The following table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis as of September 30, 2014 and December 31, 2013, and indicates the fair value hierarchy of the valuation techniques utilized by the Company to determine such fair value (in thousands): | ||||||||||||||||
| Fair Value Measurements at | ||||||||||||||||
| September 30, | 30-Sep-14 | |||||||||||||||
| 2014 | Level 1 | Level 2 | Level 3 | |||||||||||||
| Assets | ||||||||||||||||
| Cash equivalents (1) | $ | 31,801 | $ | 31,801 | $ | — | $ | — | ||||||||
| Restricted cash | 2,000 | 2,000 | — | — | ||||||||||||
| Commercial paper | 40,788 | — | 40,788 | — | ||||||||||||
| Mutual funds held for nonqualified deferred compensation plan participants (2) | 26 | 26 | — | — | ||||||||||||
| Government-sponsored enterprise securities | 3,505 | 3,505 | — | — | ||||||||||||
| Total assets | $ | 78,120 | $ | 37,332 | $ | 40,788 | $ | — | ||||||||
| Liabilities | ||||||||||||||||
| Deferred compensation (2) | $ | 26 | $ | 26 | $ | — | $ | — | ||||||||
| Total liabilities | $ | 26 | $ | 26 | $ | — | $ | — | ||||||||
| -1 | Cash equivalents included money market funds and commercial paper with a maturity of three months or less from the date of purchase. | |||||||||||||||
| -2 | Deferred compensation plans are compensation plans directed by the Company and structured as a Rabbi Trust for certain executives and non-employee directors. The investment assets of the Rabbi Trust are valued using quoted market prices multiplied by the number of shares held in each trust account. The related deferred compensation liability represents the fair value of the investment assets. | |||||||||||||||
| Fair Value Measurements at | ||||||||||||||||
| December 31, | 31-Dec-13 | |||||||||||||||
| 2013 | Level 1 | Level 2 | Level 3 | |||||||||||||
| Assets | ||||||||||||||||
| Money market funds | $ | 115,112 | $ | 115,112 | $ | — | $ | — | ||||||||
| Restricted cash | 2,050 | 2,050 | — | — | ||||||||||||
| Commercial paper | 5,095 | — | 5,095 | — | ||||||||||||
| Total assets | $ | 122,257 | $ | 117,162 | $ | 5,095 | $ | — | ||||||||
Stockholders_Equity_Tables
| Stockholders' Equity (Tables) | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Equity [Abstract] | ' | |||||||||||||||
| Schedule of Shares of Common Stock Reserved for Future Issuance | ' | |||||||||||||||
| The following shares of common stock are reserved for future issuance at September 30, 2014: | ||||||||||||||||
| Common stock warrants outstanding | 1,006,577 | |||||||||||||||
| Stock options issued and outstanding | 4,899,528 | |||||||||||||||
| Authorized for future option grants | 2,149,102 | |||||||||||||||
| Employee stock purchase plan | 659,863 | |||||||||||||||
| 8,715,070 | ||||||||||||||||
| Schedule of Assumptions Used in Black-Scholes Option-Pricing Model | ' | |||||||||||||||
| The assumptions used in the Black-Scholes option-pricing model are as follows: | ||||||||||||||||
| Stock Option | ||||||||||||||||
| Three Months Ended | Nine Months Ended | |||||||||||||||
| September 30, | September 30, | |||||||||||||||
| 2014 | 2013 | 2014 | 2013 | |||||||||||||
| Risk-free interest rate | 1.9 | % | 1.8 | % | 1.9 | % | 1.1 | % | ||||||||
| Expected dividend yield | 0 | % | 0 | % | 0 | % | 0 | % | ||||||||
| Expected volatility | 78.1 | % | 79.4 | % | 78.7 | % | 76.6 | % | ||||||||
| Expected term (in years) | 6.1 | 5.7 | 6.1 | 5.6 | ||||||||||||
| ESPP | ||||||||||||||||
| Nine Months Ended | ||||||||||||||||
| September 30, | ||||||||||||||||
| 2014 | 2013 | |||||||||||||||
| Risk-free interest rate | 0.2 | % | — | |||||||||||||
| Expected dividend yield | 0 | % | — | |||||||||||||
| Expected volatility | 62.9 | % | — | |||||||||||||
| Expected term (in years) | 1.3 | — | ||||||||||||||
| Summary for Allocation of Stock Compensation Expense | ' | |||||||||||||||
| The following table summarizes the allocation of stock compensation expense (in thousands): | ||||||||||||||||
| Three Months Ended | Nine Months Ended | |||||||||||||||
| September 30, | September 30, | |||||||||||||||
| 2014 | 2013 | 2014 | 2013 | |||||||||||||
| Cost of sales | $ | 313 | $ | (9 | ) | $ | 940 | $ | 58 | |||||||
| Selling, general & administrative | 2,979 | 861 | 8,798 | 1,370 | ||||||||||||
| Research and development | 454 | 114 | 1,310 | 183 | ||||||||||||
| Total | $ | 3,746 | $ | 966 | $ | 11,048 | $ | 1,611 | ||||||||
Organization_and_Basis_of_Pres2
| Organization and Basis of Presentation - Additional Information (Detail) (USD $) | 0 Months Ended | 9 Months Ended | 3 Months Ended | 1 Months Ended | |
| Jan. 10, 2014 | Sep. 30, 2014 | Sep. 30, 2013 | Dec. 31, 2013 | Nov. 30, 2013 | |
| Cost of sales [Member] | Initial Public Offering [Member] | ||||
| Organization And Basis Of Presentation [Line Items] | ' | ' | ' | ' | ' |
| Incorporation date | ' | 27-Jan-06 | ' | ' | ' |
| Reincorporation date | ' | 7-Jan-08 | ' | ' | ' |
| Shares offered for public offering | ' | ' | ' | ' | 8,000,000 |
| Shares offering price per share | ' | ' | ' | ' | $15 |
| Proceeds from initial public offering | ' | ' | ' | ' | $108,300,000 |
| Additional shares issued to underwriters | ' | ' | ' | ' | 1,200,000 |
| Net proceeds from additional issuance of stock | ' | 2,017,791 | 14,687 | ' | 16,700,000 |
| Converted number of common stock | ' | ' | ' | ' | 13,403,747 |
| Conversion of warrants to common shares | ' | ' | ' | ' | 1,171,352 |
| Reverse stock split | ' | '1-for-1.6756 | ' | ' | ' |
| Direct costs associated with the recall | 1,700,000 | ' | ' | 1,300,000 | ' |
| Return and replacement of affected cartridges | 700,000 | ' | ' | ' | ' |
| Write-off of affected cartridges | $1,000,000 | $163,246 | $435,419 | ' | ' |
Summary_of_Significant_Account2
| Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) | 3 Months Ended | 9 Months Ended | |||
| Share data in Millions, unless otherwise specified | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Dec. 31, 2013 | Dec. 31, 2012 |
| Summary Of Significant Accounting Policies [Line Items] | ' | ' | ' | ' | ' |
| Restricted cash | ' | $2,000,000 | ' | $2,050,000 | ' |
| Receivables considered as uncollectible, maximum past due days | ' | '120 days | ' | ' | ' |
| Deferred revenue | 1,900,000 | 500,000 | 1,900,000 | 200,000 | 1,900,000 |
| Cost of sales | ' | ' | 1,100,000 | ' | ' |
| Offered period for sales return | ' | '30 days | ' | ' | ' |
| Revenue recognition hosting period | ' | '4 years | ' | ' | ' |
| Allowance for product returns | ' | 200,000 | ' | 200,000 | ' |
| Warranty reserve | ' | 1,310,000 | ' | 1,123,000 | ' |
| Other current liabilities | ' | 2,412,812 | ' | 4,086,196 | ' |
| Equity awards outstanding | ' | 0 | ' | ' | ' |
| Change in fair value of common and preferred stock warrants | -272,030 | ' | 3,011,574 | ' | ' |
| Warranty reserves [Member] | ' | ' | ' | ' | ' |
| Summary Of Significant Accounting Policies [Line Items] | ' | ' | ' | ' | ' |
| Warranty reserve | ' | 1,300,000 | ' | 1,100,000 | ' |
| Other current liabilities | ' | 300,000 | ' | ' | ' |
| Slim Pump [Member] | ' | ' | ' | ' | ' |
| Summary Of Significant Accounting Policies [Line Items] | ' | ' | ' | ' | ' |
| Warranty period offered | ' | '4 years | ' | ' | ' |
| Slim cartridges and infusion sets [Member] | ' | ' | ' | ' | ' |
| Summary Of Significant Accounting Policies [Line Items] | ' | ' | ' | ' | ' |
| Warranty period offered | ' | '6 months | ' | ' | ' |
| Sales [Member] | ' | ' | ' | ' | ' |
| Summary Of Significant Accounting Policies [Line Items] | ' | ' | ' | ' | ' |
| Percentage of sales to distributors | ' | 72.00% | 71.00% | ' | ' |
| Original Term Loan Agreement [Member] | ' | ' | ' | ' | ' |
| Summary Of Significant Accounting Policies [Line Items] | ' | ' | ' | ' | ' |
| Restricted cash | ' | $2,000,000 | ' | ' | ' |
Summary_of_Significant_Account3
| Summary of Significant Accounting Policies - Summary of Customers Accounted for 10% or More (Detail) | 9 Months Ended | 12 Months Ended | 9 Months Ended | 12 Months Ended | 9 Months Ended | 3 Months Ended | 9 Months Ended | 3 Months Ended | 9 Months Ended | |||||||
| Sep. 30, 2014 | Sep. 30, 2014 | Dec. 31, 2013 | Sep. 30, 2014 | Dec. 31, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | |
| Accounts receivable [Member] | Accounts receivable [Member] | Accounts receivable [Member] | Accounts receivable [Member] | Accounts receivable [Member] | Sales [Member] | Sales [Member] | Sales [Member] | Sales [Member] | Sales [Member] | Sales [Member] | Sales [Member] | Sales [Member] | Sales [Member] | Sales [Member] | Sales [Member] | |
| Byram Healthcare [Member] | CCS Medical, Inc. [Member] | CCS Medical, Inc. [Member] | Edgepark Medical Supplies, Inc. [Member] | Edgepark Medical Supplies, Inc. [Member] | Byram Healthcare [Member] | CCS Medical, Inc. [Member] | CCS Medical, Inc. [Member] | CCS Medical, Inc. [Member] | CCS Medical, Inc. [Member] | Edgepark Medical Supplies, Inc. [Member] | Edgepark Medical Supplies, Inc. [Member] | Edgepark Medical Supplies, Inc. [Member] | Edgepark Medical Supplies, Inc. [Member] | |||
| Concentration Risk [Line Items] | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Customers accounted for 10% or more | 18.50% | 13.80% | 21.40% | 13.50% | 13.10% | 72.00% | 71.00% | 14.30% | 10.90% | 15.80% | 13.80% | 11.60% | 14.60% | 17.20% | 15.60% | 17.10% |
Summary_of_Significant_Account4
| Summary of Significant Accounting Policies - Summary of Reconciliation of Change in Product Warranty Liabilities (Detail) (USD $) | 9 Months Ended |
| In Thousands, unless otherwise specified | Sep. 30, 2014 |
| Movement In Standard And Extended Product Warranty Increase Decrease Roll Forward | ' |
| Beginning balance | $1,123 |
| Provision for warranties issued during the period | 2,301 |
| Settlements made during the period | -2,114 |
| Ending balance | 1,310 |
| Current portion recorded in other current liabilities | 360 |
| Non-current portion recorded in other long-term liabilities | $950 |
Summary_of_Significant_Account5
| Summary of Significant Accounting Policies - Schedule of Anti-Dilutive Securities (Detail) | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | |
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ' | ' | ' | ' |
| Antidilutive securities excluded from computation of earnings per share, amount | 3,438,619 | 16,622,422 | 3,425,069 | 15,022,059 |
| Warrants for convertible preferred stock [Member] | ' | ' | ' | ' |
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ' | ' | ' | ' |
| Antidilutive securities excluded from computation of earnings per share, amount | ' | 1,426,704 | ' | 1,426,704 |
| Warrants for common stock [Member] | ' | ' | ' | ' |
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ' | ' | ' | ' |
| Antidilutive securities excluded from computation of earnings per share, amount | 1,006,577 | 271,834 | 1,006,577 | 256,898 |
| Common stock options [Member] | ' | ' | ' | ' |
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ' | ' | ' | ' |
| Antidilutive securities excluded from computation of earnings per share, amount | 2,292,897 | 1,716,845 | 2,279,347 | 967,857 |
| Employee stock purchase plan [Member] | ' | ' | ' | ' |
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ' | ' | ' | ' |
| Antidilutive securities excluded from computation of earnings per share, amount | 139,145 | ' | 139,145 | ' |
| Restricted common stock subject to repurchase [Member] | ' | ' | ' | ' |
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ' | ' | ' | ' |
| Antidilutive securities excluded from computation of earnings per share, amount | ' | 58,555 | ' | 55,633 |
| Convertible preferred stock outstanding [Member] | ' | ' | ' | ' |
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ' | ' | ' | ' |
| Antidilutive securities excluded from computation of earnings per share, amount | ' | 13,148,484 | ' | 12,314,967 |
ShortTerm_Investments_Summary_
| Short-Term Investments - Summary of Estimated Fair Value of Short-Term Investments (Detail) (USD $) | 9 Months Ended | 12 Months Ended |
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Dec. 31, 2013 |
| Investment [Line Items] | ' | ' |
| Short-term investments, Amortized Cost | $44,300 | $5,095 |
| Short-term investments, Unrealized Gain | 19 | 0 |
| Short-term investments, Unrealized Loss | 0 | 0 |
| Short-term investments, Estimated Fair Value | 44,319 | 5,095 |
| Commercial paper [Member] | ' | ' |
| Investment [Line Items] | ' | ' |
| Short-term investments, Maturity (in years) | 'Less than 1 | 'Less than 1 |
| Short-term investments, Amortized Cost | 40,769 | 5,095 |
| Short-term investments, Unrealized Gain | 19 | 0 |
| Short-term investments, Unrealized Loss | 0 | 0 |
| Short-term investments, Estimated Fair Value | 40,788 | 5,095 |
| Government-sponsored enterprise securities [Member] | ' | ' |
| Investment [Line Items] | ' | ' |
| Short-term investments, Maturity (in years) | '1 to 2 | ' |
| Short-term investments, Amortized Cost | 3,505 | ' |
| Short-term investments, Unrealized Gain | 0 | ' |
| Short-term investments, Unrealized Loss | 0 | ' |
| Short-term investments, Estimated Fair Value | 3,505 | ' |
| Trading securities b mutual funds held for nonqualified deferred compensation plan participants [Member] | ' | ' |
| Investment [Line Items] | ' | ' |
| Short-term investments, Amortized Cost | 26 | ' |
| Short-term investments, Unrealized Gain | 0 | ' |
| Short-term investments, Unrealized Loss | 0 | ' |
| Short-term investments, Estimated Fair Value | $26 | ' |
Inventory_Schedule_of_Inventor
| Inventory - Schedule of Inventories (Detail) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| Inventory Disclosure [Abstract] | ' | ' |
| Raw materials | $6,098,000 | $6,363,000 |
| Work in process | 3,832,000 | 2,169,000 |
| Finished goods | 2,191,000 | 3,535,000 |
| Inventory gross | 12,121,000 | 12,067,000 |
| Less reserve | -229,000 | -1,737,000 |
| Total | $11,891,586 | $10,330,156 |
Inventory_Additional_Informati
| Inventory - Additional Information (Detail) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| Inventory [Line Items] | ' | ' |
| Reserve for excess and obsolete inventory | $229,000 | $1,737,000 |
| Product Recalls [Member] | ' | ' |
| Inventory [Line Items] | ' | ' |
| Reserve for excess and obsolete inventory | $0 | $900,000 |
Fair_Value_Measurements_Schedu
| Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| In Thousands, unless otherwise specified | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | $78,120 | $122,257 |
| Total liabilities | 26 | ' |
| Cash equivalents [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 31,801 | ' |
| Restricted cash [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 2,000 | 2,050 |
| Commercial paper [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 40,788 | 5,095 |
| Mutual funds held for nonqualified deferred compensation plan participants [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 26 | ' |
| Government-sponsored enterprise securities [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 3,505 | ' |
| Deferred compensation [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total liabilities | 26 | ' |
| Money Market Funds | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | ' | 115,112 |
| Level 1 [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 37,332 | 117,162 |
| Total liabilities | 26 | ' |
| Level 1 [Member] | Cash equivalents [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 31,801 | ' |
| Level 1 [Member] | Restricted cash [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 2,000 | 2,050 |
| Level 1 [Member] | Commercial paper [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 0 | ' |
| Level 1 [Member] | Mutual funds held for nonqualified deferred compensation plan participants [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 26 | ' |
| Level 1 [Member] | Government-sponsored enterprise securities [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 3,505 | ' |
| Level 1 [Member] | Deferred compensation [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total liabilities | 26 | ' |
| Level 1 [Member] | Money Market Funds | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | ' | 115,112 |
| Level 2 [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 40,788 | 5,095 |
| Total liabilities | 0 | ' |
| Level 2 [Member] | Cash equivalents [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 0 | ' |
| Level 2 [Member] | Restricted cash [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 0 | ' |
| Level 2 [Member] | Commercial paper [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 40,788 | 5,095 |
| Level 2 [Member] | Mutual funds held for nonqualified deferred compensation plan participants [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 0 | ' |
| Level 2 [Member] | Government-sponsored enterprise securities [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 0 | ' |
| Level 2 [Member] | Deferred compensation [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total liabilities | 0 | ' |
| Level 3 [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 0 | ' |
| Total liabilities | 0 | ' |
| Level 3 [Member] | Cash equivalents [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 0 | ' |
| Level 3 [Member] | Restricted cash [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 0 | ' |
| Level 3 [Member] | Commercial paper [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 0 | ' |
| Level 3 [Member] | Mutual funds held for nonqualified deferred compensation plan participants [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 0 | ' |
| Level 3 [Member] | Government-sponsored enterprise securities [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total assets | 0 | ' |
| Level 3 [Member] | Deferred compensation [Member] | ' | ' |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' |
| Total liabilities | $0 | ' |
Fair_Value_Measurements_Additi
| Fair Value Measurements - Additional Information (Detail) (USD $) | Sep. 30, 2014 |
| Fair Value Disclosures [Abstract] | ' |
| Transfer between level 1 and level 2 securities | $0 |
Loan_Agreements_Additional_Inf
| Loan Agreements - Additional Information (Detail) (USD $) | 9 Months Ended | 1 Months Ended | 1 Months Ended | 9 Months Ended | 1 Months Ended | 9 Months Ended | 9 Months Ended | 0 Months Ended | 9 Months Ended | 0 Months Ended | |||||||
| Sep. 30, 2014 | Jan. 31, 2013 | Sep. 30, 2014 | Dec. 31, 2013 | Mar. 31, 2012 | Nov. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2012 | Jan. 31, 2013 | Sep. 30, 2014 | Dec. 31, 2012 | Sep. 30, 2014 | Apr. 04, 2014 | Sep. 30, 2014 | Apr. 04, 2014 | Apr. 04, 2014 | Sep. 30, 2014 | |
| SVB Revolving Line of Credit [Member] | SVB Revolving Line of Credit [Member] | SVB Revolving Line of Credit [Member] | Silicon Valley Bank [Member] | Silicon Valley Bank Term Loan [Member] | Silicon Valley Bank Term Loan [Member] | Silicon Valley Bank Term Loan [Member] | Original Term Loan Agreement [Member] | Original Term Loan Agreement [Member] | Original Term Loan Agreement [Member] | Original Term Loan Agreement [Member] | Amended and Restated Term Loan Agreement [Member] | Amended and Restated Term Loan Agreement [Member] | Amended and Restated Term Loan Agreement [Member] | Amended and Restated Term Loan Agreement [Member] | New Tranche Term Loan Agreement [Member] | ||
| Series D Preferred Stock [Member] | Series D Preferred Stock [Member] | Series D Preferred Stock [Member] | Capital Royalty Partners [Member] | Minimum [Member] | Maximum [Member] | March 31, 2015 [Member] | |||||||||||
| Debt Instrument [Line Items] | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Bridge loan | ' | ' | ' | ' | $5,000,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Interest rate | ' | ' | ' | ' | ' | ' | ' | 4.00% | ' | 14.00% | ' | ' | 11.50% | ' | 11.50% | 14.00% | ' |
| Loan final payment | ' | ' | ' | ' | ' | ' | ' | 300,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Loan fee | ' | ' | ' | ' | ' | ' | ' | 200,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Accrued interest payments due monthly | ' | ' | ' | ' | ' | ' | 'The term loan accrued interest at an annual rate of 4%, with principal and accrued interest payments due monthly throughout the 24-month term. | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Warrants issued to purchase common stock | ' | ' | ' | ' | ' | ' | 102,270 | ' | 271,834 | ' | ' | ' | ' | ' | ' | ' | ' |
| Warrants exercise price per share | ' | ' | ' | ' | ' | ' | 4.4 | ' | 0.02 | ' | ' | ' | ' | ' | ' | ' | ' |
| Converted warrants issued to purchase shares | ' | ' | ' | ' | ' | 61,033 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Weighted average exercise price of common stock | ' | ' | ' | ' | ' | $7.37 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Available revolving line of credit | ' | 1,500,000 | ' | ' | ' | ' | ' | ' | 30,000,000 | ' | 45,000,000 | ' | ' | 30,000,000 | ' | ' | 30,000,000 |
| Revolving line of credit facility as percentage of accounts receivable | ' | 75.00% | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Revolving line of credit expiring date | ' | 31-Jan-15 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Revolving line of credit interest rate | ' | 6.00% | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Revolving line of credit amount outstanding | ' | ' | 0 | 0 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Additional loan amount available under agreement | ' | ' | ' | ' | ' | ' | ' | ' | 15,000,000 | ' | ' | ' | ' | ' | ' | ' | ' |
| Amount drawn under agreement | ' | ' | ' | ' | ' | ' | ' | ' | 30,000,000 | ' | ' | ' | ' | ' | ' | ' | ' |
| Maturity of term loan | ' | ' | ' | ' | ' | ' | ' | ' | ' | 31-Dec-17 | ' | ' | 31-Mar-20 | ' | ' | ' | ' |
| Prepayment fee percentage | ' | ' | ' | ' | ' | ' | ' | ' | ' | 5.00% | ' | ' | 3.00% | ' | ' | ' | ' |
| Prepayment fee percentage on loan repayment | ' | ' | ' | ' | ' | ' | ' | ' | ' | 1.00% | ' | ' | 1.00% | ' | ' | ' | ' |
| Interest-only payments description | 'Interest-only payments were due quarterly at March 31, June 30, September 30 and December 31 of each year through December 31, 2015. | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 'Interest-only payments are due quarterly on March 31, June 30, September 30 and December 31 of each year of the interest-only payment period. | ' | ' | ' |
| Fair value of common stock | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | $1.61 | ' | ' | ' | ' | ' | ' |
| Debt financing fee | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 400,000 | ' | ' | ' | ' | ' |
| Warrants expiry period | ' | ' | ' | ' | ' | ' | ' | ' | '2023-01 | ' | ' | ' | ' | ' | ' | ' | ' |
| Warrants fair value recorded as debt discount | ' | ' | ' | ' | ' | ' | ' | ' | ' | 400,000 | ' | ' | ' | ' | ' | ' | ' |
| Financing fee of warrant recorded as debt discount | ' | ' | ' | ' | ' | ' | ' | ' | ' | 400,000 | ' | ' | ' | ' | ' | ' | ' |
| Debt issuance cost | ' | ' | ' | ' | ' | ' | ' | ' | ' | 700,000 | ' | ' | ' | ' | ' | ' | ' |
| Interest payment period | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 31-Dec-15 | 31-Mar-18 | ' |
| Interest payable as cash | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 9.50% | ' | ' | ' | ' |
| Compounded interest payable | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 2.00% | ' | ' | ' | ' |
| Minimum annual revenues attainable in 2014 | 30,000,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Minimum annual revenues attainable in 2015 | 50,000,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Minimum annual revenues attainable in 2016 | 65,000,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Minimum annual revenues attainable in 2017 | 80,000,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Minimum annual revenues attainable in 2018 | 95,000,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Present value of the future cash flows | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 10.00% | ' | ' | ' |
| Debt discount | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | $100,000 | ' | ' | ' |
Stockholders_Equity_Schedule_o
| Stockholders' Equity - Schedule of Shares of Common Stock Reserved for Future Issuance (Detail) | Sep. 30, 2014 |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
| Common stock reserved for future issuance | 8,715,070 |
| Common stock warrants outstanding [Member] | ' |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
| Common stock reserved for future issuance | 1,006,577 |
| Stock options issued and outstanding [Member] | ' |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
| Common stock reserved for future issuance | 4,899,528 |
| Authorized for future option grants [Member] | ' |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
| Common stock reserved for future issuance | 2,149,102 |
| Employee stock purchase plan [Member] | ' |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
| Common stock reserved for future issuance | 659,863 |
Stockholders_Equity_Additional
| Stockholders' Equity - Additional Information (Detail) (USD $) | 9 Months Ended | 12 Months Ended |
| In Millions, except Share data, unless otherwise specified | Sep. 30, 2014 | Dec. 31, 2013 |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' | ' |
| Stock-based compensation cost | $0.20 | $0.30 |
| Stock Options [Member] | ' | ' |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' | ' |
| Common stock shares issued | 106,801 | 95,007 |
| ESPP [Member] | ' | ' |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' | ' |
| Common stock shares purchased under plan | 125,393 | ' |
Stockholders_Equity_Schedule_o1
| Stockholders' Equity - Schedule of Assumptions Used in Black-Scholes Option-Pricing Model (Detail) | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | |
| Stock Options [Member] | ' | ' | ' | ' |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' | ' | ' | ' |
| Risk-free interest rate | 1.90% | 1.80% | 1.90% | 1.10% |
| Expected dividend yield | 0.00% | 0.00% | 0.00% | 0.00% |
| Expected volatility | 78.10% | 79.40% | 78.70% | 76.60% |
| Expected term (in years) | '6 years 1 month 6 days | '5 years 8 months 12 days | '6 years 1 month 6 days | '5 years 7 months 6 days |
| ESPP [Member] | ' | ' | ' | ' |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' | ' | ' | ' |
| Risk-free interest rate | ' | ' | 0.20% | ' |
| Expected dividend yield | ' | ' | 0.00% | ' |
| Expected volatility | ' | ' | 62.90% | ' |
| Expected term (in years) | ' | ' | '1 year 3 months 18 days | '0 years |
Stockholders_Equity_Summary_fo
| Stockholders' Equity - Summary for Allocation of Stock Compensation Expense (Detail) (USD $) | 3 Months Ended | 9 Months Ended | ||
| In Thousands, unless otherwise specified | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' | ' | ' | ' |
| Allocation of stock compensation (benefit) expense | $3,746 | $966 | $11,048 | $1,611 |
| Cost of sales [Member] | ' | ' | ' | ' |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' | ' | ' | ' |
| Allocation of stock compensation (benefit) expense | 313 | -9 | 940 | 58 |
| Selling, general & administrative [Member] | ' | ' | ' | ' |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' | ' | ' | ' |
| Allocation of stock compensation (benefit) expense | 2,979 | 861 | 8,798 | 1,370 |
| Research and development [Member] | ' | ' | ' | ' |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' | ' | ' | ' |
| Allocation of stock compensation (benefit) expense | $454 | $114 | $1,310 | $183 |
Collaborations_Additional_Info
| Collaborations - Additional Information (Detail) (USD $) | 3 Months Ended | 9 Months Ended | 9 Months Ended | 12 Months Ended | 3 Months Ended | 9 Months Ended | ||||||||||
| Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Dec. 31, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Dec. 31, 2012 | Jul. 31, 2014 | Dec. 31, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Dec. 31, 2013 | Sep. 30, 2016 | |
| DexCom Agreement [Member] | DexCom Agreement [Member] | DexCom Agreement [Member] | DexCom Agreement [Member] | DexCom Agreement [Member] | JDRF Agreement [Member] | JDRF Agreement [Member] | JDRF Agreement [Member] | JDRF Agreement [Member] | JDRF Agreement [Member] | JDRF Agreement [Member] | ||||||
| Milestone | Forecast [Member] | |||||||||||||||
| Maximum [Member] | ||||||||||||||||
| Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Research and development cost | $4,508,004 | $2,651,580 | $11,869,567 | $7,732,818 | ' | $32,000 | $78,000 | $1,000,000 | ' | ' | ' | ' | ' | ' | ' | ' |
| Millestone payment | ' | ' | ' | ' | ' | ' | ' | ' | 1,000,000 | ' | ' | ' | ' | ' | ' | ' |
| Number of additional milestone payments | ' | ' | ' | ' | ' | 1 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Additional payment upon achievement of milestones | ' | ' | ' | ' | ' | 1,000,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Reimbursement of development costs | ' | ' | ' | ' | ' | 1,000,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Reimbursed development costs | ' | ' | 200,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Accrued development costs | ' | ' | ' | ' | ' | 0 | ' | ' | ' | 0 | ' | ' | ' | ' | ' | ' |
| Royalty payable | ' | ' | ' | ' | ' | 100 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Research and development costs offset cumulative amount | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 300,000 | ' | 300,000 | ' | ' | 3,000,000 |
| Aggregate amount of milestone payment achievements | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 700,000 | ' | ' | ' |
| Research and development offset amount | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 37,000 | 63,000 | 146,000 | 145,000 | ' | ' |
| Restricted cash | $2,000,000 | ' | $2,000,000 | ' | $2,050,000 | ' | ' | ' | ' | ' | $0 | ' | $0 | ' | $0 | ' |
Commitments_and_Contingencies_
| Commitments and Contingencies - Additional Information (Detail) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| LegalProceeding | LegalProceeding | |
| Commitments And Contingencies Disclosure [Abstract] | ' | ' |
| Regulatory proceedings | 0 | 0 |
| Loss contingency accrued | $0 | $0 |