Insulet (PODD) 10-K 26 Feb 20 2019 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 20, 2020	Jun. 30, 2019
Cover page.
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Entity File Number	001-33462
Entity Registrant Name	INSULET CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3523891
Entity Address, Address Line One	100 Nagog Park
Entity Address, City or Town	Acton
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01720
City Area Code	978
Local Phone Number	600-7000
Title of 12(b) Security	Common Stock, $0.001 Par Value Per Share
Trading Symbol	PODD
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 7.2
Entity Common Stock, Shares Outstanding		62,863,402
Document Period End Date	Dec. 31, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Central Index Key	0001145197
Current Fiscal Year End Date	--12-31
Documents Incorporated by Reference	The registrant intends to file a proxy statement pursuant to Regulation 14A within 120 days of the end of the fiscal year ended December 31, 2019 . Portions of such proxy statement are incorporated by reference into Part III of this Annual Report on Form 10-K.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 213.7	$ 113.9
Short-term investments	162.4	175
Accounts receivable trade, less allowance for doubtful accounts of $3.8 and $3.6	69.3	63.3
Unbilled receivable	13.5	13.4
Inventories	101	71.4
Prepaid expenses and other current assets	31.1	24.3
Total current assets	591	461.3
Long-term investments	58.4	140.8
Property, plant and equipment, net	399.4	258.4
Other intangible assets, net	13.2	10.4
Goodwill	39.8	39.6
Other assets	41.1	18.2
Total assets	1,142.9	928.7
Current Liabilities
Accounts payable	54.5	25.5
Accrued expenses and other current liabilities	103.2	90.2
Total current liabilities	157.7	115.7
Convertible debt, net	887.9	592
Other liabilities	21.4	8.9
Total liabilities	1,067	716.6
Commitments and contingencies
Stockholders’ Equity
Preferred stock, $.001 par value: Authorized 5,000,000 shares at December 31, 2019 and 2018. Issued and outstanding: zero shares at December 31, 2019 and 2018	0	0
Common stock, $.001 par value: Authorized: 1,000,000 shares at December 31, 2019 and 2018. Issued and outstanding: 62,685,492 and 59,188,758 shares at December 31, 2019 and 2018, respectively	0.1	0.1
Additional paid-in capital	749	898.5
Accumulated deficit	(672)	(683.6)
Accumulated other comprehensive loss	(1.2)	(2.9)
Total stockholders’ equity	75.9	212.1
Total liabilities and stockholders’ equity	$ 1,142.9	$ 928.7

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 3.8	$ 3.6
Preferred stock, par value (in USD 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 USD per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	100,000,000	100,000,000
Common stock, issued (in shares)	62,685,492	59,188,758
Common stock, outstanding (in shares)	62,685,492	59,188,758

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Total revenue	$ 738.2	$ 563.8	$ 463.8
Cost of revenue	257.9	193.6	186.6
Gross profit	480.3	370.2	277.2
Operating expenses:
Research and development	129.7	90.5	75.7
Sales and marketing	185.1	146.2	124.2
General and administrative	115.5	106.1	84.7
Total operating expenses	430.3	342.8	284.6
Operating income (loss)	50	27.4	(7.4)
Interest expense, net of portion capitalized	(34.6)	(28.9)	(21.2)
Loss on extinguishment of debt	(8.7)	0	(0.6)
Interest and other income, net	7.8	6.7	2.6
Income (loss) before income taxes	14.5	5.2	(26.6)
Income tax expense	(2.9)	(1.9)	(0.2)
Net income (loss)	$ 11.6	$ 3.3	$ (26.8)
Net income (loss) per share:
Basic (USD per share)	$ 0.19	$ 0.06	$ (0.46)
Diluted (USD per share)	$ 0.19	$ 0.05	$ (0.46)
Weighted-average number of common shares outstanding:
Basic (in shares)	60,593,846	58,859,574	58,003,434
Diluted (in shares)	62,304,348	61,008,024	58,003,434

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 11.6	$ 3.3	$ (26.8)
Other comprehensive income (loss), net of tax
Foreign currency translation adjustment, net of tax	0.6	(2.2)	0.5
Unrealized gain (loss) on available-for-sale securities, net of tax	1.1	(0.2)	(0.3)
Total other comprehensive income (loss), net of tax	1.7	(2.4)	0.2
Total comprehensive income (loss)	$ 13.3	$ 0.9	$ (26.6)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	1.375% Convertible Senior Notes	2% Convertible Senior Notes	0.375% Convertible Senior Notes	1.25% Convertible Senior Notes	Common Stock	Additional Paid-in Capital	Additional Paid-in Capital1.375% Convertible Senior Notes	Additional Paid-in Capital2% Convertible Senior Notes	Additional Paid-in Capital0.375% Convertible Senior Notes	Additional Paid-in Capital1.25% Convertible Senior Notes	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2016						57,457,967
Beginning balance at Dec. 31, 2016	$ 63.1					$ 0.1	$ 744.2					$ (680.5)	$ (0.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of options to purchase common stock (in shares)						505,207
Exercise of options to purchase common stock	14						14
Issuance for employee stock purchase plan (in shares)						59,134
Issuance of shares for employee stock purchase plan	1.8						1.8
Stock-based compensation expense	31.9						31.9
Restricted stock units vested, net of shares withheld for taxes (in shares)						297,040
Restricted stock units vested, net of shares withheld for taxes	(4)						(4)
Conversion feature, net of issuance costs		$ 117.5	$ (39.2)					$ 117.5	$ (39.2)
Net income (loss)	(26.8)											(26.8)
Other comprehensive income (loss)	0.2												0.2
Ending balance (in shares) at Dec. 31, 2017						58,319,348
Ending balance at Dec. 31, 2017	158.5					$ 0.1	866.2					(707.3)	(0.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of options to purchase common stock (in shares)						409,428
Exercise of options to purchase common stock	12.8					$ 0	12.8
Issuance for employee stock purchase plan (in shares)						46,343
Issuance of shares for employee stock purchase plan	3						3
Stock-based compensation expense	37.5						37.5
Restricted stock units vested, net of shares withheld for taxes (in shares)						413,639
Restricted stock units vested, net of shares withheld for taxes	(17.8)						(17.8)
Conversion feature, net of issuance costs			$ (3.2)						$ (3.2)
Net income (loss)	3.3											3.3
Other comprehensive income (loss)	$ (2.4)												(2.4)
Ending balance (in shares) at Dec. 31, 2018	59,188,758					59,188,758
Ending balance at Dec. 31, 2018	$ 212.1					$ 0.1	898.5					(683.6)	(2.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of options to purchase common stock (in shares)	1,345,386					1,340,297
Exercise of options to purchase common stock	$ 46.6					$ 0	46.6
Issuance for employee stock purchase plan (in shares)						51,502
Issuance of shares for employee stock purchase plan	4.3						4.3
Stock-based compensation expense	28.7						28.7
Restricted stock units vested, net of shares withheld for taxes (in shares)						229,770
Restricted stock units vested, net of shares withheld for taxes	(8.6)						(8.6)
Conversion feature, net of issuance costs				$ 207.8	$ (642.3)					$ 207.8	$ (642.3)
Issuance of shares for debt repayment (in shares)						1,875,165
Issuance of shares for debt repayment	299.4						299.4
Purchase of capped call options	(85.4)						(85.4)
Net income (loss)	11.6											11.6
Other comprehensive income (loss)	$ 1.7
Ending balance (in shares) at Dec. 31, 2019	62,685,492					62,685,492
Ending balance at Dec. 31, 2019	$ 75.9					$ 0.1	$ 749					$ (672)	$ (1.2)

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
1.375% Convertible Senior Notes
Debt, interest rate	1.375%		1.375%
2% Convertible Senior Notes
Debt, interest rate	2.00%	2.00%	2.00%
0.375% Convertible Senior Notes
Debt, interest rate	0.375%
1.25% Convertible Senior Notes
Debt, interest rate	1.25%	1.25%

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities
Net income (loss)	$ 11.6	$ 3.3	$ (26.8)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	27.9	15.6	13.9
Non-cash interest expense	35.6	29.3	18
Stock-based compensation expense	28.7	37.5	31.9
Loss on extinguishment of convertible debt	8.7	0	0.6
Provision for bad debts	4.5	3.4	1.9
Other	1.1	(0.4)	0.1
Changes in operating assets and liabilities:
Accounts and unbilled receivable	(10.9)	(22.9)	(26.3)
Inventories	(30.2)	(38.8)	1.7
Deferred revenue	2	(3.8)	1.1
Prepaid expenses and other assets	(21.9)	(11.6)	(3.3)
Accounts payable, accrued expenses and other current liabilities	36.2	21.2	27.3
Other long-term liabilities	5.1	3.1	1.2
Net cash provided by operating activities	98.4	35.9	41.3
Cash flows from investing activities
Capital expenditures	(163.7)	(157.4)	(73.8)
Acquisition of intangible assets	(7.2)	(5)	(3.4)
Purchases of investments	(150.6)	(191.4)	(298)
Receipts from the maturity or sale of investments	247.9	169.3	164.4
Net cash used in investing activities	(73.6)	(184.5)	(210.8)
Cash flows from financing activities
Principal payments of capital lease obligations	0	0	(0.3)
Proceeds from issuance of convertible debt, net of issuance costs	780.2	0	391.6
Purchase of capped call options	(85.4)	0	0
Repayment of convertible debt	(663.6)	(6.7)	(98.5)
Proceeds from exercise of stock options and issuance of common stock under employee stock purchase plan	50.9	15.8	15.8
Payment of withholding taxes in connection with vesting of restricted stock units	(8.6)	(17.8)	(4.1)
Net cash provided by (used in) financing activities	73.5	(8.7)	304.5
Effect of exchange rate changes on cash	1.5	(1.4)	0.4
Net increase (decrease) in cash and cash equivalents	99.8	(158.7)	135.4
Cash, cash equivalents and restricted cash, beginning of year	113.9	272.6	137.2
Cash, cash equivalents and restricted cash, end of year	213.7	113.9	272.6
Supplemental cash flow information
Cash paid for interest, net of amount capitalized	0	0	2.5
Cash paid for taxes	2.5	0.8	0.5
Purchases of property, plant and equipment included in accounts payable and accrued expenses	$ 13.3	$ 11.4	$ 3.8

Nature of the Business

Nature of the Business	12 Months Ended
	Dec. 31, 2019
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, manufacture and sale of its proprietary Omnipod System, an innovative, continuous insulin delivery system for people with insulin-dependent diabetes. The Omnipod System features a small, lightweight, self-adhesive disposable tubeless Omnipod device that is worn on the body for up to 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 multiple daily injections using syringes or insulin pens or the use of traditional pump and tubing. The Omnipod System consists of two product lines: the Omnipod Insulin Management System (“Omnipod”) and its next generation Omnipod DASH TM Insulin Management System (“Omnipod DASH” or “DASH”). Omnipod DASH features a secure Bluetooth enabled Pod and PDM with a color touch screen user interface supported by smartphone connectivity. The Company generates most of its revenue from sales of the Omnipod System, which is sold in the U.S., Europe, Canada and the Middle East. The Omnipod System is sold either directly to end-users or indirectly through intermediaries. Intermediaries include independent distributors who resell the Omnipod to end-users and wholesalers who sell the Company’s product to end-users through the pharmacy channel in the United States. In addition to selling 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 consists of sales of Pods to Amgen for use in the Neulasta Onpro kit, an innovative delivery system for Amgen’s white blood cell booster to help reduce the risk of infection after intense chemotherapy.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements reflect the consolidated operations of Insulet Corporation and its subsidiaries. The consolidated financial statements have been prepared in United States dollars, in accordance with accounting principles generally accepted in the United States of America (GAAP). The preparation of the consolidated financial statements in conformity with GAAP requires management to make use of estimates and assumptions that affect the reported amount of assets and liabilities, disclosure of contingent assets and liabilities, and the reported amounts of revenues and expenses. Actual results may differ from those estimates. 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. Reclassification of Prior Period Amounts Certain reclassifications have been made to prior period amounts to conform to the current period financial statement presentation. Software license costs have been reallocated from general and administrative expenses to research and development and sales and marketing expenses based on license usage. These reclassifications have no effect on previously reported net income. Foreign Currency Translation For the foreign subsidiaries of the Company, assets and liabilities are translated into U.S. dollars using exchange rates as of the balance sheet date, and income and expenses are translated using the average exchange rates in effect for the related month. The net effect of these translation adjustments is reported in accumulated other comprehensive loss within stockholders’ equity on the consolidated balance sheet. Net realized and unrealized gains (losses) from foreign currency transactions are included in interest and other income, net in the consolidated statement of operations and were $0.6 million and $1.0 million for the years ended December 31, 2019 and 2018 , respectively. The amount for 2017 was insignificant. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of 90 days or less at the time of purchase to be cash equivalents. Cash equivalents include money market mutual funds, commercial paper and U.S. government and agency bonds that are carried at cost, which approximates their fair value. Restricted cash that serves as collateral for outstanding letters of credit are included in cash and cash equivalents on the consolidated balance sheet. Investments in Marketable Securities Short-term and long-term investment securities consist of certificates of deposit, commercial paper, U.S. government and agency bonds and corporate bonds. Theses available-for-sale marketable securities are carried at fair value and unrealized gains and losses are included as a component of other comprehensive loss in stockholders’ equity on the consolidated balance sheet. Investments with a stated maturity date of more than one year from the balance sheet date and that are not expected to be used in current operations are classified as long-term investments on the consolidated balance sheet. The Company reviews investments for other-than-temporary impairment when the fair value of an investment is less than its amortized cost. If an available-for-sale security is other than temporarily impaired, the loss is included in other income, net in the consolidated statement of operations. Accounts Receivable and Allowance for Doubtful Accounts Trade accounts receivable consist of amounts due from third-party payors, customers and intermediaries and are presented net of an allowance for doubtful accounts. The allowance for doubtful accounts reflects an estimate of losses inherent in the Company’s accounts receivable portfolio determined based on historical experience, specific allowances for known troubled accounts and other available evidence. Accounts receivable are written off when management determines they are uncollectible. Inventories Inventories are stated at the lower of cost or net realizable value, with cost determined under the first-in, first-out method. The Company reduces the carrying value of inventories for those items that are potentially excess, obsolete or slow-moving based on changes in customer demand, technology developments or other economic factors in order to state inventories at net realizable value. Factors influencing these adjustments include inventories on hand compared to estimated future usage and sales. Work in process is calculated based upon a buildup of cost based on the stage of production. Manufacturing variances attributable to abnormally low production are expensed in the period incurred. Contract Acquisition Costs The Company incurs commission costs to obtain a contract related to new customer starts. These costs are capitalized as contract assets 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 costs are periodically reviewed for impairment. Fair Value Measurements Fair value is defined as the price that would be received from the sale of an asset or paid to transfer a liability in the principal or most advantageous market in an orderly transaction between market participants on the measurement date. When estimating fair value, the Company may use one or all the following approaches: • Market approach, which is based on market prices and other information from market transactions involving identical or comparable assets or liabilities. • Cost approach, which is based on the cost to acquire or construct comparable assets less an allowance for functional and/or economic obsolescence. • Income approach, which is based on the present value of the future stream of net cash flows. To measure fair value of assets and liabilities, the Company uses the following fair value hierarchy based on three levels of inputs: Level 1 — observable inputs, such as quoted prices in active markets for identical assets or liabilities; Level 2 — significant other observable inputs that are observable either directly or indirectly; Level 3 — significant unobservable inputs for which there is little or no market data, which require the Company to develop its own assumptions. Certain of the Company’s financial instruments, including cash and cash equivalents, accounts receivable, accounts payable, accrued expenses and other liabilities are carried at cost, which approximates their fair value because of their short-term maturity. See Notes 5 and 12 for financial assets and liabilities held at carrying amount on the consolidated balance sheet and Note 6 for investments measured at fair value on a recurring basis. Property, Plant and Equipment Property, plant and equipment is stated at cost less accumulated depreciation. Major improvements are capitalized, while routine repairs and maintenance are expensed as incurred. Depreciation for property, plant and equipment, other than land and construction in progress, is based upon the following estimated useful lives using the straight-line method: Building and building improvements 20 to 39 years Leasehold improvements Lesser of lease term or useful life of asset Machinery and equipment 2 to 15 years Furniture and fixtures 3 to 5 years The Company assesses the recoverability of assets whenever events or changes in circumstances suggest that the carrying value of an asset may not be recoverable. The Company recognizes an impairment loss if the carrying amount of a long-lived asset is not recoverable based on its undiscounted future cash flows. The impairment loss is measured as the difference between the carrying amount and the fair value of the asset. Business Combinations The Company recognizes the assets and liabilities assumed in business combinations based on their estimated fair values at the date of acquisition. The Company allocates the purchase price in excess of net tangible assets acquired to identifiable intangible assets. The Company assesses the fair value of assets, including intangible assets, using a variety of methods and each asset is measured at fair value from the perspective of a market participant. Assets recorded from the perspective of a market participant that are determined to not have economic use for the Company are expensed immediately. Any excess purchase price over the fair value of the net tangible and intangible assets acquired is allocated to goodwill. Transaction costs and restructuring costs associated with a business combination are expensed as incurred. Goodwill and Other Intangible Assets Goodwill represents the excess of the purchase price of an acquired entity over the amounts assigned to assets and liabilities assumed in a business combination. The Company performs an assessment of its goodwill for impairment annually on October 1 or whenever events or changes in circumstances indicate there might be impairment. Goodwill is evaluated for impairment at the reporting unit level. The Company may assess its goodwill for impairment initially using a qualitative approach to determine whether conditions exist that indicate it is more likely than not that the fair value of a reporting unit is less than its carrying value. If management concludes, based on its assessment of relevant events, facts and circumstances that it is more likely that not that a reporting unit’s carrying value is greater than its fair value, then a quantitative analysis will be performed to determine if there is any impairment. Alternatively, the Company may elect to initially perform a quantitative analysis instead of starting with a qualitative analysis. In performing the quantitative test, the Company utilizes a two-step approach. The first step compares the carrying value of the reporting unit to its fair value. If the reporting unit’s carrying value exceeds its fair value, the Company would perform the second step and record an impairment loss to the extent that the carrying value of the reporting unit’s goodwill exceeds its implied fair value. Intangible assets acquired in a business combination are recorded at fair value, while intangible assets acquired in other transactions are recorded at cost and are stated at cost less accumulated amortization. Intangible assets with finite useful lives are amortized using the straight-line method over the following estimated useful lives of the assets: Customer relationships 5 - 10 years Internal-use software 3 - 10 years Intellectual property 15 years Amortization expense is included in operating expenses in the consolidated statement of operations. The Company reviews intangible assets for impairment by comparing the fair value of the assets, estimated using an income approach, with their carrying value. If the carrying value exceeds the fair value of the intangible asset, the Company recognizes an impairment equal to the difference between the carrying value of the asset and the present value of future cash flows. The Company assesses the remaining useful life and the recoverability of intangible assets whenever events or circumstances indicate that the carrying value of an asset may not be recoverable using undiscounted cash flows. Leases The Company determines if an arrangement includes a lease at inception. Lease agreements generally have lease and non-lease components, which are accounted for separately. At lease commencement, the Company recognizes operating lease liabilities equal to the present value of the lease payments and operating lease assets representing the right to use the underlying asset for the lease term. The Company assesses if it is reasonably certain to exercise lease options to extend or terminate the lease for inclusion or exclusion in the lease term when the Company measures the lease liability. As the Company’s leases do not provide an implicit rate, the Company uses an incremental borrowing rate based on the information available at lease commencement in determining the present value of lease payments. The Company’s incremental borrowing rate estimates a secured rate that reflects the term of the lease, the nature of the underlying asset and the economic environment. The Company excludes leases with an expected term of one year or less from recognition on the consolidated balance sheet. Operating lease assets includes lease payments made prior to lease commencement and excludes lease incentives and initial direct costs incurred. Lease expense is recognized on a straight-line basis over the lease term and is included in general and administrative expenses in the consolidated statements of operations. Contingencies The Company records a liability on the consolidated balance sheet for loss contingencies when a loss is considered probable and the amount can be reasonably estimated. If the reasonable estimate of a known or probable loss is a range, and no amount within the range is a better estimate than any other, the minimum amount of the range is accrued. If a loss is reasonably possible but not known or probable, and can be reasonably estimated, the estimated loss or range of loss is disclosed. Product Warranty The Company provides a four-year warranty on its PDMs sold in the United States and Europe and a five-year warranty on PDMs sold in Canada and may replace Pods that do not function in accordance with product specifications. The Company estimates its warranty obligation 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 in the consolidated statements of operations. Costs to service the claims reflect the current product cost. Since the Company continues to introduce new products and versions, the anticipated performance of the product over the warranty period is also considered in estimating warranty reserves. Revenue Recognition Effective January 1, 2018, the Company adopted ASU 2014-09, Revenue from Contracts with Customers, and its related amendments (collectively referred to as ASC 606) using the modified retrospective method for all contracts not completed as of the date of adoption. The cumulate effect of applying the new revenue standard resulted in a $20.4 million decrease to the opening balance of accumulated deficit upon adoption, primarily related to how revenue is recognized for the Company’s drug delivery product line and the capitalization of contract acquisition costs such as commissions. Financial information for 2017 has not been restated and continues to be reported under the guidance in effect prior to the adoption of ASC 606. Revenue is recognized when a customer obtains control of the promised products. The amount of revenue recognized reflects the consideration 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: • Identify Contracts with Customers. The Company’s contracts with its direct customers generally consist of a physician order form, a customer 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. • Identify 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. In the Company’s judgment, these performance obligations are capable of being distinct and distinct in the context of the contract in that the customer can benefit from each item in conjunction with other readily available resources and the transfer of the PDM and the Pods is separately identifiable in the contract with the customer. • Determine 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 end-users. 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 (such as product return trends or forecast sale volumes) 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 it is probable that a significant future reversal of cumulative revenue under the contract will not occur; otherwise, the Company reduces the variable consideration. The variable consideration in the Company’s contracts is not typically constrained and the Company’s contracts do not contain significant financing components. • Allocate Transaction Price to Performance Obligations. 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. • Recognize Revenue as Performance Obligations are Satisfied. 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 ownership. 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, including transfer of title. 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. 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. Collaborative Arrangements The Company enters into collaborative arrangements for ongoing initiatives to develop products. Although the Company does not consider any individual alliance to be material, the following more notable alliance is described below. Concentrated Insulin Delivery : In May 2013, the Company entered into an agreement with Eli Lilly and Company (“Eli Lilly”) to develop a new version of the Omnipod System specifically designed to deliver Eli Lilly’s Humulin ® R U-500 insulin, a concentrated form of insulin used by people with highly insulin resistant Type 2 diabetes. In January 2016, the Company entered into a development agreement with Eli Lilly to develop a new version of the Omnipod System, specifically designed to deliver Eli Lilly’s Humalog ® 200 insulin, a concentrated form of insulin that provides the same dose of insulin in half the volume of Eli Lilly’s Humalog ® U-100 insulin. Under the terms of these arrangements, the parties share the responsibility of the permissible costs that are incurred. Any amounts incurred in excess of the permissible shared costs that are the responsibility of one party becomes due and payable by the other party. Consideration received and payments made by the Company under the terms of the arrangements are recorded within research and development expenses. 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 $9.7 million , $6.6 million and $5.0 million for the years ended December 31, 2019 , 2018 and 2017 , respectively. Stock-Based Compensation The Company measures stock-based compensation expense at the grant date based on the fair value of the award and recognizes the compensation expense over the requisite service period, which is generally the vesting period. The amount of stock-based compensation expense recognized during a period is based on the portion of the awards that are expected to vest. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Income Taxes The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Deferred tax assets and liabilities are determined based on differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates that will be in effect in the years in which the differences are expected to reverse. The Company reviews its deferred tax assets for recoverability considering historical profitability, projected future taxable income, and the expected timing of the reversals of existing temporary differences and tax planning strategies. A valuation allowance is provided to reduce the deferred tax assets if, based on the available evidence, it is more likely than not that some or all the deferred tax assets will not be realized. The effect of a change in enacted tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. Concentration of Credit Risk Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents, short-term and long-term investments in marketable securities and accounts receivable. The Company maintains most of its cash, and short-term and long-term investments with a limited number of financial institutions that have a high investment grade credit rating. In addition to manufacturing the Omnipod System, the Company also purchases Omnipod Systems from Flex Ltd. As of both December 31, 2019 and 2018 , liabilities to this vendor represented 10% of the combined balance of accounts payable and accrued expenses and other current liabilities. See Note 4 for customer concentration. Recently Adopted Accounting Standards Effective January 1, 2019, the Company adopted Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) (“ASU 2016-02”). ASU 2016-02 and its related amendments (collectively referred to as ASC 842). ASC 842 requires lessees to recognize operating lease liabilities and operating lease assets, representing the right to use the underlying asset for the lease term, on the balance sheet for leases classified as operating leases. The Company adopted ASC 842 on January 1, 2019 using the modified retrospective method, whereby the new guidance is applied prospectively as of the date of adoption and prior periods are not restated. The Company elected the practical expedients that permit the Company to not reassess (1) whether any expired or existing contracts are or contain leases, (2) the lease classification for any expired or existing leases, and (3) any initial direct costs for existing leases as of the effective date. Upon the adoption, the Company recorded operating lease liabilities of $10.8 million and operating lease assets of $8.8 million on its consolidated balance sheet. The difference between the value of the lease obligations and the operating lease assets was primarily attributable to a $1.1 million cease-use liability established in 2018 associated with the Company’s former headquarters, which was reclassified to an operating lease liability upon adoption of ASC 842. See Note 11 for additional information regarding leases. Effective January 1, 2019, the Company early adopted 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 certain costs to implement a cloud computing arrangement that is a service contract to be capitalized consistent with the rules applicable to internal-use software capitalization projects. The Company adopted this new guidance prospectively. The Company defers eligible costs related to the implementation of cloud computing arrangements within other current and non-current assets and amortizes such costs over the expected term of the hosting arrangement to the same income statement line as the associated cloud operating expenses. Adoption of this standard resulted in the Company capitalizing $3.6 million of cloud computing implementation costs for the year ended December 31, 2019 .

Segment and Geographic Data

Segment and Geographic Data	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment and Geographic Data	Segment and Geographic Data The Company operates under one reportable segment. Operating segments are defined as components of an enterprise for 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 that 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, as the Company’s current product offering primarily consists of the Omnipod System and drug delivery devices based on the Omnipod platform. Geographic information about revenue, based on delivery location, is as follows: Years Ended December 31, (in millions) 2019 2018 2017 United States $ 485.1 $ 391.8 $ 343.8 All other 253.1 172.0 120.0 Total $ 738.2 $ 563.8 $ 463.8 Geographic information about long-lived assets, net, excluding goodwill and other intangible assets is as follows: As of December 31, (in millions) 2019 2018 United States $ 363.0 $ 232.3 China 35.9 25.6 Other 0.5 0.9 Total $ 399.4 $ 258.8

Revenue and Contract Acquisitio

Revenue and Contract Acquisition Costs	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue and Contract Acquisition Costs	Revenue and Contract Acquisition Costs The following table summarizes the Company’s disaggregated revenues: Years Ended December 31, (in millions) 2019 2018 2017 U.S. Omnipod $ 420.4 $ 323.5 $ 271.6 International Omnipod 253.1 172.0 120.0 Total Omnipod 673.5 495.5 391.6 Drug Delivery 64.7 68.3 72.2 Total revenue $ 738.2 $ 563.8 $ 463.8 Revenue for customers comprising 10% or more of total revenue was as follows: Years Ended December 31, 2019 2018 2017 Amgen, Inc. * 12% 15% Ypsomed * * 22% Cardinal Health Inc. and affiliates 11% 12% 11% * Represents less than 10% of revenue for the period. Deferred revenue related to unsatisfied performance obligations was included in the following consolidated balance sheet accounts in the amounts shown: As of December 31, (in millions) 2019 2018 Accrued expenses and other current liabilities $ 3.2 $ 1.2 Other liabilities 1.0 0.9 Total deferred revenue $ 4.2 $ 2.1 Revenue recognized for the year ended December 31, 2019 included in deferred revenue at the beginning of 2019 was $1.2 million . Revenue recognized during the 2018 included in deferred revenue at the beginning of 2018 was $2.4 million . No revenue was recognized for the years ended December 31, 2019 and 2018 from performance obligations satisfied or partially satisfied in previous periods. Contract acquisition costs, representing capitalized commission costs related to new customers, net of amortization, were included in the following consolidated balance sheet accounts in the amounts shown: As of December 31, (in millions) 2019 2018 Prepaid expenses and other current assets $ 9.5 $ 7.3 Other assets 19.9 16.0 Total capitalized contract acquisition costs, net $ 29.4 $ 23.3 The Company recognized $8.8 million and $6.9 million of amortization of capitalized contract acquisition costs for the years ended December 31, 2019 and 2018 , respectively.

Cash and Cash Equivalents

Cash and Cash Equivalents	12 Months Ended
	Dec. 31, 2019
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents	Cash and Cash Equivalents The following tables provide a summary of cash and cash equivalents as of December 31, 2019 and 2018 and the level in the fair value hierarchy in which those measurements fall: (in millions) Fair Value Measurements December 31, 2019 Total Level 1 Level 2 (1) Cash $ 85.3 $ 85.3 $ — Money market mutual funds 115.5 115.5 — Commercial paper 10.0 10.0 Restricted cash 2.9 2.9 Total cash and cash equivalents $ 213.7 $ 203.7 $ 10.0 December 31, 2018 Cash $ 64.0 $ 64.0 $ — Money market mutual funds 47.2 47.2 — Restricted cash 2.7 2.7 Total cash and cash equivalents $ 113.9 $ 113.9 $ — (1) Fair value was determined using market prices obtained from third-party pricing sources.

Investments

Investments	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Investments	Investments The Company’s short-term and long-term investments in debt securities had maturity dates that range from two months to two years at December 31, 2019 . Realized gains or losses in each of the three years ended December 31, 2019 , 2018 and 2017 were insignificant. The following tables provides amortized costs, gross unrealized gains and losses, fair values and the level in the fair value hierarchy for the Company’s investments at December 31, 2019 and 2018 : (in millions) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Level 1 Level 2 (1) December 31, 2019 U.S. government and agency bonds $ 94.7 $ 0.3 $ — $ 95.0 $ 85.0 $ 10.0 Corporate bonds 51.0 0.1 — 51.1 — 51.1 Certificates of deposit 6.3 — — 6.3 — 6.3 Commercial paper 10.0 — — 10.0 10.0 Total short-term investments $ 162.0 $ 0.4 $ — $ 162.4 $ 85.0 $ 77.4 U.S. government and agency bonds $ 52.9 $ 0.1 $ (0.1 ) $ 52.9 $ 42.9 $ 10.0 Corporate bonds 2.8 — — 2.8 — 2.8 Certificates of deposit 2.7 — — 2.7 — 2.7 Total long-term investments $ 58.4 $ 0.1 $ (0.1 ) $ 58.4 $ 42.9 $ 15.5 December 31, 2018 U.S. government and agency bonds $ 113.0 $ — $ (0.5 ) $ 112.5 $ 69.6 $ 42.9 Corporate bonds 56.2 — (0.2 ) 56.0 — 56.0 Certificates of deposit 6.5 — — 6.5 — 6.5 Total short-term investments $ 175.7 $ — $ (0.7 ) $ 175.0 $ 69.6 $ 105.4 U.S. government and agency bonds $ 90.5 $ 0.1 $ (0.2 ) $ 90.4 $ 64.1 $ 26.3 Corporate bonds 46.7 — — 46.7 — 46.7 Certificates of deposit 3.7 — — 3.7 — 3.7 Total long-term investments $ 140.9 $ 0.1 $ (0.2 ) $ 140.8 $ 64.1 $ 76.7 (1) Fair value was determined using market prices obtained from third-party pricing sources.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2019
Inventory Disclosure [Abstract]
Inventories	Inventories At the end of each period, inventories were comprised of the following: (in millions) As of December 31, 2019 2018 Raw materials $ 23.3 $ 10.4 Work-in-process 40.3 30.2 Finished goods 37.4 30.8 Total inventories $ 101.0 $ 71.4

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Property, Plant and Equipment, Net Property, plant and equipment at cost and accumulated depreciation were as follows: As of December 31, (in millions) 2019 (1) 2018 Land $ 2.5 $ 2.5 Building and building improvements 116.9 44.2 Machinery and equipment 194.8 93.3 Furniture and fixtures 12.7 6.3 Leasehold improvements 1.6 1.4 Construction in process 161.5 176.1 Total property, plant and equipment 490.0 323.8 Less: accumulated depreciation (90.6 ) (65.4 ) Property, plant and equipment, net $ 399.4 $ 258.4 (1) Reclassification of prior period amounts were made from furniture and fixtures to building and building improvements to conform with current period financial statement presentation. Depreciation expense related to property and equipment was $25.2 million , $13.8 million and $12.7 million for the years ended December 31, 2019 , 2018 and 2017 , respectively. Construction in process primarily consists of manufacturing equipment located at the Company’s U.S. manufacturing facility in Acton, Massachusetts, which is expected to be placed into service during 2020.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets, Net	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets, Net	Goodwill and Other Intangible Assets, Net Goodwill The changes in the carrying amount of goodwill for 2019 and 2018 were as follows: Years Ended December 31, (in millions) 2019 2018 Beginning balance $ 39.6 $ 39.8 Foreign currency adjustment 0.2 (0.2 ) Ending balance $ 39.8 $ 39.6 Intangible Assets, Net The gross carrying amount, accumulated amortization and net book value of intangible assets at the end of each period were as follows: As of December 31, 2019 2018 (in millions) Gross Carrying Amount Accumulated Amortization Net Book Value Gross Carrying Amount Accumulated Amortization Net Book Value Customer relationships (1) $ 9.9 $ (2.8 ) $ 7.1 $ 6.1 $ (1.9 ) $ 4.2 Internal-use software 12.0 (6.8 ) 5.2 11.3 (5.1 ) 6.2 Intellectual property 1.0 (0.1 ) 0.9 — — — Total intangible assets $ 22.9 $ (9.7 ) $ 13.2 $ 17.4 $ (7.0 ) $ 10.4 (1) Includes customer relationships acquired from the Company’s former European distributor. See Note 13 . Intangible asset amortization expense was $2.7 million , $1.8 million and $1.2 million for the years ended December 31, 2019 , 2018 and 2017 , respectively. Amortization expense associated with the intangible assets included on the Company’s balance sheet as of December 31, 2019 is expected to be as follows: Years Ending December 31, (in millions) 2020 $ 2.9 2021 2.4 2022 1.9 2023 1.3 2024 1.2 Thereafter 3.5 Total $ 13.2

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2019
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 were as follows: As of December 31, (in millions) 2019 2018 Employee compensation and related costs $ 45.8 $ 37.8 Professional and consulting services 19.3 14.9 Accrued rebates 7.5 2.8 Supplier purchases 2.4 7.7 Value added taxes payable 1.8 8.5 Other 26.4 18.5 Accrued expenses and other current liabilities $ 103.2 $ 90.2 Reconciliations of the changes in the Company’s product warranty liability were as follows: Years Ended December 31, (in millions) 2019 2018 Product warranty liability at beginning of year $ 6.4 $ 5.3 Warranty expense 13.4 7.8 Warranty claims settled (11.3 ) (6.7 ) Product warranty liability at end of year $ 8.5 $ 6.4

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	Leases As of December 31, 2019 , the Company leased certain office spaces, laboratory space, warehouse space and automobiles, all of which were classified as operating leases. Certain of the Company’s operating leases include escalating rental payments, some include the option to extend for up to 5 years , and some include options to terminate the leases at certain times within the lease term. As of December 31, 2019 , the Company included options to extend certain leases for 5 years in the measurement of the lease liability. As of December 31, 2019 , operating lease assets and operating lease liabilities were included in the following consolidated balance sheet accounts in the amounts shown: (in millions) Operating lease asset: Other assets $ 16.1 Operating lease liabilities: Accrued expenses and other current liabilities $ 3.6 Other liabilities 14.4 Total $ 18.0 The Company’s total operating lease cost was $4.3 million for the year ended December 31, 2019 . Total rental expense was $3.3 million and $2.8 million for the years ended December 31, 2018 and 2017, respectively. Cash paid for amounts included in the measurement of lease liabilities was $ 3.6 million for the year ended December 31, 2019 . Operating lease liabilities arising from obtaining operating lease assets was $9.8 million for the year ended December 31, 2019 . Maturities of lease liabilities as of December 31, 2019 are as follows: Years Ending December 31, (in millions) 2020 $ 4.5 2021 5.0 2022 4.7 2023 2.3 2024 2.4 Thereafter 1.5 Total future minimum lease payments 20.4 Less: imputed interest (2.4 ) Present value of future minimum lease payments $ 18.0 As of December 31, 2019 , the weighted average remaining lease term for operating leases was 4.4 years and the weighted-average discount rate used to determine the operating lease liability was 5.9% .

Convertible Debt, Net

Convertible Debt, Net	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Convertible Debt, Net	Convertible Debt, Net The components of outstanding convertible debt consisted of the following: As of December 31, (in millions) 2019 2018 1.25% Convertible Senior Notes, due September 2021 $ — $ 345.0 1.375% Convertible Senior Notes, due November 2024 402.5 402.5 0.375% Convertible Senior Notes, due September 2026 800.0 — Unamortized debt discount (294.8 ) (143.6 ) Debt issuance costs (19.8 ) (11.9 ) Total convertible debt, net $ 887.9 $ 592.0 0.375% Convertible Senior Notes In September 2019, the Company issued $800.0 million aggregate principal amount of 0.375% Convertible Senior Notes due September 2026 (the “ 0.375% Notes”). The notes are convertible into the Company’s common stock at an initial conversion rate of 4.4105 shares of common stock per $1,000 principal amount of the notes, which is equivalent to a conversion price of $226.73 per share, subject to adjustment under certain circumstances. The notes will be convertible June 1, 2026 through August 28, 2026 and prior thereto under certain circumstances. The Company recorded a debt discount of $213.0 million related to the 0.375% 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 5.29% per annum. The Company also incurred debt issuance costs and other expenses of $19.8 million , of which $5.3 million was reclassified as a reduction to the value of the conversion feature allocated to equity. The remaining $14.5 million of debt issuance costs was recorded as a reduction of debt on the consolidated balance sheet. The net proceeds of $780.2 million were used to fund the redemption of the Company’s 1.25% Convertible Senior Notes due September 2021 (the “ 1.25% Notes”) and to purchase capped call options (“Capped Calls”), both of which are discussed below. Additional interest of 0.5% per annum is payable if the Company fails to timely file required documents or reports with the Securities and Exchange Commission (“SEC”). If the Company merges or consolidates with a foreign entity, the Company may be required to pay additional taxes. The Company determined that the higher interest payments and tax payments required in certain circumstances were embedded derivatives that should be bifurcated and accounted for at fair value. The Company assessed the value of the embedded derivatives at December 31, 2019 and determined it had nominal value. In conjunction with the issuance of the 0.375% Notes, the Company paid $85.4 million to enter into Capped Calls on the Company’s common stock with certain counterparties, which was recorded as a reduction to additional paid-in capital on the consolidated balance sheet. By entering into the Capped Calls, the Company expects to reduce the potential dilution to its common stock (or, in the event the conversion is settled in cash, to provide a source of cash to settle a portion of its cash payment obligation) in the event that at the time of conversion its stock price exceeds the conversion price under the 0.375% Notes. The Capped Calls have an initial strike price of $335.90 per share, which represents a premium of 100% over the last reported sale price of the Company’s common stock of $167.95 per share on the date of the transaction. The Capped Calls cover 3.5 million shares of common stock. 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 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 notes, which is equivalent to a conversion price of $93.18 per share, subject to adjustment under certain circumstances. The notes will be convertible August 15, 2024 through November 13, 2024 and prior thereto only under certain 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 Company also incurred debt issuance costs and other expenses of $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 was presented as a reduction of debt on the consolidated balance sheet. Additional interest of 0.5% per annum is payable if the Company fails to timely file required documents or reports with the SEC. If the Company merges or consolidates with a foreign entity, the Company may be required to pay additional taxes. The Company determined that the higher interest payments and tax payments required in certain circumstances were embedded derivatives that should be bifurcated and accounted for at fair value. The Company assessed the value of the embedded derivatives at each balance sheet date and determined it had nominal value. 1.25% Convertible Senior Notes In 2019, the Company repurchased its $345.0 million principal amount ( $312.0 million net of discount and issuance costs) 1.25% Notes for total consideration of $963.0 million comprised of $663.6 million in cash and $299.4 million representing the fair value of the 1.87 million shares issued. The Company allocated $642.3 million of the settlement to the fair value of the equity component and $320.7 million to the debt component, which resulted in an $8.7 million loss on extinguishment. 2% Convertible Senior Notes In 2017, the Company repurchased $63.4 million in principal of its 2% Convertible Senior Notes due June 2019 (the “2% Notes”). The Company called the remaining 2% Notes in 2018 and settled the outstanding principal and conversion feature for $6.7 million in cash. The Company allocated $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. Fair Value 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 December 31, 2019 and 2018 are as follows: As of December 31, 2019 2,019 2018 (in millions) Carrying Value Estimated Fair Value (1) Carrying Estimated Fair Value (1) 1.25% Convertible Senior Notes — — 301.0 483.9 1.375% Convertible Senior Notes 306.9 512.8 291.0 426.0 0.375% Convertible Senior Notes 581.0 840.0 — — Total $ 887.9 $ 1,352.8 $ 592.0 $ 909.9 (1) Fair value was determined using market prices obtained from third-party pricing sources.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
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 approving the settlement , but took the plaintiffs’ motion for fees and expenses under advisement, which motion remains pending. 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. The Company does not expect the outcome of these proceedings, either individually or in the aggregate, to have a material adverse effect on its results of operations. Fees to Former European Distributor Following the expiration of an agreement with a former European distributor on June 30, 2018, the Company was required to pay a quarterly per-unit fee for Omnipod sales to certain customers of the former European distributor for a one-year period through June 30, 2019. The Company recognized a liability and an associated intangible asset for this fee as qualifying sales occurred. The methodology applicable for determining the total fee under the distribution agreement is subject to an active arbitration proceeding in Switzerland. The final amount of the fee could vary significantly depending on the number of customers who count for purposes of calculating the fee under the terms of the agreement. The Company estimates that the final aggregate fee is in the range of $5 million to $55 million . As of December 31, 2019 and 2018 , the Company had accrued $2.7 million and $2.9 million , respectively, for fees related to Omnipod devices sold to qualifying customers. The associated gross intangible asset for the fee was $7.8 million and $4.2 million as of December 31, 2019 and 2018 , respectively.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation Equity Award Plan In May 2017, the Company adopted the 2017 Stock Option and Incentive Plan (the “2017 Plan”), which replaced its previous stock option and incentive plan (the “2007 Plan”). The 2017 Plan provides for a maximum of 5.2 million shares to be issued, in addition to the number of shares related to awards outstanding under the 2007 Plan that are terminated by expiration, forfeiture or cancellation. The shares can be issued as stock options, restricted stock units, stock appreciation rights, deferred stock awards, restricted stock, unrestricted stock, cash-based awards, performance share awards or dividend equivalent rights. As of December 31, 2019 , 3.9 million shares remain available for future issuance under the 2017 Plan. Stock-Based Compensation Compensation cost related to stock-based awards recognized for the years ended December 31, 2019 , 2018 and 2017 was recorded as follows: Year Ended December 31, (in millions) 2019 2018 2017 Cost of revenue $ 1.0 $ 0.8 $ 0.5 Research and development 9.1 8.2 5.9 Sales and marketing 7.8 7.6 8.8 General and administrative 10.8 20.9 16.7 Total $ 28.7 $ 37.5 $ 31.9 Stock Options Options are granted to purchase common shares at prices that are equal to the fair market value of the shares on the date the options are granted. Options generally vest in equal annual installments over a period of four years and expire 10 years after the date of grant. The grant-date fair value of options, adjusted for estimated forfeitures, is recognized as expense on a straight-line basis over the requisite service period, which is generally the vesting period. The following summarizes the activity under the Company’s stock option plans: Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in millions) Outstanding at December 31, 2018 3,077,624 $ 39.16 Granted 125,640 93.16 Exercised (1,345,386 ) 35.02 $ 119.2 Forfeited and canceled (128,366 ) 51.55 Outstanding at December 31, 2019 1,729,512 $ 45.39 5.4 $ 217.6 Vested, December 31, 2019 1,361,514 $ 38.71 4.7 $ 180.4 Vested or expected to vest, December 31, 2019 1,689,570 $ 44.59 5.3 $ 213.9 The aggregate intrinsic value of options exercised for the years ended December 31, 2018 and 2017 was $23.5 million and $11.8 million , respectively. The Company uses the Black-Scholes pricing model to determine the fair value of options granted. The calculation of the fair value of stock options is affected by the stock price on the grant date, the expected volatility of the Company’s stock over the expected term of the award, the expected life of the award, the risk-free interest rate and the dividend yield. The assumptions used in the Black-Scholes pricing model for options granted during each year, along with the weighted-average grant-date fair values, were as follows: Years Ended December 31, 2019 2018 2017 Risk-free interest rate 1.8% - 2.6% 2.2% - 2.9% 1.7% - 1.9% Expected life of options (in years) 4.4 - 4.8 4.5 - 5.4 4.7 - 5.3 Dividend yield —% —% —% Expected stock price volatility 40.1% - 40.5% 38.7% - 40.7% 38.5% - 39.1% Fair value per option $ 34.98 $ 30.34 $ 17.28 As of December 31, 2019 , there was $7.6 million of unrecognized compensation cost related to non-vested stock options. This cost is expected to be recognized over a weighted average period of 2.4 years. Restricted Stock Units Restricted Stock Units (“RSUs”) generally vest in equal annual installments over a three-year period. The grant-date fair value of RSUs, adjusted for estimated forfeitures, is recognized as expense on a straight-line basis over the requisite service period, which is generally the vesting period. The Company determines the fair value of restricted stock units based on the closing price of its common stock on the date of grant. RSU activity is as follows: Number of Shares Weighted Average Fair Value Outstanding at December 31, 2018 416,811 $ 56.51 Granted 218,810 96.62 Vested (231,647 ) 50.13 Forfeited (51,687 ) 71.32 Outstanding at December 31, 2019 352,287 $ 83.44 The weighted-average grant-date fair value per share of RSUs granted was $96.62 , $76.03 and $46.13 for the years ended December 31, 2019 , 2018 and 2017 , respectively. The total fair value of RSUs vested was $11.6 million , $ 14.7 million and $ 11.4 million for the years ended December 31, 2019 , 2018 and 2017 , respectively. As of December 31, 2019 , there was $18.9 million of unrecognized compensation cost related to time-based RSUs, which is expected to be recognized over a weighted-average period of 1.9 years. Performance Stock Units Performance stock units (“PSUs”) generally vest over a three-year period from the grant date and include both a service and performance component. Stock-based payments that contain performance conditions are recognized when such conditions are probable of being achieved. Certain of these performance stock units could ultimately vest at up to 200% of the target award depending on the achievement of the performance criteria. PSU activity is as follows: Number of Shares Weighted Average Fair Value Outstanding at December 31, 2018 335,396 $ 53.17 Granted 81,118 95.91 Vested (93,088 ) 34.27 Forfeited (24,270 ) 62.32 Outstanding at December 31, 2019 (1) 299,156 $ 73.35 (1) Based on 200% achievement of the performance metrics, approximately 172,000 shares of Insulet were earned for awards that were granted in 2017 for the performance period ended December 31, 2019. These shares vested in February 2020. The weighted-average grant-date fair value per share of PSUs granted was $95.91 , $75.07 and $50.02 for the years ended December 31, 2019 , 2018 and 2017 , respectively. The total fair value of PSUs vested was $3.2 million , $7.6 million and $0.9 million for the years ended December 31, 2019 , 2018 and 2017 , respectively. As of December 31, 2019 , there was $12.2 million of unrecognized compensation cost related to PSUs, which is expected to be recognized over a weighted-average period of 1.9 years. Employee Stock Purchase Plan The Employee Stock Purchase Plan (“ESPP”) authorizes the issuance of up to 880,000 shares of common stock to participating employees. Employees that participant in the Company’s ESPP may annually purchase up to a maximum of 800 shares per offering period or $25,000 worth of common stock by authorizing payroll deductions of up to 10% of their base salary. The purchase price for each share purchased is 85% of the lower of the fair market value of the common stock on the first or last day of the offering period. The Company issued 51,502 , 46,343 and 59,134 shares of common stock for the years ended December 31, 2019 , 2018 and 2017 , respectively, to employees participating in the ESPP. As of December 31, 2019 , 547,075 shares remain available for future issuance under the ESPP Plan. The Company uses the Black-Scholes pricing model to determine the fair value of shares purchased under the ESPP. The calculation of the fair value of shares purchased is affected by the stock price on the purchase date, the expected volatility of the Company’s stock over the expected term, the risk-free interest rate and the dividend yield. The estimated fair value of shares purchased under the ESPP were based on the following assumptions: Years Ended December 31, 2019 2018 2017 Risk-free interest rate 1.6% - 2.3% 2.1% - 2.5% 1.1% - 1.5% Expected term (in years) 0.5 0.5 0.5 Dividend yield —% —% —% Expected stock price volatility 27.5% - 31.4% 23.4% - 27.0% 22.9% - 26.7% The weighted average grant date fair value of the six-month option inherent in the ESPP was $ 46.30 , $ 26.01 , and $ 15.18 , for the years ended December 31, 2019 , 2018 and 2017 , respectively. As of December 31, 2019, there was $1.0 million of unrecognized compensation cost related to the ESPP. This cost is expected to be recognized over a weighted average period of 0.4 years.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Changes in the components of accumulated other comprehensive loss, net of tax, were as follows: (in millions) Foreign Currency Translation Adjustment Unrealized Losses on Available-for-sale Securities Accumulated Other Comprehensive Loss Balance, December 31, 2016 $ (0.5 ) $ (0.2 ) $ (0.7 ) Other comprehensive income (loss) 0.5 (0.3 ) 0.2 Balance, December 31, 2017 — (0.5 ) (0.5 ) Other comprehensive loss (2.2 ) (0.2 ) (2.4 ) Balance, December 31, 2018 (2.2 ) (0.7 ) (2.9 ) Other comprehensive income 0.6 1.1 1.7 Balance, December 31, 2019 $ (1.6 ) $ 0.4 $ (1.2 )

Defined Contribution Plan

Defined Contribution Plan	12 Months Ended
	Dec. 31, 2019
Defined Contribution Plan [Abstract]
Defined Contribution Plan	Defined Contribution Plan The Company maintains a tax-qualified 401(k) retirement plan in the United States. The Company generally makes a matching contribution equal to 50% of each employee’s elective contribution to the plan up to six percent of the employee’s eligible pay. In addition, the Company offers defined contribution plans for eligible employees in its foreign subsidiaries. The total amount contributed by the Company to these defined contribution plans was $5.3 million , $3.6 million and $3.0 million for the years ended December 31, 2019 , 2018 and 2017

Interest Expense (Notes)

Interest Expense (Notes)	12 Months Ended
	Dec. 31, 2019
Interest Expense [Abstract]
Interest Expense	Interest Expense Interest expense, net of portion capitalized was follows: Years Ended December 31, (in millions) 2019 2018 2017 Contractual coupon interest $ 9.5 $ 9.8 $ 6.3 Accretion of debt discount 32.8 26.7 15.9 Amortization of debt issuance costs 2.8 2.6 2.1 Capitalized interest (10.5 ) (10.2 ) (3.1 ) Interest expense, net of portion capitalized $ 34.6 $ 28.9 $ 21.2

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The U.S. and foreign components of income (loss) before income taxes were as follows: Years Ended December 31, (in millions) 2019 2018 2017 U.S. $ 2.5 $ (3.0 ) $ (27.7 ) Foreign 12.0 8.2 1.1 Income (loss) before income taxes $ 14.5 $ 5.2 $ (26.6 ) Income tax expense consists of the following: Years Ended December 31, (in millions) 2019 2018 2017 Current: State $ 0.2 $ 0.2 $ 0.1 Foreign 3.4 2.1 0.6 Total current expense 3.6 2.3 0.7 Deferred: Federal (0.1 ) — (0.3 ) Foreign (0.6 ) (0.4 ) (0.2 ) Total deferred expense (0.7 ) (0.4 ) (0.5 ) Income tax expense $ 2.9 $ 1.9 $ 0.2 Reconciliations of the federal statutory income rate to the Company’s effective income tax rate are as follows: Years Ended December 31, 2019 2018 2017 U.S. statutory rate 21.0 % 21.0 % 34.0 % Foreign rate differential 4.2 (2.4 ) — 0.3 State taxes, net of federal benefit 1.3 2.9 10.2 Tax credits (15.4 ) (13.7 ) 13.3 Stock-based compensation (158.7 ) (159.1 ) 33.6 Loss on extinguishment of debt 14.8 — — Non-deductible officers’ compensation 1.9 81.3 (20.2 ) Permanent items 3.0 16.8 (14.0 ) Foreign income taxed in the U.S. 19.0 26.1 — Change in valuation allowance 130.6 67.0 (57.9 ) Other (1.9 ) (2.9 ) (0.3 ) Effective income tax rate 19.8 % 37.0 % (1.0 )% As of December 31, 2019 , 2018 and 2017 the Company had no uncertain tax positions. In general, it is the Company’s practice and intention to reinvest the earnings of its non-U.S. subsidiaries in those operations. As of December 31, 2019 , the Company has chosen to indefinitely reinvest its earnings of its non-U.S. subsidiaries, except Canada. To the extent the Company repatriates its foreign earnings, certain withholding taxes and state taxes may apply. The Company has recorded a deferred tax liability for tax that could be incurred upon repatriation of the Canada earnings, the amount of which is not significant. A deferred tax liability related to the repatriation of the indefinitely reinvested earnings would not be material to the Company’s consolidated financial statements. The Company files federal, state and foreign tax returns, which are subject to examination by the relevant tax authorities. The tax filings relating to the Company’s federal and state tax returns are currently open to examination for tax years 2016 through 2018 and 2015 through 2018, respectively. The Company is currently under exam in Ontario, Canada. In addition, the Company generated tax losses from inception in 2000. These years may be subject to examination if the losses are carried forward and utilized in future years. The components of the net deferred tax asset at the end of each year are as follows: As of December 31, (in millions) 2019 2018 Deferred tax assets: Net operating loss carryforwards $ 144.6 $ 124.9 Tax credits 15.2 13.0 Provision for bad debts 1.2 1.1 Depreciation and amortization — 3.5 Capital loss carryforwards 12.7 12.6 Stock-based compensation 8.9 9.3 Other 12.6 6.4 Total deferred tax assets 195.2 170.8 Deferred tax liabilities: Prepaid assets (2.1 ) (2.0 ) Depreciation and amortization (2.2 ) — Amortization of debt discount (73.4 ) (35.7 ) Capitalized contract acquisition costs (7.1 ) (5.8 ) Other (5.0 ) (0.8 ) Total deferred tax liabilities (89.8 ) (44.3 ) Net deferred tax asset before valuation allowance 105.4 126.5 Valuation allowance (104.4 ) (126.3 ) Net deferred tax asset $ 1.0 $ 0.2 The valuation allowances for deferred tax assets of $104.4 million and $126.3 million at December 31, 2019 and 2018 , respectively, relate primarily to U.S. tax loss carryforwards that management believes are not more likely than not to be utilized. The $21.9 million decrease in the Company’s valuation allowance during the year ended December 31, 2019 was primarily due to the issuance of convertible debt discussed in Note 12 . The Company’s net operating loss carryforwards consist of the following: Years Ended December 31, (in millions) 2019 2018 Gross federal net operating loss carryforwards $ 607.4 $ 528.1 State operating loss carryforwards 298.8 246.4 Total $ 906.2 $ 774.5 For U.S. federal tax purposes, $66.8 million of the net operating losses have an indefinite carryforward period. The remaining federal carryforwards, if not utilized, will begin to expire in 2020 and will continue to expire through 2037, and the state carryforwards will continue to expire through 2038. The utilization of such net operating loss carryforwards and the realization of tax benefits in future years depends predominantly upon the Company’s ability to generate taxable income. Research and development and other tax credits were $16.1 million and $13.0 million at December 31, 2019 and 2018 , respectively. If not utilized, federal research and development credits will begin to expire in 2022.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	12 Months Ended
	Dec. 31, 2019
Earnings 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. Diluted net income (loss) per share is computed using the weighted average number of common shares outstanding and, when dilutive, 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 notes (using the if-converted method). The table below sets forth the components used in the computation of basic and diluted net income (loss) per share: Years Ended December 31, (in millions, except share and per share data) 2019 2018 2017 Numerator: Net income (loss) $ 11.6 $ 3.3 $ (26.8 ) Denominator: Weighted average number of common shares outstanding, basic 60,593,846 58,859,574 58,003,434 Effect of dilutive common share equivalents Stock options 1,486,973 1,678,535 — Restricted stock units 223,529 469,915 — Weighted average number of common shares outstanding, diluted 62,304,348 61,008,024 58,003,434 Net income (loss) per share: Basic $ 0.19 $ 0.06 $ (0.46 ) Diluted $ 0.19 $ 0.05 $ (0.46 ) The number of common share equivalents excluded from the computation of diluted net income (loss) per share because either the effect would have been anti-dilutive, or the performance criteria related to the units had not yet been met were as follows: Years Ended December 31, 2019 2018 2017 2.00% Convertible Senior Notes — — 78,783 1.25% Convertible Senior Notes — 5,910,954 5,910,954 1.375% Convertible Senior Notes 4,319,429 4,319,429 4,319,429 0.375% Convertible Senior Notes 3,528,400 — — Unvested restricted stock units 430,593 289,974 994,364 Outstanding stock options 12,820 236,648 3,377,220 Total common share equivalents excluded from computation of diluted net income (loss) per share 8,291,242 10,757,005 14,680,750

Quarterly Data (Unaudited)

Quarterly Data (Unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Data [Abstract]
Quarterly Data (Unaudited)	Quarterly Data (Unaudited) 2019 Quarters Ended (in millions, except per share data) March 31 June 30 September 30 (1) December 31 (2) Revenue $ 159.6 $ 177.1 $ 192.1 $ 209.4 Gross profit $ 106.7 $ 116.4 $ 123.1 $ 134.1 Net income $ 4.4 $ 1.4 $ 0.8 $ 5.0 Net income per share: Basic $ 0.07 $ 0.02 $ 0.01 $ 0.08 Diluted $ 0.07 $ 0.02 $ 0.01 $ 0.08 (1) Net income includes a $6.4 million loss on extinguishment of debt incurred in connection with the repurchase of the Company’s 1.25% Convertible Senior Notes. (2) Net income includes a $2.3 million loss on extinguishment of debt incurred in connection with the repurchase of the Company’s 1.25% Convertible Senior Notes. 2018 Quarters Ended (in millions, except per share data) March 31 June 30 September 30 (3) December 31 Revenue $ 123.6 $ 124.2 $ 151.1 $ 164.9 Gross profit $ 75.8 $ 82.1 $ 102.0 $ 110.3 Net income (loss) $ (6.6 ) $ (1.7 ) $ 1.7 $ 9.9 Net income (loss) per share: Basic $ (0.11 ) $ (0.03 ) $ 0.03 $ 0.17 Diluted $ (0.11 ) $ (0.03 ) $ 0.03 $ 0.16 (3) Net income includes a charge of $12.6 million for severance costs associated with the retirement of the Company’s former CEO, of which $8.2 million

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2019
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS The following table sets forth activities in the Company’s accounts receivable reserve, reserve for rebates and deferred tax valuation allowance accounts: Description Balance at Beginning of Period Additions Charged to Costs and Expenses Deductions Balance at End of Period (in millions) Year Ended December 31, 2019 Allowance for doubtful accounts $ 3.6 $ 4.5 $ (4.3 ) $ 3.8 Reserve for rebates $ 8.6 $ 59.1 $ (55.6 ) $ 12.1 Deferred tax valuation allowance $ 126.3 $ 43.6 $ (65.5 ) $ 104.4 Year Ended December 31, 2018 Allowance for doubtful accounts $ 2.5 $ 3.4 $ (2.3 ) $ 3.6 Reserve for rebates $ 6.3 $ 34.1 $ (31.8 ) $ 8.6 Deferred tax valuation allowance $ 127.9 $ 13.9 $ (15.5 ) $ 126.3 Year Ended December 31, 2017 Allowance for doubtful accounts $ 2.9 $ 1.9 $ (2.3 ) $ 2.5 Reserve for rebates $ 1.4 $ 16.1 $ (11.2 ) $ 6.3 Deferred tax valuation allowance $ 191.9 $ 14.2 $ (78.2 ) $ 127.9

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying financial statements reflect the consolidated operations of Insulet Corporation and its subsidiaries. The consolidated financial statements have been prepared in United States dollars, in accordance with accounting principles generally accepted in the United States of America (GAAP). The preparation of the consolidated financial statements in conformity with GAAP requires management to make use of estimates and assumptions that affect the reported amount of assets and liabilities, disclosure of contingent assets and liabilities, and the reported amounts of revenues and expenses. Actual results may differ from those estimates.
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.
Reclassification of Prior Period Amounts	Reclassification of Prior Period Amounts Certain reclassifications have been made to prior period amounts to conform to the current period financial statement presentation. Software license costs have been reallocated from general and administrative expenses to research and development and sales and marketing expenses based on license usage. These reclassifications have no effect on previously reported net income.
Foreign Currency Translation	Foreign Currency Translation
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of 90 days or less at the time of purchase to be cash equivalents. Cash equivalents include money market mutual funds, commercial paper and U.S. government and agency bonds that are carried at cost, which approximates their fair value. Restricted cash that serves as collateral for outstanding letters of credit are included in cash and cash equivalents on the consolidated balance sheet.
Investments in Marketable Securities	Investments in Marketable Securities Short-term and long-term investment securities consist of certificates of deposit, commercial paper, U.S. government and agency bonds and corporate bonds. Theses available-for-sale marketable securities are carried at fair value and unrealized gains and losses are included as a component of other comprehensive loss in stockholders’ equity on the consolidated balance sheet. Investments with a stated maturity date of more than one year from the balance sheet date and that are not expected to be used in current operations are classified as long-term investments on the consolidated balance sheet. The Company reviews investments for other-than-temporary impairment when the fair value of an investment is less than its amortized cost. If an available-for-sale security is other than temporarily impaired, the loss is included in other income, net in the consolidated statement of operations.
Accounts Receivables and Allowance for Doubtful Accounts, Policy	Accounts Receivable and Allowance for Doubtful Accounts Trade accounts receivable consist of amounts due from third-party payors, customers and intermediaries and are presented net of an allowance for doubtful accounts. The allowance for doubtful accounts reflects an estimate of losses inherent in the Company’s accounts receivable portfolio determined based on historical experience, specific allowances for known troubled accounts and other available evidence. Accounts receivable are written off when management determines they are uncollectible.
Inventories	Inventories Inventories are stated at the lower of cost or net realizable value, with cost determined under the first-in, first-out method. The Company reduces the carrying value of inventories for those items that are potentially excess, obsolete or slow-moving based on changes in customer demand, technology developments or other economic factors in order to state inventories at net realizable value. Factors influencing these adjustments include inventories on hand compared to estimated future usage and sales. Work in process is calculated based upon a buildup of cost based on the stage of production. Manufacturing variances attributable to abnormally low production are expensed in the period incurred.
Contract Acquisition Costs and Revenue Recognition	Contract Acquisition Costs The Company incurs commission costs to obtain a contract related to new customer starts. These costs are capitalized as contract assets 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 costs are periodically reviewed for impairment. Revenue Recognition Effective January 1, 2018, the Company adopted ASU 2014-09, Revenue from Contracts with Customers, and its related amendments (collectively referred to as ASC 606) using the modified retrospective method for all contracts not completed as of the date of adoption. The cumulate effect of applying the new revenue standard resulted in a $20.4 million decrease to the opening balance of accumulated deficit upon adoption, primarily related to how revenue is recognized for the Company’s drug delivery product line and the capitalization of contract acquisition costs such as commissions. Financial information for 2017 has not been restated and continues to be reported under the guidance in effect prior to the adoption of ASC 606. Revenue is recognized when a customer obtains control of the promised products. The amount of revenue recognized reflects the consideration 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: • Identify Contracts with Customers. The Company’s contracts with its direct customers generally consist of a physician order form, a customer 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. • Identify 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. In the Company’s judgment, these performance obligations are capable of being distinct and distinct in the context of the contract in that the customer can benefit from each item in conjunction with other readily available resources and the transfer of the PDM and the Pods is separately identifiable in the contract with the customer. • Determine 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 end-users. 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 (such as product return trends or forecast sale volumes) 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 it is probable that a significant future reversal of cumulative revenue under the contract will not occur; otherwise, the Company reduces the variable consideration. The variable consideration in the Company’s contracts is not typically constrained and the Company’s contracts do not contain significant financing components. • Allocate Transaction Price to Performance Obligations. 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. • Recognize Revenue as Performance Obligations are Satisfied. 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 ownership. 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, including transfer of title. 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. 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.
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price that would be received from the sale of an asset or paid to transfer a liability in the principal or most advantageous market in an orderly transaction between market participants on the measurement date. When estimating fair value, the Company may use one or all the following approaches: • Market approach, which is based on market prices and other information from market transactions involving identical or comparable assets or liabilities. • Cost approach, which is based on the cost to acquire or construct comparable assets less an allowance for functional and/or economic obsolescence. • Income approach, which is based on the present value of the future stream of net cash flows. To measure fair value of assets and liabilities, the Company uses the following fair value hierarchy based on three levels of inputs: Level 1 — observable inputs, such as quoted prices in active markets for identical assets or liabilities; Level 2 — significant other observable inputs that are observable either directly or indirectly; Level 3 — significant unobservable inputs for which there is little or no market data, which require the Company to develop its own assumptions.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment is stated at cost less accumulated depreciation. Major improvements are capitalized, while routine repairs and maintenance are expensed as incurred. Depreciation for property, plant and equipment, other than land and construction in progress, is based upon the following estimated useful lives using the straight-line method: Building and building improvements 20 to 39 years Leasehold improvements Lesser of lease term or useful life of asset Machinery and equipment 2 to 15 years Furniture and fixtures 3 to 5 years The Company assesses the recoverability of assets whenever events or changes in circumstances suggest that the carrying value of an asset may not be recoverable. The Company recognizes an impairment loss if the carrying amount of a long-lived asset is not recoverable based on its undiscounted future cash flows. The impairment loss is measured as the difference between the carrying amount and the fair value of the asset.
Business Combinations	Business Combinations The Company recognizes the assets and liabilities assumed in business combinations based on their estimated fair values at the date of acquisition. The Company allocates the purchase price in excess of net tangible assets acquired to identifiable intangible assets. The Company assesses the fair value of assets, including intangible assets, using a variety of methods and each asset is measured at fair value from the perspective of a market participant. Assets recorded from the perspective of a market participant that are determined to not have economic use for the Company are expensed immediately. Any excess purchase price over the fair value of the net tangible and intangible assets acquired is allocated to goodwill. Transaction costs and restructuring costs associated with a business combination are expensed as incurred.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill represents the excess of the purchase price of an acquired entity over the amounts assigned to assets and liabilities assumed in a business combination. The Company performs an assessment of its goodwill for impairment annually on October 1 or whenever events or changes in circumstances indicate there might be impairment. Goodwill is evaluated for impairment at the reporting unit level. The Company may assess its goodwill for impairment initially using a qualitative approach to determine whether conditions exist that indicate it is more likely than not that the fair value of a reporting unit is less than its carrying value. If management concludes, based on its assessment of relevant events, facts and circumstances that it is more likely that not that a reporting unit’s carrying value is greater than its fair value, then a quantitative analysis will be performed to determine if there is any impairment. Alternatively, the Company may elect to initially perform a quantitative analysis instead of starting with a qualitative analysis. In performing the quantitative test, the Company utilizes a two-step approach. The first step compares the carrying value of the reporting unit to its fair value. If the reporting unit’s carrying value exceeds its fair value, the Company would perform the second step and record an impairment loss to the extent that the carrying value of the reporting unit’s goodwill exceeds its implied fair value. Intangible assets acquired in a business combination are recorded at fair value, while intangible assets acquired in other transactions are recorded at cost and are stated at cost less accumulated amortization. Intangible assets with finite useful lives are amortized using the straight-line method over the following estimated useful lives of the assets: Customer relationships 5 - 10 years Internal-use software 3 - 10 years Intellectual property 15 years Amortization expense is included in operating expenses in the consolidated statement of operations. The Company reviews intangible assets for impairment by comparing the fair value of the assets, estimated using an income approach, with their carrying value. If the carrying value exceeds the fair value of the intangible asset, the Company recognizes an impairment equal to the difference between the carrying value of the asset and the present value of future cash flows. The Company assesses the remaining useful life and the recoverability of intangible assets whenever events or circumstances indicate that the carrying value of an asset may not be recoverable using undiscounted cash flows.
Leases	Leases The Company determines if an arrangement includes a lease at inception. Lease agreements generally have lease and non-lease components, which are accounted for separately. At lease commencement, the Company recognizes operating lease liabilities equal to the present value of the lease payments and operating lease assets representing the right to use the underlying asset for the lease term. The Company assesses if it is reasonably certain to exercise lease options to extend or terminate the lease for inclusion or exclusion in the lease term when the Company measures the lease liability. As the Company’s leases do not provide an implicit rate, the Company uses an incremental borrowing rate based on the information available at lease commencement in determining the present value of lease payments. The Company’s incremental borrowing rate estimates a secured rate that reflects the term of the lease, the nature of the underlying asset and the economic environment. The Company excludes leases with an expected term of one year or less from recognition on the consolidated balance sheet. Operating lease assets includes lease payments made prior to lease commencement and excludes lease incentives and initial direct costs incurred. Lease expense is recognized on a straight-line basis over the lease term and is included in general and administrative expenses in the consolidated statements of operations.
Contingencies	Contingencies The Company records a liability on the consolidated balance sheet for loss contingencies when a loss is considered probable and the amount can be reasonably estimated. If the reasonable estimate of a known or probable loss is a range, and no amount within the range is a better estimate than any other, the minimum amount of the range is accrued. If a loss is reasonably possible but not known or probable, and can be reasonably estimated, the estimated loss or range of loss is disclosed.
Product Warranty	Product Warranty The Company provides a four-year warranty on its PDMs sold in the United States and Europe and a five-year warranty on PDMs sold in Canada and may replace Pods that do not function in accordance with product specifications. The Company estimates its warranty obligation 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 in the consolidated statements of operations. Costs to service the claims reflect the current product cost. Since the Company continues to introduce new products and versions, the anticipated performance of the product over the warranty period is also considered in estimating warranty reserves.
Collaborative Arrangements	Collaborative Arrangements The Company enters into collaborative arrangements for ongoing initiatives to develop products. Although the Company does not consider any individual alliance to be material, the following more notable alliance is described below. Concentrated Insulin Delivery : In May 2013, the Company entered into an agreement with Eli Lilly and Company (“Eli Lilly”) to develop a new version of the Omnipod System specifically designed to deliver Eli Lilly’s Humulin ® R U-500 insulin, a concentrated form of insulin used by people with highly insulin resistant Type 2 diabetes. In January 2016, the Company entered into a development agreement with Eli Lilly to develop a new version of the Omnipod System, specifically designed to deliver Eli Lilly’s Humalog ® 200 insulin, a concentrated form of insulin that provides the same dose of insulin in half the volume of Eli Lilly’s Humalog ®
Shipping and Handling Costs	Shipping and Handling Costs
Stock-Based Compensation	Stock-Based Compensation The Company measures stock-based compensation expense at the grant date based on the fair value of the award and recognizes the compensation expense over the requisite service period, which is generally the vesting period. The amount of stock-based compensation expense recognized during a period is based on the portion of the awards that are expected to vest. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.
Income Taxes	Income Taxes The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Deferred tax assets and liabilities are determined based on differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates that will be in effect in the years in which the differences are expected to reverse. The Company reviews its deferred tax assets for recoverability considering historical profitability, projected future taxable income, and the expected timing of the reversals of existing temporary differences and tax planning strategies. A valuation allowance is provided to reduce the deferred tax assets if, based on the available evidence, it is more likely than not that some or all the deferred tax assets will not be realized. The effect of a change in enacted tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents, short-term and long-term investments in marketable securities and accounts receivable. The Company maintains most of its cash, and short-term and long-term investments with a limited number of financial institutions that have a high investment grade credit rating.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards Effective January 1, 2019, the Company adopted Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) (“ASU 2016-02”). ASU 2016-02 and its related amendments (collectively referred to as ASC 842). ASC 842 requires lessees to recognize operating lease liabilities and operating lease assets, representing the right to use the underlying asset for the lease term, on the balance sheet for leases classified as operating leases. The Company adopted ASC 842 on January 1, 2019 using the modified retrospective method, whereby the new guidance is applied prospectively as of the date of adoption and prior periods are not restated. The Company elected the practical expedients that permit the Company to not reassess (1) whether any expired or existing contracts are or contain leases, (2) the lease classification for any expired or existing leases, and (3) any initial direct costs for existing leases as of the effective date. Upon the adoption, the Company recorded operating lease liabilities of $10.8 million and operating lease assets of $8.8 million on its consolidated balance sheet. The difference between the value of the lease obligations and the operating lease assets was primarily attributable to a $1.1 million cease-use liability established in 2018 associated with the Company’s former headquarters, which was reclassified to an operating lease liability upon adoption of ASC 842. See Note 11 for additional information regarding leases. Effective January 1, 2019, the Company early adopted 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 certain costs to implement a cloud computing arrangement that is a service contract to be capitalized consistent with the rules applicable to internal-use software capitalization projects. The Company adopted this new guidance prospectively. The Company defers eligible costs related to the implementation of cloud computing arrangements within other current and non-current assets and amortizes such costs over the expected term of the hosting arrangement to the same income statement line as the associated cloud operating expenses. Adoption of this standard resulted in the Company capitalizing $3.6 million of cloud computing implementation costs for the year ended December 31, 2019 .

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Property, Plant and Equipment	Depreciation for property, plant and equipment, other than land and construction in progress, is based upon the following estimated useful lives using the straight-line method: Building and building improvements 20 to 39 years Leasehold improvements Lesser of lease term or useful life of asset Machinery and equipment 2 to 15 years Furniture and fixtures 3 to 5 years Property, plant and equipment at cost and accumulated depreciation were as follows: As of December 31, (in millions) 2019 (1) 2018 Land $ 2.5 $ 2.5 Building and building improvements 116.9 44.2 Machinery and equipment 194.8 93.3 Furniture and fixtures 12.7 6.3 Leasehold improvements 1.6 1.4 Construction in process 161.5 176.1 Total property, plant and equipment 490.0 323.8 Less: accumulated depreciation (90.6 ) (65.4 ) Property, plant and equipment, net $ 399.4 $ 258.4 (1) Reclassification of prior period amounts were made from furniture and fixtures to building and building improvements to conform with current period financial statement presentation.
Intangible Assets with Finite Useful Life	Intangible assets with finite useful lives are amortized using the straight-line method over the following estimated useful lives of the assets: Customer relationships 5 - 10 years Internal-use software 3 - 10 years Intellectual property 15 years The gross carrying amount, accumulated amortization and net book value of intangible assets at the end of each period were as follows: As of December 31, 2019 2018 (in millions) Gross Carrying Amount Accumulated Amortization Net Book Value Gross Carrying Amount Accumulated Amortization Net Book Value Customer relationships (1) $ 9.9 $ (2.8 ) $ 7.1 $ 6.1 $ (1.9 ) $ 4.2 Internal-use software 12.0 (6.8 ) 5.2 11.3 (5.1 ) 6.2 Intellectual property 1.0 (0.1 ) 0.9 — — — Total intangible assets $ 22.9 $ (9.7 ) $ 13.2 $ 17.4 $ (7.0 ) $ 10.4 (1) Includes customer relationships acquired from the Company’s former European distributor. See Note 13 .

Segment and Geographic Data (Ta

Segment and Geographic Data (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Revenue by geographic region based on delivery location	Geographic information about revenue, based on delivery location, is as follows: Years Ended December 31, (in millions) 2019 2018 2017 United States $ 485.1 $ 391.8 $ 343.8 All other 253.1 172.0 120.0 Total $ 738.2 $ 563.8 $ 463.8
Long-lived assets, net, excluding goodwill and other intangible assets by geographic area	Geographic information about long-lived assets, net, excluding goodwill and other intangible assets is as follows: As of December 31, (in millions) 2019 2018 United States $ 363.0 $ 232.3 China 35.9 25.6 Other 0.5 0.9 Total $ 399.4 $ 258.8

Revenue and Contract Acquisit_2

Revenue and Contract Acquisition Costs (Tables)	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Summary of Revenue from Contracts with Customers	The following table summarizes the Company’s disaggregated revenues: Years Ended December 31, (in millions) 2019 2018 2017 U.S. Omnipod $ 420.4 $ 323.5 $ 271.6 International Omnipod 253.1 172.0 120.0 Total Omnipod 673.5 495.5 391.6 Drug Delivery 64.7 68.3 72.2 Total revenue $ 738.2 $ 563.8 $ 463.8
Schedule of Revenue from Major Customers	Revenue for customers comprising 10% or more of total revenue was as follows: Years Ended December 31, 2019 2018 2017 Amgen, Inc. * 12% 15% Ypsomed * * 22% Cardinal Health Inc. and affiliates 11% 12% 11% * Represents less than 10% of revenue for the period.
Summary of Deferred Revenue	Deferred revenue related to unsatisfied performance obligations was included in the following consolidated balance sheet accounts in the amounts shown: As of December 31, (in millions) 2019 2018 Accrued expenses and other current liabilities $ 3.2 $ 1.2 Other liabilities 1.0 0.9 Total deferred revenue $ 4.2 $ 2.1
Summary of Contract Acquisition Costs	Contract acquisition costs, representing capitalized commission costs related to new customers, net of amortization, were included in the following consolidated balance sheet accounts in the amounts shown: As of December 31, (in millions) 2019 2018 Prepaid expenses and other current assets $ 9.5 $ 7.3 Other assets 19.9 16.0 Total capitalized contract acquisition costs, net $ 29.4 $ 23.3 The Company recognized $8.8 million and $6.9 million of amortization of capitalized contract acquisition costs for the years ended December 31, 2019 and 2018 , respectively.

Cash and Cash Equivalents (Tabl

Cash and Cash Equivalents (Tables)	12 Months Ended
	Dec. 31, 2019
Cash and Cash Equivalents [Abstract]
Summary of Cash and Cash Equivalents	The following tables provide a summary of cash and cash equivalents as of December 31, 2019 and 2018 and the level in the fair value hierarchy in which those measurements fall: (in millions) Fair Value Measurements December 31, 2019 Total Level 1 Level 2 (1) Cash $ 85.3 $ 85.3 $ — Money market mutual funds 115.5 115.5 — Commercial paper 10.0 10.0 Restricted cash 2.9 2.9 Total cash and cash equivalents $ 213.7 $ 203.7 $ 10.0 December 31, 2018 Cash $ 64.0 $ 64.0 $ — Money market mutual funds 47.2 47.2 — Restricted cash 2.7 2.7 Total cash and cash equivalents $ 113.9 $ 113.9 $ — (1) Fair value was determined using market prices obtained from third-party pricing sources.
Summary of Restricted Cash and Cash Equivalents	The following tables provide a summary of cash and cash equivalents as of December 31, 2019 and 2018 and the level in the fair value hierarchy in which those measurements fall: (in millions) Fair Value Measurements December 31, 2019 Total Level 1 Level 2 (1) Cash $ 85.3 $ 85.3 $ — Money market mutual funds 115.5 115.5 — Commercial paper 10.0 10.0 Restricted cash 2.9 2.9 Total cash and cash equivalents $ 213.7 $ 203.7 $ 10.0 December 31, 2018 Cash $ 64.0 $ 64.0 $ — Money market mutual funds 47.2 47.2 — Restricted cash 2.7 2.7 Total cash and cash equivalents $ 113.9 $ 113.9 $ — (1) Fair value was determined using market prices obtained from third-party pricing sources.

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Schedule of Investments	The following tables provides amortized costs, gross unrealized gains and losses, fair values and the level in the fair value hierarchy for the Company’s investments at December 31, 2019 and 2018 : (in millions) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Level 1 Level 2 (1) December 31, 2019 U.S. government and agency bonds $ 94.7 $ 0.3 $ — $ 95.0 $ 85.0 $ 10.0 Corporate bonds 51.0 0.1 — 51.1 — 51.1 Certificates of deposit 6.3 — — 6.3 — 6.3 Commercial paper 10.0 — — 10.0 10.0 Total short-term investments $ 162.0 $ 0.4 $ — $ 162.4 $ 85.0 $ 77.4 U.S. government and agency bonds $ 52.9 $ 0.1 $ (0.1 ) $ 52.9 $ 42.9 $ 10.0 Corporate bonds 2.8 — — 2.8 — 2.8 Certificates of deposit 2.7 — — 2.7 — 2.7 Total long-term investments $ 58.4 $ 0.1 $ (0.1 ) $ 58.4 $ 42.9 $ 15.5 December 31, 2018 U.S. government and agency bonds $ 113.0 $ — $ (0.5 ) $ 112.5 $ 69.6 $ 42.9 Corporate bonds 56.2 — (0.2 ) 56.0 — 56.0 Certificates of deposit 6.5 — — 6.5 — 6.5 Total short-term investments $ 175.7 $ — $ (0.7 ) $ 175.0 $ 69.6 $ 105.4 U.S. government and agency bonds $ 90.5 $ 0.1 $ (0.2 ) $ 90.4 $ 64.1 $ 26.3 Corporate bonds 46.7 — — 46.7 — 46.7 Certificates of deposit 3.7 — — 3.7 — 3.7 Total long-term investments $ 140.9 $ 0.1 $ (0.2 ) $ 140.8 $ 64.1 $ 76.7 (1) Fair value was determined using market prices obtained from third-party pricing sources.

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2019
Inventory Disclosure [Abstract]
Components of Inventories	At the end of each period, inventories were comprised of the following: (in millions) As of December 31, 2019 2018 Raw materials $ 23.3 $ 10.4 Work-in-process 40.3 30.2 Finished goods 37.4 30.8 Total inventories $ 101.0 $ 71.4

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Components of Property and Equipment	Depreciation for property, plant and equipment, other than land and construction in progress, is based upon the following estimated useful lives using the straight-line method: Building and building improvements 20 to 39 years Leasehold improvements Lesser of lease term or useful life of asset Machinery and equipment 2 to 15 years Furniture and fixtures 3 to 5 years Property, plant and equipment at cost and accumulated depreciation were as follows: As of December 31, (in millions) 2019 (1) 2018 Land $ 2.5 $ 2.5 Building and building improvements 116.9 44.2 Machinery and equipment 194.8 93.3 Furniture and fixtures 12.7 6.3 Leasehold improvements 1.6 1.4 Construction in process 161.5 176.1 Total property, plant and equipment 490.0 323.8 Less: accumulated depreciation (90.6 ) (65.4 ) Property, plant and equipment, net $ 399.4 $ 258.4 (1) Reclassification of prior period amounts were made from furniture and fixtures to building and building improvements to conform with current period financial statement presentation.

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Changes in Carrying Amounts of Goodwill	The changes in the carrying amount of goodwill for 2019 and 2018 were as follows: Years Ended December 31, (in millions) 2019 2018 Beginning balance $ 39.6 $ 39.8 Foreign currency adjustment 0.2 (0.2 ) Ending balance $ 39.8 $ 39.6
Components of Other Intangible Assets	Intangible assets with finite useful lives are amortized using the straight-line method over the following estimated useful lives of the assets: Customer relationships 5 - 10 years Internal-use software 3 - 10 years Intellectual property 15 years The gross carrying amount, accumulated amortization and net book value of intangible assets at the end of each period were as follows: As of December 31, 2019 2018 (in millions) Gross Carrying Amount Accumulated Amortization Net Book Value Gross Carrying Amount Accumulated Amortization Net Book Value Customer relationships (1) $ 9.9 $ (2.8 ) $ 7.1 $ 6.1 $ (1.9 ) $ 4.2 Internal-use software 12.0 (6.8 ) 5.2 11.3 (5.1 ) 6.2 Intellectual property 1.0 (0.1 ) 0.9 — — — Total intangible assets $ 22.9 $ (9.7 ) $ 13.2 $ 17.4 $ (7.0 ) $ 10.4 (1) Includes customer relationships acquired from the Company’s former European distributor. See Note 13 .
Amortization Expense Expected for Next Five Years	Amortization expense associated with the intangible assets included on the Company’s balance sheet as of December 31, 2019 is expected to be as follows: Years Ending December 31, (in millions) 2020 $ 2.9 2021 2.4 2022 1.9 2023 1.3 2024 1.2 Thereafter 3.5 Total $ 13.2

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Payables and Accruals [Abstract]
Components of Accrued Expenses and Other Current Liabilities	The components of accrued expenses and other current liabilities were as follows: As of December 31, (in millions) 2019 2018 Employee compensation and related costs $ 45.8 $ 37.8 Professional and consulting services 19.3 14.9 Accrued rebates 7.5 2.8 Supplier purchases 2.4 7.7 Value added taxes payable 1.8 8.5 Other 26.4 18.5 Accrued expenses and other current liabilities $ 103.2 $ 90.2
Reconciliation of Changes in Product Warranty Liability	Reconciliations of the changes in the Company’s product warranty liability were as follows: Years Ended December 31, (in millions) 2019 2018 Product warranty liability at beginning of year $ 6.4 $ 5.3 Warranty expense 13.4 7.8 Warranty claims settled (11.3 ) (6.7 ) Product warranty liability at end of year $ 8.5 $ 6.4

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Summary of ROU Assets and Operating Lease Liabilities	As of December 31, 2019 , operating lease assets and operating lease liabilities were included in the following consolidated balance sheet accounts in the amounts shown: (in millions) Operating lease asset: Other assets $ 16.1 Operating lease liabilities: Accrued expenses and other current liabilities $ 3.6 Other liabilities 14.4 Total $ 18.0
Future Minimum Undiscounted Lease Payments	Maturities of lease liabilities as of December 31, 2019 are as follows: Years Ending December 31, (in millions) 2020 $ 4.5 2021 5.0 2022 4.7 2023 2.3 2024 2.4 Thereafter 1.5 Total future minimum lease payments 20.4 Less: imputed interest (2.4 ) Present value of future minimum lease payments $ 18.0

Convertible Debt, Net (Tables)

Convertible Debt, Net (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Outstanding Convertible Debt and Related Deferred Financing Costs	The components of outstanding convertible debt consisted of the following: As of December 31, (in millions) 2019 2018 1.25% Convertible Senior Notes, due September 2021 $ — $ 345.0 1.375% Convertible Senior Notes, due November 2024 402.5 402.5 0.375% Convertible Senior Notes, due September 2026 800.0 — Unamortized debt discount (294.8 ) (143.6 ) Debt issuance costs (19.8 ) (11.9 ) Total convertible debt, net $ 887.9 $ 592.0
Summary of Carrying Amount and Estimated Fair Value of Convertible Debt	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 December 31, 2019 and 2018 are as follows: As of December 31, 2019 2,019 2018 (in millions) Carrying Value Estimated Fair Value (1) Carrying Estimated Fair Value (1) 1.25% Convertible Senior Notes — — 301.0 483.9 1.375% Convertible Senior Notes 306.9 512.8 291.0 426.0 0.375% Convertible Senior Notes 581.0 840.0 — — Total $ 887.9 $ 1,352.8 $ 592.0 $ 909.9 (1) Fair value was determined using market prices obtained from third-party pricing sources.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Share-Based Compensation	Compensation cost related to stock-based awards recognized for the years ended December 31, 2019 , 2018 and 2017 was recorded as follows: Year Ended December 31, (in millions) 2019 2018 2017 Cost of revenue $ 1.0 $ 0.8 $ 0.5 Research and development 9.1 8.2 5.9 Sales and marketing 7.8 7.6 8.8 General and administrative 10.8 20.9 16.7 Total $ 28.7 $ 37.5 $ 31.9
Stock Option Activity	The following summarizes the activity under the Company’s stock option plans: Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in millions) Outstanding at December 31, 2018 3,077,624 $ 39.16 Granted 125,640 93.16 Exercised (1,345,386 ) 35.02 $ 119.2 Forfeited and canceled (128,366 ) 51.55 Outstanding at December 31, 2019 1,729,512 $ 45.39 5.4 $ 217.6 Vested, December 31, 2019 1,361,514 $ 38.71 4.7 $ 180.4 Vested or expected to vest, December 31, 2019 1,689,570 $ 44.59 5.3 $ 213.9
Assumptions Used for Options Granted	The assumptions used in the Black-Scholes pricing model for options granted during each year, along with the weighted-average grant-date fair values, were as follows: Years Ended December 31, 2019 2018 2017 Risk-free interest rate 1.8% - 2.6% 2.2% - 2.9% 1.7% - 1.9% Expected life of options (in years) 4.4 - 4.8 4.5 - 5.4 4.7 - 5.3 Dividend yield —% —% —% Expected stock price volatility 40.1% - 40.5% 38.7% - 40.7% 38.5% - 39.1% Fair value per option $ 34.98 $ 30.34 $ 17.28
Summary of Restricted Stock Units	RSU activity is as follows: Number of Shares Weighted Average Fair Value Outstanding at December 31, 2018 416,811 $ 56.51 Granted 218,810 96.62 Vested (231,647 ) 50.13 Forfeited (51,687 ) 71.32 Outstanding at December 31, 2019 352,287 $ 83.44
Summary of Performance Stock Units	PSU activity is as follows: Number of Shares Weighted Average Fair Value Outstanding at December 31, 2018 335,396 $ 53.17 Granted 81,118 95.91 Vested (93,088 ) 34.27 Forfeited (24,270 ) 62.32 Outstanding at December 31, 2019 (1) 299,156 $ 73.35 (1) Based on 200% achievement of the performance metrics, approximately 172,000 shares of Insulet were earned for awards that were granted in 2017 for the performance period ended December 31, 2019. These shares vested in February 2020.
Estimated Fair Value of Share Purchase Under ESPP	The estimated fair value of shares purchased under the ESPP were based on the following assumptions: Years Ended December 31, 2019 2018 2017 Risk-free interest rate 1.6% - 2.3% 2.1% - 2.5% 1.1% - 1.5% Expected term (in years) 0.5 0.5 0.5 Dividend yield —% —% —% Expected stock price volatility 27.5% - 31.4% 23.4% - 27.0% 22.9% - 26.7%

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Schedule of accumulated other comprehensive income (loss)	Changes in the components of accumulated other comprehensive loss, net of tax, were as follows: (in millions) Foreign Currency Translation Adjustment Unrealized Losses on Available-for-sale Securities Accumulated Other Comprehensive Loss Balance, December 31, 2016 $ (0.5 ) $ (0.2 ) $ (0.7 ) Other comprehensive income (loss) 0.5 (0.3 ) 0.2 Balance, December 31, 2017 — (0.5 ) (0.5 ) Other comprehensive loss (2.2 ) (0.2 ) (2.4 ) Balance, December 31, 2018 (2.2 ) (0.7 ) (2.9 ) Other comprehensive income 0.6 1.1 1.7 Balance, December 31, 2019 $ (1.6 ) $ 0.4 $ (1.2 )

Interest Expense (Tables)

Interest Expense (Tables)	12 Months Ended
	Dec. 31, 2019
Interest Expense [Abstract]
Interest and Other Expense	Interest expense, net of portion capitalized was follows: Years Ended December 31, (in millions) 2019 2018 2017 Contractual coupon interest $ 9.5 $ 9.8 $ 6.3 Accretion of debt discount 32.8 26.7 15.9 Amortization of debt issuance costs 2.8 2.6 2.1 Capitalized interest (10.5 ) (10.2 ) (3.1 ) Interest expense, net of portion capitalized $ 34.6 $ 28.9 $ 21.2

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Components of Income (Loss) before Income Taxe	The U.S. and foreign components of income (loss) before income taxes were as follows: Years Ended December 31, (in millions) 2019 2018 2017 U.S. $ 2.5 $ (3.0 ) $ (27.7 ) Foreign 12.0 8.2 1.1 Income (loss) before income taxes $ 14.5 $ 5.2 $ (26.6 )
Income Tax Expense	Income tax expense consists of the following: Years Ended December 31, (in millions) 2019 2018 2017 Current: State $ 0.2 $ 0.2 $ 0.1 Foreign 3.4 2.1 0.6 Total current expense 3.6 2.3 0.7 Deferred: Federal (0.1 ) — (0.3 ) Foreign (0.6 ) (0.4 ) (0.2 ) Total deferred expense (0.7 ) (0.4 ) (0.5 ) Income tax expense $ 2.9 $ 1.9 $ 0.2
Reconciliations of the Federal Statutory Income Rate	Reconciliations of the federal statutory income rate to the Company’s effective income tax rate are as follows: Years Ended December 31, 2019 2018 2017 U.S. statutory rate 21.0 % 21.0 % 34.0 % Foreign rate differential 4.2 (2.4 ) — 0.3 State taxes, net of federal benefit 1.3 2.9 10.2 Tax credits (15.4 ) (13.7 ) 13.3 Stock-based compensation (158.7 ) (159.1 ) 33.6 Loss on extinguishment of debt 14.8 — — Non-deductible officers’ compensation 1.9 81.3 (20.2 ) Permanent items 3.0 16.8 (14.0 ) Foreign income taxed in the U.S. 19.0 26.1 — Change in valuation allowance 130.6 67.0 (57.9 ) Other (1.9 ) (2.9 ) (0.3 ) Effective income tax rate 19.8 % 37.0 % (1.0 )%
Components of Company's Deferred Tax Assets (Liabilities)	The components of the net deferred tax asset at the end of each year are as follows: As of December 31, (in millions) 2019 2018 Deferred tax assets: Net operating loss carryforwards $ 144.6 $ 124.9 Tax credits 15.2 13.0 Provision for bad debts 1.2 1.1 Depreciation and amortization — 3.5 Capital loss carryforwards 12.7 12.6 Stock-based compensation 8.9 9.3 Other 12.6 6.4 Total deferred tax assets 195.2 170.8 Deferred tax liabilities: Prepaid assets (2.1 ) (2.0 ) Depreciation and amortization (2.2 ) — Amortization of debt discount (73.4 ) (35.7 ) Capitalized contract acquisition costs (7.1 ) (5.8 ) Other (5.0 ) (0.8 ) Total deferred tax liabilities (89.8 ) (44.3 ) Net deferred tax asset before valuation allowance 105.4 126.5 Valuation allowance (104.4 ) (126.3 ) Net deferred tax asset $ 1.0 $ 0.2
Net Operating Loss Carryforwards and Other Tax Credits	The Company’s net operating loss carryforwards consist of the following: Years Ended December 31, (in millions) 2019 2018 Gross federal net operating loss carryforwards $ 607.4 $ 528.1 State operating loss carryforwards 298.8 246.4 Total $ 906.2 $ 774.5

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The table below sets forth the components used in the computation of basic and diluted net income (loss) per share: Years Ended December 31, (in millions, except share and per share data) 2019 2018 2017 Numerator: Net income (loss) $ 11.6 $ 3.3 $ (26.8 ) Denominator: Weighted average number of common shares outstanding, basic 60,593,846 58,859,574 58,003,434 Effect of dilutive common share equivalents Stock options 1,486,973 1,678,535 — Restricted stock units 223,529 469,915 — Weighted average number of common shares outstanding, diluted 62,304,348 61,008,024 58,003,434 Net income (loss) per share: Basic $ 0.19 $ 0.06 $ (0.46 ) Diluted $ 0.19 $ 0.05 $ (0.46 )
Potential Common Shares Excluded from Computation of Diluted Net Loss per Share	The number of common share equivalents excluded from the computation of diluted net income (loss) per share because either the effect would have been anti-dilutive, or the performance criteria related to the units had not yet been met were as follows: Years Ended December 31, 2019 2018 2017 2.00% Convertible Senior Notes — — 78,783 1.25% Convertible Senior Notes — 5,910,954 5,910,954 1.375% Convertible Senior Notes 4,319,429 4,319,429 4,319,429 0.375% Convertible Senior Notes 3,528,400 — — Unvested restricted stock units 430,593 289,974 994,364 Outstanding stock options 12,820 236,648 3,377,220 Total common share equivalents excluded from computation of diluted net income (loss) per share 8,291,242 10,757,005 14,680,750

Quarterly Data (Unaudited) (Tab

Quarterly Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Data [Abstract]
Quarterly Data (Unaudited)	2019 Quarters Ended (in millions, except per share data) March 31 June 30 September 30 (1) December 31 (2) Revenue $ 159.6 $ 177.1 $ 192.1 $ 209.4 Gross profit $ 106.7 $ 116.4 $ 123.1 $ 134.1 Net income $ 4.4 $ 1.4 $ 0.8 $ 5.0 Net income per share: Basic $ 0.07 $ 0.02 $ 0.01 $ 0.08 Diluted $ 0.07 $ 0.02 $ 0.01 $ 0.08 (1) Net income includes a $6.4 million loss on extinguishment of debt incurred in connection with the repurchase of the Company’s 1.25% Convertible Senior Notes. (2) Net income includes a $2.3 million loss on extinguishment of debt incurred in connection with the repurchase of the Company’s 1.25% Convertible Senior Notes. 2018 Quarters Ended (in millions, except per share data) March 31 June 30 September 30 (3) December 31 Revenue $ 123.6 $ 124.2 $ 151.1 $ 164.9 Gross profit $ 75.8 $ 82.1 $ 102.0 $ 110.3 Net income (loss) $ (6.6 ) $ (1.7 ) $ 1.7 $ 9.9 Net income (loss) per share: Basic $ (0.11 ) $ (0.03 ) $ 0.03 $ 0.17 Diluted $ (0.11 ) $ (0.03 ) $ 0.03 $ 0.16 (3) Net income includes a charge of $12.6 million for severance costs associated with the retirement of the Company’s former CEO, of which $8.2 million

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019	Jan. 01, 2018
Accounting Policies [Abstract]
Net foreign currency realized and unrealized gain (losses)	$ 0.6	$ 1
Significant Accounting Policies [Line Items]
Adoption of ASC 606 (Note 2)					$ 20.4
Shipping and handling costs	9.7	6.6	$ 5
Present value of future minimum lease payments	18
Other assets	16.1
Lease exit charge		$ 1.1
Accounting Standards Update 2016-02
Significant Accounting Policies [Line Items]
Present value of future minimum lease payments				$ 10.8
Other assets				$ 8.8
Accounting Standards Update 2018-15
Significant Accounting Policies [Line Items]
Cloud computing implementation costs	$ 3.6
United States and Europe
Significant Accounting Policies [Line Items]
Product warranty term	4 years
CANADA
Significant Accounting Policies [Line Items]
Product warranty term	5 years
Flex Ltd. | Supplier Concentration Risk | Accounts Payable
Significant Accounting Policies [Line Items]
Concentration risk, percentage	10.00%	10.00%
Retained earnings
Significant Accounting Policies [Line Items]
Adoption of ASC 606 (Note 2)					20.4
Retained earnings | Accounting Standards Update 2014-09
Significant Accounting Policies [Line Items]
Adoption of ASC 606 (Note 2)					$ 20.4

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Property Plant and Equipment (Details)	12 Months Ended
	Dec. 31, 2019
Minimum | Building and building improvements
Property, Plant and Equipment [Line Items]
Useful life of property plant and equipment	20 years
Minimum | Machinery and equipment
Property, Plant and Equipment [Line Items]
Useful life of property plant and equipment	2 years
Minimum | Furniture and fixtures
Property, Plant and Equipment [Line Items]
Useful life of property plant and equipment	3 years
Maximum | Building and building improvements
Property, Plant and Equipment [Line Items]
Useful life of property plant and equipment	39 years
Maximum | Machinery and equipment
Property, Plant and Equipment [Line Items]
Useful life of property plant and equipment	15 years
Maximum | Furniture and fixtures
Property, Plant and Equipment [Line Items]
Useful life of property plant and equipment	5 years

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Intangible Assets (Details)	12 Months Ended
	Dec. 31, 2019
Intellectual property
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible asset	15 years
Minimum | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible asset	5 years
Minimum | Internal-use software
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible asset	3 years
Maximum | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible asset	10 years
Maximum | Internal-use software
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible asset	10 years

Segment and Geographic Data - N

Segment and Geographic Data - Narrative (Details)	12 Months Ended
	Dec. 31, 2019segment
Segment Reporting [Abstract]
Number of operating segments	1

Segment and Geographic Data - R

Segment and Geographic Data - Revenue by Geographic Location (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total revenue	$ 209.4	$ 192.1	$ 177.1	$ 159.6	$ 164.9	$ 151.1	$ 124.2	$ 123.6	$ 738.2	$ 563.8	$ 463.8
United States
Segment Reporting Information [Line Items]
Total revenue									485.1	391.8	343.8
All other
Segment Reporting Information [Line Items]
Total revenue									$ 253.1	$ 172	$ 120

Segment and Geographic Data - L

Segment and Geographic Data - Long-lived Assets by Geographical Location (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Long-lived assets	$ 399.4	$ 258.8
United States
Segment Reporting Information [Line Items]
Long-lived assets	363	232.3
China
Segment Reporting Information [Line Items]
Long-lived assets	35.9	25.6
Other
Segment Reporting Information [Line Items]
Long-lived assets	$ 0.5	$ 0.9

Revenue and Contract Acquisit_3

Revenue and Contract Acquisition Costs - Summary of Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Total revenue	$ 209.4	$ 192.1	$ 177.1	$ 159.6	$ 164.9	$ 151.1	$ 124.2	$ 123.6	$ 738.2	$ 563.8	$ 463.8
Total Omnipod
Disaggregation of Revenue [Line Items]
Total revenue									673.5	495.5	391.6
U.S. Omnipod
Disaggregation of Revenue [Line Items]
Total revenue									420.4	323.5	271.6
International Omnipod
Disaggregation of Revenue [Line Items]
Total revenue									253.1	172	120
Drug Delivery
Disaggregation of Revenue [Line Items]
Total revenue									$ 64.7	$ 68.3	$ 72.2

Revenue and Contract Acquisit_4

Revenue and Contract Acquisition Costs - Schedule of Revenue from Major Customers - Concentration Risk (Details) - Sales revenue - Customer concentration risk	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amgen, Inc.
Concentration Risk [Line Items]
Total revenue, percentage		12.00%	15.00%
Ypsomed
Concentration Risk [Line Items]
Total revenue, percentage			22.00%
Cardinal Health Inc. and affiliates
Concentration Risk [Line Items]
Total revenue, percentage	11.00%	12.00%	11.00%

Revenue and Contract Acquisit_5

Revenue and Contract Acquisition Costs - Summary of Deferred Revenue (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Accrued expenses and other current liabilities	$ 3.2	$ 1.2
Other liabilities	1	0.9
Total deferred revenue	$ 4.2	$ 2.1

Revenue and Contract Acquisit_6

Revenue and Contract Acquisition Costs - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue recognized	$ 1,200,000	$ 2,400,000
Revenue recognized from performance obligations satisfied in previous periods	0	0
Amortization of capitalized commission costs	$ 8,800,000	$ 6,900,000

Revenue and Contract Acquisit_7

Revenue and Contract Acquisition Costs - Summary of Contract Acquisition Costs (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Prepaid expenses and other current assets	$ 9.5	$ 7.3
Other assets	19.9	16
Total capitalized contract acquisition costs, net	$ 29.4	$ 23.3

Cash and Cash Equivalents (Deta

Cash and Cash Equivalents (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents	$ 213.7	$ 113.9
Level 1
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents	203.7	113.9
Level 2
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents	10	0
Cash
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents	85.3	64
Cash | Level 1
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents	85.3	64
Cash | Level 2
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents	0	0
Money market mutual funds
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents	115.5	47.2
Money market mutual funds | Level 1
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents	115.5	47.2
Money market mutual funds | Level 2
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents	0	0
Commercial paper
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents	10
Commercial paper | Level 1
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents
Commercial paper | Level 2
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents	10
Restricted cash
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents	2.9	2.7
Restricted cash | Level 1
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents	2.9	2.7
Restricted cash | Level 2
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents

Investments (Details)

Investments (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Short-term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 162	$ 175.7
Gross Unrealized Gains	0.4	0
Gross Unrealized Losses	0	(0.7)
Fair Value	162.4	175
Short-term Investments | U.S. government and agency bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	94.7	113
Gross Unrealized Gains	0.3	0
Gross Unrealized Losses	0	(0.5)
Fair Value	95	112.5
Short-term Investments | Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	51	56.2
Gross Unrealized Gains	0.1	0
Gross Unrealized Losses	0	(0.2)
Fair Value	51.1	56
Short-term Investments | Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	6.3	6.5
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	6.3	6.5
Short-term Investments | Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	10
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	10
Short-term Investments | Level 1
Debt Securities, Available-for-sale [Line Items]
Fair Value	85	69.6
Short-term Investments | Level 1 | U.S. government and agency bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value	85	69.6
Short-term Investments | Level 1 | Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value	0	0
Short-term Investments | Level 1 | Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Fair Value	0	0
Short-term Investments | Level 1 | Commercial paper
Debt Securities, Available-for-sale [Line Items]
Fair Value
Short-term Investments | Level 2
Debt Securities, Available-for-sale [Line Items]
Fair Value	77.4	105.4
Short-term Investments | Level 2 | U.S. government and agency bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value	10	42.9
Short-term Investments | Level 2 | Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value	51.1	56
Short-term Investments | Level 2 | Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Fair Value	6.3	6.5
Short-term Investments | Level 2 | Commercial paper
Debt Securities, Available-for-sale [Line Items]
Fair Value	10
Long Term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	58.4	140.9
Gross Unrealized Gains	0.1	0.1
Gross Unrealized Losses	(0.1)	(0.2)
Fair Value	58.4	140.8
Long Term Investments | U.S. government and agency bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	52.9	90.5
Gross Unrealized Gains	0.1	0.1
Gross Unrealized Losses	(0.1)	(0.2)
Fair Value	52.9	90.4
Long Term Investments | Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2.8	46.7
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	2.8	46.7
Long Term Investments | Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2.7	3.7
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	2.7	3.7
Long Term Investments | Level 1
Debt Securities, Available-for-sale [Line Items]
Fair Value	42.9	64.1
Long Term Investments | Level 1 | U.S. government and agency bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value	42.9	64.1
Long Term Investments | Level 1 | Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value	0	0
Long Term Investments | Level 1 | Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Fair Value	0	0
Long Term Investments | Level 2
Debt Securities, Available-for-sale [Line Items]
Fair Value	15.5	76.7
Long Term Investments | Level 2 | U.S. government and agency bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value	10	26.3
Long Term Investments | Level 2 | Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value	2.8	46.7
Long Term Investments | Level 2 | Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 2.7	$ 3.7

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Raw materials	$ 23.3	$ 10.4
Work-in-process	40.3	30.2
Finished goods	37.4	30.8
Total inventories	$ 101	$ 71.4

Property and Equipment, Net - C

Property and Equipment, Net - Component of Property and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 490	$ 323.8
Less: accumulated depreciation	(90.6)	(65.4)
Property, plant and equipment, net	399.4	258.4
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	2.5	2.5
Building and building improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	116.9	44.2
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	194.8	93.3
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	12.7	6.3
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	1.6	1.4
Construction in process
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 161.5	$ 176.1

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 25.2	$ 13.8	$ 12.7

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets, Net - Schedule of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Beginning balance	$ 39.6	$ 39.8
Foreign currency adjustment	0.2	(0.2)
Ending balance	$ 39.8	$ 39.6

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets, Net - Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 22.9	$ 17.4
Accumulated Amortization	(9.7)	(7)
Total	13.2	10.4
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	9.9	6.1
Accumulated Amortization	(2.8)	(1.9)
Total	7.1	4.2
Internal-use software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	12	11.3
Accumulated Amortization	(6.8)	(5.1)
Total	5.2	6.2
Intellectual property
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1	0
Accumulated Amortization	(0.1)	0
Total	$ 0.9	$ 0

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets, Net - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of other intangible assets	$ 2.7	$ 1.8	$ 1.2

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets, Net - Amortization Expense Expected for Next Five Years (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Years Ending December 31,
2020	$ 2.9
2021	2.4
2022	1.9
2023	1.3
2024	1.2
Thereafter	3.5
Total	$ 13.2	$ 10.4

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Components of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Employee compensation and related costs	$ 45.8	$ 37.8
Professional and consulting services	19.3	14.9
Accrued rebates	7.5	2.8
Supplier purchases	2.4	7.7
Value added taxes payable	1.8	8.5
Other	26.4	18.5
Accrued expenses and other current liabilities	$ 103.2	$ 90.2

Accrued Expenses and Other Cu_4

Accrued Expenses and Other Current Liabilities - Reconciliation of Changes in Product Warranty Liability (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Product warranty liability at beginning of year	$ 6.4	$ 5.3
Warranty expense	13.4	7.8
Warranty claims settled	(11.3)	(6.7)
Product warranty liability at end of year	$ 8.5	$ 6.4

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Option to extend lease, maximum number of years	5 years
Operating lease cost	$ 4.3
Rent expense		$ 3.3	$ 2.8
Operating cash outflows from operating leases	3.6
Operating lease asset	$ 9.8
Weighted average remaining lease term	4 years 4 months 24 days
Weighted average discount rate	5.90%

Leases - Summary of ROU Assets

Leases - Summary of ROU Assets and Operating Lease Liabilities (Details) $ in Millions	Dec. 31, 2019USD ($)
Leases [Abstract]
Other assets	$ 16.1
Operating lease liabilities:
Accrued expenses and other current liabilities	3.6
Other liabilities	14.4
Total	$ 18

Leases - Future Minimum Undisco

Leases - Future Minimum Undiscounted Lease Payments (Details) $ in Millions	Dec. 31, 2019USD ($)
Years Ending December 31,
2020	$ 4.5
2021	5
2022	4.7
2023	2.3
2024	2.4
Thereafter	1.5
Total future minimum lease payments	20.4
Less: imputed interest	(2.4)
Total	$ 18

Convertible Debt, Net - Outstan

Convertible Debt, Net - Outstanding Convertible Debt and Related Deferred Financing Costs (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Unamortized debt discount	$ (294.8)	$ (143.6)
Debt issuance costs	19.8	11.9
Convertible debt, net	$ 887.9	$ 592
1.25% Convertible Senior Notes
Debt Instrument [Line Items]
Debt, interest rate	1.25%	1.25%
1.375% Convertible Senior Notes
Debt Instrument [Line Items]
Debt, interest rate	1.375%		1.375%
0.375% Convertible Senior Notes
Debt Instrument [Line Items]
Debt, interest rate	0.375%
Convertible Debt | 1.25% Convertible Senior Notes
Debt Instrument [Line Items]
Convertible debt, gross	$ 0	$ 345
Convertible Debt | 1.375% Convertible Senior Notes
Debt Instrument [Line Items]
Convertible debt, gross	402.5	402.5
Convertible Debt | 0.375% Convertible Senior Notes
Debt Instrument [Line Items]
Convertible debt, gross	$ 800	$ 0

Convertible Debt, Net - Narrati

Convertible Debt, Net - Narrative (Details) $ / shares in Units, shares in Thousands	1 Months Ended		12 Months Ended
	Sep. 30, 2019USD ($)$ / shares$ / optionshares	Nov. 30, 2017USD ($)$ / shares	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Unamortized discount			$ 294,800,000	$ 143,600,000
Proceeds from issuance of convertible notes, net of issuance costs			780,200,000	0	$ 391,600,000
Repayment of convertible debt			663,600,000	6,700,000	98,500,000
Loss on extinguishment of debt			$ 8,700,000	$ 0	$ 600,000
0.375% Convertible Senior Notes
Debt Instrument [Line Items]
Debt, interest rate			0.375%
1.375% Convertible Senior Notes
Debt Instrument [Line Items]
Debt, interest rate			1.375%		1.375%
2% Convertible Senior Notes
Debt Instrument [Line Items]
Debt, interest rate			2.00%	2.00%	2.00%
Senior Notes | 0.375% Convertible Senior Notes
Debt Instrument [Line Items]
Debt, interest rate	0.375%
Principal amount of senior notes	$ 800,000,000
Debt conversion rate	0.0044105
Principal amount per note used in conversion rate	$ 1,000
Conversion price (in dollars per share) | $ / shares	$ 226.73
Unamortized discount	$ 213,000,000
Nonconvertible debt borrowing rate	5.29%
Debt issuance costs incurred	$ 19,800,000
Finance costs reclassified against equity	5,300,000
Debt issuance costs as a reduction of debt	14,500,000
Proceeds from issuance of convertible notes, net of issuance costs	780,200,000
Price at which capped call options entered	$ 85,400,000
Share price (in dollars per share) | $ / shares	$ 167.95
Number of capped shares (in shares) | shares	3,500
Senior Notes | 1.375% Convertible Senior Notes
Debt Instrument [Line Items]
Debt, interest rate		1.375%
Principal amount of senior notes		$ 402,500,000
Debt conversion rate		10.7315
Principal amount per note used in conversion rate		$ 1,000
Conversion price (in dollars per share) | $ / shares		$ 93.18
Unamortized discount		$ 120,700,000
Nonconvertible debt borrowing rate		6.80%
Debt issuance costs incurred		$ 10,900,000
Finance costs reclassified against equity		3,300,000
Debt issuance costs as a reduction of debt		$ 7,600,000
Senior Notes | 1.25% Convertible Senior Notes
Debt Instrument [Line Items]
Debt, interest rate	1.25%		1.25%
Repurchased face amount			$ 345,000,000
Repurchase amount			312,000,000
Total consideration			963,000,000
Repayment of convertible debt			663,600,000
Debt fair value			$ 299,400,000
Shares issued | shares			1,870
Carrying amount of equity component			$ 642,300,000
Convertible debt			320,700,000
Loss on extinguishment of debt			$ 8,700,000
Senior Notes | 2% Convertible Senior Notes
Debt Instrument [Line Items]
Debt, interest rate					2.00%
Repurchased face amount					$ 63,400,000
Repayment of convertible debt					6,700,000
Carrying amount of equity component					3,200,000
Convertible debt					3,500,000
Loss on extinguishment of debt					$ 0
Senior Notes | Upto 360 Days | 0.375% Convertible Senior Notes
Debt Instrument [Line Items]
Debt instrument, additional interest in event of reporting violation	0.50%
Senior Notes | Upto 360 Days | 1.375% Convertible Senior Notes
Debt Instrument [Line Items]
Debt instrument, additional interest in event of reporting violation		0.50%
Senior Notes | Price Risk Derivative | 0.375% Convertible Senior Notes
Debt Instrument [Line Items]
Cap price (in dollars per share) | $ / option	335.90
Sale price premium (as a percentage)	100.00%

Convertible Debt, Net - Summary

Convertible Debt, Net - Summary of Carrying Amount and Estimated Fair Value of Convertible Debt (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
1.25% Convertible Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt, interest rate	1.25%	1.25%
1.375% Convertible Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt, interest rate	1.375%		1.375%
0.375% Convertible Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt, interest rate	0.375%
Carrying Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	$ 887.9	$ 592
Carrying Value | 1.25% Convertible Senior Notes | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	0	301
Carrying Value | 1.375% Convertible Senior Notes | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	306.9	291
Carrying Value | 0.375% Convertible Senior Notes | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	581	0
Estimated Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	1,352.8	909.9
Estimated Fair Value | 1.25% Convertible Senior Notes | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	0	483.9
Estimated Fair Value | 1.375% Convertible Senior Notes | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	512.8	426
Estimated Fair Value | 0.375% Convertible Senior Notes | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument value	$ 840	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	1 Months Ended
	Jun. 16, 2015lawsuit	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Loss Contingencies [Line Items]
Number of class actions filed (in legal matters) | lawsuit	3
Number of class actions dismissed (in legal matters) | lawsuit	2
Associated gross intangible asset		$ 7.8	$ 4.2
Fees To Former European Distributor
Loss Contingencies [Line Items]
Accrued liabilities		2.7	$ 2.9
Fees To Former European Distributor | Minimum
Loss Contingencies [Line Items]
Commitment due in next twelve months		5
Fees To Former European Distributor | Maximum
Loss Contingencies [Line Items]
Commitment due in next twelve months		$ 55

Stock-Based Compensation - Equi

Stock-Based Compensation - Equity Award Plan (Details) - 2017 Plan - shares shares in Millions	Dec. 31, 2019	May 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)		5.2
Shares available for issuance (in sharers)	3.9

Stock-Based Compensation - Cost

Stock-Based Compensation - Cost Related to Stock-Based Compensation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 28.7	$ 37.5	$ 31.9
Cost of revenue
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	1	0.8	0.5
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	9.1	8.2	5.9
Sales and marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	7.8	7.6	8.8
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 10.8	$ 20.9	$ 16.7

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number of Options
Beginning balance (in shares)	3,077,624
Granted (in shares)	125,640
Exercised (in shares)	(1,345,386)
Canceled (in shares)	(128,366)
Ending balance (in shares)	1,729,512	3,077,624
Vested, at end of period (in shares)	1,361,514
Vested or expected to vest (in shares)	1,689,570
Weighted Average Exercise Price
Beginning balance (in USD per share)	$ 39.16
Granted (in USD per share)	93.16
Exercised (in USD per share)	35.02
Canceled (in USD per share)	51.55
Ending balance (in USD per share)	45.39	$ 39.16
Vested, at end of period (in USD per share)	38.71
Vested or expected to vest (in USD per share)	$ 44.59
Options outstanding, weighted average remaining contractual life	5 years 4 months 24 days
Options exercisable, weighted average remaining contractual life	4 years 8 months 12 days
Expected to vest, outstanding, weighted average remaining contractual term	5 years 3 months 18 days
Intrinsic value, exercised in the period	$ 119.2	$ 23.5	$ 11.8
Intrinsic value, options outstanding	217.6
Intrinsic value, options vested	180.4
Intrinsic value, options vested and expected to vest	$ 213.9

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Options Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value, exercised in the period	$ 119.2	$ 23.5	$ 11.8
Unrecognized compensation cost	$ 7.6
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period	2 years 4 months 24 days

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions Used for Options Granted (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value per option (in USD per share)	$ 34.98	$ 30.34	$ 17.28
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate, minimum	1.80%	2.20%	1.70%
Risk-free interest rate, maximum	2.60%	2.90%	1.90%
Dividend yield	0.00%	0.00%	0.00%
Expected volatility, minimum	40.10%	38.70%	38.50%
Expected volatility, maximum	40.50%	40.70%	39.10%
Stock options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	4 years 4 months 24 days	4 years 6 months	4 years 8 months 12 days
Stock options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	4 years 9 months 18 days	5 years 4 months 24 days	5 years 3 months 18 days

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Restricted Stock Units (Details) - Restricted stock units - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number of Shares
Beginning balance (in shares)	416,811
Granted (in shares)	218,810
Vested (in shares)	(231,647)
Forfeited (in shares)	(51,687)
Ending balance (in shares)	352,287	416,811
Weighted Average Fair Value
Beginning balance (in USD per share)	$ 56.51
Granted (in USD per share)	96.62	$ 76.03	$ 46.13
Vested (in USD per share)	50.13
Forfeited (in USD per share)	71.32
Ending balance (in USD per share)	$ 83.44	$ 56.51

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Units Narrative (Details) - Restricted stock units - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value per share (in USD per share)	$ 96.62	$ 76.03	$ 46.13
Total fair value	$ 11.6	$ 14.7	$ 11.4
Unrecognized compensation cost	$ 18.9
Weighted average period	1 year 10 months 24 days

Stock-Based Compensation - Perf

Stock-Based Compensation - Performance Stock Units Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 7.6
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Target award percentage	200.00%
Weighted-average grant-date fair value per share (in USD per share)	$ 95.91	$ 75.07	$ 50.02
Total fair value	$ 3.2	$ 7.6	$ 0.9
Unrecognized compensation cost	$ 12.2
Weighted average period	1 year 10 months 24 days

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Performance Stock Units (Details) - Performance Shares - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number of Shares
Beginning balance (in shares)	335,396
Granted (in shares)	81,118
Vested (in shares)	(93,088)
Forfeited (in shares)	(24,270)
Ending balance (in shares)	299,156	335,396
Weighted Average Fair Value
Beginning balance (in USD per share)	$ 53.17
Granted (in USD per share)	95.91	$ 75.07	$ 50.02
Vested (in USD per share)	34.27
Forfeited (in USD per share)	62.32
Ending balance (in USD per share)	$ 73.35	$ 53.17
Target award percentage	200.00%
Achievement of internal metrics of 200%
Weighted Average Fair Value
Granted (in USD per share)			$ 172,000

Stock-Based Compensation - Empl

Stock-Based Compensation - Employee Stock Purchase Plan Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 7,600,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value per share (in USD per share)	$ 46.30	$ 26.01	$ 15.18
Unrecognized compensation cost	$ 1,000,000
Weighted average period	4 months 24 days
ESPP | ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	880,000
Annual maximum shares per employee (in shares)	800
Annual maximum common stock value purchase per employee	$ 25,000
Percentage of employees' compensation deduction for share purchase	10.00%
Purchase price percentage of fair market value	85.00%
Issuance for employee stock purchase plan (in shares)	51,502	46,343	59,134
Shares available for issuance (in sharers)	547,075

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary Employee Stock Purchase Plan (Details) - ESPP	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate, minimum	1.60%	2.10%	1.10%
Risk-free interest rate, maximum	2.30%	2.50%	1.50%
Expected term (in years)	6 months	6 months	6 months
Dividend yield	0.00%	0.00%	0.00%
Expected volatility, minimum	27.50%	23.40%	22.90%
Expected volatility, maximum	31.40%	27.00%	26.70%

Defined Contribution Plan (Deta

Defined Contribution Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Contribution Plan [Abstract]
Employer matching percentage of employees contribution percentage	50.00%
Maximum elective contributions of employee's eligible pay	6.00%
Contributions by employer	$ 5.3	$ 3.6	$ 3

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 212.1	$ 158.5	$ 63.1
Other comprehensive income (loss)	1.7	(2.4)	0.2
Ending balance	75.9	212.1	158.5
Foreign Currency Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2.2)	0	(0.5)
Other comprehensive income (loss)	0.6	(2.2)	0.5
Ending balance	(1.6)	(2.2)	0
Unrealized Losses on Available-for-sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(0.7)	(0.5)	(0.2)
Other comprehensive income (loss)	1.1	(0.2)	(0.3)
Ending balance	0.4	(0.7)	(0.5)
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2.9)	(0.5)	(0.7)
Other comprehensive income (loss)		(2.4)	0.2
Ending balance	$ (1.2)	$ (2.9)	$ (0.5)

Interest Expense (Details)

Interest Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest Expense [Abstract]
Contractual coupon interest	$ 9.5	$ 9.8	$ 6.3
Accretion of debt discount	32.8	26.7	15.9
Amortization of debt issuance costs	2.8	2.6	2.1
Capitalized interest	(10.5)	(10.2)	(3.1)
Interest expense, net of portion capitalized	$ 34.6	$ 28.9	$ 21.2

Income Taxes - Components of In

Income Taxes - Components of Income (Loss) Before Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
U.S.	$ 2.5	$ (3)	$ (27.7)
Foreign	12	8.2	1.1
Income (loss) before income taxes	$ 14.5	$ 5.2	$ (26.6)

Income Taxes - Income Tax Expen

Income Taxes - Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
State	$ 0.2	$ 0.2	$ 0.1
Foreign	3.4	2.1	0.6
Total current expense	3.6	2.3	0.7
Deferred:
Federal	(0.1)	0	(0.3)
Foreign	(0.6)	(0.4)	(0.2)
Total deferred expense	(0.7)	(0.4)	(0.5)
Total income tax expense	$ 2.9	$ 1.9	$ 0.2

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Tax Expense (Benefit) at Statutory Federal Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Foreign rate differential	21.00%	21.00%	34.00%
State taxes, net of federal benefit	4.20%	(2.40%)	0.30%
State taxes, net of federal benefit	1.30%	2.90%	10.20%
Tax credits	(15.40%)	(13.70%)	13.30%
Share-based compensation	(158.70%)	(159.10%)	33.60%
Loss on extinguishment of debt	14.80%	0.00%	0.00%
Non-deductible officer's compensation	1.90%	81.30%	(20.20%)
Permanent items	3.00%	16.80%	(14.00%)
Foreign income taxed in the U.S.	19.00%	26.10%	0.00%
Change in valuation allowance	130.60%	67.00%	(57.90%)
Other	(1.90%)	(2.90%)	(0.30%)
Effective income tax rate	19.80%	37.00%	(1.00%)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 0	$ 0	$ 0
Valuation allowance	104,400,000	126,300,000
Valuation allowance decreases due to increase in liabilities	21,900,000
Net operating losses that have an indefinite carryforward period	66,800,000
Research and development and other tax credits	$ 16,100,000	$ 13,000,000

Income Taxes - Components of Co

Income Taxes - Components of Company's Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 144.6	$ 124.9
Tax credits	15.2	13
Provision for bad debts	1.2	1.1
Depreciation and amortization	0	3.5
Capital loss carryforwards	12.7	12.6
Stock-based compensation	8.9	9.3
Other	12.6	6.4
Total deferred tax assets	195.2	170.8
Deferred tax liabilities:
Prepaid assets	(2.1)	(2)
Depreciation and amortization	(2.2)	0
Amortization of debt discount	(73.4)	(35.7)
Capitalized contract acquisition costs	(7.1)	(5.8)
Other	(5)	(0.8)
Total deferred tax liabilities	(89.8)	(44.3)
Net deferred tax asset before valuation allowance	105.4	126.5
Valuation allowance	(104.4)	(126.3)
Net deferred tax asset	$ 1	$ 0.2

Income Taxes - Net Operating Lo

Income Taxes - Net Operating Loss Carryforwards (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Total	$ 906.2	$ 774.5
Gross federal net operating loss carryforwards
Operating Loss Carryforwards [Line Items]
Total	607.4	528.1
State operating loss carryforwards
Operating Loss Carryforwards [Line Items]
Total	$ 298.8	$ 246.4

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 Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net income (loss)	$ 5	$ 0.8	$ 1.4	$ 4.4	$ 9.9	$ 1.7	$ (1.7)	$ (6.6)	$ 11.6	$ 3.3	$ (26.8)
Denominator:
Weighted average number of common shares outstanding, basic (in shares)									60,593,846	58,859,574	58,003,434
Weighted average number of common shares outstanding, diluted (in shares)									62,304,348	61,008,024	58,003,434
Net income (loss) per share:
Basic (USD per share)	$ 0.08	$ 0.01	$ 0.02	$ 0.07	$ 0.17	$ 0.03	$ (0.03)	$ (0.11)	$ 0.19	$ 0.06	$ (0.46)
Diluted (USD per share)	$ 0.08	$ 0.01	$ 0.02	$ 0.07	$ 0.16	$ 0.03	$ (0.03)	$ (0.11)	$ 0.19	$ 0.05	$ (0.46)
Stock options
Denominator:
Effect of dilutive common share equivalents (in shares)									1,486,973	1,678,535	0
Restricted stock units
Denominator:
Effect of dilutive common share equivalents (in shares)									223,529	469,915	0

Net Income (Loss) Per Share - P

Net Income (Loss) Per Share - Potential Common Shares Excluded from Computation of Diluted Net Loss Per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	8,291,242	10,757,005	14,680,750
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	430,593	289,974	994,364
Outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	12,820	236,648	3,377,220
2.00% Convertible Senior Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt, interest rate	2.00%	2.00%	2.00%
2.00% Convertible Senior Notes | Convertible Debt Securities
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	0	0	78,783
1.25% Convertible Senior Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt, interest rate	1.25%	1.25%
1.25% Convertible Senior Notes | Convertible Debt Securities
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	0	5,910,954	5,910,954
1.375% Convertible Senior Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt, interest rate	1.375%		1.375%
1.375% Convertible Senior Notes | Convertible Debt Securities
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	4,319,429	4,319,429	4,319,429
0.375% Convertible Senior Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt, interest rate	0.375%
0.375% Convertible Senior Notes | Convertible Debt Securities
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	3,528,400	0	0

Quarterly Data (Unaudited) (Det

Quarterly Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Data [Abstract]
Total revenue	$ 209.4	$ 192.1	$ 177.1	$ 159.6	$ 164.9	$ 151.1	$ 124.2	$ 123.6	$ 738.2	$ 563.8	$ 463.8
Gross profit	134.1	123.1	116.4	106.7	110.3	102	82.1	75.8	480.3	370.2	277.2
Net income (loss)	$ 5	$ 0.8	$ 1.4	$ 4.4	$ 9.9	$ 1.7	$ (1.7)	$ (6.6)	$ 11.6	$ 3.3	$ (26.8)
Net income per share:
Basic (USD per share)	$ 0.08	$ 0.01	$ 0.02	$ 0.07	$ 0.17	$ 0.03	$ (0.03)	$ (0.11)	$ 0.19	$ 0.06	$ (0.46)
Diluted (USD per share)	$ 0.08	$ 0.01	$ 0.02	$ 0.07	$ 0.16	$ 0.03	$ (0.03)	$ (0.11)	$ 0.19	$ 0.05	$ (0.46)
Debt Instrument [Line Items]
Loss on extinguishment of debt									$ 8.7	$ 0	$ 0.6
Severance costs						$ 12.6
Accelerated compensation cost						$ 8.2
1.25% Convertible Senior Notes
Debt Instrument [Line Items]
Loss on extinguishment of debt	$ 2.3	$ 6.4
Debt, interest rate	1.25%				1.25%				1.25%	1.25%

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 3.6	$ 2.5	$ 2.9
Additions Charged to Costs and Expenses	4.5	3.4	1.9
Deductions	(4.3)	(2.3)	(2.3)
Balance at End of Period	3.8	3.6	2.5
Reserve for rebates
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	8.6	6.3	1.4
Additions Charged to Costs and Expenses	59.1	34.1	16.1
Deductions	(55.6)	(31.8)	(11.2)
Balance at End of Period	12.1	8.6	6.3
Deferred tax valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	126.3	127.9	191.9
Additions Charged to Costs and Expenses	43.6	13.9	14.2
Deductions	(65.5)	(15.5)	(78.2)
Balance at End of Period	$ 104.4	$ 126.3	$ 127.9