Insulet (PODD) 10-Q 2 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 31, 2018
Document Documentand Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	PODD
Entity Registrant Name	INSULET CORPORATION
Entity Central Index Key	1,145,197
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding (in shares)		59,077,244

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current Assets
Cash and cash equivalents	$ 126,563	$ 272,577
Short-term investments	163,281	167,479
Accounts receivable, net	69,950	53,373
Unbilled receivable	9,963	0
Inventories	58,050	33,793
Prepaid expenses and other current assets	17,905	9,949
Total current assets	445,712	537,171
Long-term investments	145,539	125,549
Property and equipment, net	229,433	107,864
Other intangible assets, net	7,791	4,351
Goodwill	39,774	39,840
Other assets	18,057	1,969
Total assets	886,306	816,744
Current Liabilities
Accounts payable	26,845	24,413
Accrued expenses and other current liabilities	68,169	59,256
Deferred revenue	2,210	2,356
Total current liabilities	97,224	86,025
Convertible debt, net of current portion	584,485	566,173
Other long-term liabilities	6,668	6,030
Total liabilities	688,377	658,228
Commitments and contingencies
Stockholders’ Equity
Authorized: 5,000,000 shares at September 30, 2018 and December 31, 2017. Issued and outstanding: zero shares at September 30, 2018 and December 31, 2017.	0	0
Authorized: 100,000,000 at September 30, 2018 and December 31, 2017. Issued and outstanding: 59,068,586 and 58,319,348 at September 30, 2018 and December 31, 2017, respectively.	59	58
Additional paid-in capital	893,829	866,206
Accumulated other comprehensive loss	(2,452)	(493)
Accumulated deficit	(693,507)	(707,255)
Total stockholders’ equity	197,929	158,516
Total liabilities and stockholders’ equity	$ 886,306	$ 816,744

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, authorized (in shares)	5,000,000	5,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	100,000,000	100,000,000
Common stock, issued (in shares)	59,068,586	58,319,348
Common stock, outstanding (in shares)	59,068,586	58,319,348

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue	$ 151,076	$ 121,775	$ 398,916	$ 333,244
Cost of revenue	49,107	48,151	139,060	135,583
Gross profit	101,969	73,624	259,856	197,661
Operating expenses:
Research and development	21,762	20,141	60,092	55,670
Sales and marketing	34,922	28,718	102,660	86,288
General and administrative	38,420	22,718	85,914	62,322
Total operating expenses	95,104	71,577	248,666	204,280
Operating income (loss)	6,865	2,047	11,190	(6,619)
Interest expense	6,846	4,709	22,054	14,512
Other income, net	1,834	556	5,202	1,478
Interest expense and other income, net	5,012	4,153	16,852	13,034
Income (loss) before income taxes	1,853	(2,106)	(5,662)	(19,653)
Income tax expense	194	121	939	318
Net income (loss)	$ 1,659	$ (2,227)	$ (6,601)	$ (19,971)
Net income (loss) per share:
Net income (loss) per share: basic (in dollars per share)	$ 0.03	$ (0.04)	$ (0.11)	$ (0.34)
Net income (loss) per shares: diluted (in dollars per share)	$ 0.03	$ (0.04)	$ (0.11)	$ (0.34)
Weighted average number of shares outstanding, basic (in shares)	59,016,863	58,099,593	58,779,672	57,924,920
Weighted average number of shares outstanding, diluted (in shares)	61,146,466	58,099,593	58,779,672	57,924,920

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 1,659	$ (2,227)	$ (6,601)	$ (19,971)
Other comprehensive income (loss), net of tax
Foreign currency translation adjustment, net of tax	4	329	(1,055)	594
Unrealized (loss) gain on available-for-sale debt securities, net of tax	(70)	76	(904)	9
Total other comprehensive (loss) income, net of tax	(66)	405	(1,959)	603
Total comprehensive income (loss)	$ 1,593	$ (1,822)	$ (8,560)	$ (19,368)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Cash flows from operating activities
Net income (loss)		$ 1,659	$ (2,227)	$ (6,601)	$ (19,971)
Adjustments to reconcile net income (loss) to net cash used in operating activities
Depreciation and amortization				11,254	10,533
Non-cash interest expense		7,363	4,117	21,790	12,185
Stock-based compensation expense				31,205	23,551
Provision for bad debts				2,588	1,502
Other				(235)	519
Changes in operating assets and liabilities:
Accounts receivable and unbilled receivable				(24,581)	(19,757)
Inventories				(25,279)	428
Prepaid expenses and other assets				(5,258)	(1,290)
Accounts payable, accrued expenses and other current liabilities				2,938	10,502
Deferred revenue				(2,761)	537
Other long-term liabilities				400	668
Net cash provided by operating activities				5,460	19,407
Cash flows from investing activities
Purchases of property, equipment and software	[1]			(127,559)	(47,813)
Purchases of investments				(145,575)	(115,056)
Receipts from the maturity or sale of investments				129,415	101,384
Net cash used in investing activities				(143,719)	(61,485)
Cash flows from financing activities
Principal payments of capital lease obligations				0	(269)
Repayment of convertible debt				(6,699)	0
Proceeds from exercise of stock options	[2]			13,464	10,735
Payment of withholding taxes in connection with vesting of restricted stock units				(13,846)	(3,816)
Net cash (used in) provided by financing activities				(7,081)	6,650
Effect of exchange rate changes on cash				(674)	487
Net decrease in cash, cash equivalents and restricted cash				(146,014)	(34,941)
Cash, cash equivalents and restricted cash, beginning of period				272,577	137,174	$ 137,174
Cash, cash equivalents and restricted cash, end of period		$ 126,563	$ 102,233	126,563	$ 102,233	272,577
Purchases of property, equipment and software, previously recorded in accounts payable				$ 4,000		$ 12,700
Number of shares acquired (in shares)				9,733
Payments for repurchase of common stock				$ 800
[1]	Cash outflows from purchases of property, equipment and intangible assets for the nine months ended September 30, 2018 includes $4.0 million of purchases made in prior periods that were included in accounts payable and accrued expenses as of December 31, 2017 and excludes $12.7 million of purchases made during the nine months ended September 30, 2018 that were included in accounts payable and accrued expenses as of September 30, 2018.
[2]	During the period, the Company acquired 9,733 shares of its common stock with a value of $0.8 million in return for the exercise of stock options. The acquired shares were subsequently retired.

Nature of the Business

Nature of the Business	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	Nature of the Business Insulet Corporation (the "Company") is primarily engaged in the development, manufacturing and sale of its proprietary Omnipod Insulin Management System (the “Omnipod System”), an innovative, discreet and easy-to-use continuous insulin delivery system for people with insulin-dependent diabetes. There are two primary types of insulin therapy practiced today: multiple daily injection (“MDI”) therapy using syringes or insulin pens; and pump therapy using insulin pumps. Insulin pumps are used to perform continuous subcutaneous insulin infusion, or insulin pump therapy, and typically use a programmable device and an infusion set to administer insulin into the person’s body. Insulin pump therapy has been shown to provide people with insulin-dependent diabetes with numerous advantages relative to MDI therapy. The Company estimates that approximately one-third of the Type 1 diabetes population in the United States use insulin pump therapy, and that less than 10% of the Type 2 diabetes population in the United States who are insulin-dependent use insulin pump therapy. The Omnipod System features a small, lightweight, self-adhesive disposable tubeless Omnipod device, which is worn on the body for approximately three days at a time (the "Pod"), and its wireless companion, the handheld Personal Diabetes Manager ("PDM"). The Omnipod System, which features two discreet, easy-to-use devices, communicates wirelessly, provides for virtually pain-free automated cannula insertion and eliminates the need for traditional MDI therapy or the use of traditional pump and tubing. The Company believes that the Omnipod System’s unique proprietary design and features allow people with insulin-dependent diabetes to manage their diabetes with unprecedented freedom, comfort, convenience, and ease. Commercial sales of the Omnipod System began in the United States in 2005. The Company sells the Omnipod System through direct sales to customers or through intermediaries. The Omnipod System is currently available in multiple countries in Europe, as well as in Canada and Israel. On July 1, 2018, the Company commenced direct sales of the Omnipod System in Europe following the expiration of its distribution agreement on June 30, 2018 with Ypsomed Distribution AG ("Ypsomed" or the "European Distributor"). In addition to using the Omnipod System for insulin delivery, the Company also partners with global pharmaceutical and biotechnology companies to tailor the Omnipod System technology platform for the delivery of subcutaneous drugs across other therapeutic areas. The majority of the Company's drug delivery revenue currently consists of sales of Amgen's Neulasta Onpro kit. To lower manufacturing costs, increase supply redundancy, add capacity closer to its largest customer base and support growth, the Company is constructing a highly-automated manufacturing facility in Acton, Massachusetts, with planned production out of the facility beginning in early 2019. The facility will also serve as the Company's global headquarters.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation The unaudited consolidated financial statements in this Quarterly Report on Form 10-Q have been prepared in accordance with generally accepted accounting principles (“U.S. GAAP” or "GAAP") for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, these unaudited consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments, consisting of normal recurring adjustments, considered necessary for a fair presentation have been included. Operating results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the full year ending December 31, 2018 , or for any other subsequent interim period. The unaudited consolidated financial statements in this Quarterly Report on Form 10-Q should be read in conjunction with the Company’s consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 . Use of Estimates in Preparation of Financial Statements The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions in the application of certain of its significant accounting policies that may materially affect the reported amounts of assets, liabilities, equity, revenue and expenses. Actual results may differ from those estimates. See Note 3 related to the Company's adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers, for a discussion of judgments associated with the recognition of revenue and deferral of cost to obtain a contract. Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Summary of Significant Accounting Policies The Company's significant accounting policies are described in Note 2, "Summary of Significant Accounting Policies", in the Company's Annual Report on Form 10-K for fiscal year 2017. Segment Reporting Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated on a regular basis by the chief operating decision-maker ("CODM") in deciding how to allocate resources to an individual segment and in assessing performance of the segment. The Company has concluded its Chief Executive Officer ("CEO") is the CODM as the CEO is the ultimate decision maker for key operating decisions, determining the allocation of resources and assessing the financial performance of the Company. These decisions, allocations and assessments are performed by the CODM using consolidated financial information. The Company’s products are relatively consistent and manufacturing is centralized and consistent across product offerings. Based on these factors, key operating decisions and resource allocations are made by the CODM using consolidated financial data and as such the Company has concluded that it operates as one segment. Shipping and Handling Costs The Company does not typically charge its customers for shipping and handling costs associated with shipping its product to its customers unless non-standard shipping and handling services are requested. These shipping and handling costs are included in general and administrative expenses and were $2.2 million and $1.3 million for the three months ended September 30, 2018 and 2017 , respectively, and were $4.6 million and $3.5 million for the nine months ended September 30, 2018 and 2017, respectively. Recently Adopted Accounting Standards In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers ("ASU 2014-09"). ASU 2014-09 and its related amendments (collectively referred to as ASC 606) requires that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Under this guidance, an entity makes additional estimates regarding performance conditions and the allocation of variable consideration and must evaluate whether revenue derived from a contract should be recognized at a point in time or over time. The Company adopted the standard as of the required effective date of January 1, 2018 using the modified retrospective method. Under this method, the new guidance was applied to contracts that were not yet completed as of January 1, 2018 with the cumulative effect of initially applying the guidance recognized through accumulated deficit as the date of initial application. See Note 3 "Revenue from Contracts with Customers". Effective January 1, 2018, the Company adopted ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01"). ASU 2016-01 changes the GAAP model for the accounting of equity investments, whereby equity investments with readily determinable fair value are carried at fair value with changes reported in net income (loss) as opposed to other comprehensive income (loss). The Company adopted ASU 2016-01 as of the required effective date of January 1, 2018. There was no impact on the consolidated financial statements upon the adoption of ASU 2016-01 as of the effective date or as of and for the period ended September 30, 2018. Effective January 1, 2018, the Company retrospectively adopted ASU 2016-15, Statement of Cash Flows (Topic 230), Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) ("ASU 2016-15"). ASU 2016-15 clarifies how entities should classify certain cash receipts and cash payments on the statement of cash flows. The guidance also clarifies how the predominance principle should be applied when cash receipts and cash payments have aspects of more than one class of cash flows. There was no impact on the consolidated statements of cash flows upon the adoption of ASU 2016-15. Effective January 1, 2018, the Company adopted ASU 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting . ("ASU 2017-09"). ASU 2017-09 specifies the types of changes to the terms or conditions of a share-based payment award that require an entity to apply modification accounting in accordance with Topic 718. The adoption of ASU 2017-09 did not have an impact on the Company's consolidated financial statements. Effective January 1, 2018, the Company adopted ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory ("ASU 2016-16"). ASU 2016-16 requires than an entity recognized the income tax effects of an intra-entity transfer of an asset, other than inventory, when the transfer occurs as opposed to when the asset is sold to a third party. The adoption of this guidance did not have an impact on the Company's consolidated financial statements. Accounting Standards Issued and Not Yet Adopted In February 2016, the FASB issued ASU 2016-02, Leases ("ASU 2016-02"). ASU 2016-02 and its related amendments (collectively referred to as ASC 842) requires lessees to recognize the assets and liabilities on their balance sheet for the rights and obligations created by most leases and continue to recognize expenses on their income statements over the lease term. ASC 842 will also require disclosures designed to give financial statement users information on the amount, timing, and uncertainty of cash flows arising from leases. The guidance is effective for annual reporting periods beginning after December 15, 2018, and interim periods within those years. While the Company continues to assess all potential impacts of the standard and its method of adoption, the Company expects to record right-of-use assets, with an associated amount recorded to lease obligations, on its balance sheet primarily related to its leased office and warehousing space. While the Company expects that the adoption of this standard will require updates to its processes and internal controls over financial reporting, the Company has concluded that it will not be required to implement new information systems to account for its lease portfolio. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment ("ASU 2017-04"). ASU 2017-04 simplifies the accounting for goodwill impairments by eliminating "Step 2" from the goodwill impairment test, which requires an entity to calculate the implied fair value of goodwill to measure a goodwill impairment charge, and alternatively, requires an entity to measure the impairment of goodwill assigned to a reporting unit as the amount by which the carrying value of the assets and liabilities of the reporting unit, including goodwill, exceeds the reporting unit's fair value. The guidance is effective for annual reporting periods beginning after December 15, 2019, and interim periods within those years. Early adoption is permitted for all entities. The Company is currently evaluating the impact of ASU 2017-04 but does not expect it to be material to the consolidated financial statements. In August 2017, the FASB issued ASU 2017-12, Targeted Improvements to Accounting for Hedging Activities ("ASU 2017-12"). ASU 2017-12 updates the current hedge accounting guidance with the objective of improving the financial reporting of hedging activities by better portraying the economic results of an entity's risk management activities in its financial statements. The new guidance is effective for the Company on January 1, 2019 and early adoption is permitted. As the Company currently does not use derivative financial instruments, this guidance is not expected to impact on Company's financial statements upon adoption. In August 2018, the FASB issued ASU 2018-13, Changes to the Disclosure Requirements for Fair Value Measurement ("ASU 2018-13"). ASU 2018-13 modifies certain disclosure requirements related to fair value measurements primarily associated with Level 3 investments. The guidance is effective no later than January 1, 2020 for the Company and can be early-adopted prospectively in any interim period for certain disclosure requirements or retrospectively for others. The Company does not expect the adoption of this guidance to have a material impact on its fair value disclosures. In August 2018, the FASB issued ASU 2018-15, Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract ("ASU 2018-15"). ASU 2018-15 requires that entities capitalize certain costs to implement a cloud computing arrangement that is service contract consistent with the rules applicable to internal use software capitalization projects. The guidance is effective no later than January 1, 2020 for the Company and can be early-adopted prospectively in any interim period or retrospectively. The Company is evaluating when and how it will adopt this new guidance. Upon adoption, the Company would defer eligible costs related to the implementation of cloud computing arrangements within other current and non-current assets and amortize these costs to the same income statement line as the associated hosting fees.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customers	Revenue from Contracts with Customers The Company adopted ASC 606 on January 1, 2018 using the modified retrospective method for all contracts not completed as of the date of adoption. Under this method, the new guidance was applied to contracts that were not yet completed as of January 1, 2018 with the cumulative effect of initially applying the guidance recognized through accumulated deficit as the date of initial application. For contracts that were modified before the effective date, the Company reflected the aggregate effect of all modifications when identifying performance obligations and allocating transaction price, which did not have a material effect on the adjustment to accumulated deficit. The reported results for 2018 reflect the application of ASC 606 guidance while the reported results for 2017 were prepared under the guidance of ASC 605, Revenue Recognition (ASC 605), which is also referred to herein as the "previous guidance". The adoption of ASC 606 represents a change in accounting principle that primarily impacts how revenue is recognized for the Company's drug delivery product line and how the Company accounts for contract acquisition costs such as commissions. In accordance with ASC 606, revenue is recognized when a customer obtains control of the promised products. The amount of revenue recognized reflects the consideration to which the Company expects to be entitled to receive in exchange for these products. To achieve this core principle, the Company applies the following five steps as outlined in ASC 606: 1) Identify the contract with a customer; 2) Identify the performance obligations in the contract; 3) Determine the transaction price; 4) Allocate the transaction price to performance obligations in the contract; 5) Recognize revenue when or as the Company satisfies a performance obligation. The following table summarizes revenue from contracts with customers for the three and nine months ended September 30, 2018 and 2017: Three months Nine months (in thousands) 2018 2017 2018 2017 U.S. Omnipod $ 81,970 $ 70,065 $ 230,289 $ 195,081 International Omnipod 50,214 32,481 117,127 84,200 Drug Delivery 18,892 19,229 51,500 53,963 Total $ 151,076 $ 121,775 $ 398,916 $ 333,244 U.S. and International Omnipod The Company generates the majority of its revenue from sales of its Omnipod, which is sold in the U.S., Europe, Canada and Israel. The Omnipod is sold either directly to end users or indirectly through intermediaries, such as independent distributors who resell the Omnipod to end users or wholesalers who sell the Company's product to end users through the pharmacy channel. • Contracts with Customers. The Company's contracts with its direct customers generally consist of a physician order form, a patient information form and, if applicable, third-party insurance (payor) approval. Contracts with the Company's intermediaries are generally in the form of master service agreements against which firm purchase orders are issued. At the outset of the contract, the Company assesses the customer’s ability and intention to pay, which is based on a variety of factors including historical payment experience or, in the case of a new intermediary, published credit, credit references and other available financial information pertaining to the customer and in the case of a new direct customer, an investigation of insurance eligibility. • Performance Obligations. The performance obligations in contracts for the delivery of the Omnipod to new end users, either directly to end users or through intermediaries, primarily consist of the PDM and the initial and subsequent quantity of Pods ordered. To the extent a contract includes multiple promised items, the Company must apply judgment to determine whether promised items are capable of being distinct and distinct in the context of the contract. If these criteria are not met, the promised services are accounted for as a combined performance obligation. • Transaction Price. The price charged for the PDM and Pods is dependent on the Company's pricing as established with third party payors and intermediaries. The Company provides a right of return for sales of its Omnipod to new patients. The Company also provides for certain rebates and discounts for sales of its product through intermediaries. These rights of return, discounts and rebates represent variable consideration and reduce the transaction price at the outset of the contract based on the Company's estimates, which are primarily based on the expected value method using historical and other data related to actual product returns, discounts and rebates paid in each market in which the Omnipod is sold. Variable consideration is included in the transaction price if, in the Company’s judgment, it is probable that a significant future reversal of cumulative revenue under the contract will not occur. There were no constraints recorded to variable consideration and none of the Company's contracts as of January 1, 2018 or September 30, 2018 contained a significant financing component. • Allocation of Transaction Price. The Company allocates the transaction price to each performance obligation based on its relative stand-alone selling price, which is determined based on the price at which the Company typically sells the deliverable or, if the performance obligation is not typically sold separately, the stand-alone selling price is estimated based on cost plus a reasonable profit margin or the price that a third party would charge for a similar product or service. • Recognition of Revenue. The Company transfers the Omnipod at a point in time, which is determined based on when the customer gains control of the product. Generally, intermediaries in the U.S. obtain control upon shipment based on the contractual terms including right to payment and transfer of title and risk of loss. For sales directly to end users and international intermediaries, control is generally transferred at the time of delivery based on customary business practices related to risk of ownership. Drug Delivery The Company's drug delivery product line includes sales of a modified version of the Omnipod to pharmaceutical and biotechnology companies who use the Company’s technology as a delivery method for their drugs. Under ASC 606, for the majority of this product line, revenue is recognized as the product is produced pursuant to the customer’s firm purchase commitments as the Company has an enforceable right to payment for performance completed to date and the inventory has no alternative use to the Company. Judgment is required in the assessment of progress toward completion of in-process inventory. The Company recognizes revenue over time using a blend of costs incurred to date relative to total estimated costs at completion and time incurred to date relative to total production time to measure progress toward the satisfaction of its performance obligations. The Company believes that both incurred cost and elapsed time reflect the value generated, which best depicts the transfer of control to the customer. Contract costs include third party costs as well as an allocation of manufacturing overhead. Changes from quarter to quarter in quantity and stage of production of in-process inventory could have a significant quarterly impact on revenue. Financial Statement Impact of Adopting ASC 606 The cumulative effect of applying the new guidance to all contracts with customers that were not completed as of January 1, 2018 was recorded as an adjustment to accumulated deficit as of the adoption date. The following table shows the adjustments made to accounts on the consolidated balance sheet as of January 1, 2018 as a result of adopting the new guidance. The table also compares the reported consolidated balance sheet accounts as of September 30, 2018 that were impacted by the new guidance to pro forma balance sheet amounts had the previous guidance been in effect. As Reported Adjustments As Adjusted As Reported Adjustments Pro forma (in thousands) 12/31/2017 1/1/2018 1/1/2018 9/30/2018 9/30/2018 9/30/2018 Unbilled receivable (a) $ — $ 5,119 $ 5,119 $ 9,963 $ (9,963 ) $ — Inventories 33,793 (753 ) 33,040 58,050 1,430 59,480 Prepaid expenses and other current assets (b) 9,949 5,568 15,517 17,905 (6,869 ) 11,036 Total current assets 537,171 9,934 547,105 445,712 (15,402 ) 430,310 Other assets (b) 1,969 13,326 15,295 18,057 (15,567 ) 2,490 Total assets 816,744 23,260 840,004 886,306 (30,969 ) 855,337 Deferred revenue (c) 2,356 2,625 4,981 2,210 (771 ) 1,439 Total current liabilities 86,025 2,625 88,650 97,224 (771 ) 96,453 Other long-term liabilities 6,030 271 6,301 6,668 (270 ) 6,398 Total liabilities 658,228 2,896 661,124 688,377 (1,041 ) 687,336 Accumulated deficit (707,255 ) 20,349 (686,906 ) (693,507 ) (29,937 ) (723,444 ) Total stockholders' equity 158,516 20,364 178,880 197,929 (29,928 ) 168,001 Total liabilities and stockholders' equity 816,744 23,260 840,004 886,306 (30,969 ) 855,337 (a) Unbilled receivable that reflects revenue for a portion of the Company's drug delivery product line as the product is produced. The unbilled receivable is reclassified to accounts receivable as the product is completed and shipped to the customer. (b) Other current and non-current assets include contract acquisition costs related to the sale of the Omnipod. These costs are amortized over the estimated period of benefit. (c) The adoption of ASC 606 required the Company to record a contract liability, or deferred revenue, on January 1, 2018, primarily associated with a volume-based pricing discount granted to the Company's European Distributor at the outset of the distribution contract in 2010. The deferred revenue was recognized as revenue through the completion of the distributor contract during the first half of 2018. The following summarizes the significant changes on the Company’s consolidated statement of operations for the three and nine months ended September 30, 2018 as a result of the adoption of ASC 606 on January 1, 2018 compared to if the Company had continued to recognize revenue under ASC 605: Three months ended September 30, 2018 Nine months ended September 30, 2018 (in thousands, except per share amounts) As reported Adjustments Pro forma As reported Adjustments Pro forma U.S. Omnipod $ 81,970 $ (135 ) $ 81,835 $ 230,289 $ (9 ) $ 230,280 International Omnipod (a) 50,214 53 50,267 117,127 (1,845 ) 115,282 Drug Delivery (b) 18,892 3,995 22,887 51,500 (4,844 ) 46,656 Revenue 151,076 3,913 154,989 398,916 (6,698 ) 392,218 Cost of revenue 49,107 674 49,781 139,060 (677 ) 138,383 Gross profit 101,969 3,239 105,208 259,856 (6,021 ) 253,835 Sales and marketing (c) 34,922 394 35,316 102,660 3,567 106,227 Total operating expenses 95,104 394 95,498 248,666 3,567 252,233 Operating income 6,865 2,845 9,710 11,190 (9,588 ) 1,602 Income (loss) before income taxes 1,853 2,845 4,698 (5,662 ) (9,588 ) (15,250 ) Net income (loss) $ 1,659 $ 2,845 $ 4,504 $ (6,601 ) $ (9,588 ) $ (16,189 ) Net income (loss) per share: basic $ 0.03 $ 0.05 $ 0.08 $ (0.11 ) $ (0.17 ) $ (0.28 ) Net income (loss) per shares: diluted $ 0.03 $ 0.04 $ 0.07 $ (0.11 ) $ (0.17 ) $ (0.28 ) (a) International Omnipod revenue under ASC 606 includes the amortization of a material right associated with a volume-based pricing discount granted to the Company's European Distributor at the outset of the distribution contract in 2010. The deferred revenue was recognized as revenue through the completion of the distributor contract during the first half of 2018. (b) ASC 606 accelerated the recognition of revenue and fulfillment costs related to certain drug delivery contracts for which recognition was previously recorded when the product was shipped to the customer and is recorded as the product is produced under ASC 606. During the three and nine months ended September 30, 2018, revenue was lower by $4.0 million and higher by $4.8 million , respectively, due to changes in quantity and stage of production of in-process inventory relative to the prior period. (c) ASC 606 resulted in the amortization of capitalized commission costs that were recorded as part of the cumulative effect adjustment upon adoption and during the nine months ended September 30, 2018. Amortization of these capitalized costs to selling and marketing expenses, net of commission costs that were capitalized in the three and nine month periods, reduced sales and marketing expenses in each period . Nine Months Ended September 30, 2018 Statement of Cash Flows (in thousands) As Reported Adjustments Pro Forma Net loss $ (6,601 ) $ (9,588 ) $ (16,189 ) Adjustments to reconcile net loss to net cash used in operating activities Non-cash items 66,602 — 66,602 Changes in operating assets and liabilities: — Accounts receivable and unbilled receivable (24,581 ) 4,844 (19,737 ) Inventories (25,279 ) (677 ) (25,956 ) Prepaid expenses and other assets (5,258 ) 3,567 (1,691 ) Accounts payable, accrued expenses and other current liabilities 2,938 — 2,938 Deferred revenue (2,761 ) 1,854 (907 ) Other long-term liabilities 400 — 400 Net cash provided by operating activities $ 5,460 $ — $ 5,460 The adoption of ASC 606 had no net impact on the Company’s cash used in operating, investing or financing activities. Revenue recognized during the three and nine months ended September 30, 2018 from amounts included in deferred revenue at the beginning of the period was approximately $0.6 million and $2.5 million , respectively. No revenue was recognized during the three and nine months ended September 30, 2018 from performance obligations satisfied or partially satisfied in previous periods. As of September 30, 2018, unbilled receivable associated with the Company's drug delivery product line increased by $4.8 million relative to the beginning of the year due to an increase in the quantity and stage of production of in-process inventory during the year. There were no contract modifications entered into during the three and nine months ended September 30, 2018 impacting the Company’s unbilled receivable or deferred revenue. Revenue for customers comprising more than 10% of total revenue were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Amgen, Inc. 12% 16% 13% 16% Ypsomed and affiliates * 23% 11% 21% Cardinal Health Inc. and affiliates 12% 11% 12% 10% * Represents less than 10% of consolidated revenue.

Investments and Fair Value

Investments and Fair Value	9 Months Ended
	Sep. 30, 2018
Short-term Investments [Abstract]
Investment and Fair Value	Investments and Fair Value Cash and Cash Equivalents: For the purpose of financial statement classification, the Company considers all highly-liquid investment instruments with original maturities of 90 days or less, when purchased, to be cash equivalents. Cash equivalents include money market mutual funds, corporate bonds, U.S. government and agency bonds, and certificates of deposit, and are carried at cost which approximates their fair value. Included in the Company's cash and cash equivalents are restricted cash amounts set aside for collateral on outstanding letters of credit totaling $2.7 million as of September 30, 2018 and $0.5 million as of December 31, 2017 . Marketable Securities: The Company's short-term and long-term investments in debt securities have maturity dates that range from 11 days to 23.9 months as of September 30, 2018 . The Company’s investment portfolio included approximately 75 available-for-sale debt securities that had insignificant unrealized loss positions as of September 30, 2018. The Company has the intent and ability to hold these investments until maturity whereby these unrealized losses are expected to be recovered. There were no charges recorded in the period for other-than-temporary declines in the fair value of available-for-sale debt securities. The Company's investments had insignificant realized gains or losses for the nine months ended September 30, 2018 . To measure fair value of assets and liabilities required to be measured or disclosed at fair value, the Company uses the following fair value hierarchy based on three levels of inputs of which the first two are considered observable and the last unobservable: Level 1 — quoted prices in active markets for identical assets or liabilities; Level 2 — observable inputs other than quoted prices in active markets for identical assets or liabilities; Level 3 — unobservable inputs in which there is little or no market data available, which require the reporting entity to develop its own assumptions. The Company had no Level 3 assets or liabilities as of September 30, 2018. The following table provides amortized cost, gross unrealized gains and loses, fair value and the level in the fair value hierarchy within which those measurements fall: (in thousands) Amortized cost Gross Unrealized Gains (Losses) Fair Value Level 1 Level 2 September 30, 2018 Money market mutual funds $ 66,141 $ — $ 66,141 $ 66,141 $ — Total cash equivalents $ 66,141 $ — $ 66,141 $ 66,141 $ — U.S. government and agency bonds $ 120,832 $ (444 ) $ 120,388 $ 77,128 $ 43,260 Corporate bonds 38,897 (108 ) 38,789 — 38,789 Certificates of deposit 4,104 — 4,104 — 4,104 Total short-term investments $ 163,833 $ (552 ) $ 163,281 $ 77,128 $ 86,153 U.S. government and agency bonds $ 96,038 $ (646 ) $ 95,392 $ 73,652 $ 21,740 Corporate bonds 44,808 (245 ) 44,563 — 44,563 Certificates of deposit 5,584 — 5,584 — 5,584 Total long-term investments $ 146,430 $ (891 ) $ 145,539 $ 73,652 $ 71,887 December 31, 2017 Money market mutual funds $ 236,936 $ — $ 236,936 $ 236,936 $ — U.S government and agency bonds $ 5,000 — $ 5,000 $ 5,000 — Total cash equivalents $ 241,936 $ — $ 241,936 $ 241,936 $ — U.S. government and agency bonds $ 112,311 $ (235 ) $ 112,076 $ 90,703 $ 21,373 Corporate bonds 47,713 (32 ) 47,681 — 47,681 Certificates of deposit 7,722 — 7,722 — 7,722 Total short-term investments $ 167,746 $ (267 ) $ 167,479 $ 90,703 $ 76,776 U.S. government and agency bonds $ 92,677 $ (213 ) $ 92,464 $ 49,651 $ 42,813 Corporate bonds 27,871 (59 ) 27,812 — 27,812 Certificates of deposit 5,273 — 5,273 — 5,273 Total long-term investments $ 125,821 $ (272 ) $ 125,549 $ 49,651 $ 75,898

Convertible Debt, Net

Convertible Debt, Net	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Convertible Debt, Net	Convertible Debt, Net The Company had outstanding convertible debt and related debt issuance costs on its consolidated balance sheet as follows: As of (in thousands) September 30, 2018 December 31, 2017 Principal amount of 2.0% Convertible Senior Notes, due June 2019 $ — $ 3,664 Principal amount of 1.25% Convertible Senior Notes, due September 2021 344,992 345,000 Principal amount of 1.375% Convertible Senior Notes, due November 2024 402,500 402,500 Unamortized debt discount (150,439 ) (170,448 ) Debt issuance costs (12,568 ) (14,543 ) Total convertible debt, net $ 584,485 $ 566,173 Interest expense related to the convertible debt was as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Contractual coupon interest $ 2,440 $ 1,449 $ 7,382 $ 4,276 Accretion of debt discount 6,702 3,612 19,840 10,690 Amortization of debt issuance costs 661 505 1,950 1,495 Total interest expense related to convertible debt $ 9,803 $ 5,566 $ 29,172 $ 16,461 Interest expense related to convertible debt for the three and nine months ended September 30, 2018 is as follows: Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 (in thousands) 1.375% 1.25% Total 1.375% 1.25% 2.0% Total Contractual coupon interest $ 1,362 $ 1,078 $ 2,440 $ 4,129 $ 3,234 $ 19 $ 7,382 Amortization of debt discount and issuance costs 3,736 3,627 7,363 11,001 10,729 60 21,790 Total interest expense $ 5,098 $ 4,705 $ 9,803 $ 15,130 $ 13,963 $ 79 $ 29,172 Interest expense related to convertible debt for the three and nine months ended September 30, 2017 is as follows: Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (in thousands) 1.25% 2.0% Total 1.25% 2.0% Total Contractual coupon interest $ 1,102 $ 347 $ 1,449 $ 3,259 $ 1,017 $ 4,276 Amortization of debt discount and issuance costs 3,403 714 4,117 10,073 2,112 12,185 Total interest expense $ 4,505 $ 1,061 $ 5,566 $ 13,332 $ 3,129 $ 16,461 The carrying amount and the estimated fair value of the Company's convertible debt, which is based on the Level 2 quoted market prices as of September 30, 2018 and December 31, 2017 are as follows: As of September 30, 2018 December 31, 2017 (in thousands) Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value 2% Convertible Senior Notes, due June 2019 $ — $ — $ 3,421 $ 5,467 1.375% Convertible Senior Notes, due November 2024 287,183 515,627 276,172 407,652 1.25% Convertible Senior Notes, due September 2021 297,302 630,041 286,580 450,881 Total $ 584,485 $ 1,145,668 $ 566,173 $ 864,000 1.375% Convertible Senior Notes In November 2017, the Company issued and sold $402.5 million in aggregate principal amount of 1.375% Convertible Senior Notes, due November 15, 2024 (the " 1.375% Notes"). The interest rate on the notes is 1.375% per annum, payable semi-annually in arrears in cash on May 15 and November 15 of each year. Interest began accruing on November 10, 2017 and the first interest payment was made on May 15, 2018. The 1.375% Notes are convertible into the Company’s common stock at an initial conversion rate of 10.7315 shares of common stock per $1,000 principal amount of the 1.375% Notes, which is equivalent to a conversion price of approximately $93.18 per share, subject to adjustment under certain circumstances. The 1.375% Notes will be convertible prior to the close of business on the business day immediately preceding August 15, 2024 only under certain circumstances and during certain periods, and will be convertible on or after August 15, 2024 until the close of business on the second scheduled trading day immediately preceding November 15, 2024, regardless of those circumstances. The Company recorded a debt discount of $120.7 million related to the 1.375% Notes resulting from the allocation of a portion of the proceeds to the fair value of the conversion feature reflecting a nonconvertible debt borrowing rate of 6.8% per annum. The debt discount was recorded as additional paid-in capital and is being amortized as non-cash interest expense over the seven year term of the 1.375% Notes. The Company also incurred debt issuance costs and other expenses related to the 1.375% Notes of approximately $10.9 million , of which $3.3 million was reclassified as a reduction to the value of the conversion feature allocated to equity. The remaining $7.6 million of debt issuance costs is presented as a reduction of debt in the consolidated balance sheet and is being amortized using the effective interest method as non-cash interest expense over the seven year term of the 1.375% Notes. As of September 30, 2018 , the Company included $287.2 million on its balance sheet in long-term debt related to the 1.375% Notes. 1.25% Convertible Senior Notes In September 2016, the Company issued and sold $345.0 million in principal amount of 1.25% Convertible Senior Notes, due September 15, 2021 (the " 1.25% Notes"). The interest rate on the notes is 1.25% per annum, payable semi-annually in arrears in cash on March 15 and September 15 of each year. The 1.25% Notes are convertible into the Company’s common stock at an initial conversion rate of 17.1332 shares of common stock per $1,000 principal amount of the 1.25% Notes, which is equivalent to a conversion price of approximately $58.37 per share, subject to adjustment under certain circumstances. The 1.25% Notes will be convertible prior to the close of business on the business day immediately preceding June 15, 2021 only under certain circumstances and during certain periods, and will be convertible on or after June 15, 2021 until the close of business on the second scheduled trading day immediately preceding September 15, 2021, regardless of those circumstances. The Company recorded a debt discount of $ 66.7 million related to the 1.25% Notes resulting from allocating a portion of the proceeds to the fair value of the conversion feature reflecting a nonconvertible debt borrowing rate of 5.8% per annum. The debt discount is being amortized as non-cash interest expense over the five year term of the 1.25% Notes. The Company incurred debt issuance costs and other expenses related to this offering of approximately $11.3 million , of which $2.2 million was reclassified as a reduction to the value of the amount allocated to equity. The remainder is presented as a reduction of debt in the consolidated balance sheet and is being amortized using the effective interest method as non-cash interest expense over the five year term of the 1.25% Notes. As of September 30, 2018 , the Company has $297.3 million , net of discounts and issuance costs, on its balance sheet in long-term debt related to the 1.25% Notes. 2% Convertible Senior Notes In June 2014, the Company issued and sold $201.3 million in principal amount of 2% Convertible Senior Notes due June 15, 2019 (the " 2% Notes"). The 2% Notes were convertible into the Company’s common stock at an initial conversion rate of 21.5019 shares of common stock per $1,000 principal amount of the 2% Notes, which is equivalent to a conversion price of approximately $46.51 per share. In separately negotiated transactions, the Company repurchased $134.2 million in principal of the notes in September 2016 and $63.4 million in principal of the notes in November 2017. The Company elected to call the remaining notes in March 2018 and settled the outstanding principal and conversion feature of the notes for $6.7 million in cash in the second quarter of 2018. The Company allocated approximately $3.2 million of the settlement to the fair value of the equity component and $3.5 million to the debt component, which was consistent with the carrying value of the notes as of the settlement date, resulting in no gain or loss on extinguishment.

Accounts Receivable, Net

Accounts Receivable, Net	9 Months Ended
	Sep. 30, 2018
Receivables [Abstract]
Accounts Receivable, Net	Accounts Receivable, Net Accounts receivable consist of amounts due from third-party payors, patients and third-party intermediaries. The Company records an allowance for doubtful accounts at the time potential collection risk is identified. The Company estimates its allowance based on historical experience, assessment of specific risk, and discussions with individual customers. The Company believes the reserve is adequate to mitigate current collection risk. There were no customers that represented greater than 10% of gross accounts receivable as of September 30, 2018 . The components of accounts receivable are as follows: As of (in thousands) September 30, 2018 December 31, 2017 Trade receivables $ 73,428 $ 55,914 Allowance for doubtful accounts (3,478 ) (2,541 ) Total accounts receivable, net $ 69,950 $ 53,373

Net Income (Loss) Per Share

Net Income (Loss) Per Share	9 Months Ended
	Sep. 30, 2018
Disclosure Potential Common Shares Excluded From Computation Of Diluted Net Loss Per Share [Abstract]
Net Income (Loss) Per Share	Net Income (Loss) Per Share Basic net income (loss) per share is computed by dividing net income (loss) by the weighted average number of common shares outstanding for the period, excluding unvested restricted common shares. Diluted net income (loss) per share is computed using the weighted average number of common shares outstanding and, when dilutive, potential common share equivalents from outstanding stock options and restricted stock units (using the treasury-stock method), and potential common shares from the Company's convertible debt (using the if-converted method). The following table sets forth the components used in the computation of basic and diluted net income (loss) per share for the three and nine months ended September 30, 2018. Because the Company reported a net loss for the three and nine months ended September 30, 2017, all potential dilutive common shares have been excluded from the computation of the diluted net loss per share for the three and nine months ended September 30, 2017, as the effect would have been anti-dilutive. September 30, 2018 (in thousands, except share and per share data) Three months ended Nine months ended Numerator: Net income (loss) $ 1,659 $ (6,601 ) Denominator: Weighted average common shares outstanding 59,016,863 58,779,672 Effective of dilutive potential common share equivalents Stock options 1,719,796 — Restricted stock units 409,807 — Convertible debt — — Shares used for diluted net income (loss) per share 61,146,466 58,779,672 Net income (loss) per share: Basic $ 0.03 $ (0.11 ) Diluted $ 0.03 $ (0.11 ) For the three months ended September 30, 2018, certain potential outstanding shares from stock options, restricted stock units and convertible debt were excluded from the computation of diluted net income per share because the effect of including these items was anti-dilutive. Additionally, certain performance-based restricted stock units were excluded from the computation of diluted net income per share because the underlying performance conditions for such restricted stock units had not been met as of these dates. The number of potential common share equivalents excluded from the computation of diluted net income (loss) per share for the three and nine months ended September 30, 2018 and 2017 are as follows: Three Months Ended September 30, Nine Months Ended September 30, Three and Nine Months Ended September 30, 2018 2018 2017 1.375% Convertible Senior Notes 4,319,429 4,319,429 — 2.00% Convertible Senior Notes — — 1,442,433 1.25% Convertible Senior Notes 5,910,954 5,910,954 5,910,954 Unvested restricted stock units 300,438 865,206 1,007,729 Outstanding stock options 223,183 3,117,326 3,489,393 Total potential common share equivalents excluded from computation of diluted net income (loss) per share 10,754,004 14,212,915 11,850,509

Inventories

Inventories	9 Months Ended
	Sep. 30, 2018
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories are carried at the lower of cost or market, determined under the first-in, first-out method, and include the costs of material, labor and overhead. Inventory has been recorded at cost, or net realizable value as appropriate, as of September 30, 2018 and December 31, 2017 . The Company reviews inventories for net realizable value based on quantities on hand and expectations of future use. Work in process is calculated based upon a buildup in the stage of completion using estimated labor inputs for each stage in production. The components of inventories are as follows: As of (in thousands) September 30, 2018 December 31, 2017 Raw materials $ 5,390 $ 2,146 Work-in-process 17,187 23,918 Finished goods, net 35,473 7,729 Total inventories $ 58,050 $ 33,793

Prepaid Expenses and Other Asse

Prepaid Expenses and Other Assets (Notes)	9 Months Ended
	Sep. 30, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Assets	Prepaid Expenses and Other Assets The components of prepaid expenses and other current assets are as follows: As of (in thousands) September 30, 2018 December 31, 2017 Prepaid expenses and other current assets $ 11,036 $ 9,949 Capitalized contract acquisition costs, current portion 6,869 — Total prepaid expenses and other current assets $ 17,905 $ 9,949 The components of other assets are as follows: As of (in thousands) September 30, 2018 December 31, 2017 Other assets $ 2,487 $ 1,969 Capitalized contract acquisition costs, net of current portion 15,570 — Total other assets $ 18,057 $ 1,969 The Company capitalizes commission costs that are related to new patient starts. These costs are deferred in other assets, net of the short term portion included in prepaid and other current assets. Costs to obtain a contract are amortized as sales and marketing expense on a straight line basis over the expected period of benefit, which considers future product upgrades for which a commission would be paid. These capitalized costs are periodically reviewed for impairment. As of September 30, 2018, capitalized contract acquisition costs were $22.4 million , including a current balance of $6.9 million and a non-current balance of $15.6 million . The Company recognized $5.0 million of amortization of capitalized commission costs during the nine months ended September 30, 2018. There were no impairments to capitalized costs to obtain a contract recorded during the period.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets, Net	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Other Intangible Assets, Net	Other Intangible Assets, Net Goodwill The Company has $39.8 million of goodwill on its balance sheet from prior business acquisitions. The Company performs an assessment of its goodwill for impairment on at least an annual basis or whenever events or changes in circumstances indicate there might be an impairment. The Company's annual impairment test date is October 1st. There was no impairment of goodwill during the three and nine months ended September 30, 2018 . Intangible Assets, Net The Company’s finite-lived intangible assets are stated at cost less accumulated amortization and include customer relationships acquired in prior business acquisitions and from the Company's former European Distributor. See Note 12 for a discussion of the Company's accounting for estimated fees owed to its former European Distributor following the expiration of its distribution agreement on June 30, 2018. The components of other intangible assets are as follows: As of September 30, 2018 December 31, 2017 (in thousands) Gross Carrying Amount Accumulated Amortization Net Book Value Gross Carrying Amount Accumulated Amortization Net Book Value Customer and contractual relationships $ 4,078 $ (1,859 ) $ 2,219 $ 2,135 $ (1,764 ) $ 371 Internal-use software 10,271 (4,699 ) 5,572 7,545 (3,565 ) 3,980 Total intangible assets $ 14,349 $ (6,558 ) $ 7,791 $ 9,680 $ (5,329 ) $ 4,351 Amortization expense for intangible assets was approximately $0.5 million and $0.3 million for the three months ended September 30, 2018 and 2017 , respectively. Amortization expense for intangible assets was approximately $1.3 million and $0.8 million for the nine months ended September 30, 2018 and 2017 , respectively. Amortization expense is recorded in general and administrative expenses in the consolidated statements of operations. Amortization expense expected for the next five years and thereafter is as follows: (in thousands) Years Ending December 31, Customer and Contractual Relationships Internal-Use Software Total 2018 (remaining) $ 90 $ 465 $ 555 2019 334 1,767 2,101 2020 266 1,505 1,771 2021 200 1,080 1,280 2022 200 571 771 Thereafter 1,129 184 1,313 Total $ 2,219 $ 5,572 $ 7,791 As of September 30, 2018 , the weighted average amortization period of the Company’s customer and contractual relationships intangible assets and internal-use software intangible assets are approximately 9.1 years and 3.5 years , respectively.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities (Notes)	9 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities The components of accrued expenses and other current liabilities are as follows: As of (in thousands) September 30, 2018 December 31, 2017 Employee compensation and related costs $ 32,265 $ 34,942 Professional and consulting services 10,190 9,273 Supplier charges 3,863 3,542 Warranty 2,303 1,653 Other 19,548 9,846 Total accrued expenses and other current liabilities $ 68,169 $ 59,256 Product Warranty Costs The Company generally provides a four -year warranty on its PDMs sold in the United States and Europe and a five -year warranty on its PDMs sold in Canada and may replace any Omnipod that does not function in accordance with product specifications. The Company estimates its warranty at the time the product is shipped based on historical experience and the estimated cost to service the claims. Warranty expense is recorded in cost of goods sold on the statement of operations. Cost to service the claims reflects the current product cost. As these estimates are based on historical experience, and the Company continues to introduce new products and versions, the Company also considers the anticipated performance of the product over its warranty period in estimating warranty reserves. A reconciliation of the changes in the Company’s product warranty liability is as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Product warranty liability at the beginning of the period $ 5,503 $ 4,817 $ 5,337 $ 4,388 Warranty expense 1,763 1,483 5,264 3,123 Warranty claims settled (1,548 ) (1,303 ) (4,883 ) (2,514 ) Product warranty liability at the end of the period $ 5,718 $ 4,997 $ 5,718 $ 4,997 Composition of balance: As of (in thousands) September 30, 2018 December 31, 2017 Short-term $ 2,303 $ 1,653 Long-term 3,415 3,684 Total warranty liability: $ 5,718 $ 5,337

Commitments and Contingencies (

Commitments and Contingencies (Notes)	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings Between May 5, 2015 and June 16, 2015, three class action lawsuits were filed by shareholders in the U.S. District Court, for the District of Massachusetts, against the Company and certain individual current and former executives of the Company. Two suits subsequently were voluntarily dismissed. Arkansas Teacher Retirement System v. Insulet, et al., 1:15-cv-12345, (“ATRS”) alleged that the Company (and certain executives) committed violations of Sections 10(b) and 20(a) and Rule 10b-5 of the Securities Exchange Act of 1934 by making allegedly false and misleading statements about the Company’s business, operations, and prospects. On February 8, 2018, the parties executed a binding stipulation of settlement, under which all claims were released and a payment was made to the plaintiffs and the class they purport to represent. On August 6, 2018, the Court issued an order finally approving the settlement. The Company had previously accrued fees and expenses in connection with this matter for the amount of the final settlement liability that was not covered by insurance, which amount was not material to the Company's consolidated financial statements. In addition, on April 26, 2017, a derivative action (Walker v. DeSisto, et al., 1:17-cv-10738) (“Walker”) was filed, and on October 13, 2017, a second derivative action (Carnazza v. DeSisto, et al., 1:17-cv-11977) (“Carnazza”) was filed, both on behalf of the Company, each by a shareholder in the U.S. District Court for the District of Massachusetts against the Company (as a nominal defendant) and certain individual current and former officers and directors of the Company. The allegations in the actions are substantially similar to those alleged in the securities class action. The actions seek, among other things, damages, disgorgement of certain types of compensation or profits, and attorneys’ fees and costs. On July 11, 2018, the parties executed a binding stipulation of settlement, under which all claims were released and a payment of attorneys’ fees and reimbursement of expenses will be paid to plaintiffs’ counsel, subject to the Court’s approval. On July 13, 2018, the plaintiffs filed a motion for preliminary approval of the settlement, which is pending. The Company expects that such fees and expenses payable to plaintiff's counsel will be covered by the Company's insurance. The Company is, from time to time, involved in the normal course of business in various legal proceedings, including intellectual property, contract, employment and product liability suits. Although the Company is unable to quantify the exact financial impact of any of these matters, the Company believes that none of these currently pending matters will have an outcome material to its financial condition or business. Fees To Former European Distributor Following the expiration of its distribution agreement on June 30, 2018, the Company is required to pay to its former European Distributor a quarterly per unit fee for sales of its Omnipod device to identified customers (as that term is defined in the distribution agreement) of the former European Distributor over the twelve months following the expiration of the distribution agreement. The Company is recognizing a liability and an associated intangible asset for this fee as qualifying sales of the Omnipod device are made to these identified customers during the twelve-month period between July 1, 2018 and June 30, 2019. T he actual total fee could vary significantly depending on the number of customers who qualify as eligible to be considered for purposes of calculating the fee under the terms of the distribution agreement, which is under dispute between the parties, and the number of Omnipod devices sold to those customers over the twelve month period. The Company estimates that the total fee could be in the range of approximately $10 million to $55 million over the twelve month period. The Company has accrued approximately $2 million for fees related to Omnipod devices sold to qualifying customers for the three months ended September 30, 2018. Operating Leases The Company leases approximately 100,000 square feet of laboratory and office space for its corporate headquarters in Billerica, Massachusetts. The lease expires in November 2022 and contains escalating payments over the its life. Additionally, the Company leases approximately 29,000 square feet of warehousing space in Billerica, Massachusetts under a lease expiring in September 2019. The Company also leases international and U.S. facilities under leases expiring from October 2018 to June 2021. Rental expense under operating leases was $0.9 million and $2.6 million for the three and nine months ended September 30, 2018, respectively. There have been no material changes to the Company's lease obligation in the nine months ended September 30, 2018.

Stock-Based Compensation and St

Stock-Based Compensation and Stockholder' Equity	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation and Stockholder' Equity	Stock-Based Compensation and Stockholder' Equity The Company grants stock options, and both time-based and performance-based restricted stock units under its 2017 Stock Option and Incentive Plan and offers employees the opportunity to purchase its common stock through an Employee Stock Purchase Plan. The following table reflects the Company's stock-based compensation expense related to share-based awards recognized in the three and nine months ended September 30, 2018 and 2017 : Three Months Ended September 30, Nine Months Ended September 30, Unamortized Expense Weighted Average Remaining Expense Period (Years) ($ in thousands) 2018 2017 2018 2017 At September 30, 2018 Stock options $ 3,957 $ 3,127 $ 8,587 $ 8,815 $ 13,632 2.5 Restricted stock units 11,835 5,621 21,734 14,358 25,054 1.9 Employee stock purchase plan 296 149 884 379 197 0.2 Total $ 16,088 $ 8,897 $ 31,205 $ 23,552 $ 38,883 The following summarizes stock option activity during the nine months ended September 30, 2018 : Number of Options (#) Weighted Average Exercise Price ($) Aggregate Intrinsic Value ($ in thousands) Weighted Average Remaining Contractual Term (Years) Outstanding at December 31, 2017 3,377,220 $ 35.10 Granted 287,199 77.05 Exercised (384,887 ) 33.11 $ 21,419 Cancelled (162,206 ) 40.45 Outstanding at September 30, 2018 3,117,326 $ 38.94 $ 208,898 7.1 Vested, September 30, 2018 2,077,854 $ 34.40 $ 148,671 6.6 Vested or expected to vest, September 30, 2018 (1) 3,019,139 $ 203,882 (1) Represents total outstanding stock options as of September 30, 2018 , adjusted for estimated forfeitures. The following table summarizes the status of the Company’s restricted stock units during the nine months ended September 30, 2018 : Number of Shares (#) Weighted Average Fair Value ($) Outstanding at December 31, 2017 994,364 $ 38.08 Granted 328,342 75.51 Adjustment (1) 147,301 29.54 Vested (526,638 ) 33.59 Forfeited (78,163 ) 44.58 Outstanding at September 30, 2018 865,206 $ 52.98 (1) Certain performance-based restricted stock units are subject to a three -year vesting period subject to meeting performance targets and continued employment. During the three months ended March 31, 2018, the Compensation Committee of the Board of Directors determined that the performance was achieved at 200% of target for certain performance-based awards issued in 2016, resulting in an adjustment to the shares that will ultimately vest for these awards.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company accounts for income taxes in accordance with ASC 740-10, Income Taxes (“ASC 740-10”). The Tax Cuts and Jobs Act ("Tax Reform Act"), which was enacted in December 2017, significantly changed U.S. tax law by, among other things, lowering corporate income tax rates to a flat 21% rate effective January 1, 2018 and imposing a tax on deemed repatriated earnings of foreign subsidiaries. The Company recognized the impact of the Tax Reform Act in the consolidated financial statements as of December 31, 2017. In accordance with Staff Accounting Bulletin No. 118 ("SAB 118"), the Company recorded provisional amounts reflecting the impact of certain requirements of the Tax Reform Act in its consolidated financial statements and related disclosures as of December 31, 2017, including a reduction in net operating losses in 2017 of $0.8 million offset by an associated reduction in the valuation allowance of the $0.8 million related to the deemed repatriation. The deemed repatriation tax computation will be finalized in conjunction with the filing of the Company's federal and state tax returns in the fourth quarter and are not expected to vary significantly from the original estimate. The Tax Reform Act also subjects the Company to current tax on global intangible low-taxed income, or ("GILTI") earned by certain of its foreign subsidiaries. The Company has elected to recognize the income tax related to GILTI as a period expense in the period the tax is incurred or expected to occur for the year ended December 31, 2018. The inclusion of GILTI had no impact on the Company's income tax expense or effective tax rate in the period due to the full valuation allowance applied to the U.S. entity. The Company files federal, state and foreign tax returns. These returns are generally open to examination by the relevant tax authorities from three to four years from the date they are filed. The tax filings relating to the Company's federal and state tax returns are currently open to examination for tax years 2015 through 2016 and 2014 through 2016, respectively. In addition, the Company has generated tax losses since its inception in 2000. These years may be subject to examination if the losses are carried forward and utilized in future years. As of September 30, 2018 and December 31, 2017 , the Company has provided a full valuation allowance against its domestic net deferred tax asset because it is not more likely than not that the future tax benefit will be realized. In addition, the Company has a net deferred tax asset in foreign jurisdictions where no valuation allowance is recorded as it is more likely than not that the future tax benefit will be realized. As of September 30, 2018, the Company had no uncertain tax positions. Income tax expense was $0.2 million and $0.1 million for the three months ended September 30, 2018 and 2017. Income tax expense was $0.9 million and $0.3 million for the nine months ended September 30, 2018 and 2017 , respectively. Income tax expense for both periods in the current year was primarily driven by taxable income generated in foreign jurisdictions, mainly the United Kingdom and Canada.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The unaudited consolidated financial statements in this Quarterly Report on Form 10-Q have been prepared in accordance with generally accepted accounting principles (“U.S. GAAP” or "GAAP") for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, these unaudited consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments, consisting of normal recurring adjustments, considered necessary for a fair presentation have been included. Operating results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the full year ending December 31, 2018 , or for any other subsequent interim period. The unaudited consolidated financial statements in this Quarterly Report on Form 10-Q should be read in conjunction with the Company’s consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 .
Use of Estimates in Preparation of Financial Statements	Use of Estimates in Preparation of Financial Statements The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions in the application of certain of its significant accounting policies that may materially affect the reported amounts of assets, liabilities, equity, revenue and expenses. Actual results may differ from those estimates. See Note 3 related to the Company's adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers, for a discussion of judgments associated with the recognition of revenue and deferral of cost to obtain a contract.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Segment Reporting	Segment Reporting Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated on a regular basis by the chief operating decision-maker ("CODM") in deciding how to allocate resources to an individual segment and in assessing performance of the segment. The Company has concluded its Chief Executive Officer ("CEO") is the CODM as the CEO is the ultimate decision maker for key operating decisions, determining the allocation of resources and assessing the financial performance of the Company. These decisions, allocations and assessments are performed by the CODM using consolidated financial information. The Company’s products are relatively consistent and manufacturing is centralized and consistent across product offerings. Based on these factors, key operating decisions and resource allocations are made by the CODM using consolidated financial data and as such the Company has concluded that it operates as one segment.
Shipping and Handling Costs	Shipping and Handling Costs The Company does not typically charge its customers for shipping and handling costs associated with shipping its product to its customers unless non-standard shipping and handling services are requested.
Recently Adopted and Not Yet Adopted Accounting Pronouncements	Recently Adopted Accounting Standards In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers ("ASU 2014-09"). ASU 2014-09 and its related amendments (collectively referred to as ASC 606) requires that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Under this guidance, an entity makes additional estimates regarding performance conditions and the allocation of variable consideration and must evaluate whether revenue derived from a contract should be recognized at a point in time or over time. The Company adopted the standard as of the required effective date of January 1, 2018 using the modified retrospective method. Under this method, the new guidance was applied to contracts that were not yet completed as of January 1, 2018 with the cumulative effect of initially applying the guidance recognized through accumulated deficit as the date of initial application. See Note 3 "Revenue from Contracts with Customers". Effective January 1, 2018, the Company adopted ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01"). ASU 2016-01 changes the GAAP model for the accounting of equity investments, whereby equity investments with readily determinable fair value are carried at fair value with changes reported in net income (loss) as opposed to other comprehensive income (loss). The Company adopted ASU 2016-01 as of the required effective date of January 1, 2018. There was no impact on the consolidated financial statements upon the adoption of ASU 2016-01 as of the effective date or as of and for the period ended September 30, 2018. Effective January 1, 2018, the Company retrospectively adopted ASU 2016-15, Statement of Cash Flows (Topic 230), Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) ("ASU 2016-15"). ASU 2016-15 clarifies how entities should classify certain cash receipts and cash payments on the statement of cash flows. The guidance also clarifies how the predominance principle should be applied when cash receipts and cash payments have aspects of more than one class of cash flows. There was no impact on the consolidated statements of cash flows upon the adoption of ASU 2016-15. Effective January 1, 2018, the Company adopted ASU 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting . ("ASU 2017-09"). ASU 2017-09 specifies the types of changes to the terms or conditions of a share-based payment award that require an entity to apply modification accounting in accordance with Topic 718. The adoption of ASU 2017-09 did not have an impact on the Company's consolidated financial statements. Effective January 1, 2018, the Company adopted ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory ("ASU 2016-16"). ASU 2016-16 requires than an entity recognized the income tax effects of an intra-entity transfer of an asset, other than inventory, when the transfer occurs as opposed to when the asset is sold to a third party. The adoption of this guidance did not have an impact on the Company's consolidated financial statements. Accounting Standards Issued and Not Yet Adopted In February 2016, the FASB issued ASU 2016-02, Leases ("ASU 2016-02"). ASU 2016-02 and its related amendments (collectively referred to as ASC 842) requires lessees to recognize the assets and liabilities on their balance sheet for the rights and obligations created by most leases and continue to recognize expenses on their income statements over the lease term. ASC 842 will also require disclosures designed to give financial statement users information on the amount, timing, and uncertainty of cash flows arising from leases. The guidance is effective for annual reporting periods beginning after December 15, 2018, and interim periods within those years. While the Company continues to assess all potential impacts of the standard and its method of adoption, the Company expects to record right-of-use assets, with an associated amount recorded to lease obligations, on its balance sheet primarily related to its leased office and warehousing space. While the Company expects that the adoption of this standard will require updates to its processes and internal controls over financial reporting, the Company has concluded that it will not be required to implement new information systems to account for its lease portfolio. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment ("ASU 2017-04"). ASU 2017-04 simplifies the accounting for goodwill impairments by eliminating "Step 2" from the goodwill impairment test, which requires an entity to calculate the implied fair value of goodwill to measure a goodwill impairment charge, and alternatively, requires an entity to measure the impairment of goodwill assigned to a reporting unit as the amount by which the carrying value of the assets and liabilities of the reporting unit, including goodwill, exceeds the reporting unit's fair value. The guidance is effective for annual reporting periods beginning after December 15, 2019, and interim periods within those years. Early adoption is permitted for all entities. The Company is currently evaluating the impact of ASU 2017-04 but does not expect it to be material to the consolidated financial statements. In August 2017, the FASB issued ASU 2017-12, Targeted Improvements to Accounting for Hedging Activities ("ASU 2017-12"). ASU 2017-12 updates the current hedge accounting guidance with the objective of improving the financial reporting of hedging activities by better portraying the economic results of an entity's risk management activities in its financial statements. The new guidance is effective for the Company on January 1, 2019 and early adoption is permitted. As the Company currently does not use derivative financial instruments, this guidance is not expected to impact on Company's financial statements upon adoption. In August 2018, the FASB issued ASU 2018-13, Changes to the Disclosure Requirements for Fair Value Measurement ("ASU 2018-13"). ASU 2018-13 modifies certain disclosure requirements related to fair value measurements primarily associated with Level 3 investments. The guidance is effective no later than January 1, 2020 for the Company and can be early-adopted prospectively in any interim period for certain disclosure requirements or retrospectively for others. The Company does not expect the adoption of this guidance to have a material impact on its fair value disclosures. In August 2018, the FASB issued ASU 2018-15, Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract ("ASU 2018-15"). ASU 2018-15 requires that entities capitalize certain costs to implement a cloud computing arrangement that is service contract consistent with the rules applicable to internal use software capitalization projects. The guidance is effective no later than January 1, 2020 for the Company and can be early-adopted prospectively in any interim period or retrospectively. The Company is evaluating when and how it will adopt this new guidance. Upon adoption, the Company would defer eligible costs related to the implementation of cloud computing arrangements within other current and non-current assets and amortize these costs to the same income statement line as the associated hosting fees.
Accounts Receivable, Net	Accounts receivable consist of amounts due from third-party payors, patients and third-party intermediaries. The Company records an allowance for doubtful accounts at the time potential collection risk is identified. The Company estimates its allowance based on historical experience, assessment of specific risk, and discussions with individual customers. The Company believes the reserve is adequate to mitigate current collection risk.
Inventories	Inventories are carried at the lower of cost or market, determined under the first-in, first-out method, and include the costs of material, labor and overhead. Inventory has been recorded at cost, or net realizable value as appropriate, as of September 30, 2018 and December 31, 2017 . The Company reviews inventories for net realizable value based on quantities on hand and expectations of future use. Work in process is calculated based upon a buildup in the stage of completion using estimated labor inputs for each stage in production.
Goodwill	The Company performs an assessment of its goodwill for impairment on at least an annual basis or whenever events or changes in circumstances indicate there might be an impairment. The Company's annual impairment test date is October 1st.
Intangible Assets, Net	Intangible Assets, Net The Company’s finite-lived intangible assets are stated at cost less accumulated amortization and include customer relationships acquired in prior business acquisitions and from the Company's former European Distributor. See Note 12 for a discussion of the Company's accounting for estimated fees owed to its former European Distributor following the expiration of its distribution agreement on June 30, 2018.
Product Warranty Costs	Product Warranty Costs The Company generally provides a four -year warranty on its PDMs sold in the United States and Europe and a five -year warranty on its PDMs sold in Canada and may replace any Omnipod that does not function in accordance with product specifications. The Company estimates its warranty at the time the product is shipped based on historical experience and the estimated cost to service the claims. Warranty expense is recorded in cost of goods sold on the statement of operations. Cost to service the claims reflects the current product cost. As these estimates are based on historical experience, and the Company continues to introduce new products and versions, the Company also considers the anticipated performance of the product over its warranty period in estimating warranty reserves.
Income Taxes	The Company files federal, state and foreign tax returns. These returns are generally open to examination by the relevant tax authorities from three to four years from the date they are filed.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table summarizes revenue from contracts with customers for the three and nine months ended September 30, 2018 and 2017: Three months Nine months (in thousands) 2018 2017 2018 2017 U.S. Omnipod $ 81,970 $ 70,065 $ 230,289 $ 195,081 International Omnipod 50,214 32,481 117,127 84,200 Drug Delivery 18,892 19,229 51,500 53,963 Total $ 151,076 $ 121,775 $ 398,916 $ 333,244
Summary of Financial Statement Impact of ASC 606 Adoption	The table also compares the reported consolidated balance sheet accounts as of September 30, 2018 that were impacted by the new guidance to pro forma balance sheet amounts had the previous guidance been in effect. As Reported Adjustments As Adjusted As Reported Adjustments Pro forma (in thousands) 12/31/2017 1/1/2018 1/1/2018 9/30/2018 9/30/2018 9/30/2018 Unbilled receivable (a) $ — $ 5,119 $ 5,119 $ 9,963 $ (9,963 ) $ — Inventories 33,793 (753 ) 33,040 58,050 1,430 59,480 Prepaid expenses and other current assets (b) 9,949 5,568 15,517 17,905 (6,869 ) 11,036 Total current assets 537,171 9,934 547,105 445,712 (15,402 ) 430,310 Other assets (b) 1,969 13,326 15,295 18,057 (15,567 ) 2,490 Total assets 816,744 23,260 840,004 886,306 (30,969 ) 855,337 Deferred revenue (c) 2,356 2,625 4,981 2,210 (771 ) 1,439 Total current liabilities 86,025 2,625 88,650 97,224 (771 ) 96,453 Other long-term liabilities 6,030 271 6,301 6,668 (270 ) 6,398 Total liabilities 658,228 2,896 661,124 688,377 (1,041 ) 687,336 Accumulated deficit (707,255 ) 20,349 (686,906 ) (693,507 ) (29,937 ) (723,444 ) Total stockholders' equity 158,516 20,364 178,880 197,929 (29,928 ) 168,001 Total liabilities and stockholders' equity 816,744 23,260 840,004 886,306 (30,969 ) 855,337 (a) Unbilled receivable that reflects revenue for a portion of the Company's drug delivery product line as the product is produced. The unbilled receivable is reclassified to accounts receivable as the product is completed and shipped to the customer. (b) Other current and non-current assets include contract acquisition costs related to the sale of the Omnipod. These costs are amortized over the estimated period of benefit. (c) The adoption of ASC 606 required the Company to record a contract liability, or deferred revenue, on January 1, 2018, primarily associated with a volume-based pricing discount granted to the Company's European Distributor at the outset of the distribution contract in 2010. The deferred revenue was recognized as revenue through the completion of the distributor contract during the first half of 2018. The following summarizes the significant changes on the Company’s consolidated statement of operations for the three and nine months ended September 30, 2018 as a result of the adoption of ASC 606 on January 1, 2018 compared to if the Company had continued to recognize revenue under ASC 605: Three months ended September 30, 2018 Nine months ended September 30, 2018 (in thousands, except per share amounts) As reported Adjustments Pro forma As reported Adjustments Pro forma U.S. Omnipod $ 81,970 $ (135 ) $ 81,835 $ 230,289 $ (9 ) $ 230,280 International Omnipod (a) 50,214 53 50,267 117,127 (1,845 ) 115,282 Drug Delivery (b) 18,892 3,995 22,887 51,500 (4,844 ) 46,656 Revenue 151,076 3,913 154,989 398,916 (6,698 ) 392,218 Cost of revenue 49,107 674 49,781 139,060 (677 ) 138,383 Gross profit 101,969 3,239 105,208 259,856 (6,021 ) 253,835 Sales and marketing (c) 34,922 394 35,316 102,660 3,567 106,227 Total operating expenses 95,104 394 95,498 248,666 3,567 252,233 Operating income 6,865 2,845 9,710 11,190 (9,588 ) 1,602 Income (loss) before income taxes 1,853 2,845 4,698 (5,662 ) (9,588 ) (15,250 ) Net income (loss) $ 1,659 $ 2,845 $ 4,504 $ (6,601 ) $ (9,588 ) $ (16,189 ) Net income (loss) per share: basic $ 0.03 $ 0.05 $ 0.08 $ (0.11 ) $ (0.17 ) $ (0.28 ) Net income (loss) per shares: diluted $ 0.03 $ 0.04 $ 0.07 $ (0.11 ) $ (0.17 ) $ (0.28 ) (a) International Omnipod revenue under ASC 606 includes the amortization of a material right associated with a volume-based pricing discount granted to the Company's European Distributor at the outset of the distribution contract in 2010. The deferred revenue was recognized as revenue through the completion of the distributor contract during the first half of 2018. (b) ASC 606 accelerated the recognition of revenue and fulfillment costs related to certain drug delivery contracts for which recognition was previously recorded when the product was shipped to the customer and is recorded as the product is produced under ASC 606. During the three and nine months ended September 30, 2018, revenue was lower by $4.0 million and higher by $4.8 million , respectively, due to changes in quantity and stage of production of in-process inventory relative to the prior period. (c) ASC 606 resulted in the amortization of capitalized commission costs that were recorded as part of the cumulative effect adjustment upon adoption and during the nine months ended September 30, 2018. Amortization of these capitalized costs to selling and marketing expenses, net of commission costs that were capitalized in the three and nine month periods, reduced sales and marketing expenses in each period . Nine Months Ended September 30, 2018 Statement of Cash Flows (in thousands) As Reported Adjustments Pro Forma Net loss $ (6,601 ) $ (9,588 ) $ (16,189 ) Adjustments to reconcile net loss to net cash used in operating activities Non-cash items 66,602 — 66,602 Changes in operating assets and liabilities: — Accounts receivable and unbilled receivable (24,581 ) 4,844 (19,737 ) Inventories (25,279 ) (677 ) (25,956 ) Prepaid expenses and other assets (5,258 ) 3,567 (1,691 ) Accounts payable, accrued expenses and other current liabilities 2,938 — 2,938 Deferred revenue (2,761 ) 1,854 (907 ) Other long-term liabilities 400 — 400 Net cash provided by operating activities $ 5,460 $ — $ 5,460
Schedule of revenue from major customers	Revenue for customers comprising more than 10% of total revenue were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Amgen, Inc. 12% 16% 13% 16% Ypsomed and affiliates * 23% 11% 21% Cardinal Health Inc. and affiliates 12% 11% 12% 10% * Represents less than 10% of consolidated revenue.

Investments and Fair Value (Tab

Investments and Fair Value (Tables)	9 Months Ended
	Sep. 30, 2018
Short-term Investments [Abstract]
Schedule investments	The following table provides amortized cost, gross unrealized gains and loses, fair value and the level in the fair value hierarchy within which those measurements fall: (in thousands) Amortized cost Gross Unrealized Gains (Losses) Fair Value Level 1 Level 2 September 30, 2018 Money market mutual funds $ 66,141 $ — $ 66,141 $ 66,141 $ — Total cash equivalents $ 66,141 $ — $ 66,141 $ 66,141 $ — U.S. government and agency bonds $ 120,832 $ (444 ) $ 120,388 $ 77,128 $ 43,260 Corporate bonds 38,897 (108 ) 38,789 — 38,789 Certificates of deposit 4,104 — 4,104 — 4,104 Total short-term investments $ 163,833 $ (552 ) $ 163,281 $ 77,128 $ 86,153 U.S. government and agency bonds $ 96,038 $ (646 ) $ 95,392 $ 73,652 $ 21,740 Corporate bonds 44,808 (245 ) 44,563 — 44,563 Certificates of deposit 5,584 — 5,584 — 5,584 Total long-term investments $ 146,430 $ (891 ) $ 145,539 $ 73,652 $ 71,887 December 31, 2017 Money market mutual funds $ 236,936 $ — $ 236,936 $ 236,936 $ — U.S government and agency bonds $ 5,000 — $ 5,000 $ 5,000 — Total cash equivalents $ 241,936 $ — $ 241,936 $ 241,936 $ — U.S. government and agency bonds $ 112,311 $ (235 ) $ 112,076 $ 90,703 $ 21,373 Corporate bonds 47,713 (32 ) 47,681 — 47,681 Certificates of deposit 7,722 — 7,722 — 7,722 Total short-term investments $ 167,746 $ (267 ) $ 167,479 $ 90,703 $ 76,776 U.S. government and agency bonds $ 92,677 $ (213 ) $ 92,464 $ 49,651 $ 42,813 Corporate bonds 27,871 (59 ) 27,812 — 27,812 Certificates of deposit 5,273 — 5,273 — 5,273 Total long-term investments $ 125,821 $ (272 ) $ 125,549 $ 49,651 $ 75,898

Convertible Debt, Net (Tables)

Convertible Debt, Net (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Outstanding Convertible Debt and Related Deferred Financing Costs	The Company had outstanding convertible debt and related debt issuance costs on its consolidated balance sheet as follows: As of (in thousands) September 30, 2018 December 31, 2017 Principal amount of 2.0% Convertible Senior Notes, due June 2019 $ — $ 3,664 Principal amount of 1.25% Convertible Senior Notes, due September 2021 344,992 345,000 Principal amount of 1.375% Convertible Senior Notes, due November 2024 402,500 402,500 Unamortized debt discount (150,439 ) (170,448 ) Debt issuance costs (12,568 ) (14,543 ) Total convertible debt, net $ 584,485 $ 566,173
Interest and Other Expense	Interest expense related to the convertible debt was as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Contractual coupon interest $ 2,440 $ 1,449 $ 7,382 $ 4,276 Accretion of debt discount 6,702 3,612 19,840 10,690 Amortization of debt issuance costs 661 505 1,950 1,495 Total interest expense related to convertible debt $ 9,803 $ 5,566 $ 29,172 $ 16,461 Interest expense related to convertible debt for the three and nine months ended September 30, 2018 is as follows: Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 (in thousands) 1.375% 1.25% Total 1.375% 1.25% 2.0% Total Contractual coupon interest $ 1,362 $ 1,078 $ 2,440 $ 4,129 $ 3,234 $ 19 $ 7,382 Amortization of debt discount and issuance costs 3,736 3,627 7,363 11,001 10,729 60 21,790 Total interest expense $ 5,098 $ 4,705 $ 9,803 $ 15,130 $ 13,963 $ 79 $ 29,172 Interest expense related to convertible debt for the three and nine months ended September 30, 2017 is as follows: Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (in thousands) 1.25% 2.0% Total 1.25% 2.0% Total Contractual coupon interest $ 1,102 $ 347 $ 1,449 $ 3,259 $ 1,017 $ 4,276 Amortization of debt discount and issuance costs 3,403 714 4,117 10,073 2,112 12,185 Total interest expense $ 4,505 $ 1,061 $ 5,566 $ 13,332 $ 3,129 $ 16,461
Fair Value, Liabilities Measured on Recurring and Nonrecurring Basis	The carrying amount and the estimated fair value of the Company's convertible debt, which is based on the Level 2 quoted market prices as of September 30, 2018 and December 31, 2017 are as follows: As of September 30, 2018 December 31, 2017 (in thousands) Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value 2% Convertible Senior Notes, due June 2019 $ — $ — $ 3,421 $ 5,467 1.375% Convertible Senior Notes, due November 2024 287,183 515,627 276,172 407,652 1.25% Convertible Senior Notes, due September 2021 297,302 630,041 286,580 450,881 Total $ 584,485 $ 1,145,668 $ 566,173 $ 864,000

Accounts Receivable, Net (Table

Accounts Receivable, Net (Tables)	9 Months Ended
	Sep. 30, 2018
Receivables [Abstract]
Components of Accounts Receivable	The components of accounts receivable are as follows: As of (in thousands) September 30, 2018 December 31, 2017 Trade receivables $ 73,428 $ 55,914 Allowance for doubtful accounts (3,478 ) (2,541 ) Total accounts receivable, net $ 69,950 $ 53,373

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure Potential Common Shares Excluded From Computation Of Diluted Net Loss Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the components used in the computation of basic and diluted net income (loss) per share for the three and nine months ended September 30, 2018. Because the Company reported a net loss for the three and nine months ended September 30, 2017, all potential dilutive common shares have been excluded from the computation of the diluted net loss per share for the three and nine months ended September 30, 2017, as the effect would have been anti-dilutive. September 30, 2018 (in thousands, except share and per share data) Three months ended Nine months ended Numerator: Net income (loss) $ 1,659 $ (6,601 ) Denominator: Weighted average common shares outstanding 59,016,863 58,779,672 Effective of dilutive potential common share equivalents Stock options 1,719,796 — Restricted stock units 409,807 — Convertible debt — — Shares used for diluted net income (loss) per share 61,146,466 58,779,672 Net income (loss) per share: Basic $ 0.03 $ (0.11 ) Diluted $ 0.03 $ (0.11 )
Potential Common Shares Excluded from Computation of Diluted Net Loss per Share	The number of potential common share equivalents excluded from the computation of diluted net income (loss) per share for the three and nine months ended September 30, 2018 and 2017 are as follows: Three Months Ended September 30, Nine Months Ended September 30, Three and Nine Months Ended September 30, 2018 2018 2017 1.375% Convertible Senior Notes 4,319,429 4,319,429 — 2.00% Convertible Senior Notes — — 1,442,433 1.25% Convertible Senior Notes 5,910,954 5,910,954 5,910,954 Unvested restricted stock units 300,438 865,206 1,007,729 Outstanding stock options 223,183 3,117,326 3,489,393 Total potential common share equivalents excluded from computation of diluted net income (loss) per share 10,754,004 14,212,915 11,850,509

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2018
Inventory Disclosure [Abstract]
Components of Inventories	The components of inventories are as follows: As of (in thousands) September 30, 2018 December 31, 2017 Raw materials $ 5,390 $ 2,146 Work-in-process 17,187 23,918 Finished goods, net 35,473 7,729 Total inventories $ 58,050 $ 33,793

Prepaid Expenses and Other As_2

Prepaid Expenses and Other Assets (Tables)	9 Months Ended
	Sep. 30, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of prepaid expenses and other assets	The components of prepaid expenses and other current assets are as follows: As of (in thousands) September 30, 2018 December 31, 2017 Prepaid expenses and other current assets $ 11,036 $ 9,949 Capitalized contract acquisition costs, current portion 6,869 — Total prepaid expenses and other current assets $ 17,905 $ 9,949 The components of other assets are as follows: As of (in thousands) September 30, 2018 December 31, 2017 Other assets $ 2,487 $ 1,969 Capitalized contract acquisition costs, net of current portion 15,570 — Total other assets $ 18,057 $ 1,969

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets, Net (Tables)	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Components of Other Intangible Assets	The components of other intangible assets are as follows: As of September 30, 2018 December 31, 2017 (in thousands) Gross Carrying Amount Accumulated Amortization Net Book Value Gross Carrying Amount Accumulated Amortization Net Book Value Customer and contractual relationships $ 4,078 $ (1,859 ) $ 2,219 $ 2,135 $ (1,764 ) $ 371 Internal-use software 10,271 (4,699 ) 5,572 7,545 (3,565 ) 3,980 Total intangible assets $ 14,349 $ (6,558 ) $ 7,791 $ 9,680 $ (5,329 ) $ 4,351
Amortization Expense Expected for Next Five Years	Amortization expense expected for the next five years and thereafter is as follows: (in thousands) Years Ending December 31, Customer and Contractual Relationships Internal-Use Software Total 2018 (remaining) $ 90 $ 465 $ 555 2019 334 1,767 2,101 2020 266 1,505 1,771 2021 200 1,080 1,280 2022 200 571 771 Thereafter 1,129 184 1,313 Total $ 2,219 $ 5,572 $ 7,791

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
Components of accrued expenses and other current liabilities	The components of accrued expenses and other current liabilities are as follows: As of (in thousands) September 30, 2018 December 31, 2017 Employee compensation and related costs $ 32,265 $ 34,942 Professional and consulting services 10,190 9,273 Supplier charges 3,863 3,542 Warranty 2,303 1,653 Other 19,548 9,846 Total accrued expenses and other current liabilities $ 68,169 $ 59,256
Reconciliation of Changes in Product Warranty Liability	A reconciliation of the changes in the Company’s product warranty liability is as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Product warranty liability at the beginning of the period $ 5,503 $ 4,817 $ 5,337 $ 4,388 Warranty expense 1,763 1,483 5,264 3,123 Warranty claims settled (1,548 ) (1,303 ) (4,883 ) (2,514 ) Product warranty liability at the end of the period $ 5,718 $ 4,997 $ 5,718 $ 4,997 Composition of balance: As of (in thousands) September 30, 2018 December 31, 2017 Short-term $ 2,303 $ 1,653 Long-term 3,415 3,684 Total warranty liability: $ 5,718 $ 5,337

Stock-Based Compensation and _2

Stock-Based Compensation and Stockholder' Equity (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of compensation related costs, share-based payments	Stock-Based Compensation and Stockholder' Equity The Company grants stock options, and both time-based and performance-based restricted stock units under its 2017 Stock Option and Incentive Plan and offers employees the opportunity to purchase its common stock through an Employee Stock Purchase Plan. The following table reflects the Company's stock-based compensation expense related to share-based awards recognized in the three and nine months ended September 30, 2018 and 2017 : Three Months Ended September 30, Nine Months Ended September 30, Unamortized Expense Weighted Average Remaining Expense Period (Years) ($ in thousands) 2018 2017 2018 2017 At September 30, 2018 Stock options $ 3,957 $ 3,127 $ 8,587 $ 8,815 $ 13,632 2.5 Restricted stock units 11,835 5,621 21,734 14,358 25,054 1.9 Employee stock purchase plan 296 149 884 379 197 0.2 Total $ 16,088 $ 8,897 $ 31,205 $ 23,552 $ 38,883 The following summarizes stock option activity during the nine months ended September 30, 2018 : Number of Options (#) Weighted Average Exercise Price ($) Aggregate Intrinsic Value ($ in thousands) Weighted Average Remaining Contractual Term (Years) Outstanding at December 31, 2017 3,377,220 $ 35.10 Granted 287,199 77.05 Exercised (384,887 ) 33.11 $ 21,419 Cancelled (162,206 ) 40.45 Outstanding at September 30, 2018 3,117,326 $ 38.94 $ 208,898 7.1 Vested, September 30, 2018 2,077,854 $ 34.40 $ 148,671 6.6 Vested or expected to vest, September 30, 2018 (1) 3,019,139 $ 203,882 (1) Represents total outstanding stock options as of September 30, 2018 , adjusted for estimated forfeitures. The following table summarizes the status of the Company’s restricted stock units during the nine months ended September 30, 2018 : Number of Shares (#) Weighted Average Fair Value ($) Outstanding at December 31, 2017 994,364 $ 38.08 Granted 328,342 75.51 Adjustment (1) 147,301 29.54 Vested (526,638 ) 33.59 Forfeited (78,163 ) 44.58 Outstanding at September 30, 2018 865,206 $ 52.98 (1) Certain performance-based restricted stock units are subject to a three -year vesting period subject to meeting performance targets and continued employment. During the three months ended March 31, 2018, the Compensation Committee of the Board of Directors determined that the performance was achieved at 200% of target for certain performance-based awards issued in 2016, resulting in an adjustment to the shares that will ultimately vest for these awards.
Stock option activity	The following table reflects the Company's stock-based compensation expense related to share-based awards recognized in the three and nine months ended September 30, 2018 and 2017 : Three Months Ended September 30, Nine Months Ended September 30, Unamortized Expense Weighted Average Remaining Expense Period (Years) ($ in thousands) 2018 2017 2018 2017 At September 30, 2018 Stock options $ 3,957 $ 3,127 $ 8,587 $ 8,815 $ 13,632 2.5 Restricted stock units 11,835 5,621 21,734 14,358 25,054 1.9 Employee stock purchase plan 296 149 884 379 197 0.2 Total $ 16,088 $ 8,897 $ 31,205 $ 23,552 $ 38,883 The following summarizes stock option activity during the nine months ended September 30, 2018 : Number of Options (#) Weighted Average Exercise Price ($) Aggregate Intrinsic Value ($ in thousands) Weighted Average Remaining Contractual Term (Years) Outstanding at December 31, 2017 3,377,220 $ 35.10 Granted 287,199 77.05 Exercised (384,887 ) 33.11 $ 21,419 Cancelled (162,206 ) 40.45 Outstanding at September 30, 2018 3,117,326 $ 38.94 $ 208,898 7.1 Vested, September 30, 2018 2,077,854 $ 34.40 $ 148,671 6.6 Vested or expected to vest, September 30, 2018 (1) 3,019,139 $ 203,882 (1) Represents total outstanding stock options as of September 30, 2018 , adjusted for estimated forfeitures.
Summary of restricted stock units	The following table summarizes the status of the Company’s restricted stock units during the nine months ended September 30, 2018 : Number of Shares (#) Weighted Average Fair Value ($) Outstanding at December 31, 2017 994,364 $ 38.08 Granted 328,342 75.51 Adjustment (1) 147,301 29.54 Vested (526,638 ) 33.59 Forfeited (78,163 ) 44.58 Outstanding at September 30, 2018 865,206 $ 52.98 (1) Certain performance-based restricted stock units are subject to a three -year vesting period subject to meeting performance targets and continued employment. During the three months ended March 31, 2018, the Compensation Committee of the Board of Directors determined that the performance was achieved at 200% of target for certain performance-based awards issued in 2016, resulting in an adjustment to the shares that will ultimately vest for these awards.

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)segment	Sep. 30, 2017USD ($)
Significant Accounting Policies [Line Items]
Number of operating segments (in segments) | segment			1
Cost of revenue	$ 49,107	$ 48,151	$ 139,060	$ 135,583
Shipping and Handling
Significant Accounting Policies [Line Items]
Cost of revenue	$ 2,200	$ 1,300	$ 4,600	$ 3,500

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net cash used in operating activities		$ 5,460,000	$ 19,407,000
Net cash used in investing activities		(143,719,000)	(61,485,000)
Net cash (used in) provided by financing activities		(7,081,000)	$ 6,650,000
Revenue recognized	$ 600,000	2,500,000
Revenue recognized from performance obligations satisfied in previous periods	$ 0	0
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net cash used in operating activities		0
Net cash used in investing activities		0
Net cash (used in) provided by financing activities		$ 0

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Summary of Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 151,076	$ 121,775	$ 398,916	$ 333,244
U.S. Omnipod
Disaggregation of Revenue [Line Items]
Revenue	81,970	70,065	230,289	195,081
International Omnipod
Disaggregation of Revenue [Line Items]
Revenue	50,214	32,481	117,127	84,200
Drug Delivery
Disaggregation of Revenue [Line Items]
Revenue	$ 18,892	$ 19,229	$ 51,500	$ 53,963

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Financial Statement Impact of Adopting ASC 606 (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
Balance Sheet
Unbilled receivable	$ 9,963,000		$ 9,963,000		$ 5,119,000	$ 0
Inventories	58,050,000		58,050,000		33,040,000	33,793,000
Prepaid expenses and other current assets	17,905,000		17,905,000		15,517,000	9,949,000
Total current assets	445,712,000		445,712,000		547,105,000	537,171,000
Other assets	2,487,000		2,487,000		15,295,000	1,969,000
Total assets	886,306,000		886,306,000		840,004,000	816,744,000
Deferred revenue	2,210,000		2,210,000		4,981,000	2,356,000
Total current liabilities	97,224,000		97,224,000		88,650,000	86,025,000
Other long-term liabilities	6,668,000		6,668,000		6,301,000	6,030,000
Total liabilities	688,377,000		688,377,000		661,124,000	658,228,000
Accumulated deficit	(693,507,000)		(693,507,000)		(686,906,000)	(707,255,000)
Total stockholders' equity	197,929,000		197,929,000		178,880,000	158,516,000
Total liabilities and stockholders' equity	886,306,000		886,306,000		840,004,000	816,744,000
Statement of Operations
Revenue	151,076,000	$ 121,775,000	398,916,000	$ 333,244,000
Cost of revenue	49,107,000	48,151,000	139,060,000	135,583,000
Gross profit	101,969,000	73,624,000	259,856,000	197,661,000
Sales and marketing	34,922,000	28,718,000	102,660,000	86,288,000
Total operating expenses	95,104,000	71,577,000	248,666,000	204,280,000
Operating income	6,865,000	2,047,000	11,190,000	(6,619,000)
Loss before income taxes	1,853,000	(2,106,000)	(5,662,000)	(19,653,000)
Net income (loss)	$ 1,659,000	$ (2,227,000)	$ (6,601,000)	$ (19,971,000)
Net income (loss) per share: basic (in dollars per share)	$ 0.03	$ (0.04)	$ (0.11)	$ (0.34)
Net income (loss) per shares: diluted (in dollars per share)	$ 0.03	$ (0.04)	$ (0.11)	$ (0.34)
Statement of Cash Flows
Non-cash interest expense	$ 7,363,000	$ 4,117,000	$ 21,790,000	$ 12,185,000
Accounts receivable and unbilled receivable			24,581,000	19,757,000
Inventories			(25,279,000)	428,000
Prepaid expenses and other assets			(5,258,000)	(1,290,000)
Accounts payable, accrued expenses and other current liabilities			2,938,000	10,502,000
Deferred revenue			(2,761,000)	537,000
Other long-term liabilities			400,000	668,000
Net cash used in operating activities			5,460,000	19,407,000
U.S. Omnipod
Statement of Operations
Revenue	81,970,000	70,065,000	230,289,000	195,081,000
International Omnipod
Statement of Operations
Revenue	50,214,000	32,481,000	117,127,000	84,200,000
Drug Delivery
Statement of Operations
Revenue	18,892,000	$ 19,229,000	51,500,000	$ 53,963,000
Pro Forma
Balance Sheet
Unbilled receivable	0		0
Inventories	59,480,000		59,480,000
Prepaid expenses and other current assets	11,036,000		11,036,000
Total current assets	430,310,000		430,310,000
Other assets	2,490,000		2,490,000
Total assets	855,337,000		855,337,000
Deferred revenue	1,439,000		1,439,000
Total current liabilities	96,453,000		96,453,000
Other long-term liabilities	6,398,000		6,398,000
Total liabilities	687,336,000		687,336,000
Accumulated deficit	(723,444,000)		(723,444,000)
Total stockholders' equity	168,001,000		168,001,000
Total liabilities and stockholders' equity	855,337,000		855,337,000
Statement of Operations
Revenue	154,989,000		392,218,000
Cost of revenue	49,781,000		138,383,000
Gross profit	105,208,000		253,835,000
Sales and marketing	35,316,000		106,227,000
Total operating expenses	95,498,000		252,233,000
Operating income	9,710,000		1,602,000
Loss before income taxes	4,698,000		(15,250,000)
Net income (loss)	$ 4,504,000		$ (16,189,000)
Net income (loss) per share: basic (in dollars per share)	$ 0.08		$ (0.28)
Net income (loss) per shares: diluted (in dollars per share)	$ 0.07		$ (0.28)
Statement of Cash Flows
Non-cash interest expense			$ 66,602,000
Accounts receivable and unbilled receivable			19,737,000
Inventories			(25,956,000)
Prepaid expenses and other assets			(1,691,000)
Accounts payable, accrued expenses and other current liabilities			2,938,000
Deferred revenue			(907,000)
Other long-term liabilities			400,000
Net cash used in operating activities			5,460,000
Pro Forma | U.S. Omnipod
Statement of Operations
Revenue	$ 81,835,000		230,280,000
Pro Forma | International Omnipod
Statement of Operations
Revenue	50,267,000		115,282,000
Pro Forma | Drug Delivery
Statement of Operations
Revenue	22,887,000		46,656,000
Calculated under Revenue Guidance in Effect before Topic 606
Balance Sheet
Unbilled receivable	9,963,000		9,963,000			0
Inventories	58,050,000		58,050,000			33,793,000
Prepaid expenses and other current assets	17,905,000		17,905,000			9,949,000
Total current assets	445,712,000		445,712,000			537,171,000
Other assets	18,057,000		18,057,000			1,969,000
Total assets	886,306,000		886,306,000			816,744,000
Deferred revenue	2,210,000		2,210,000			2,356,000
Total current liabilities	97,224,000		97,224,000			86,025,000
Other long-term liabilities	6,668,000		6,668,000			6,030,000
Total liabilities	688,377,000		688,377,000			658,228,000
Accumulated deficit	(693,507,000)		(693,507,000)			(707,255,000)
Total stockholders' equity	197,929,000		197,929,000			158,516,000
Total liabilities and stockholders' equity	886,306,000		886,306,000			$ 816,744,000
Statement of Operations
Revenue	151,076,000		398,916,000
Cost of revenue	49,107,000		139,060,000
Gross profit	101,969,000		259,856,000
Sales and marketing	34,922,000		102,660,000
Total operating expenses	95,104,000		248,666,000
Operating income	6,865,000		11,190,000
Loss before income taxes	1,853,000		(5,662,000)
Net income (loss)	$ 1,659,000		$ (6,601,000)
Net income (loss) per share: basic (in dollars per share)	$ 0.03		$ (0.11)
Net income (loss) per shares: diluted (in dollars per share)	$ 0.03		$ (0.11)
Statement of Cash Flows
Non-cash interest expense			$ 66,602,000
Accounts receivable and unbilled receivable			24,581,000
Inventories			(25,279,000)
Prepaid expenses and other assets			(5,258,000)
Accounts payable, accrued expenses and other current liabilities			2,938,000
Deferred revenue			(2,761,000)
Other long-term liabilities			400,000
Net cash used in operating activities			5,460,000
Calculated under Revenue Guidance in Effect before Topic 606 | U.S. Omnipod
Statement of Operations
Revenue	$ 81,970,000		230,289,000
Calculated under Revenue Guidance in Effect before Topic 606 | International Omnipod
Statement of Operations
Revenue	50,214,000		117,127,000
Calculated under Revenue Guidance in Effect before Topic 606 | Drug Delivery
Statement of Operations
Revenue	18,892,000		51,500,000
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Balance Sheet
Unbilled receivable	(9,963,000)		(9,963,000)		5,119,000
Inventories	1,430,000		1,430,000		(753,000)
Prepaid expenses and other current assets	(6,869,000)		(6,869,000)		5,568,000
Total current assets	(15,402,000)		(15,402,000)		9,934,000
Other assets	(15,567,000)		(15,567,000)		13,326,000
Total assets	(30,969,000)		(30,969,000)		23,260,000
Deferred revenue	(771,000)		(771,000)		2,625,000
Total current liabilities	(771,000)		(771,000)		2,625,000
Other long-term liabilities	(270,000)		(270,000)		271,000
Total liabilities	(1,041,000)		(1,041,000)		2,896,000
Accumulated deficit	(29,937,000)		(29,937,000)		20,349,000
Total stockholders' equity	(29,928,000)		(29,928,000)		20,364,000
Total liabilities and stockholders' equity	(30,969,000)		(30,969,000)		$ 23,260,000
Statement of Operations
Revenue	3,913,000		(6,698,000)
Cost of revenue	674,000		(677,000)
Gross profit	3,239,000		(6,021,000)
Sales and marketing	394,000		3,567,000
Total operating expenses	394,000		3,567,000
Operating income	2,845,000		(9,588,000)
Loss before income taxes	2,845,000		(9,588,000)
Net income (loss)	$ 2,845,000		$ (9,588,000)
Net income (loss) per share: basic (in dollars per share)	$ 0.05		$ (0.17)
Net income (loss) per shares: diluted (in dollars per share)	$ 0.04		$ (0.17)
Statement of Cash Flows
Non-cash interest expense			$ 0
Accounts receivable and unbilled receivable			(4,844,000)
Inventories			(677,000)
Prepaid expenses and other assets			3,567,000
Accounts payable, accrued expenses and other current liabilities			0
Deferred revenue			1,854,000
Other long-term liabilities			0
Net cash used in operating activities			0
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09 | U.S. Omnipod
Statement of Operations
Revenue	$ (135,000)		(9,000)
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09 | International Omnipod
Statement of Operations
Revenue	53,000		(1,845,000)
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09 | Drug Delivery
Statement of Operations
Revenue	$ 3,995,000		$ (4,844,000)

Revenue from Contracts with C_6

Revenue from Contracts with Customers - Summary of Revenue from Customers (Details) - Customer concentration risk - Sales revenue	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Amgen, Inc.
Significant Accounting Policies [Line Items]
Total revenue, percentage	12.00%	16.00%	13.00%	16.00%
Ypsomed
Significant Accounting Policies [Line Items]
Total revenue, percentage		23.00%	11.00%	21.00%
Cardinal Health Inc.
Significant Accounting Policies [Line Items]
Total revenue, percentage	12.00%	11.00%	12.00%	10.00%

Investments and Fair Value - Na

Investments and Fair Value - Narrative (Details) $ in Millions	3 Months Ended
	Sep. 30, 2018USD ($)Security	Dec. 31, 2017USD ($)
Debt Securities, Available-for-sale [Line Items]
Restricted cash and cash equivalents | $	$ 2.7	$ 0.5
Number of positions | Security	80
Minimum
Debt Securities, Available-for-sale [Line Items]
Derivative maturity date range	11 days
Maximum
Debt Securities, Available-for-sale [Line Items]
Derivative maturity date range	1 year 11 months 27 days

Investments and Fair Value - Sc

Investments and Fair Value - Schedule of Assets Measured on a Recurring and Nonrecurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Recurring fair value measurements:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 66,141
Recurring fair value measurements: | Money market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	66,141	$ 236,936
Recurring fair value measurements: | U.S. government and agency bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		5,000
Level 1 | Recurring fair value measurements:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	66,141	241,936
Level 1 | Recurring fair value measurements: | Money market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	66,141	236,936
Level 1 | Recurring fair value measurements: | U.S. government and agency bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		5,000
Level 2 | Recurring fair value measurements:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level 2 | Recurring fair value measurements: | Money market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level 2 | Recurring fair value measurements: | U.S. government and agency bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		0
Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized cost	163,833	167,746
Gross Unrealized Gains (Losses)	(552)	(267)
Fair Value	163,281	167,479
Short-term investments | Level 1 | Recurring fair value measurements:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	77,128	90,703
Short-term investments | Level 1 | Recurring fair value measurements: | U.S. government and agency bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	77,128	90,703
Short-term investments | Level 1 | Recurring fair value measurements: | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Short-term investments | Level 1 | Recurring fair value measurements: | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Short-term investments | Level 2 | Recurring fair value measurements:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	86,153	76,776
Short-term investments | Level 2 | Recurring fair value measurements: | U.S. government and agency bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	43,260	21,373
Short-term investments | Level 2 | Recurring fair value measurements: | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	38,789	47,681
Short-term investments | Level 2 | Recurring fair value measurements: | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	4,104	7,722
Short-term investments | U.S. government and agency bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized cost	120,832	112,311
Gross Unrealized Gains (Losses)	(444)	(235)
Fair Value	120,388	112,076
Short-term investments | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized cost	38,897	47,713
Gross Unrealized Gains (Losses)	(108)	(32)
Fair Value	38,789	47,681
Short-term investments | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized cost	4,104	7,722
Gross Unrealized Gains (Losses)	0	0
Fair Value	4,104	7,722
Long-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized cost	146,430	125,821
Gross Unrealized Gains (Losses)	(891)	(272)
Fair Value	145,539	125,549
Long-term investments | Level 1 | Recurring fair value measurements:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	73,652	49,651
Long-term investments | Level 1 | Recurring fair value measurements: | U.S. government and agency bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	73,652	49,651
Long-term investments | Level 1 | Recurring fair value measurements: | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Long-term investments | Level 1 | Recurring fair value measurements: | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Long-term investments | Level 2 | Recurring fair value measurements:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	71,887	75,898
Long-term investments | Level 2 | Recurring fair value measurements: | U.S. government and agency bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	21,740	42,813
Long-term investments | Level 2 | Recurring fair value measurements: | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	44,563	27,812
Long-term investments | Level 2 | Recurring fair value measurements: | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,584	5,273
Long-term investments | U.S. government and agency bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized cost	96,038	92,677
Gross Unrealized Gains (Losses)	(646)	(213)
Fair Value	95,392	92,464
Long-term investments | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized cost	44,808	27,871
Gross Unrealized Gains (Losses)	(245)	(59)
Fair Value	44,563	27,812
Long-term investments | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized cost	5,584	5,273
Gross Unrealized Gains (Losses)	0	0
Fair Value	$ 5,584	$ 5,273

Convertible Debt, Net - Outstan

Convertible Debt, Net - Outstanding Convertible Debt and Related Deferred Financing Costs (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2016	Jun. 30, 2014
Debt Instrument [Line Items]
Unamortized debt discount	$ (150,439)	$ (170,448)
Debt issuance costs	(12,568)	(14,543)
Total convertible debt, net	$ 584,485	566,173
2% Convertible Senior Notes
Debt Instrument [Line Items]
Debt, interest rate	2.00%			2.00%
1.25% Convertible Notes
Debt Instrument [Line Items]
Debt, interest rate	1.25%		1.25%
1.375% Convertible Senior Notes
Debt Instrument [Line Items]
Total convertible debt, net	$ 287,200
Debt, interest rate	1.375%
Convertible Debt | 2% Convertible Senior Notes
Debt Instrument [Line Items]
Principal amount of Senior Notes	$ 0	3,664
Convertible Debt | 1.25% Convertible Notes
Debt Instrument [Line Items]
Principal amount of Senior Notes	344,992	345,000
Convertible Debt | 1.375% Convertible Senior Notes
Debt Instrument [Line Items]
Principal amount of Senior Notes	$ 402,500	$ 402,500

Convertible Debt, Net - Interes

Convertible Debt, Net - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Debt Instrument [Line Items]
Contractual coupon interest	$ 2,440	$ 1,449	$ 7,382	$ 4,276
Accretion of debt discount	6,702	3,612	19,840	10,690
Amortization of debt issuance costs	661	505	1,950	1,495
Total interest expense related to convertible debt	9,803	5,566	29,172	16,461
Non-cash interest expense	7,363	4,117	21,790	12,185
1.375% Convertible Senior Notes
Debt Instrument [Line Items]
Contractual coupon interest	1,362		4,129
Total interest expense related to convertible debt	5,098		15,130
Non-cash interest expense	3,736		11,001
1.25% Convertible Notes
Debt Instrument [Line Items]
Contractual coupon interest	1,078	1,102	3,234	3,259
Total interest expense related to convertible debt	4,705	4,505	13,963	13,332
Non-cash interest expense	$ 3,627	3,403	10,729	10,073
2% Convertible Senior Notes
Debt Instrument [Line Items]
Contractual coupon interest		347	19	1,017
Total interest expense related to convertible debt		1,061	79	3,129
Non-cash interest expense		$ 714	$ 60	$ 2,112

Convertible Debt, Net Convertib

Convertible Debt, Net Convertible Debt, Net - Summary of Convertible Debt (Details) - Level 2 - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	$ 584,485	$ 566,173
Carrying Value | 2% Convertible Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	0	3,421
Carrying Value | 1.375% Convertible Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	287,183	276,172
Carrying Value | 1.25% Convertible Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	297,302	286,580
Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	1,145,668	864,000
Estimated Fair Value | 2% Convertible Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	0	5,467
Estimated Fair Value | 1.375% Convertible Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	515,627	407,652
Estimated Fair Value | 1.25% Convertible Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	$ 630,041	$ 450,881

Convertible Debt, Net - Narrati

Convertible Debt, Net - Narrative (Details)	1 Months Ended			3 Months Ended		9 Months Ended
	Nov. 30, 2017USD ($)$ / shares	Sep. 30, 2016USD ($)$ / shares	Jun. 30, 2014USD ($)$ / shares	Jun. 30, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)
Debt Instrument [Line Items]
Unamortized discount					$ 170,448,000	$ 150,439,000
Convertible debt, net of current portion					566,173,000	584,485,000
Repayment of convertible notes						$ 6,699,000	$ 0
1.375% Convertible Senior Notes
Debt Instrument [Line Items]
Principal amount of senior notes	$ 402,500,000
Debt, interest rate						1.375%
Convertible debt, net of current portion						$ 287,200,000
1.25% Convertible Notes
Debt Instrument [Line Items]
Principal amount of senior notes		$ 344,992,000
Debt, interest rate		1.25%				1.25%
Conversion price, per share (USD per share) | $ / shares		$ 58.37
Nonconvertible debt borrowing rate		5.80%
Debt discount amortization period		5 years
Deferred financing costs, gross		$ 11,300,000
Finance costs reclassified against equity		$ 2,200,000
Deferred financing costs, amortization period		5 years
Long-term debt						$ 297,300,000
1.25% Convertible Notes | Investor
Debt Instrument [Line Items]
Unamortized discount		$ 66,700,000
2% Convertible Senior Notes
Debt Instrument [Line Items]
Principal amount of senior notes	$ 63,400,000		$ 201,300,000
Debt, interest rate			2.00%			2.00%
Conversion price, per share (USD per share) | $ / shares			$ 46.51
Repurchased amount		$ 134,200,000
Repayment of convertible notes				$ 6,700,000
Carrying amount of equity component				3,200,000
Convertible debt				3,500,000
Gain (loss) on extinguishment of debt				$ 0
Senior Notes | 1.375% Convertible Senior Notes
Debt Instrument [Line Items]
Debt, interest rate	1.375%
Debt conversion rate	0.0107315
Conversion price, per share (USD per share) | $ / shares	$ 93.18
Nonconvertible debt borrowing rate	6.80%
Debt discount amortization period	7 years
Deferred financing costs, gross					10,900,000
Finance costs reclassified against equity					3,300,000
Debt issuance costs					$ 7,600,000
Senior Notes | 1.375% Convertible Senior Notes | Investor
Debt Instrument [Line Items]
Unamortized discount	$ 120,700,000
Senior Notes | 1.25% Convertible Notes
Debt Instrument [Line Items]
Debt conversion rate		0.0171332
Senior Notes | 2% Convertible Senior Notes
Debt Instrument [Line Items]
Debt conversion rate			0.0215019

Accounts Receivable, Net (Detai

Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Receivables [Abstract]
Trade receivables	$ 73,428	$ 55,914
Allowance for doubtful accounts	(3,478)	(2,541)
Total accounts receivable, net	$ 69,950	$ 53,373

Net Income (Loss) Per Share - S

Net Income (Loss) Per Share - Schedule of Earnings per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Numerator:
Net income (loss)	$ 1,659	$ (2,227)	$ (6,601)	$ (19,971)
Denominator:
Weighted average number of shares outstanding, basic (in shares)	59,016,863	58,099,593	58,779,672	57,924,920
Effective of dilutive potential common share equivalents
Weighted average number of shares outstanding, diluted (in shares)	61,146,466	58,099,593	58,779,672	57,924,920
Net income (loss) per share:
Net income (loss) per share: basic (in dollars per share)	$ 0.03	$ (0.04)	$ (0.11)	$ (0.34)
Net income (loss) per shares: diluted (in dollars per share)	$ 0.03	$ (0.04)	$ (0.11)	$ (0.34)
Stock options
Effective of dilutive potential common share equivalents
Effective of dilutive potential common share equivalents	1,719,796		0
Stock options
Effective of dilutive potential common share equivalents
Effective of dilutive potential common share equivalents	409,807		0
Convertible debt
Effective of dilutive potential common share equivalents
Effective of dilutive potential common share equivalents	0		0

- Potential Common Shares Exclu

- Potential Common Shares Excluded from Computation of Diluted Net Loss Per Share (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total dilutive common shares (in shares)	10,754,004	11,850,509	14,212,915	11,914,219
1.375% Convertible Senior Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total dilutive common shares (in shares)	4,319,429	0	4,319,429	0
Debt, interest rate	1.375%		1.375%
2% Convertible Senior Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total dilutive common shares (in shares)	0	1,442,433	0	1,442,433
Debt, interest rate	2.00%		2.00%
1.25% Convertible Senior Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total dilutive common shares (in shares)	5,910,954	5,910,954	5,910,954	5,910,954
Debt, interest rate	1.25%		1.25%
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total dilutive common shares (in shares)	300,438	1,007,729	865,206	978,683
Outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total dilutive common shares (in shares)	223,183	3,489,393	3,117,326	3,582,149

Inventories - Components of Inv

Inventories - Components of Inventories (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 5,390		$ 2,146
Work-in-process	17,187		23,918
Finished goods, net	35,473		7,729
Total inventories	$ 58,050	$ 33,040	$ 33,793

Prepaid Expenses and Other As_3

Prepaid Expenses and Other Assets - Summary of Prepaid Expenses and Other Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid expenses and other current assets	$ 11,036		$ 9,949
Capitalized contract acquisition costs, current portion	6,869		0
Total prepaid expenses and other current assets	17,905	$ 15,517	9,949
Other assets	2,487	$ 15,295	1,969
Capitalized contract acquisition costs, net of current portion	15,570		0
Total other assets	$ 18,057		$ 1,969

Prepaid Expenses and Other As_4

Prepaid Expenses and Other Assets - Narrative (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Capitalized contract acquisition costs	$ 22,400,000
Capitalized contract acquisition costs, current portion	6,869,000	$ 0
Capitalized contract acquisition costs, net of current portion	15,570,000	$ 0
Amortization of capitalized commission costs	5,000,000
impairments to capitalized costs	$ 0

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets, Net - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Impairment of goodwill			$ 0
Goodwill	$ 39,774,000		39,774,000		$ 39,840,000
Amortization of other intangible assets	$ 500,000	$ 300,000	$ 1,300,000	$ 800,000
Customer and Contractual Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible asset, weighted average amortization period			9 years 1 month
Internal-use software
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible asset, weighted average amortization period			3 years 6 months

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets, Net - Components of Other Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 14,349	$ 9,680
Accumulated Amortization	(6,558)	(5,329)
Net Book Value	7,791	4,351
Customer and Contractual Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,078	2,135
Accumulated Amortization	(1,859)	(1,764)
Net Book Value	2,219	371
Internal-use software
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	10,271	7,545
Accumulated Amortization	(4,699)	(3,565)
Net Book Value	$ 5,572	$ 3,980

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets, Net - Amortization Expense Expected for Next Five Years (Details) $ in Thousands	Sep. 30, 2018USD ($)
Expected Amortization Expense [Line Items]
2018 (remaining)	$ 555
2,019	2,101
2,020	1,771
2,021	1,280
2,022	771
Thereafter	1,313
Net Book Value	7,791
Customer and Contractual Relationships
Expected Amortization Expense [Line Items]
2018 (remaining)	90
2,019	334
2,020	266
2,021	200
2,022	200
Thereafter	1,129
Net Book Value	2,219
Internal-use software
Expected Amortization Expense [Line Items]
2018 (remaining)	465
2,019	1,767
2,020	1,505
2,021	1,080
2,022	571
Thereafter	184
Net Book Value	$ 5,572

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Employee compensation and related costs	$ 32,265	$ 34,942
Professional and consulting services	10,190	9,273
Supplier charges	3,863	3,542
Short-term	2,303	1,653
Other	19,548	9,846
Total accrued expenses and other current liabilities	$ 68,169	$ 59,256

Accrued Expenses and Other Cu_4

Accrued Expenses and Other Current Liabilities - Narrative (Details)	9 Months Ended
	Sep. 30, 2018
United States
Product Warranty Liability [Line Items]
Product warranty term for PDMs	4 years
CANADA
Product Warranty Liability [Line Items]
Product warranty term for PDMs	5 years

Accrued Expenses and Other Cu_5

Accrued Expenses and Other Current Liabilities - Product Warranty Liability (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Dec. 31, 2017
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Product warranty liability at the beginning of the period	$ 5,503	$ 4,817	$ 5,337	$ 4,388
Warranty expense	1,763	1,483	5,264	3,123
Warranty claims settled	(1,548)	(1,303)	(4,883)	(2,514)
Product warranty liability at the end of the period	5,718	4,997	5,718	4,997
Composition of balance:
Short-term					$ 2,303	$ 1,653
Long-term					3,415	3,684
Total warranty balance	$ 5,503	$ 4,817	$ 5,337	$ 4,388	$ 5,718	$ 5,337

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) ft² in Thousands, $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Jun. 16, 2015LegalMatter	Sep. 30, 2018USD ($)ft²	Sep. 30, 2018USD ($)ft²
Loss Contingencies [Line Items]
Number of class actions filed (in legal matters) | LegalMatter	3
Number of class actions dismissed (in legal matters) | LegalMatter	2
Operating leases, rent expense		$ 0.9	$ 2.6
Laboratory And Office Space | Billerica Massachusetts
Loss Contingencies [Line Items]
Area of real estate property | ft²		100	100
Warehouse | Billerica Massachusetts
Loss Contingencies [Line Items]
Area of real estate property | ft²		29	29
Fees To Former European Distributor | Minimum
Loss Contingencies [Line Items]
Commitment due in next twelve months		$ 10	$ 10
Accrued liabilities		2	2
Fees To Former European Distributor | Maximum
Loss Contingencies [Line Items]
Commitment due in next twelve months		$ 55	$ 55

Stock-Based Compensation and _3

Stock-Based Compensation and Stockholder' Equity - Schedule of Stock-Based Compensation Expense Related to Share-Based Awards (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 16,088	$ 8,897	$ 31,205	$ 23,552
Unamortized Expense	38,883		38,883
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	296	149	884	379
Unamortized Expense	197		$ 197
Share-based compensation arrangement by share-based payment award, equity instruments other than options, outstanding, weighted average remaining contractual term			2 months
Stock options
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	3,957	3,127	$ 8,587	8,815
Unamortized Expense	13,632		$ 13,632
Share-based compensation arrangement by share-based payment award, options, vested and expected to vest, exercisable, weighted average remaining contractual term			2 years 5 months 17 days
Unvested restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	11,835	$ 5,621	$ 21,734	$ 14,358
Unamortized Expense	$ 25,054		$ 25,054
Share-based compensation arrangement by share-based payment award, equity instruments other than options, outstanding, weighted average remaining contractual term			1 year 11 months

Stock-Based Compensation and _4

Stock-Based Compensation and Stockholder' Equity - Stock Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)$ / sharesshares
Number of Options
Beginning balance (in shares)	3,377,220
Granted (in shares)	287,199
Exercised (in shares)	(384,887)
Canceled (in shares)	(162,206)
Ending balance (in shares)	3,117,326
Vested, at end of period (in shares)	2,077,854
Vested and expected to vest, at end of period (in shares)	3,019,139
Weighted Average Exercise Price
Beginning balance (in dollars per share) | $ / shares	$ 35.10
Granted (in dollars per share) | $ / shares	77.05
Exercised (in dollars per share) | $ / shares	33.11
Canceled (in dollars per share) | $ / shares	40.45
Ending balance (in dollars per share) | $ / shares	38.94
Vested, at end of period (in dollars per share) | $ / shares	$ 34.40
Aggregate Intrinsic Value
Exercised | $	$ 21,419
Ending balance | $	208,898
Vested, at end of period | $	148,671
Vested and expected to vest, at end of period | $	$ 203,882
Options outstanding, weighted average remaining contractual life	7 years 1 month
Options exercisable, weighted average remaining contractual life	6 years 6 months 25 days

Stock-Based Compensation and _5

Stock-Based Compensation and Stockholder' Equity - Summary of Restricted Stock Units (Details) - Unvested restricted stock units	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Number of Shares
Beginning balance (in shares) | shares	994,364
Granted (in shares) | shares	328,342
Adjustment (in shares) | shares	147,301
Vested (in shares) | shares	(526,638)
Forfeited (in shares) | shares	(78,163)
Ending balance (in shares) | shares	865,206
Weighted Average Grant Date Fair Value
Beginning balance (in dollars per share) | $ / shares	$ 38.08
Granted (in dollars per share) | $ / shares	75.51
Adjustment (in dollars per share) | $ / shares	29.54
Vested (in dollars per share) | $ / shares	33.59
Forfeited (in dollars per share) | $ / shares	44.58
Ending balance (in dollars per share) | $ / shares	$ 52.98

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Significant Accounting Policies [Line Items]
Unrecognized tax benefits	$ 0		$ 0
Reduction in net operating loss					$ 800,000
Reduction in valuation allowance					$ 800,000
Income tax expense	$ 194,000	$ 121,000	$ 939,000	$ 318,000
Minimum
Significant Accounting Policies [Line Items]
Number of open tax years			3 years
Maximum
Significant Accounting Policies [Line Items]
Number of open tax years			4 years