Vocera Communications (VCRA) 10-K 27 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Feb. 25, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	VOCERA COMMUNICATIONS, INC.
Entity Central Index Key	1,129,260
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Common Stock, Shares Outstanding		30,804,783
Entity Public Float			$ 746

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 34,276	$ 28,726
Short-term investments	186,894	52,507
Accounts receivable, net	40,127	35,105
Other receivables	4,148	1,331
Inventories	4,350	2,815
Prepaid expenses and other current assets	4,691	3,957
Total current assets	274,486	124,441
Property and equipment, net	7,468	5,751
Intangible assets, net	9,070	13,567
Goodwill	49,246	49,246
Deferred commissions		10,301
Other long-term assets	1,525	1,667
Total assets	352,098	204,973
Current liabilities
Accounts payable	4,217	2,678
Accrued payroll and other current liabilities	12,885	14,689
Deferred revenue, current	44,053	40,734
Total current liabilities	61,155	58,101
Deferred revenue, long-term	14,579	14,417
Other long-term liabilities	2,957	4,455
Total liabilities	189,231	76,973
Commitments and contingencies (Note 7)
Stockholders' equity
Preferred stock, $0.0003 par value - 5,000,000 shares authorized as of December 31, 2018 and December 31, 2017; zero shares issued and outstanding	0	0
Common stock, $0.0003 par value - 100,000,000 shares authorized as of December 31, 2018 and December 31, 2017; 30,708,138 and 29,412,116 shares issued and outstanding as of December 31, 2018 and December 31, 2017, respectively	9	9
Additional paid-in capital	295,647	250,854
Accumulated other comprehensive loss	(443)	(191)
Accumulated deficit	(132,346)	(122,672)
Total stockholders’ equity	162,867	128,000
Total liabilities and stockholders’ equity	352,098	204,973
Convertible Debt, Noncurrent	$ 110,540	$ 0

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Paranthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Liabilities, Convertible Preferred Stock and Stockholders' Deficit
Common stock, par value	$ 0.0003	$ 0.0003
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	29,412,116	27,568,103
Common stock, shares outstanding	29,412,116	27,568,103
Preferred Stock
Liabilities, Convertible Preferred Stock and Stockholders' Deficit
Preferred stock, par value	$ 0.0003	$ 0.0003
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue
Total revenue	$ 179,630	$ 165,989	$ 132,026
Cost of Revenue [Abstract]
Total cost of revenue	67,743	64,927	49,075
Gross profit	111,887	101,062	82,951
Operating expenses
Research and development	30,879	27,685	18,266
Sales and marketing	62,214	60,107	51,274
General and administrative	25,099	23,970	24,499
Total operating expenses	118,192	111,762	94,039
Loss from operations	(6,305)	(10,700)	(11,088)
Interest income	3,044	604	684
Interest Expense	5,241	0	0
Other expense, net	(1,523)	(42)	(467)
Loss before income taxes	(10,025)	(10,138)	(10,871)
Benefit from (provision for) income taxes	351	(759)	(529)
Net loss	$ (9,674)	$ (10,897)	$ (11,400)
Net loss per share:
Basic and diluted	$ (0.32)	$ (0.38)	$ (0.42)
Weighted average shares used to compute net loss per share:
Basic	30,041	28,655	26,859
Diluted	30,041	28,655	26,859
Product
Revenue
Total revenue	$ 97,447	$ 91,585	$ 74,235
Cost of Revenue [Abstract]
Total cost of revenue	27,425	27,244	22,788
Service
Revenue
Total revenue	82,183	74,404	57,791
Cost of Revenue [Abstract]
Total cost of revenue	$ 40,318	37,683	26,287
As Reported
Revenue
Total revenue		162,548	127,696
Cost of Revenue [Abstract]
Gross profit		97,621	78,621
Operating expenses
Total operating expenses		111,641	95,576
Loss from operations		(14,020)	(16,955)
Net loss		(14,217)	(17,267)
Net loss per share:
Basic and diluted	$ (0.32)
As Reported | Product
Revenue
Total revenue		88,865	70,667
As Reported | Service
Revenue
Total revenue		$ 73,683	$ 57,029

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net loss	$ (9,674)	$ (10,897)	$ (11,400)
Other comprehensive loss, net:
Change in unrealized gain (loss) on investments, net of tax	(252)	(122)	93
Comprehensive loss	$ (9,926)	$ (11,019)	$ (11,307)

Statements of Stockholders' Equ

Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated other comprehensive gain	Accumulated deficit	Restricted stock units	Restricted stock unitsCommon stock	Restricted stock unitsAdditional paid-in capital	Cash Exercise [Member]Common stock	Convertible DebtConvertible Senior Notes At 1.50%, Option Portion
Balance (shares) at Dec. 31, 2015		26,322,322
Balance at Dec. 31, 2015	$ 114,269	$ 8	$ 214,421	$ (162)	$ (99,998)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (shares)		643,005
Exercise of stock options	2,502		2,502
Vested, Number of Shares							414,404
RSUs released net of shares withheld for tax settlement						$ (2,675)		$ (2,675)
ESPP, Shares Purchased for Award		188,372
Stock Issued During Period, Value, Employee Stock Purchase Plan	1,690		1,690
Exercise of common stock warrants									0
NoncashCompensationAcquisitionRelatedExpenses	2,632
Employee stock-based compensation expense	12,035		12,035
Net loss	(11,400)				(11,400)
Other comprehensive income	93			93
Balance (shares) at Dec. 31, 2016		27,568,103
Balance at Dec. 31, 2016	119,146	$ 8	230,605	(69)	(111,398)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock in a public offering		$ 1
Exercise of stock options (shares)		1,085,041
Exercise of stock options	7,917		7,916
RSUs released net of shares withheld for tax settlement	$ (8,990)							(8,990)
ESPP, Shares Purchased for Award	159,532	159,532
Stock Issued During Period, Value, Employee Stock Purchase Plan	$ 2,750		2,750
NoncashCompensationAcquisitionRelatedExpenses	0
Issuance of restricted stock awards							599,440
Employee stock-based compensation expense	18,196		18,196
Net loss	(10,897)				(10,897)
Other comprehensive income	(122)			(122)
Balance (shares) at Dec. 31, 2017		29,412,116
Balance at Dec. 31, 2017	128,000	$ 9	250,854	(191)	(122,672)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity component of convertible senior notes, net	0		377		(377)
Exercise of stock options (shares)		531,788
Exercise of stock options	7,334		7,334
Vested, Number of Shares						979,074
RSUs released net of shares withheld for tax settlement	$ (10,082)							$ (10,082)
ESPP, Shares Purchased for Award	157,426	157,426
Stock Issued During Period, Value, Employee Stock Purchase Plan	$ 3,270		3,270
NoncashCompensationAcquisitionRelatedExpenses	0
Issuance of restricted stock awards							606,808
Employee stock-based compensation expense	20,964		20,964
Net loss	(9,674)				(9,674)
Other comprehensive income	(252)
Balance (shares) at Dec. 31, 2018		30,708,138
Balance at Dec. 31, 2018	162,867	$ 9	$ 295,647	$ (443)	$ (132,346)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax	$ (252)
Carrying amount of equity component, net of capped calls										$ 23,307

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	$ 1,066	$ 0	$ 0
Proceeds from issuance of convertible senior notes, net of issuance costs	138,854	0	0
Amortization of Debt Issuance Costs and Discounts	3,899	0	0
Cash flows from operating activities
Net loss	(9,674)	(10,897)	(11,400)
Depreciation, Depletion and Amortization	7,662	7,643	3,770
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Inventory provision	362	380	168
Change in lease-related performance liabilities	(998)	(864)	(811)
Share-based Compensation	20,964	18,196	12,035
NoncashCompensationAcquisitionRelatedExpenses	0	0	2,632
Other Operating Activities, Cash Flow Statement	22	26	42
Changes in assets and liabilities
Accounts receivable	(5,017)	(10,963)	(322)
Other receivables	(2,810)	(120)	120
Inventories	(1,898)	1,361	(1,985)
Prepaid expenses and other assets	(592)	(866)	(833)
Deferred commissions	(2)	121	(1,538)
Accounts payable	1,527	(611)	170
Increase (Decrease) in Other Operating Liabilities	(2,629)	(1,104)	2,355
Deferred revenue	3,482	5,434	6,863
Net cash provided by operating activities	14,298	7,736	11,266
Cash flows from investing activities
Payment for purchase of property and equipment	(4,892)	(2,834)	(4,707)
Payments to Acquire Businesses, Net of Cash Acquired	0	0	(52,500)
Purchase of short-term investments	(206,824)	(67,426)	(86,551)
Maturities of short-term investments	72,183	53,831	111,809
Sale of short-term investments	0	0	32,061
Net cash provided by (used in) investing activities	(139,533)	(16,429)	112
Cash flows from financing activities
Cash from lease-related performance obligations	340	693	1,596
Proceeds from Issuance of Shares under Incentive and Share-based Compensation Plans, Excluding Stock Options	3,269	2,750	1,690
Proceeds from exercise of stock options	7,327	7,917	2,502
RSUs released and tax settlement	(10,098)	(8,974)	(2,705)
Net cash provided by financing activities	130,785	2,386	3,083
Net increase (decrease) in cash and cash equivalents	5,550	(6,307)	14,461
Cash and cash equivalents at beginning of period	28,726	35,033	20,572
Cash and cash equivalents at end of period	34,276	28,726	35,033
Supplemental cash flow information
Cash paid for income taxes	216	342	245
Supplemental disclosure of non-cash investing and financing activities
Property and equipment in accounts payable and accrued liabilities	114	102	44
Payment for purchase of capped calls	$ (8,907)	$ 0	$ 0

Revenue, deferred revenue, and

Revenue, deferred revenue, and deferred commissions	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue, deferred revenue, and deferred commissions	2. Revenue, deferred revenue and deferred commissions Effective January 1, 2018, the Company adopted ASC 606 using the full retrospective method, which requires the Company to present its historical financial information for fiscal years 2017 and 2016 as if the new revenue guidance had been applied to all prior periods. The most significant impact of the standard relates to the timing of revenue recognition for software licenses sold with professional services where the Company did not have vendor specific objective evidence (VSOE) for professional services under prior guidance. Under the new standard, the requirement to have VSOE for undelivered elements is eliminated and the Company recognizes revenue for software licenses upon transfer of control to its customers. Additionally, the new standard requires the capitalization and amortization of costs related to obtaining a contract, such as sales commissions, which were previously recorded as an expense to sales and marketing at the time incurred. 606 Adoption Impact to Previously Reported Results The Company adjusted its consolidated financial statements from amounts previously reported due to the adoption of ASC 606. Select consolidated balance sheet line items, which reflects the adoption of ASC 606, are as follows: Consolidated Balance Sheet As of December 31, 2017 (in thousands) As Reported Impact of Adoption As Adjusted Other receivables $ 1,170 $ 161 (1) $ 1,331 Deferred commissions — 10,301 (2) 10,301 Deferred revenue - current 47,276 (6,542 ) (1) 40,734 Deferred revenue - long-term 16,438 (2,021 ) (1) 14,417 Total deferred revenue $ 63,714 $ (8,563 ) $ 55,151 Stockholders' equity $ 108,975 $ 19,025 $ 128,000 (1) Impact of cumulative change in revenue. (2) Impact of cumulative change in commissions expense. Select consolidated statement of operations line items, which reflects the adoption of ASC 606, are as follows: Consolidated Statement of Operations Year ended December 31, 2017 Year ended December 31, 2016 (in thousands, except per share data) As Reported Impact of Adoption As Adjusted As Reported Impact of Adoption As Adjusted Revenue Product Device $ 60,869 $ 877 $ 61,746 $ 50,061 $ 553 $ 50,614 Software 27,996 1,843 29,839 20,606 3,015 23,621 Total product 88,865 2,720 91,585 70,667 3,568 74,235 Service Maintenance and support 52,542 (200 ) 52,342 43,438 (30 ) 43,408 Professional services and training 21,141 921 22,062 13,591 792 14,383 Total service 73,683 721 74,404 57,029 762 57,791 Total revenue $ 162,548 $ 3,441 $ 165,989 $ 127,696 $ 4,330 $ 132,026 Gross profit $ 97,621 $ 3,441 $ 101,062 $ 78,621 $ 4,330 $ 82,951 Operating expenses $ 111,641 $ 121 $ 111,762 $ 95,576 $ (1,537 ) $ 94,039 Loss from operations $ (14,020 ) $ 3,320 $ (10,700 ) $ (16,955 ) $ 5,867 $ (11,088 ) Net loss $ (14,217 ) $ 3,320 $ (10,897 ) $ (17,267 ) $ 5,867 $ (11,400 ) Basic net income (loss) per share $ (0.50 ) $ 0.12 $ (0.38 ) $ (0.64 ) $ 0.22 $ (0.42 ) Diluted net income (loss) per share $ (0.50 ) $ 0.12 $ (0.38 ) $ (0.64 ) $ 0.22 $ (0.42 ) Revenue by geographic region, based on customer location, adjusted for the adoption of ASC 606, is as follows: Year ended December 31, 2017 Year ended December 31, 2016 (in thousands) As Reported Impact of Adoption As Adjusted As Reported Impact of Adoption As Adjusted Revenue United States $ 145,548 $ 3,445 $ 148,993 $ 114,160 $ 4,118 $ 118,278 International 17,000 (4 ) 16,996 13,536 212 13,748 Total revenue $ 162,548 $ 3,441 $ 165,989 $ 127,696 $ 4,330 $ 132,026 The adoption impacted certain line items in the cash flows from operating activities as follows: Cash flows from operating activities: Year ended December 31, 2017 Year ended December 31, 2016 (in thousands) As Reported Impact of Adoption As Adjusted As Reported Impact of Adoption As Adjusted Net loss $ (14,217 ) $ 3,320 $ (10,897 ) $ (17,267 ) $ 5,867 $ (11,400 ) Adjustments to reconcile net loss to net cash provided by operating activities: Other receivables 41 (161 ) (120 ) 120 — 120 Deferred commissions — 121 121 — (1,538 ) (1,538 ) Deferred revenue 8,714 (3,280 ) 5,434 11,192 (4,329 ) 6,863 The core principle of ASC 606 is to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This principle is achieved through applying the following five-step approach: • Identification of the contract, or contracts, with a customer - A contract with a customer exists when (i) the Company enters into an enforceable contract with a customer that defines each party’s rights regarding the goods or services to be transferred and identifies the payment terms related to these goods or services, (ii) the contract has commercial substance and, (iii) the Company determines that collection of substantially all consideration for goods or services that are transferred is probable based on the customer’s intent and ability to pay the promised consideration. The Company applies judgment in determining the customer’s ability and intention to pay, which is based on a variety of factors including the customer’s historical payment experience or, in the case of a new customer, published credit and financial information pertaining to the customer. Customer payments received by the Company are non-refundable. • Identification of the performance obligations in the contract - Performance obligations promised in a contract are identified based on the goods or services that will be transferred to the customer that are capable of being both: a) functionally distinct, whereby the customer can benefit from the goods or service either on their own or together with other resources that are readily available from third parties or from the Company, and b) contractually distinct, whereby the transfer of the goods or services is separately identifiable from other promises in the contract. To the extent a contract includes multiple promised goods or services, the Company applies judgment to determine whether promised goods or services are capable of being distinct and distinct in the context of the contract. If these criteria are not met the promised goods or services are accounted for as a combined performance obligation. • Determination of the transaction price - The transaction price is determined based on the consideration to which the Company will be entitled in exchange for transferring goods or services to the customer. • Allocation of the transaction price to the performance obligations in the contract - If the contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. Contracts that contain multiple performance obligations require an allocation of the transaction price to each performance obligation based on a relative standalone selling price, (SSP) basis. The Company determines standalone selling price based on the price at which the performance obligation is sold separately. If the standalone selling price is not observable through past transactions, the Company estimates the standalone selling price taking into account available information such as market conditions and internally approved pricing guidelines related to the performance obligations. • Recognition of revenue when, or as, the Company satisfies a performance obligation - The Company satisfies performance obligations either over time or at a point in time as discussed in further detail below. Revenue is recognized at the time the related performance obligation is satisfied by transferring a promised good or service to a customer. Disaggregation of Revenue A typical sales arrangement involves multiple arrangements, such as sales of the Company’s proprietary communication device ("Vocera Badge"), perpetual software licenses, professional services, and maintenance and support services which entitle customers to unspecified upgrades, patch releases and telephone-based support. The following table depicts the disaggregation of revenue according to revenue type and is consistent with how the Company evaluates its financial performance: Years ended December 31, (in thousands) 2018 2017 2016 Revenue Product Device $ 60,130 $ 61,746 $ 50,614 Software 37,317 29,839 23,621 Total product 97,447 91,585 74,235 Service Maintenance and support 62,267 52,342 43,408 Professional services and training 19,916 22,062 14,383 Total service 82,183 74,404 57,791 Total revenue $ 179,630 $ 165,989 $ 132,026 Device revenue - In transactions where the Company delivers hardware, the Company considers itself to be the principal in the transaction and records revenue and costs of goods sold on a gross basis. Hardware revenue is generally recognized upon transfer of control to the customer. Software revenue - Revenue from the Company’s software products is generally recognized upon transfer of control to the customer. Maintenance and support revenue - The Company generates maintenance and support revenue primarily from post contract support (PCS) contracts, and, to a lesser extent, from sales of extended warranties on the Vocera Badge. The majority of software sales are in conjunction with PCS contracts, which generally have one-year terms. The Company recognizes revenue from PCS contracts ratably over the contractual service period. The service period typically commences upon transfer of control of the corresponding software products to the customer. The Company recognizes revenue from extended warranty contracts ratably over their contractual service period, which is typically one year. This period starts one year from the date on which the transfer of control on the underlying hardware occurs because the hardware generally carries a one-year warranty. Professional services and training revenue - Professional services and training revenue is generated when the Company installs and configures its software and devices at new or existing customer sites. The Company recognizes revenue related to professional services as they are performed. Contracts with multiple performance obligations - Some of the Company’s contracts with customers contain multiple performance obligations. For these contracts, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to the separate performance obligations on a relative stand-alone selling price basis. For deliverables that are routinely sold separately, such as maintenance and support on the core offerings, the Company determines SSP by evaluating renewals over the trailing 12-months. For those that are not sold routinely, the Company determines SSP based on its overall pricing trends and objectives, taking into consideration market conditions and other factors, including the value of the contracts and the products sold. Contract balances - The timing of revenue recognition, billings and cash collections result in billed accounts receivable, unbilled accounts receivable (contract asset). Accounts receivable are recorded at the invoiced amount. A receivable is recognized in the period the Company delivers goods or provides services or when the right to consideration is unconditional. Payment terms on invoiced amounts are typically 30 days. The balance of accounts receivable, net of allowance for doubtful accounts, as of December 31, 2018 and 2017 is presented in the accompanying consolidated balance sheets. As of December 31, 2018 and 2017 contract assets totaled $2.4 million and $0.2 million . Costs to obtain and fulfill a contract - The Company capitalizes certain incremental contract acquisition costs consisting primarily of commissions paid and the related payroll taxes when customer contracts are signed. The Company determines whether costs should be deferred based on its sales compensation plans, if the commissions are incremental and would not have been incurred absent the execution of the customer contract. Sales commissions for renewals of customer contracts are not commensurate with the commissions paid for the acquisition of the initial contract given the substantive difference in commission rates in proportion to their respective contract values. Commissions paid upon the initial acquisition of a contract are amortized over the estimated period of benefit, which may exceed the term of the initial contract. Accordingly, amortization of deferred costs is recognized on a systematic basis that is consistent with the pattern of revenue recognition allocated to each performance obligation and is included in sales and marketing expense in the consolidated statements of operations. The Company determines its estimated period of benefit, up to five years, by evaluating the expected renewals of its customer contracts, the duration of its relationships with its customers and other factors. Deferred costs are periodically reviewed for impairment. Changes in the balance of total deferred commissions (contract asset) during the year ended December 31, 2018 and 2017 are as follows: (in thousands) December 31, 2017 *As Adjusted Additions Commissions Recognized December 31, 2018 Deferred commissions $ 10,301 $ 8,327 $ (8,325 ) $ 10,303 (in thousands) December 31, 2016 *As Adjusted Additions Commissions Recognized December 31, 2017 *As Adjusted Deferred commissions $ 10,422 $ 8,201 $ (8,322 ) $ 10,301 Of the $10.3 million total deferred commissions balance as of December 31, 2018, the Company expects to recognize approximately 46.6% as commission expense over the next 12 months and the remainder thereafter. Deferred revenue - The Company records deferred revenue when cash payments are received in advance of the performance under the contract. The current portion of deferred revenue represents the amounts that are expected to be recognized as revenue within one year of the consolidated balance sheet date. Changes in the balance of total deferred revenue (contract liability) during the years ended December 31, 2018 and 2017 are as follows: (in thousands) December 31, 2017 *As Adjusted Additions Revenue Recognized December 31, 2018 Deferred revenue $ 55,151 $ 77,969 $ (74,488 ) $ 58,632 (in thousands) December 31, 2016 *As Adjusted Additions Revenue Recognized December 31, 2017 *As Adjusted Deferred revenue $ 49,717 $ 69,519 $ (64,085 ) $ 55,151 * See details above for the summary of adjustments to deferred commission and deferred revenue as a result of the adoption of ASC 606. Revenue recognized during the year ended December 31, 2018 from deferred revenue balances as of December 31, 2017 was $42.6 million . Revenue recognized during the year ended December 31, 2017 from deferred revenue balances as of December 31, 2016 was $41.5 million . The majority of the Company’s “contracted not recognized” performance obligations are not subject to cancellation terms. The Company’s “contracted not recognized” revenue, which represents revenue allocated to performance obligations for revenue contracted, and which includes deferred revenue and non-cancelable amounts that will be invoiced and recognized as revenue in future periods, was $120.4 million as of December 31, 2018, of which the Company expects to recognize approximately 62% of the revenue over the next 12 months and the remainder thereafter.

The Company and Summary of Sign

The Company and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
The Company and Summary of Significant Accounting Policies	The Company and Summary of Significant Accounting Policies Background Vocera Communications, Inc. and its subsidiaries (collectively, the Company) is a provider of secure, integrated, intelligent communication and clinical workflow solutions, focused on empowering mobile workers in healthcare, hospitality, energy, and other mission-critical mobile work environments, in the United States and internationally. The significant majority of the Company's business is generated from sales of its solutions in the healthcare market to help its customers improve quality of care, patient and staff experience and increase operational efficiency. The Vocera Communication and Workflow System is comprised of a unique software platform that connects communication devices, including our hands-free, wearable, voice-controlled communication badges, and third-party mobile devices that use our software applications to our enterprise-class software platform. The system transforms the way mobile workers communicate by enabling them to instantly connect via voice or secure text messaging. With a portfolio of over 120 third-party clinical integrations, our system also enables the intelligent delivery of alerts and alarms to a variety of mobile devices, providing real time situation awareness to care providers. The Company's unique hands-free voice capability allows mobile workers to connect with the right person simply by saying or selecting the name, function or group name of the person they want to reach, often while remaining at the point-of-care. The Company's system responds to over 100 spoken commands. The Company was incorporated in Delaware on February 16, 2000. The Company formed wholly-owned subsidiaries Vocera Communications UK Ltd and Vocera Communications Australia Pty Ltd. in 2005, Vocera Canada, Ltd. in 2010, Vocera Communications India Private Ltd. in 2013, Vocera Communications Middle East FZ LLC in 2014 and acquired Extension, LLC in 2016. Since its inception, the Company has incurred significant losses and, as of December 31, 2018 , had an accumulated deficit of $132.3 million . The Company has funded its operations primarily with customer payments for its products and services, proceeds from the issuance of common stock in connection with its initial public offering (IPO) and follow-on offering and proceeds from the issuance of convertible senior notes. As of December 31, 2018 , the Company had cash, cash equivalents and short-term investments of $221.2 million . The Company believes that its existing sources of liquidity will satisfy its working capital and capital requirements for at least the next twelve months. Basis of presentation The consolidated financial statements include the accounts of Vocera Communications, Inc. and its wholly owned subsidiaries. All inter-company transactions and balances have been eliminated in consolidation. The accompanying notes are prepared in accordance with accounting principles generally accepted in the United States (GAAP). Effective January 1, 2018, we adopted Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers (ASC 606), as discussed in detail in Note 2. All amounts and disclosures set forth in this Annual Report on Form 10-K have been updated to comply with ASC 606, as indicated by the "as adjusted" note. Certain prior period amounts have been adjusted as a result of our adoption of ASC 606. Refer to "Recently Adopted Accounting Pronouncements" below for more information. Use of estimates and reclassifications The preparation of financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reporting periods. The estimates include, but are not limited to, revenue recognition, warranty reserves, inventory reserves, goodwill and intangible assets, stock-based compensation expense, provisions for income taxes and contingencies. Actual results could differ from these estimates, and such differences could be material to the Company’s financial position and results of operations. Cash, cash equivalents and short-term investments The Company’s cash equivalents and short-term investments consist of money market funds, commercial paper, U.S. government agency notes, U.S. Treasury notes, municipal debt and corporate debt. These investments are classified as available-for-sale securities and are carried at fair value with the unrealized gains and losses reported as a component of stockholders’ equity. Management determines the appropriate classification of its investments at the time of purchase and re-evaluates the available-for-sale designations as of each balance sheet date. Investments with an original purchase maturity of three months or less are classified as cash equivalents, all those with longer maturities are classified as short-term investments, which are available-for-sale. Allowance for doubtful accounts The allowance for doubtful accounts reflects the Company’s best estimate of probable losses inherent in the Company’s receivables portfolio determined on the basis of historical experience, specific allowances for known troubled accounts and other currently available evidence. The Company has not experienced significant credit losses from its accounts receivable. The Company performs a regular review of its customers’ payment histories and associated credit risks as it does not require collateral from its customers. The following table presents the changes in the allowance for doubtful accounts: Years ended December 31, (in thousands) 2018 2017 2016 Allowance—beginning of period $ — $ — $ (451 ) Provisions for bad debts — — — Recoveries from bad debts — — — Write-offs and other — — 451 Allowance—end of period $ — $ — $ — Inventories Inventories are valued at the lower of standard cost (which approximates actual cost on a first-in, first-out basis) or market (net realizable value or replacement cost). The Company assesses the valuation of inventory and periodically writes down the value for estimated excess and obsolete inventory based upon assumptions about future demand and market conditions. Concentration of credit risk and other risks and uncertainties Financial instruments that subject the Company to concentration of credit risk consist primarily of cash, cash equivalents and short-term investments. The Company’s cash and cash equivalents are primarily deposited with high quality financial institutions and in money market funds. Deposits at these institutions and funds may, at times, exceed federally insured limits. Management believes that these financial institutions and funds are financially sound and, accordingly, that minimal credit risk exists. The Company has not experienced any losses on its deposits of cash and cash equivalents. Marketable securities are stated at fair value, and accounted for as available-for-sale within short-term investments. The counterparties to the agreements relating to the Company’s investment securities consist of major corporations, financial institutions and government agencies of high credit standing. The primary hardware components of the Company’s products is currently manufactured by third-party contractors in Mexico and Taiwan. A significant disruption in the operations of these contractors may impact the production of the Company’s products for a substantial period of time, which could harm the Company’s business, financial condition and results of operations. Concentration of credit risk with respect to trade accounts receivable is considered to be limited due to the diversity of the Company’s customer base and geographic sales areas. At December 31, 2018 and 2017 , no customer accounted for 10% or more of accounts receivable. At December 31, 2018 and 2017, one reseller represented 26.4% and 26.3% , respectively of accounts receivable. For the years ended December 31, 2018 , 2017 and 2016 , no customer represented 10% or more of revenue. Property and equipment Property and equipment are stated at cost and depreciated on a straight-line basis over the estimated useful economic lives of the assets. Assets generally have useful economic lives of three years except for leasehold improvements, which are amortized using the straight-line method over the shorter of the remaining lease term or the estimated useful life of the related assets. Purchased or developed software also generally has a three year useful economic life, except for major ERP implementations, for which the Company assumes a five year useful economic life. Upon retirement or sale, the cost and related accumulated depreciation and amortization are removed from the consolidated balance sheet and the resulting gain or loss is reflected in operations. Maintenance and repairs which are not considered improvements and do not extend the useful life of the assets are charged to operations as incurred. The Company periodically reviews property and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset is impaired or the estimated useful lives are no longer appropriate. Fair value is estimated based on discounted future cash flows. If indicators of impairment exist and the undiscounted projected cash flows associated with such assets are less than the carrying amount of the asset, an impairment loss is recorded to write the asset down to its estimated fair values. To date, the Company has not recorded any impairment charges. Internal-use software development costs For internal-use software, the Company capitalizes certain internal and external costs incurred in its acquisition and creation. Capitalized internal-use software is included in property and equipment when development is complete and is amortized on a straight-line basis over the estimated useful life of the related asset, generally three years, except that five years is assumed for major ERP implementations. Based on the authoritative guidance, costs incurred either before or after the period satisfying the capitalization criteria, together with costs incurred for training and maintenance, are expensed as incurred. For the years ended December 31, 2018 , 2017 and 2016 , the Company capitalized costs of $0.7 million , $0.3 million and zero , respectively. Goodwill and intangible assets The Company allocates the purchase price of any acquisitions to tangible assets and liabilities and identifiable intangible assets acquired. Any residual purchase price is recorded as goodwill. Goodwill Goodwill is tested for impairment at the reporting unit level at least annually, or more often if events or changes in circumstances indicate the carrying value may not be recoverable. The Company has identified two operating segments (Product and Service) which management also considers to be reporting units. In testing for goodwill impairment, the Company may elect to utilize a qualitative assessment to evaluate whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. If such qualitative assessment indicates that goodwill impairment is more likely than not, the Company performs a two-step impairment test. The Company performed its goodwill impairment assessment on October 1, 2018 using a qualitative assessment and determined that no impairment existed as of the date of the impairment test because the fair value of each reporting unit exceeded its carrying value. As of December 31, 2018 , no changes in circumstances indicate that goodwill carrying values may not be recoverable. Intangible assets Intangible assets are amortized over their estimated useful lives. Upon completion of development, acquired in-process research and development assets are generally considered amortizable, finite-lived assets and are amortized over their estimated useful lives. Finite-lived intangible assets consist of customer relationships, developed technology, trademarks, backlog and non-compete agreements. The Company evaluates intangible assets for impairment by assessing the recoverability of these assets whenever adverse events or changes in circumstances or business climate indicate that expected undiscounted future cash flows related to such intangible assets may not be sufficient to support the net book value of such assets. An impairment is recognized in the period of identification to the extent the carrying amount of an asset exceeds the fair value of such asset. No impairment of intangible assets was recorded in the years ended December 31, 2018 , 2017 or 2016 . Revenue recognition Effective January 1, 2018, we adopted ASC 606 using the full retrospective method. Refer to Note 2 for a detailed discussion of accounting policies related to revenue recognition, including deferred revenue and commissions. Revenue from sales-type leases A portion of the Company's sales are made through multi-year lease agreements with customers. When these arrangements are considered sales-type leases, upon delivery of leased products to customers, the Company recognizes revenue for such products in an amount equal to the net present value of the minimum lease payments. Unearned income is recognized as part of product revenue under the effective interest method. The Company recognizes revenue related to certain executory costs, including maintenance and extended warranty, ratably over the term of the underlying arrangements. The Company recognizes revenue related to battery refresh executory costs when such executory costs are incurred. Proceeds from transfers of sales-type leases to third-party financial companies are allocated between the net investment in sales-type leases and the executory cost component for remaining service obligations based on relative present value. The difference between the amount of proceeds allocated to the net investment in lease and the carrying value of the net investment in lease is included in product revenue. Proceeds allocated to the executory cost component are accounted for as financing liabilities. For the year ended December 31, 2018 , the Company transferred $0.4 million of lease receivables, recording an immaterial net loss and $0.3 million of new financing liabilities for future performance of executory service obligations. For the year ended December 31, 2017 , the Company transferred $0.9 million of lease receivables, recording an immaterial net loss and $0.7 million of new financing liabilities for future performance of executory service obligations. For lease receivables retained as of December 31, 2018 and 2017 , the Company recorded $0.7 million and $1.3 million , respectively, of net investment in sales-type leases, equivalent to the minimum lease payments for the delivered product. Shipping and handling costs Shipping and handling costs charged to customers are included in revenue and the associated expense is recorded in cost of revenue in the consolidated statements of operations for all periods presented. Research and development expenditures Research and development costs are charged to operations as incurred. Software development costs incurred for external products prior to the establishment of technological feasibility are included in research and development and are expensed as incurred. After technological feasibility is established, material software development costs up to general availability of the software will be capitalized and amortized on a straight-line basis over the estimated product life, or based on the ratio of current revenues to total projected product revenue, whichever is greater. To date, the time between the establishment of technological feasibility and general availability has been very short and therefore no significant costs have been incurred. Accordingly, the Company has not capitalized any software development costs related to research and development expenditures. Advertising costs Advertising costs are included in sales and marketing expense and are expensed as incurred. Advertising costs for the years ended December 31, 2018 , 2017 and 2016 were immaterial. Product warranties The Company offers warranties on certain products and records a liability for the estimated future costs associated with warranty claims, which is based upon historical experience and the Company’s estimate of the level of future costs. The Company provides for the estimated costs of hardware warranties at the time the related revenue is recognized. Costs are estimated based on historical and projected product failure rates, historical and projected repair costs, and knowledge of specific product failures (if any). The specific hardware warranty includes parts and labor over a period generally ranging from one to three years. The Company provides no warranty for software. The Company regularly re-evaluates its estimates to assess the adequacy of the recorded warranty liabilities and adjust the amounts as necessary. Warranty costs are reflected in the consolidated statement of operations as cost of revenue. Stock-based compensation Stock-based compensation is measured at grant date based on the fair value of the award using the grant date closing stock price and is expensed on a straight-line basis over the requisite service period. Income taxes The Company uses the asset and liability method of accounting for income taxes. Under this method, the Company records deferred income taxes based on temporary differences between the financial reporting and tax bases of assets and liabilities and use enacted tax rates and laws that the Company expects will be in effect when they recover those assets or settle those liabilities, as the case may be, to measure those taxes. In cases where the expiration date of tax carryforwards or the projected operating results indicate that realization is not likely, the Company provides for a valuation allowance. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized. The Company has deferred tax assets, resulting from net operating losses, research and development credits and temporary differences that may reduce taxable income in future periods. A valuation allowance is required when it is more likely than not that all or a portion of a deferred tax asset will not be realized. In assessing the need for a valuation allowance, the Company estimates future taxable income, considering the feasibility of ongoing tax-planning strategies and the realizability of tax loss carryforwards. Valuation allowances related to deferred tax assets can be impacted by changes in tax laws, changes in statutory tax rates and future taxable income levels. If the Company were to determine that it would be able to realize its deferred tax assets in the future in excess of the net carrying amounts, it would decrease the recorded valuation allowance through an increase to income in the period in which that determination is made. Due to the history of losses the Company has generated in the past, the Company believes that it is not more likely than not that all of the deferred tax assets in the U.S. and Canada can be realized as of December 31, 2018 and 2017, respectively. Accordingly, the Company has recorded a full valuation allowance on its deferred tax assets for these years. At December 31, 2018 , the Company had a valuation allowance against net deferred tax assets of $40.1 million . There is inherent uncertainty in evaluating the sustainability of the income tax positions the Company takes on its tax returns. The Company assesses its income tax positions and records tax benefits for all years subject to examination based upon management’s evaluation of the facts, circumstances and information available at the reporting date. For those tax positions where it is more likely than not that a tax benefit will be sustained, the Company has recorded the highest amount of tax benefit with a greater than 50% likelihood of being realized upon ultimate settlement with a taxing authority that has full knowledge of all relevant information. For those income tax positions where it is not more likely than not that a tax benefit will be realizable, no tax benefit has been recognized in the financial statements. The Company includes interest and penalties with income taxes in the accompanying statement of operations. All of the Company’s net operating losses and research credit carryforwards are subject to adjustment by tax authorities and all years after 2011 are still subject to tax authority examinations. The Company is currently not subject to any income tax audit examinations by tax authorities in any jurisdictions including U.S. federal, state and local or foreign countries. Foreign currency translation The functional currency of the Company’s foreign subsidiaries is the U.S. dollar. Accordingly, monetary assets and liabilities in non-functional currency of these subsidiaries are remeasured using exchange rates in effect at the end of the period. Revenues and costs in local currency are remeasured using average exchange rates for the period, except for costs related to those consolidated balance sheet items that are remeasured using historical exchange rates. The resulting remeasurement gains and losses are included in the Company’s consolidated statements of operations. Translation gains and losses have not been significant to date. Segments Operating segments are components of an enterprise for which separate financial information is available and is evaluated regularly by the Company’s chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is the Chief Executive Officer. The Company has two operating segments which are both reportable business segments: (i) Product; and (ii) Service. Comprehensive loss For the years ended December 31, 2018 , 2017 and 2016, the only component of other comprehensive loss was unrealized (losses) gains on available-for-sale securities. Related party transactions During the years ended December 31, 2018 , 2017 and 2016 , the Company had revenue transactions with a related party, the University of Chicago Medical Center (UCMC), for $0.4 million , $0.4 million and $0.4 million , respectively, relating to consulting services and technology solutions. One of the Company's board members is the President of UCMC. Recently adopted accounting pronouncement In May 2014, the Financial Accounting Standards Board (FASB) together with the International Accounting Standards Board issued converged guidance for revenue recognition that replaces most existing guidance, eliminates industry-specific guidance and provides a unified model for determining how and when revenue from contracts with customers should be recognized. Under the new guidance, an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The new guidance permits two methods of adoption: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (modified retrospective method). The Company adopted the new guidance on January 1, 2018 using the full retrospective method, which requires the Company to present its historical financial information for fiscal years 2017 and 2016 as if the new revenue guidance had been applied to all prior periods. Refer to Note 2 for the details of the impact to previously reported results. In October 2016, the FASB issued amended guidance on the accounting for income taxes. The new guidance requires the recognition of the income tax consequences of an intercompany asset transfer, other than transfers of inventory, when the transfer occurs. The guidance is effective for reporting periods beginning after December 15, 2017, with early adoption permitted. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements. In January 2017, the FASB issued new guidance which clarifies the definition of a business to assist companies with evaluating whether transactions should be accounted for as acquisitions of assets or businesses. The new guidance requires a company to evaluate if substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets; if so, the set of assets and activities is not a business. The guidance also requires a business to include at least one substantive process and narrows the definition of outputs by more closely aligning it with how outputs are described in the guidance for revenue from contracts with customers. The new guidance was effective for the Company in the first quarter of 2018. The guidance was applied prospectively to any transactions occurring within the period of adoption. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements. In May 2017, the FASB amended the scope of modification accounting for share-based payment arrangements. The guidance clarifies the type of changes to terms or conditions of share-based payment awards to which an entity would be required to apply modification accounting. Specifically, under this guidance, an entity would not apply modification accounting if the fair value, vesting conditions, and classification of the awards are the same immediately before and after the modification. The new standard is effective for the Company in the first quarter of 2018. The guidance was applied prospectively to awards modified on or after the adoption date. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements. Recent accounting pronouncements In February 2016, the FASB amended lease accounting requirements to begin recording assets and liabilities arising from leases on the balance sheet. The new guidance will also require significant additional disclosures about the amount, timing and uncertainty of cash flows from leases. This new guidance will be effective beginning on January 1, 2019 under a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients that entities may elect to apply. The Company will elect the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allows us to carryforward the historical lease classification. The Company will make an accounting policy election to keep leases with an initial term of 12 months or less off of the balance sheet. The Company will recognize those lease payments in the consolidated statements of operations on a straight-line basis over the lease term. The Company estimates the adoption of the standard will result in recognition of right-of-use assets, which includes the impact of existing deferred rents and tenant improvement allowances of $5.1 million and lease liabilities of $6.7 million , respectively as of January 1, 2019. The Company does not believe the standard will materially affect our consolidated net earnings. These are preliminary estimates that are subject to change as we finalize our adoption. In June 2016, the FASB issued new guidance related to the accounting for credit losses on instruments for both financial services and non-financial services entities. The new guidance introduces an approach based on expected losses to estimate credit losses on certain types of financial instruments. It also modifies the impairment model for available-for-sale debt securities and provides for a simplified accounting model for purchased financial assets with credit deterioration since their origination. The guidance will be effective beginning January 1, 2020. Early adoption is permitted. The Company is currently evaluating the impact of this new guidance on its consolidated financial statements. In January 2017, the FASB issued new guidance to simplify the accounting for goodwill impairment. The guidance simplifies the measurement of goodwill impairment by removing step 2 of the goodwill impairment test, which requires the determination of the fair value of individual assets and liabilities of a reporting unit. The new guidance requires goodwill impairment to be measured as the amount by which a reporting unit’s carrying value exceeds its fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The amendments should be applied on a prospective basis. The new standard is effective for fiscal years beginning after December 15, 2019 with early adoption permitted for interim or annual goodwill impairment tests performed after January 1, 2017. The Company is evaluating the impact of this new accounting guidance on its consolidated financial statements. In February 2018, the FASB issued new guidance which allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act and required certain disclosures about stranded tax effects. This standard will be effective for the Company beginning January 1, 2019 and may be applied either in the period of adoption or retrospectively. Early adoption is permitted. The adoption of this guidance is not expected to have a material impact on the Company’s consolidated financial statements. In August 2018, the SEC adopted the final rule under SEC Release No. 33-10532, Disclosure Update and Simplification, amending certain disclosure requirements that were redundant, duplicative, overlapping, outdated or superseded. In addition, the amendments expanded the disclosure requirements on the analysis of stockholders' equity for interim financial statements. Under the amendments, an analysis of changes in each caption of stockholders' equity presented in the balance sheet must be provided in a note or separate statement. The analysis should present a reconciliation of the beginning balance to the ending balance of each period for which a statement of comprehensive income is required to be filed. This final rule was effective on November 5, 2018. The Company is evaluating the impact of this guidance on its condensed consolidated financial statements and expects to adopt this guidance in the first quarter of fiscal 2019.

Fair value of financial instrum

Fair value of financial instruments	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair value of financial instruments	air value of financial instruments The carrying values of the Company’s cash and cash equivalents and short-term investments approximate their fair value due to their short-term nature. As a basis for determining the fair value of its assets and liabilities, the Company utilizes a three-tier fair value hierarchy which prioritizes the inputs used in measuring fair value as follows: (Level 1) observable inputs such as quoted prices in active markets; (Level 2) inputs other than the quoted prices in active markets that are observable either directly or indirectly; and (Level 3) unobservable inputs in which there is little or no market data which requires the Company to develop its own assumptions. This hierarchy requires the Company to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value. For the years ended December 31, 2018 , 2017 and 2016 , there have been no transfers between Level 1 and Level 2 fair value instruments and no transfers in or out of Level 3. The Company's money market funds are classified within Level 1 of the fair value hierarchy because they are valued using quoted market prices. The fair value of the Company's Level 2 fixed income securities are obtained from independent pricing services, which may use quoted market prices for identical or comparable instruments or model-driven valuations using observable market data or other inputs corroborated by observable market data. The Company does not have any financial instruments which are valued using Level 3 inputs. In addition to its cash, cash equivalents and short-term investments, the Company measures the fair value of its Convertible Senior Notes on a quarterly basis for disclosure purposes. The Company considers the fair value of the Convertible Senior Notes at December 31, 2018 to be a Level 2 measurement due to limited trading activity of the Convertible Senior Notes. Refer to Note 8 to the consolidated financial statements for further information. The table below summarizes the Company’s assets that are measured at fair value on a recurring basis, by level, within the fair value hierarchy as of December 31, 2018 and 2017 , respectively. December 31, 2018 December 31, 2017 (in thousands) Level 1 Level 2 Total Level 1 Level 2 Total Assets Money market funds $ 3,737 $ — $ 3,737 $ 3,232 $ — $ 3,232 Commercial paper — 16,570 16,570 — 1,201 1,201 U.S. government agency securities — 3,325 3,325 — 8,648 8,648 U.S. Treasury securities — 2,730 2,730 — 5,561 5,561 Corporate debt securities — 166,759 166,759 — 37,530 37,530 Total assets measured at fair value $ 3,737 $ 189,384 $ 193,121 $ 3,232 $ 52,940 $ 56,172 The financial accounts that are not subject to recurring fair value measurement include trade and other receivables, prepaid expenses and other current assets, total current liabilities and deferred revenues, both current and long-term. Due to their short maturities, the carrying amounts of these accounts approximate their fair values.

Cash, Cash Equivalents and Shor

Cash, Cash Equivalents and Short-term Investments	12 Months Ended
	Dec. 31, 2018
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents, and Short-term Investments	Cash, Cash Equivalents and Short-Term Investments The following tables display gross unrealized gains and losses for cash, cash equivalents and available-for-sale investments for the periods presented: December 31, 2018 (in thousands) Amortized Cost Unrealized Gains Unrealized Losses Fair value Cash and cash equivalents: Demand deposits and other cash $ 28,049 $ — $ — $ 28,049 Money market funds 3,737 — — 3,737 Commercial paper 2,491 — (1 ) 2,490 Corporate debt securities — — — — Total cash and cash equivalents 34,277 — (1 ) 34,276 Short-Term Investments: Commercial paper 14,091 — (11 ) 14,080 U.S. government agency securities 3,339 — (14 ) 3,325 U.S. Treasury securities 2,740 — (10 ) 2,730 Corporate debt securities 167,110 28 (379 ) 166,759 Total short-term investments 187,280 28 (414 ) 186,894 Total cash, cash equivalents and short-term investments $ 221,557 $ 28 $ (415 ) $ 221,170 December 31, 2017 (in thousands) Amortized Cost Unrealized Gains Unrealized Losses Fair value Cash and cash equivalents: Demand deposits and other cash $ 25,061 $ — $ — $ 25,061 Money market funds 3,232 — — 3,232 Commercial paper — — — — Corporate debt securities 433 — — 433 Total cash and cash equivalents 28,726 — — 28,726 Short-Term Investments: Commercial paper 1,202 — (1 ) 1,201 U.S. government agency securities 8,678 — (30 ) 8,648 U.S. Treasury securities 5,586 — (25 ) 5,561 Corporate debt securities 37,176 1 (80 ) 37,097 Total short-term investments 52,642 1 (136 ) 52,507 Total cash, cash equivalents and short-term investments $ 81,368 $ 1 $ (136 ) $ 81,233 The Company has determined that the unrealized losses on its short-term investments as of December 31, 2018 and 2017 do not constitute an "other than temporary impairment". The unrealized losses for the short-term investments as of December 31, 2018 and 2017 have all been in a continuous unrealized loss position for less than twelve months. The Company’s conclusion of no “other than temporary impairment” is based on the high credit quality of the securities, their short remaining maturity and the Company’s intent and ability to hold such loss securities until maturity. Classification of the cash, cash equivalent and short-term investments by contractual maturity was as follows: (in thousands) One year or shorter Between 1 and 2 years Total Balances as of December 31, 2018 Cash and cash equivalents (1) $ 34,276 $ — $ 34,276 Short-term investments 109,451 77,443 186,894 Cash, cash equivalents and short-term investments $ 143,727 $ 77,443 $ 221,170 Balances as of December 31, 2017 Cash and cash equivalents (1) $ 28,726 $ — $ 28,726 Short-term investments 34,750 17,757 52,507 Cash, cash equivalents and short-term investments $ 63,476 $ 17,757 $ 81,233 (1) Includes demand deposits and other cash, money market funds and other cash equivalent securities, all with 0-90 day maturity at purchase.

Income (loss) per share

Income (loss) per share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Income (loss) per share	oss per share The following table presents the calculation of basic and diluted net income (loss) per share: Years ended December 31, (in thousands, except for share and per share amounts) 2018 2017 2016 * As Adjusted * As Adjusted Numerator: Net loss $ (9,674 ) $ (10,897 ) $ (11,400 ) Denominator: Weighted-average shares used to compute net loss per common share - basic and diluted 30,041 28,655 26,859 Net loss per share Basic and diluted $(0.32) $(0.38) $(0.42) For the years ended December 31, 2018, 2017 and 2016, the following securities were not included in the calculation of diluted shares outstanding as the effect would have been anti-dilutive: December 31, (in thousands) 2018 2017 2016 Options to purchase common stock 1,085 1,365 2,454 Restricted stock units 1,925 2,046 2,129

Goodwill and intangible assets

Goodwill and intangible assets	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and intangible assets	Goodwill and intangible assets Goodwill The Company had $49.2 million and $49.2 million of goodwill as of December 31, 2018 and 2017 , respectively. Goodwill is tested for impairment at the reporting unit level at least annually or more often if events or changes in circumstances indicate the carrying value may not be recoverable. The Company has two reporting units: Product and Service. As of December 31, 2018 , $41.2 million of the Company's goodwill resides in the Product reporting unit and $8.0 million resides in the Service reporting unit. The Company performed an impairment assessment in 2018 which determined that no impairment existed. For the years ended December 31, 2018 and 2017, the Company used the qualitative assessment permitted under authoritative accounting guidance. Among the qualitative factors considered were changes since the prior impairment test in the following: industry and competitive environment, business strategy, product mix, buyer and supplier bargaining power, potential market size, consistency in operating margins and cash flows, change in reporting unit or product life cycle stage and earnings quality and sustainability. No impairment was recorded in the years ended December 31, 2018 , 2017 or 2016 . Intangible assets The fair values for acquired intangible assets were determined by management with consideration of, in part, valuations performed by independent valuation specialists. Acquisition-related intangible assets are amortized over the life of the assets on an accelerated basis that approximates the expected economic benefit of the assets. This assumption results in amortization that is higher in earlier periods of the useful life. To date there has been no impairment of the Company's intangible assets. The estimated useful lives and carrying value of acquired intangible assets are as follows: December 31, 2018 December 31, 2017 (in thousands) Weighted average useful life (years) Gross carrying amount Accumulated amortization Net carrying amount Gross carrying amount Accumulated amortization Net carrying amount Intangible assets: Customer relationships 7 to 9 $ 10,920 $ 4,645 $ 6,275 $ 10,920 $ 3,469 $ 7,451 Developed technology 3 to 7 10,050 7,731 2,319 10,050 5,302 4,748 Trademarks 3 to 7 1,110 831 279 1,110 497 613 Backlog 3 1,400 1,203 197 1,400 650 750 Non-compete agreements 2 to 4 460 460 — 460 455 5 Intangible assets, net book value $ 23,940 $ 14,870 $ 9,070 $ 23,940 $ 10,373 $ 13,567 Amortization of intangible assets was $4.5 million , $4.6 million and $1.4 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. Amortization of acquired intangible assets is reflected in the cost of revenues for developed technology and backlog and in operating expenses for the other intangibles. The estimated future amortization of acquired intangible assets as of December 31, 2018 was as follows: (in thousands) Future amortization 2019 $ 3,717 2020 1,251 2021 1,127 2022 1,050 2023 1,050 2024 875 Future amortization expense $ 9,070

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2018
Balance Sheet Components [Abstract]
Balance Sheet Components	Consolidated balance sheet components Inventories December 31, (in thousands) 2018 2017 Raw materials $ 197 $ 4 Finished goods 4,153 2,811 Total inventories $ 4,350 $ 2,815 Property and equipment, net December 31, (in thousands) 2018 2017 Computer equipment and software $ 10,433 $ 8,832 Furniture, fixtures and equipment 2,246 1,764 Leasehold improvements 5,183 4,794 Manufacturing tools and equipment 2,371 2,624 Construction in process 520 157 Property and equipment, at cost 20,753 18,171 Less: Accumulated depreciation (13,285 ) (12,420 ) Property and equipment, net $ 7,468 $ 5,751 Depreciation and amortization expense for property and equipment for the years ended December 31, 2018 , 2017 and 2016 was $3.2 million , $3.0 million and $2.4 million , respectively. Net investment in sales-type leases The Company has sales-type leases with terms of 3 to 4 years. Sales-type lease receivables are collateralized by the underlying equipment. The components of the net investment in sales-type leases are as follows: December 31, (in thousands) 2018 2017 Net minimum lease payments to be received $ 2,111 $ 2,758 Less: Unearned interest income and executory revenue portion (1,387 ) (1,469 ) Net investment in sales-type leases 724 1,289 Less: Current portion (427 ) (916 ) Non-current net investment in sales-type leases $ 297 $ 373 There were no allowances for doubtful accounts on these leases as of December 31, 2018 and 2017 . There is no guaranteed or unguaranteed residual value on the leased equipment. The current and non-current net investments in sales-types leases are reported as components of the consolidated balance sheet captions "other receivables" and "other long-term assets", respectively. The minimum lease payments expected for future years under sales-type leases as of December 31, 2018 were as follows: (in thousands) Future lease payments 2019 $ 1,145 2020 736 2021 205 2022 25 Total $ 2,111 Accrued payroll and other current liabilities December 31, (in thousands) 2018 2017 Payroll and related expenses $ 7,241 $ 9,569 Accrued payables 2,115 1,801 Deferred rent, current portion 376 271 Lease financing, current portion 956 832 Product warranty 376 353 Customer prepayments 629 1,084 Sales and use tax payable 379 505 Other 813 274 Total accrued payroll and other current liabilities $ 12,885 $ 14,689 A reconciliation of the changes in the Company’s warranty reserve for the years ended December 31, 2018 , 2017 and 2016 is as follows: Years ended December 31, (in thousands) 2018 2017 2016 Warranty balance at the beginning of the period $ 353 $ 596 $ 806 Warranty expense accrued for shipments during the period 468 503 757 Changes in estimate related to pre-existing warranties (223 ) (450 ) (537 ) Warranty settlements made (222 ) (296 ) (430 ) Total product warranty $ 376 $ 353 $ 596

Commitments

Commitments	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments	Commitments and contingencies Non-cancelable purchase commitments The Company enters into non-cancelable purchase commitments with its third-party manufacturers whereby the Company is required to purchase any inventory held by the third-party manufacturer that have been purchased by them based on confirmed orders from the Company. As of December 31, 2018 and 2017 , approximately $11.1 million and $4.4 million , respectively, of raw material inventory was purchased and held by the third-party manufacturer which was subject to such purchase requirements. Leases The Company leases office space for its headquarters and subsidiaries under non-cancelable operating leases, which will expire between January 2019 and February 2023. Total rent expense for the years ended December 31, 2018 , 2017 and 2016 was $2.7 million , $2.6 million and $2.4 million , respectively. The Company recognizes rent expense on a straight-line basis over the lease period and has accrued for rent expense incurred but not paid. Future minimum lease payments at December 31, 2018 under non-cancelable operating leases are as follows: (in thousands) Operating leases 2019 $ 2,224 2020 2,077 2021 1,835 2022 612 2023 35 Total minimum lease payments $ 6,783 Indemnifications The Company undertakes, in the ordinary course of business, to (i) defend customers and other parties from certain third-party claims associated with allegations of trade secret misappropriation, infringement of copyright, patent or other intellectual property right, or tortious damage to persons or property and (ii) indemnify and hold harmless such parties from certain resulting damages, costs and other liabilities. The term of these undertakings may be perpetual and the maximum potential liability of the Company under certain of these undertakings is not determinable. Based on its historical experience, the Company believes the liability associated with these undertakings is minimal. The Company has entered into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers, other than liabilities arising from willful misconduct of the individual. The Company currently has directors and officers insurance. As there has been no significant history of losses, no expense accrual has been made. Litigation The Company is currently, and from time to time, the Company may be, involved in lawsuits, claims, investigations and proceedings, consisting of intellectual property, commercial, employment and other matters which arise in the ordinary course of business. The Company defends itself vigorously against any such claims. Although the outcome of these matters is currently not determinable, management expects that any losses from existing matters that are probable or reasonably possible of being incurred as a result of these matters would not be material to the financial statements as a whole.

Common stock

Common stock	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Common Stock	Common Stock and Share-based Compensation The Company’s certificate of incorporation, as amended, authorizes the Company to issue 100 million shares of $0.0003 par value common stock. At December 31, 2018 , the Company has 2,377,888 shares of common stock reserved for issuance under stock option plans. Incentive stock option plans The Company has four equity incentive plans: the 2000 Stock Option Plan (the 2000 Plan), the 2006 Stock Option Plan (the 2006 Plan), the 2012 Stock Option Plan (the 2012 Plan) and the 2016 Equity Inducement Plan (the 2016 Plan). On March 26, 2012, all shares that were reserved under the 2006 Plan but not subject to outstanding awards became available for grant under the 2012 Plan. No additional shares will be issued under the 2006 Plan. The 2000 Plan terminated in March 2010 and no additional shares will be issued under this plan. All options currently outstanding under the 2000 Plan and the 2006 Plan continue to be governed by the terms and conditions of those plans. The 2016 Plan was adopted by the Company's Board of Directors without shareholder approval pursuant to the inducement exemption provided under the NYSE listing rules for the issuance of restricted stock units (RSUs) to employee's who joined the Company after the acquisition of Extension Healthcare. No additional shares will be issued under the 2016 Plan. Under the 2012 Plan, the Company has the ability to issue incentive stock options (ISOs), stock appreciation rights, restricted stock awards, RSUs, performance awards and stock bonuses. The ISOs will be granted at a price per share not less than the fair value at date of grant. Stock Option Activity The following table summarizes the combined stock option activity under the 2000 Plan, the 2006 Plan and the 2012 Plan and non-plan stock option agreements: Options outstanding Number of options Weighted average exercise price Weighted average remaining contractual term Aggregate intrinsic value (in years) (in thousands) Outstanding at December 31, 2017 1,332,063 $ 13.48 5.36 $ 22,298 Options granted — — Options exercised (531,788 ) 13.79 Options canceled (2,774 ) 4.97 Outstanding at December 31, 2018 797,501 $ 13.31 4.71 $ 20,767 Options vested and expected to vest as of December 31, 2018 797,501 $ 13.31 4.71 $ 20,767 Options vested and exercisable as of December 31, 2018 788,546 $ 13.35 4.69 $ 20,502 At December 31, 2018 , there was $0.1 million of unrecognized compensation cost related to options which is expected to be recognized over a weighted-average period of 0.24 year. No options were granted during the years ended December 31, 2018 and 2017. Further information regarding the value of employee options vested and exercised during the years ended December 31, 2018 , 2017 and 2016 is set forth below. Years ended December 31, (in thousands) 2018 2017 2016 Intrinsic value of options exercised during period $ 10,243 $ 18,603 $ 7,816 Employee Stock Purchase Plan The Company's 2012 Employee Stock Purchase Plan (ESPP) allows eligible employees to purchase shares of common stock at a discount through payroll deductions of up to 15% of their eligible compensation, subject to any plan limitations. The ESPP provides for six -month offering periods. At the end of each offering period, eligible employees are able to purchase shares at 85% of the lower of the fair market value of the Company's common stock on the first trading day of the offering period or on the last day of the offering period. During the years ended December 31, 2018 and 2017 , employees purchased 157,426 and 159,532 shares, respectively, of common stock at an average purchase price of $20.77 and $17.23 , respectively. As of December 31, 2018 , 721,303 shares remained available for future issuance under the ESPP. The Company uses the Black-Scholes option-pricing model to calculate the fair value of periodic ESPP offerings on their offer date. The following assumptions were used for each respective period for the ESPP: Years ended December 31, 2018 2017 2016 Expected term (in years) 0.5 0.5 0.5 Volatility 33.0% - 37.8% 29.0% - 32.0% 32.0% - 41.5% Risk-free interest rate 2.09% - 2.51% 0.61% - 1.39% 0.33% - 0.61% Dividend yield 0.0% 0.0% 0.0% Restricted Stock Units The Company issues RSUs as an element of its compensation plans. A summary of the restricted stock activity for the year ended December 31, 2018 is presented below: Restricted Stock Units Number of shares Weighted Average Grant Date Fair Value per Share Outstanding at December 31, 2017 2,045,589 $ 18.84 Granted 868,956 26.29 Vested (979,074 ) 17.19 Forfeited (128,291 ) 21.45 Outstanding at December 31, 2018 1,807,180 $ 23.13 At December 31, 2018 , there was $29.0 million of unrecognized compensation cost related to RSUs, which is expected to be recognized over a weighted-average period of 1.55 years. Allocation of Stock-Based Compensation Expense Stock-based compensation expense is recognized based on a straight-line amortization method over the respective vesting period of the award. For the years ended December 31, 2017 and 2018 the straight-line amortization is reduced by actual forfeitures. For the year ended December 31, 2016 the straight-line amortization has been reduced for estimated forfeitures. The Company estimated the expected forfeiture rate based on its historical experience, considering voluntary termination behaviors, trends of actual award forfeitures, and other events that will impact the forfeiture rate. To the extent the Company’s actual forfeiture rate is different from the estimate, the stock-based compensation expense is adjusted accordingly. The following table presents the allocation of stock-based compensation expense: Years ended December 31, (in thousands) 2018 2017 2016 Cost of revenue $ 3,614 $ 2,871 $ 1,268 Research and development 2,976 2,122 1,072 Sales and marketing 6,560 6,563 4,486 General and administrative 7,814 6,640 4,179 Total stock-based compensation $ 20,964 $ 18,196 $ 11,005

Segments

Segments	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Segments	Segments The Company has two operating segments which are both reportable segments: (i) Product; and (ii) Service, which are comprised of the Company’s and its wholly-owned subsidiaries’ results from operations. Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker (CODM), or decision-making group, in deciding how to allocate resources and in assessing performance. The Company’s CODM is its Chief Executive Officer. The CODM regularly receives information related to revenue, cost of revenue, and gross profit for each operating segment, and uses this information to assess performance and make resource allocation decisions. All other financial information, including operating expenses and assets, is prepared and reviewed by the CODM on a consolidated basis. Assets are not a measure used to assess the performance of the Company by the CODM, therefore the Company does not report assets by segment internally or in its financial statements. The following table presents a summary of the operating segments: Years ended December 31, (in thousands) 2018 2017 2016 * As Adjusted * As Adjusted Revenue Product $ 97,447 $ 91,585 $ 74,235 Service 82,183 74,404 57,791 Total revenue 179,630 165,989 132,026 Cost of revenue Product 27,425 27,244 22,788 Service 40,318 37,683 26,287 Total cost of revenue 67,743 64,927 49,075 Gross profit Product 70,022 64,341 51,447 Service 41,865 36,721 31,504 Total gross profit 111,887 101,062 82,951 Operating expenses 118,192 111,762 94,039 (Loss) income from operations (6,305 ) (10,700 ) (11,088 ) Interest income (expense), net and other (3,720 ) 562 217 Loss before income taxes $ (10,025 ) $ (10,138 ) $ (10,871 ) The following tables present the Company’s revenue by product line, as well as revenue and long-lived assets by geographic region. Years ended December 31, * As Adjusted * As Adjusted (in thousands) 2018 2017 2016 Revenue Product Device $ 60,130 $ 61,746 $ 50,614 Software 37,317 29,839 23,621 Total product 97,447 91,585 74,235 Service Maintenance and support 62,267 52,342 43,408 Professional services and training 19,916 22,062 14,383 Total service 82,183 74,404 57,791 Total revenue $ 179,630 $ 165,989 $ 132,026 The Company’s revenue by geographic region, based on customer location, is summarized as follows: Years ended December 31, * As Adjusted * As Adjusted (in thousands) 2018 2017 2016 Revenue United States $ 161,338 $ 148,993 $ 118,278 International 18,292 16,996 13,748 Total revenue $ 179,630 $ 165,989 $ 132,026 The Company’s tangible long-lived assets by geographic region, consisting of net property and equipment, are summarized as follows: December 31, (in thousands) 2018 2017 2016 Property and equipment, net United States $ 6,265 $ 4,621 $ 5,448 International 1,203 1,130 446 Total property and equipment, net $ 7,468 $ 5,751 $ 5,894

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income taxes The components of loss before income taxes are as follows: Years ended December 31, (in thousands) 2018 2017 2016 United States $ (10,852 ) $ (10,930 ) $ (11,498 ) International 827 792 627 Total loss before income taxes $ (10,025 ) $ (10,138 ) $ (10,871 ) The components of the provision for income taxes are as follows: Years ended December 31, (in thousands) 2018 2017 2016 Current Federal $ — $ (10 ) $ — State 53 54 36 Foreign 368 324 194 421 368 230 Deferred Federal (822 ) 311 334 State 99 119 26 Foreign (49 ) (39 ) (61 ) (772 ) 391 299 Total income tax provision (benefit) $ (351 ) $ 759 $ 529 The Company had an effective tax rate of (3.5)% , 7.5% and 4.9% for the years ended December 31, 2018 , 2017 and 2016 , respectively. Reconciliation of the provision for income taxes at the statutory rate to the Company’s provision for income tax is as follows: Years ended December 31, (in thousands) 2018 2017 2016 U.S. federal (tax benefit) provision at statutory rate $ (2,105 ) $ (4,576 ) $ (5,691 ) State (tax benefit) income taxes, net of federal benefit (373 ) (437 ) (574 ) Foreign income taxes at rates other than the US rate 92 (21 ) (94 ) Stock-based compensation (3,503 ) (8,373 ) 581 Change in valuation allowance 4,710 (6,023 ) 6,657 Non-deductible executive compensation 2,418 1,624 — Rate differential impact on Tax Cuts and Jobs Act — 18,975 — Research and development credits (994 ) (602 ) (449 ) Indefinite net operating losses carryforward (1,470 ) — — Other 874 192 99 Total $ (351 ) $ 759 $ 529 Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The following table presents the significant components of the Company’s deferred tax assets and liabilities for the periods presented: December 31, (in thousands) 2018 2017 Deferred tax assets Net operating loss carryforward $ 29,798 $ 27,289 Research and development credits 6,840 5,826 Depreciation and amortization 3,007 2,082 Reserves and accruals 9,661 10,242 Total deferred tax assets 49,306 45,439 Valuation allowance (40,070 ) (45,255 ) Net deferred tax assets 9,236 184 Deferred tax liabilities - convertible senior notes (7,503 ) — Deferred tax liabilities - other (2,208 ) (1,437 ) Net deferred tax liabilities $ (475 ) $ (1,253 ) The Company's deferred tax liabilities are primarily related to tax deductible goodwill. The Company determines its valuation allowance on deferred tax assets by considering both positive and negative evidence in order to ascertain whether it is more likely than not that deferred tax assets will be realized. Realization of deferred tax assets is dependent upon the generation of future taxable income, if any, the timing and amount of which are uncertain. Due to the history of losses the Company has generated in the past, the Company believes that it is not more likely than not that all of the deferred tax assets in the U.S. and Canada can be realized as of December 31, 2018 ; accordingly, the Company has recorded a full valuation allowance on its deferred tax assets. On December 22, 2017, the Tax Cuts and Jobs Act (P.L. 115-97) was signed into law. Among other changes is a permanent reduction in the federal corporate income tax rate from 35% to 21% effective January 1, 2018. As a result of the reduction in the corporate income tax rate, the Company has revalued its net deferred tax liability at December 31, 2017. This resulted in a reduction in the value of the Company's net deferred tax asset of approximately $19.0 million , which is offset by the change in valuation allowance of $19.7 million . This resulted in a deferred tax benefit of $0.7 million recorded in the statement of operations in the three months ended December 31, 2017. The Act includes certain anti-deferral and anti-abuse erosion provisions, including a new minimum tax on global intangible low-taxed income ('GILTI'). The Act subjects the Company to current tax on GILTI of its controlled foreign corporations. At December 31, 2018, the Company recognized $1.1 million GILTI inclusion reducing the deferred tax assets, which will be fully offset by the change in valuation allowance. There is no tax expense impact related to GILTI inclusion The Company’s valuation allowance increased by $5.2 million and $2.9 million for the years ended December 31, 2018 and 2017 , respectively. The change in the 2018 valuation allowance was primarily due to the addition of current year loss carryforwards and federal rate reduction. The change in the 2017 valuation allowance was primarily due to the addition of current year loss carryforwards. At December 31, 2018 , the Company had $124 million and $63 million , respectively, of federal and state net operating loss carryforwards. The federal net operating loss carryforward generated in the years ended December 31, 2002 through 2017 begin expiring in 2022. Net operating losses originating before January 1, 2018 are eligible to offset taxable income, if not otherwise limited under IRS Section 382. Net operating losses generated after December 31, 2017 have an infinite carryforward period and subject to 80% deduction limitation based upon pre-net operating deduction taxable income. The state net operating loss carryforward begins expiring in 2030, if not utilized. In addition, the Company has federal research and development tax credits carryforwards of approximately $3.9 million and state research and development tax credit carryforwards of approximately $5.3 million . The federal credit carryforwards begin expiring 2026 and the state credits carry forward indefinitely . The Internal Revenue Code (IRC) contains provisions which limit the amount of net operating loss (NOL) and research credit carryforwards that can be used in any given year if a significant change in ownership has occurred. As of December 31, 2018, $11.5 million of the Company's NOL carryovers and $0.5 million of credit carryovers are subject to an annual $0.6 million limitation, of which $5.3 million NOLs would be available to offset future taxable income in the twenty-year carryforward period. The following table displays by contributing factor the changes in the valuation allowance for deferred tax assets since January 1, 2017: Years Ended December 31, (in thousands) 2018 2017 2016 Balance at the beginning of the period $ 45,255 $ 42,339 $ 30,072 Net operating loss carryforwards generated (utilization) 2,509 3,050 5,049 R&D tax credit increase 1,014 1,121 1,345 Depreciation and amortization increase 925 237 1,195 Reserves and accruals increase (decrease) (581 ) (1,479 ) 4,821 Deferred tax assets decrease (increase) (9,052 ) (13 ) (143 ) Balance at the end of the period $ 40,070 $ 45,255 $ 42,339 The following table reflects changes in the unrecognized tax benefits since January 1, 2017: Years ended December 31, (in thousands) 2018 2017 Gross amount of unrecognized tax benefits as of the beginning of the period $ 1,673 $ 1,458 Decreases related to prior year tax provisions 7 — Increases related to current year tax provisions 251 215 Gross amount of unrecognized tax benefits as of the end of the period $ 1,931 $ 1,673 As a result of the Company’s historical losses and related valuation allowances, the Company has recorded substantially all of the uncertain tax amounts above as reductions to deferred tax assets which are subject to a full valuation allowance in its consolidated balance sheet with an insignificant portion recorded in other long-term liabilities. The Company recognizes interest and penalties relating to uncertain tax positions in income tax expense. As the Company is not currently under examination, it is reasonable to assume that the balance of gross unrecognized tax benefits will likely not change in the next twelve months. The Company files income tax returns in the United States on a federal basis and in various states. The Company is not currently under any international or any United States federal, state and local income tax examinations for any taxable years. All of the Company’s net operating losses and research credit carryforwards prior to 2018 are subject to tax authority adjustment and all years after 2011 are still subject to the tax authority examinations. The 2017 tax reform legislation provides for a one-time “deemed repatriation” of accumulated foreign earnings for the year ended December 31, 2017. The Company does not expect to pay U.S. federal cash taxes on the deemed repatriation due to its historical net operating loss for tax purposes. The Company does not expect that the future foreign earnings will be subject to U.S. federal income tax since the Company intends to continue reinvesting such earnings outside the U.S. indefinitely. On December 22, 2017, the SEC issued Staff Accounting Bulletin 118 (“SAB 118”), which provides guidance on accounting for tax effects of the Tax Act. SAB 118’s measurement period closed on December 22, 2018, one year from the Tax Act enactment. The Company completed its accounting for the impact of the Tax Act and there were no subsequent revisions from the provisional amounts recorded in the prior year financial statements.

Business Acquisitions (Notes)

Business Acquisitions (Notes)	12 Months Ended
	Dec. 31, 2018
mVisum Net Assets Acquired [Abstract]
Business acquisitions	Business acquisitions Acquisition of Extension Healthcare On October 27, 2016 , the Company acquired all of the outstanding equity interest of Extension Healthcare for $52.5 million in cash. The Company incurred $5.8 million in merger and integration costs for the year ended December 31, 2016, which were recorded in cost of revenue and operating expenses in the consolidated statements of operations. Based in Fort Wayne, Ind., Extension Healthcare is a provider of clinical, event-driven communication and workflow collaboration software for the hospital environment. Extension Healthcare is known in the market for its clinical integration software solution Engage, which features an advanced clinical rules engine that unifies data from multiple sources simultaneously, enables prioritization of notifications, adds patient context, and sends messages to the right care team members on their mobile devices. The Engage platform allows clinicians to be away from the bedside while staying informed about their patients. The following table presents the fair value of the identifiable assets acquired and liabilities assumed as of the acquisition date: (in thousands) Fair value of net assets acquired Accounts receivable, net of allowance $ 1,569 Prepaid expenses and other current assets 774 Property and equipment, net 48 Intangibles assets, net 17,200 Goodwill 39,258 Total assets 58,849 Accounts payable (149 ) Accrued payroll and other current liabilities (1,984 ) Deferred revenue, current (2,992 ) Deferred revenue, long-term (1,224 ) Total liabilities assumed (6,349 ) Net assets acquired $ 52,500 The estimated fair values of identifiable intangible assets were primarily determined using discounted cash flow models. The table below shows the valuation of the intangible assets acquired from Extension Healthcare along with their estimated useful lives: (in thousands, except for useful lives) Fair value acquired Useful life (years) Customer relationships $ 8,400 8 Developed technology 6,400 3 Trademarks 1,000 3 Backlog 1,400 3 Total intangible assets $ 17,200 The amortization of developed technology and backlog is recorded in "cost of revenues" for product and the amortization for the remaining intangibles is recorded in "sales and marketing" expenses on the consolidated statement of operations. The excess of the acquisition consideration over the fair values of the underlying net assets acquired was recorded as goodwill. Goodwill is largely attributable to the synergy of Extension Healthcare’s proprietary solutions with the Company’s existing customer base, dedicated sales force and cross selling opportunities with the Company’s other solutions. Goodwill is not amortized but instead is tested for impairment at least annually or more frequently if indicators of impairment are present. For federal income tax purposes, the entire purchase consideration, including goodwill, is capitalizable and deductible over fifteen years. The goodwill recorded from the acquisition of Extension Healthcare was allocated with $31.2 million attributable to the Product reporting unit and $8.0 million attributable to the Service reporting unit. In connection with the acquisition the Company recorded a charge of $2.6 million related to the planned redistribution of proceeds by the selling shareholders to employees of Extension Healthcare who will be retained by the Company post-acquisition. (Employee Payments). These payments are not dependent on continued employment with the Company and will be reduced by any escrow claims made by the Company prior to redistribution. Under GAAP, including guidance promulgated by the U.S. Securities and Exchange Commission, actions of economic interest holders in a company may be imputed to the company itself. The selling shareholders of Extension Healthcare meet the criteria of economic interest holders of the Company due to their ability to earn additional consideration in connection with the close of escrow. As such, the redistribution of this portion of the purchase price to the acquired employees who did not have a right to such payments based on their existing interest in Extension Healthcare at the time of acquisition are deemed to represent payments for services that benefit the Company and must therefore be recorded as non-cash compensation expense incurred by the Company and a capital contribution received from the selling shareholders. In substance, the Employee Payments are a second and separate transaction from the acquisition of Extension Healthcare, which is recorded as a separate non-cash accounting entry. Additionally, in connection with the acquisition the Company established a retention bonus plan for Extension Healthcare with potential additional compensation over a two -year period of approximately $2.6 million , based on continued employment. Such amounts are not considered part of the purchase consideration and are being recorded as compensation expense as earned. During the years ended December 31, 2018, 2017 and 2016, $0.5 million , $1.0 million and $0.5 million , respectively, of this retention bonus was paid and $0.3 million , $1.0 million and $0.7 million , respectively, was recorded as compensation expense. Immediately subsequent to the acquisition the Company initiated a restructuring plan which resulted in $0.5 million of severance charges of which $0.1 million was recorded to cost of revenue and $0.4 million was recorded to operating expenses. Substantially all of the amounts have been paid as of December 31, 2016. The results of operations of Extension Healthcare are included in Vocera's consolidated results of operations beginning in the fourth quarter of fiscal 2016. For the fiscal year ended December 31, 2016, immaterial revenue and operating loss of approximately $7.1 million attributable to Extension Healthcare were included in the consolidated results of operations. The unaudited pro forma financial information for the years ended December 31, 2016 is presented as if the acquisition had occurred on January 1, 2016. The historical financial information is adjusted in the unaudited pro forma financial information to give effect to pro forma events that are (1) directly attributable to the proposed acquisition, (2) factually supportable, and (3) expected to have a continuing impact on the combined results. The unaudited pro forma financial information are not necessarily indicative of or intended to represent the results that would have been achieved had the transaction been consummated as of the dates indicated or that may be achieved in the future. The actual results reported by the combined company in periods following the acquisition may differ significantly from those reflected in this unaudited pro forma financial information for a number of reasons, including cost saving synergies from operating efficiencies and the effect of the incremental costs incurred to integrate the two companies. Year Ended (in thousands) December 31, 2016 Revenues $ 134,330 Net loss $ (31,787 ) Net loss per share attributable to Vocera Basic and diluted $ (1.18 )

Quarterly results of operations

Quarterly results of operations (unaudited) (Notes)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information [Table Text Block]	14. Quarterly results of operations (unaudited) The following tables present certain unaudited consolidated quarterly financial information for each of the eight quarters ended December 31, 2018 . This quarterly information has been prepared on the same basis as the consolidated financial statements and includes all adjustments necessary to state fairly the information for the periods presented. (In thousands, except per share data) Quarters Ended 2018 March 31, June 30, September 30, December 31, Total revenue $ 40,242 $ 42,686 $ 47,822 $ 48,880 Gross profit $ 23,901 $ 25,651 $ 31,138 $ 31,197 Net loss $ (4,770 ) $ (3,554 ) $ (249 ) $ (1,101 ) Net loss attributable to common stockholders $ (4,770 ) $ (3,554 ) $ (249 ) $ (1,101 ) Net loss per share attributable to common stockholders: Basic and diluted $ (0.24 ) $ (0.26 ) $ (0.10 ) $ (0.04 ) Weighted average shares used to compute net loss per share attributable to common stockholders: Basic and diluted 29,476 29,867 29,861 30,592 Quarters Ended 2017 March 31, June 30, September 30, December 31, Total revenue $ 36,626 $ 39,658 $ 45,585 $ 44,120 Gross profit $ 21,062 $ 22,889 $ 29,136 $ 27,975 Net income (loss) $ (6,650 ) $ (6,012 ) $ 1,391 $ 374 Net income (loss) attributable to common stockholders $ (6,650 ) $ (6,012 ) $ 1,391 $ 374 Net loss per share attributable to common stockholders: Basic $ (0.24 ) $ (0.21 ) $ 0.05 $ 0.01 Diluted $ (0.24 ) $ (0.21 ) $ 0.05 $ 0.01 Weighted average shares used to compute net loss per common share: Basic 27,751 28,422 29,130 29,317 Diluted 27,751 28,422 30,473 30,704

The Company and Summary of Si_2

The Company and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of presentation The consolidated financial statements include the accounts of Vocera Communications, Inc. and its wholly owned subsidiaries. All inter-company transactions and balances have been eliminated in consolidation. The accompanying notes are prepared in accordance with accounting principles generally accepted in the United States (GAAP). Effective January 1, 2018, we adopted Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers (ASC 606), as discussed in detail in Note 2. All amounts and disclosures set forth in this Annual Report on Form 10-K have been updated to comply with ASC 606, as indicated by the "as adjusted" note. Certain prior period amounts have been adjusted as a result of our adoption of ASC 606. Refer to "Recently Adopted Accounting Pronouncements" below for more information.
Consolidation	The consolidated financial statements include the accounts of Vocera Communications, Inc. and its wholly owned subsidiaries. All inter-company transactions and balances have been eliminated in consolidation.
Use of Estimates	Use of estimates and reclassifications The preparation of financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reporting periods. The estimates include, but are not limited to, revenue recognition, warranty reserves, inventory reserves, goodwill and intangible assets, stock-based compensation expense, provisions for income taxes and contingencies. Actual results could differ from these estimates, and such differences could be material to the Company’s financial position and results of operations.
Cash, Cash Equivalents and Short-term Investments	Cash, cash equivalents and short-term investments The Company’s cash equivalents and short-term investments consist of money market funds, commercial paper, U.S. government agency notes, U.S. Treasury notes, municipal debt and corporate debt. These investments are classified as available-for-sale securities and are carried at fair value with the unrealized gains and losses reported as a component of stockholders’ equity. Management determines the appropriate classification of its investments at the time of purchase and re-evaluates the available-for-sale designations as of each balance sheet date. Investments with an original purchase maturity of three months or less are classified as cash equivalents, all those with longer maturities are classified as short-term investments, which are available-for-sale.
Allowance for Doubtful Accounts	Allowance for doubtful accounts The allowance for doubtful accounts reflects the Company’s best estimate of probable losses inherent in the Company’s receivables portfolio determined on the basis of historical experience, specific allowances for known troubled accounts and other currently available evidence. The Company has not experienced significant credit losses from its accounts receivable. The Company performs a regular review of its customers’ payment histories and associated credit risks as it does not require collateral from its customers. The following table presents the changes in the allowance for doubtful accounts: Years ended December 31, (in thousands) 2018 2017 2016 Allowance—beginning of period $ — $ — $ (451 ) Provisions for bad debts — — — Recoveries from bad debts — — — Write-offs and other — — 451 Allowance—end of period $ — $ — $ —
Inventories	Inventories Inventories are valued at the lower of standard cost (which approximates actual cost on a first-in, first-out basis) or market (net realizable value or replacement cost). The Company assesses the valuation of inventory and periodically writes down the value for estimated excess and obsolete inventory based upon assumptions about future demand and market conditions.
Concentration of credit risk and other risks and uncertainties	Concentration of credit risk and other risks and uncertainties Financial instruments that subject the Company to concentration of credit risk consist primarily of cash, cash equivalents and short-term investments. The Company’s cash and cash equivalents are primarily deposited with high quality financial institutions and in money market funds. Deposits at these institutions and funds may, at times, exceed federally insured limits. Management believes that these financial institutions and funds are financially sound and, accordingly, that minimal credit risk exists. The Company has not experienced any losses on its deposits of cash and cash equivalents. Marketable securities are stated at fair value, and accounted for as available-for-sale within short-term investments. The counterparties to the agreements relating to the Company’s investment securities consist of major corporations, financial institutions and government agencies of high credit standing. The primary hardware components of the Company’s products is currently manufactured by third-party contractors in Mexico and Taiwan. A significant disruption in the operations of these contractors may impact the production of the Company’s products for a substantial period of time, which could harm the Company’s business, financial condition and results of operations. Concentration of credit risk with respect to trade accounts receivable is considered to be limited due to the diversity of the Company’s customer base and geographic sales areas. At December 31, 2018 and 2017 , no customer accounted for 10% or more of accounts receivable. At December 31, 2018 and 2017, one reseller represented 26.4% and 26.3% , respectively of accounts receivable. For the years ended December 31, 2018 , 2017 and 2016 , no customer represented 10% or more of revenue.
Property and Equipment	Property and equipment Property and equipment are stated at cost and depreciated on a straight-line basis over the estimated useful economic lives of the assets. Assets generally have useful economic lives of three years except for leasehold improvements, which are amortized using the straight-line method over the shorter of the remaining lease term or the estimated useful life of the related assets. Purchased or developed software also generally has a three year useful economic life, except for major ERP implementations, for which the Company assumes a five year useful economic life. Upon retirement or sale, the cost and related accumulated depreciation and amortization are removed from the consolidated balance sheet and the resulting gain or loss is reflected in operations. Maintenance and repairs which are not considered improvements and do not extend the useful life of the assets are charged to operations as incurred. The Company periodically reviews property and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset is impaired or the estimated useful lives are no longer appropriate. Fair value is estimated based on discounted future cash flows. If indicators of impairment exist and the undiscounted projected cash flows associated with such assets are less than the carrying amount of the asset, an impairment loss is recorded to write the asset down to its estimated fair values. To date, the Company has not recorded any impairment charges.
Software Development Costs	oftware development costs For internal-use software, the Company capitalizes certain internal and external costs incurred in its acquisition and creation. Capitalized internal-use software is included in property and equipment when development is complete and is amortized on a straight-line basis over the estimated useful life of the related asset, generally three years, except that five years is assumed for major ERP implementations. Based on the authoritative guidance, costs incurred either before or after the period satisfying the capitalization criteria, together with costs incurred for training and maintenance, are expensed as incurred. For the years ended December 31, 2018 , 2017 and 2016 , the Company capitalized costs of $0.7 million , $0.3 million and zero , respectively.
Goodwill and Intangible Assets	Goodwill and intangible assets The Company allocates the purchase price of any acquisitions to tangible assets and liabilities and identifiable intangible assets acquired. Any residual purchase price is recorded as goodwill. Goodwill Goodwill is tested for impairment at the reporting unit level at least annually, or more often if events or changes in circumstances indicate the carrying value may not be recoverable. The Company has identified two operating segments (Product and Service) which management also considers to be reporting units. In testing for goodwill impairment, the Company may elect to utilize a qualitative assessment to evaluate whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. If such qualitative assessment indicates that goodwill impairment is more likely than not, the Company performs a two-step impairment test. The Company performed its goodwill impairment assessment on October 1, 2018 using a qualitative assessment and determined that no impairment existed as of the date of the impairment test because the fair value of each reporting unit exceeded its carrying value. As of December 31, 2018 , no changes in circumstances indicate that goodwill carrying values may not be recoverable. Intangible assets Intangible assets are amortized over their estimated useful lives. Upon completion of development, acquired in-process research and development assets are generally considered amortizable, finite-lived assets and are amortized over their estimated useful lives. Finite-lived intangible assets consist of customer relationships, developed technology, trademarks, backlog and non-compete agreements. The Company evaluates intangible assets for impairment by assessing the recoverability of these assets whenever adverse events or changes in circumstances or business climate indicate that expected undiscounted future cash flows related to such intangible assets may not be sufficient to support the net book value of such assets. An impairment is recognized in the period of identification to the extent the carrying amount of an asset exceeds the fair value of such asset. No impairment of intangible assets was recorded in the years ended December 31, 2018 , 2017 or 2016 .
Revenue Recognition, Policy	Shipping and handling costs Shipping and handling costs charged to customers are included in revenue and the associated expense is recorded in cost of revenue in the consolidated statements of operations for all periods presented. Revenue from sales-type leases A portion of the Company's sales are made through multi-year lease agreements with customers. When these arrangements are considered sales-type leases, upon delivery of leased products to customers, the Company recognizes revenue for such products in an amount equal to the net present value of the minimum lease payments. Unearned income is recognized as part of product revenue under the effective interest method. The Company recognizes revenue related to certain executory costs, including maintenance and extended warranty, ratably over the term of the underlying arrangements. The Company recognizes revenue related to battery refresh executory costs when such executory costs are incurred. Proceeds from transfers of sales-type leases to third-party financial companies are allocated between the net investment in sales-type leases and the executory cost component for remaining service obligations based on relative present value. The difference between the amount of proceeds allocated to the net investment in lease and the carrying value of the net investment in lease is included in product revenue. Proceeds allocated to the executory cost component are accounted for as financing liabilities. For the year ended December 31, 2018 , the Company transferred $0.4 million of lease receivables, recording an immaterial net loss and $0.3 million of new financing liabilities for future performance of executory service obligations. For the year ended December 31, 2017 , the Company transferred $0.9 million of lease receivables, recording an immaterial net loss and $0.7 million of new financing liabilities for future performance of executory service obligations. For lease receivables retained as of December 31, 2018 and 2017 , the Company recorded $0.7 million and $1.3 million , respectively, of net investment in sales-type leases, equivalent to the minimum lease payments for the delivered product.
Revenue Recognition, sales type leases	Revenue from sales-type leases A portion of the Company's sales are made through multi-year lease agreements with customers. When these arrangements are considered sales-type leases, upon delivery of leased products to customers, the Company recognizes revenue for such products in an amount equal to the net present value of the minimum lease payments. Unearned income is recognized as part of product revenue under the effective interest method. The Company recognizes revenue related to certain executory costs, including maintenance and extended warranty, ratably over the term of the underlying arrangements. The Company recognizes revenue related to battery refresh executory costs when such executory costs are incurred. Proceeds from transfers of sales-type leases to third-party financial companies are allocated between the net investment in sales-type leases and the executory cost component for remaining service obligations based on relative present value. The difference between the amount of proceeds allocated to the net investment in lease and the carrying value of the net investment in lease is included in product revenue. Proceeds allocated to the executory cost component are accounted for as financing liabilities. For the year ended December 31, 2018 , the Company transferred $0.4 million of lease receivables, recording an immaterial net loss and $0.3 million of new financing liabilities for future performance of executory service obligations. For the year ended December 31, 2017 , the Company transferred $0.9 million of lease receivables, recording an immaterial net loss and $0.7 million of new financing liabilities for future performance of executory service obligations. For lease receivables retained as of December 31, 2018 and 2017 , the Company recorded $0.7 million and $1.3 million , respectively, of net investment in sales-type leases, equivalent to the minimum lease payments for the delivered product.
Commissions Expense, Policy
Research and Development Expenditures	Research and development expenditures Research and development costs are charged to operations as incurred. Software development costs incurred for external products prior to the establishment of technological feasibility are included in research and development and are expensed as incurred. After technological feasibility is established, material software development costs up to general availability of the software will be capitalized and amortized on a straight-line basis over the estimated product life, or based on the ratio of current revenues to total projected product revenue, whichever is greater. To date, the time between the establishment of technological feasibility and general availability has been very short and therefore no significant costs have been incurred. Accordingly, the Company has not capitalized any software development costs related to research and development expenditures.
Advertising Costs	Advertising costs Advertising costs are included in sales and marketing expense and are expensed as incurred. Advertising costs for the years ended December 31, 2018 , 2017 and 2016 were immaterial.
Product Warranties	Product warranties The Company offers warranties on certain products and records a liability for the estimated future costs associated with warranty claims, which is based upon historical experience and the Company’s estimate of the level of future costs. The Company provides for the estimated costs of hardware warranties at the time the related revenue is recognized. Costs are estimated based on historical and projected product failure rates, historical and projected repair costs, and knowledge of specific product failures (if any). The specific hardware warranty includes parts and labor over a period generally ranging from one to three years. The Company provides no warranty for software. The Company regularly re-evaluates its estimates to assess the adequacy of the recorded warranty liabilities and adjust the amounts as necessary. Warranty costs are reflected in the consolidated statement of operations as cost of revenue.
Product Warranties	A reconciliation of the changes in the Company’s warranty reserve for the years ended December 31, 2018 , 2017 and 2016 is as follows: Years ended December 31, (in thousands) 2018 2017 2016 Warranty balance at the beginning of the period $ 353 $ 596 $ 806 Warranty expense accrued for shipments during the period 468 503 757 Changes in estimate related to pre-existing warranties (223 ) (450 ) (537 ) Warranty settlements made (222 ) (296 ) (430 ) Total product warranty $ 376 $ 353 $ 596
Stock-based Compensation	Stock-based compensation Stock-based compensation is measured at grant date based on the fair value of the award using the grant date closing stock price and is expensed on a straight-line basis over the requisite service period.
Income Taxes	Income taxes The Company uses the asset and liability method of accounting for income taxes. Under this method, the Company records deferred income taxes based on temporary differences between the financial reporting and tax bases of assets and liabilities and use enacted tax rates and laws that the Company expects will be in effect when they recover those assets or settle those liabilities, as the case may be, to measure those taxes. In cases where the expiration date of tax carryforwards or the projected operating results indicate that realization is not likely, the Company provides for a valuation allowance. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized. The Company has deferred tax assets, resulting from net operating losses, research and development credits and temporary differences that may reduce taxable income in future periods. A valuation allowance is required when it is more likely than not that all or a portion of a deferred tax asset will not be realized. In assessing the need for a valuation allowance, the Company estimates future taxable income, considering the feasibility of ongoing tax-planning strategies and the realizability of tax loss carryforwards. Valuation allowances related to deferred tax assets can be impacted by changes in tax laws, changes in statutory tax rates and future taxable income levels. If the Company were to determine that it would be able to realize its deferred tax assets in the future in excess of the net carrying amounts, it would decrease the recorded valuation allowance through an increase to income in the period in which that determination is made. Due to the history of losses the Company has generated in the past, the Company believes that it is not more likely than not that all of the deferred tax assets in the U.S. and Canada can be realized as of December 31, 2018 and 2017, respectively. Accordingly, the Company has recorded a full valuation allowance on its deferred tax assets for these years. At December 31, 2018 , the Company had a valuation allowance against net deferred tax assets of $40.1 million . There is inherent uncertainty in evaluating the sustainability of the income tax positions the Company takes on its tax returns. The Company assesses its income tax positions and records tax benefits for all years subject to examination based upon management’s evaluation of the facts, circumstances and information available at the reporting date. For those tax positions where it is more likely than not that a tax benefit will be sustained, the Company has recorded the highest amount of tax benefit with a greater than 50% likelihood of being realized upon ultimate settlement with a taxing authority that has full knowledge of all relevant information. For those income tax positions where it is not more likely than not that a tax benefit will be realizable, no tax benefit has been recognized in the financial statements. The Company includes interest and penalties with income taxes in the accompanying statement of operations. All of the Company’s net operating losses and research credit carryforwards are subject to adjustment by tax authorities and all years after 2011 are still subject to tax authority examinations. The Company is currently not subject to any income tax audit examinations by tax authorities in any jurisdictions including U.S. federal, state and local or foreign countries.
Foreign Currency Translation	Foreign currency translation The functional currency of the Company’s foreign subsidiaries is the U.S. dollar. Accordingly, monetary assets and liabilities in non-functional currency of these subsidiaries are remeasured using exchange rates in effect at the end of the period. Revenues and costs in local currency are remeasured using average exchange rates for the period, except for costs related to those consolidated balance sheet items that are remeasured using historical exchange rates. The resulting remeasurement gains and losses are included in the Company’s consolidated statements of operations. Translation gains and losses have not been significant to date
Segments	Segments Operating segments are components of an enterprise for which separate financial information is available and is evaluated regularly by the Company’s chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is the Chief Executive Officer. The Company has two operating segments which are both reportable business segments: (i) Product; and (ii) Service.
Comprehensive Income (Loss)	Comprehensive loss For the years ended December 31, 2018 , 2017 and 2016, the only component of other comprehensive loss was unrealized (losses) gains on available-for-sale securities.
Related Party Transactions Disclosure	Related party transactions During the years ended December 31, 2018 , 2017 and 2016 , the Company had revenue transactions with a related party, the University of Chicago Medical Center (UCMC), for $0.4 million , $0.4 million and $0.4 million , respectively, relating to consulting services and technology solutions. One of the Company's board members is the President of UCMC.
Recent Accounting Pronouncements	Recent accounting pronouncements In February 2016, the FASB amended lease accounting requirements to begin recording assets and liabilities arising from leases on the balance sheet. The new guidance will also require significant additional disclosures about the amount, timing and uncertainty of cash flows from leases. This new guidance will be effective beginning on January 1, 2019 under a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients that entities may elect to apply. The Company will elect the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allows us to carryforward the historical lease classification. The Company will make an accounting policy election to keep leases with an initial term of 12 months or less off of the balance sheet. The Company will recognize those lease payments in the consolidated statements of operations on a straight-line basis over the lease term. The Company estimates the adoption of the standard will result in recognition of right-of-use assets, which includes the impact of existing deferred rents and tenant improvement allowances of $5.1 million and lease liabilities of $6.7 million , respectively as of January 1, 2019. The Company does not believe the standard will materially affect our consolidated net earnings. These are preliminary estimates that are subject to change as we finalize our adoption. In June 2016, the FASB issued new guidance related to the accounting for credit losses on instruments for both financial services and non-financial services entities. The new guidance introduces an approach based on expected losses to estimate credit losses on certain types of financial instruments. It also modifies the impairment model for available-for-sale debt securities and provides for a simplified accounting model for purchased financial assets with credit deterioration since their origination. The guidance will be effective beginning January 1, 2020. Early adoption is permitted. The Company is currently evaluating the impact of this new guidance on its consolidated financial statements. In January 2017, the FASB issued new guidance to simplify the accounting for goodwill impairment. The guidance simplifies the measurement of goodwill impairment by removing step 2 of the goodwill impairment test, which requires the determination of the fair value of individual assets and liabilities of a reporting unit. The new guidance requires goodwill impairment to be measured as the amount by which a reporting unit’s carrying value exceeds its fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The amendments should be applied on a prospective basis. The new standard is effective for fiscal years beginning after December 15, 2019 with early adoption permitted for interim or annual goodwill impairment tests performed after January 1, 2017. The Company is evaluating the impact of this new accounting guidance on its consolidated financial statements. In February 2018, the FASB issued new guidance which allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act and required certain disclosures about stranded tax effects. This standard will be effective for the Company beginning January 1, 2019 and may be applied either in the period of adoption or retrospectively. Early adoption is permitted. The adoption of this guidance is not expected to have a material impact on the Company’s consolidated financial statements. In August 2018, the SEC adopted the final rule under SEC Release No. 33-10532, Disclosure Update and Simplification, amending certain disclosure requirements that were redundant, duplicative, overlapping, outdated or superseded. In addition, the amendments expanded the disclosure requirements on the analysis of stockholders' equity for interim financial statements. Under the amendments, an analysis of changes in each caption of stockholders' equity presented in the balance sheet must be provided in a note or separate statement. The analysis should present a reconciliation of the beginning balance to the ending balance of each period for which a statement of comprehensive income is required to be filed. This final rule was effective on November 5, 2018. The Company is evaluating the impact of this guidance on its condensed consolidated financial statements and expects to adopt this guidance in the first quarter of fiscal 2019.

The Company and Summary of Si_3

The Company and Summary of Significant Accounting Policies The Company and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
New Accounting Pronouncement, Early Adoption [Table Text Block]
Allowance for Credit Losses on Financing Receivables [Table Text Block]	The following table presents the changes in the allowance for doubtful accounts: Years ended December 31, (in thousands) 2018 2017 2016 Allowance—beginning of period $ — $ — $ (451 ) Provisions for bad debts — — — Recoveries from bad debts — — — Write-offs and other — — 451 Allowance—end of period $ — $ — $ —

Fair value of financial instr_2

Fair value of financial instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of assets and liabilities measured at fair value on a recurring basis, by level	he table below summarizes the Company’s assets that are measured at fair value on a recurring basis, by level, within the fair value hierarchy as of December 31, 2018 and 2017 , respectively. December 31, 2018 December 31, 2017 (in thousands) Level 1 Level 2 Total Level 1 Level 2 Total Assets Money market funds $ 3,737 $ — $ 3,737 $ 3,232 $ — $ 3,232 Commercial paper — 16,570 16,570 — 1,201 1,201 U.S. government agency securities — 3,325 3,325 — 8,648 8,648 U.S. Treasury securities — 2,730 2,730 — 5,561 5,561 Corporate debt securities — 166,759 166,759 — 37,530 37,530 Total assets measured at fair value $ 3,737 $ 189,384 $ 193,121 $ 3,232 $ 52,940 $ 56,172

Cash, Cash Equivalents and Sh_2

Cash, Cash Equivalents and Short-term Investments (Tables)	12 Months Ended
	Dec. 31, 2018
Cash and Cash Equivalents [Abstract]
Schedule of cash, cash equivalents and available-for-sale investments	he following tables display gross unrealized gains and losses for cash, cash equivalents and available-for-sale investments for the periods presented: December 31, 2018 (in thousands) Amortized Cost Unrealized Gains Unrealized Losses Fair value Cash and cash equivalents: Demand deposits and other cash $ 28,049 $ — $ — $ 28,049 Money market funds 3,737 — — 3,737 Commercial paper 2,491 — (1 ) 2,490 Corporate debt securities — — — — Total cash and cash equivalents 34,277 — (1 ) 34,276 Short-Term Investments: Commercial paper 14,091 — (11 ) 14,080 U.S. government agency securities 3,339 — (14 ) 3,325 U.S. Treasury securities 2,740 — (10 ) 2,730 Corporate debt securities 167,110 28 (379 ) 166,759 Total short-term investments 187,280 28 (414 ) 186,894 Total cash, cash equivalents and short-term investments $ 221,557 $ 28 $ (415 ) $ 221,170 December 31, 2017 (in thousands) Amortized Cost Unrealized Gains Unrealized Losses Fair value Cash and cash equivalents: Demand deposits and other cash $ 25,061 $ — $ — $ 25,061 Money market funds 3,232 — — 3,232 Commercial paper — — — — Corporate debt securities 433 — — 433 Total cash and cash equivalents 28,726 — — 28,726 Short-Term Investments: Commercial paper 1,202 — (1 ) 1,201 U.S. government agency securities 8,678 — (30 ) 8,648 U.S. Treasury securities 5,586 — (25 ) 5,561 Corporate debt securities 37,176 1 (80 ) 37,097 Total short-term investments 52,642 1 (136 ) 52,507 Total cash, cash equivalents and short-term investments $ 81,368 $ 1 $ (136 ) $ 81,233
Investments Classified by Contractual Maturity Date [Table Text Block]	Classification of the cash, cash equivalent and short-term investments by contractual maturity was as follows: (in thousands) One year or shorter Between 1 and 2 years Total Balances as of December 31, 2018 Cash and cash equivalents (1) $ 34,276 $ — $ 34,276 Short-term investments 109,451 77,443 186,894 Cash, cash equivalents and short-term investments $ 143,727 $ 77,443 $ 221,170 Balances as of December 31, 2017 Cash and cash equivalents (1) $ 28,726 $ — $ 28,726 Short-term investments 34,750 17,757 52,507 Cash, cash equivalents and short-term investments $ 63,476 $ 17,757 $ 81,233 (1) Includes demand deposits and other cash, money market funds and other cash equivalent securities, all with 0-90 day maturity at purchase.

Income (loss) per share (Tables

Income (loss) per share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Schedule of the computation of basic and diluted net income (loss) per share	The following table presents the calculation of basic and diluted net income (loss) per share: Years ended December 31, (in thousands, except for share and per share amounts) 2018 2017 2016 * As Adjusted * As Adjusted Numerator: Net loss $ (9,674 ) $ (10,897 ) $ (11,400 ) Denominator: Weighted-average shares used to compute net loss per common share - basic and diluted 30,041 28,655 26,859 Net loss per share Basic and diluted $(0.32) $(0.38) $(0.42)
Schedule of antidilutive securities excluded from computation of earnings per share	For the years ended December 31, 2018, 2017 and 2016, the following securities were not included in the calculation of diluted shares outstanding as the effect would have been anti-dilutive: December 31, (in thousands) 2018 2017 2016 Options to purchase common stock 1,085 1,365 2,454 Restricted stock units 1,925 2,046 2,129

Goodwill and intangible assets

Goodwill and intangible assets (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	Intangible assets The fair values for acquired intangible assets were determined by management with consideration of, in part, valuations performed by independent valuation specialists. Acquisition-related intangible assets are amortized over the life of the assets on an accelerated basis that approximates the expected economic benefit of the assets. This assumption results in amortization that is higher in earlier periods of the useful life. To date there has been no impairment of the Company's intangible assets. The estimated useful lives and carrying value of acquired intangible assets are as follows: December 31, 2018 December 31, 2017 (in thousands) Weighted average useful life (years) Gross carrying amount Accumulated amortization Net carrying amount Gross carrying amount Accumulated amortization Net carrying amount Intangible assets: Customer relationships 7 to 9 $ 10,920 $ 4,645 $ 6,275 $ 10,920 $ 3,469 $ 7,451 Developed technology 3 to 7 10,050 7,731 2,319 10,050 5,302 4,748 Trademarks 3 to 7 1,110 831 279 1,110 497 613 Backlog 3 1,400 1,203 197 1,400 650 750 Non-compete agreements 2 to 4 460 460 — 460 455 5 Intangible assets, net book value $ 23,940 $ 14,870 $ 9,070 $ 23,940 $ 10,373 $ 13,567 Amortization of intangible assets was $4.5 million , $4.6 million and $1.4 million for the years ended December 31, 2018 , 2017 and 2016 , respectively.
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	Amortization of acquired intangible assets is reflected in the cost of revenues for developed technology and backlog and in operating expenses for the other intangibles. The estimated future amortization of acquired intangible assets as of December 31, 2018 was as follows: (in thousands) Future amortization 2019 $ 3,717 2020 1,251 2021 1,127 2022 1,050 2023 1,050 2024 875 Future amortization expense $ 9,070

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2018
Balance Sheet Components [Abstract]
Inventories	Inventories December 31, (in thousands) 2018 2017 Raw materials $ 197 $ 4 Finished goods 4,153 2,811 Total inventories $ 4,350 $ 2,815
Property and Equipment	Property and equipment, net December 31, (in thousands) 2018 2017 Computer equipment and software $ 10,433 $ 8,832 Furniture, fixtures and equipment 2,246 1,764 Leasehold improvements 5,183 4,794 Manufacturing tools and equipment 2,371 2,624 Construction in process 520 157 Property and equipment, at cost 20,753 18,171 Less: Accumulated depreciation (13,285 ) (12,420 ) Property and equipment, net $ 7,468 $ 5,751 Depreciation and amortization expense for property and equipment for the years ended December 31, 2018 , 2017 and 2016 was $3.2 million , $3.0 million and $2.4 million , respectively.
Investment in sales-type leases	Net investment in sales-type leases The Company has sales-type leases with terms of 3 to 4 years. Sales-type lease receivables are collateralized by the underlying equipment. The components of the net investment in sales-type leases are as follows: December 31, (in thousands) 2018 2017 Net minimum lease payments to be received $ 2,111 $ 2,758 Less: Unearned interest income and executory revenue portion (1,387 ) (1,469 ) Net investment in sales-type leases 724 1,289 Less: Current portion (427 ) (916 ) Non-current net investment in sales-type leases $ 297 $ 373 There were no allowances for doubtful accounts on these leases as of December 31, 2018 and 2017 . There is no guaranteed or unguaranteed residual value on the leased equipment. The current and non-current net investments in sales-types leases are reported as components of the consolidated balance sheet captions "other receivables" and "other long-term assets", respectively.
Future Minimum Lease Payments for sales-type Leases	The minimum lease payments expected for future years under sales-type leases as of December 31, 2018 were as follows: (in thousands) Future lease payments 2019 $ 1,145 2020 736 2021 205 2022 25 Total $ 2,111
Accrued Liabilities	Accrued payroll and other current liabilities December 31, (in thousands) 2018 2017 Payroll and related expenses $ 7,241 $ 9,569 Accrued payables 2,115 1,801 Deferred rent, current portion 376 271 Lease financing, current portion 956 832 Product warranty 376 353 Customer prepayments 629 1,084 Sales and use tax payable 379 505 Other 813 274 Total accrued payroll and other current liabilities $ 12,885 $ 14,689
Product Warranty Disclosure	A reconciliation of the changes in the Company’s warranty reserve for the years ended December 31, 2018 , 2017 and 2016 is as follows: Years ended December 31, (in thousands) 2018 2017 2016 Warranty balance at the beginning of the period $ 353 $ 596 $ 806 Warranty expense accrued for shipments during the period 468 503 757 Changes in estimate related to pre-existing warranties (223 ) (450 ) (537 ) Warranty settlements made (222 ) (296 ) (430 ) Total product warranty $ 376 $ 353 $ 596
Schedule of Product Warranty Liability	A reconciliation of the changes in the Company’s warranty reserve for the years ended December 31, 2018 , 2017 and 2016 is as follows: Years ended December 31, (in thousands) 2018 2017 2016 Warranty balance at the beginning of the period $ 353 $ 596 $ 806 Warranty expense accrued for shipments during the period 468 503 757 Changes in estimate related to pre-existing warranties (223 ) (450 ) (537 ) Warranty settlements made (222 ) (296 ) (430 ) Total product warranty $ 376 $ 353 $ 596

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	Future minimum lease payments at December 31, 2018 under non-cancelable operating leases are as follows: (in thousands) Operating leases 2019 $ 2,224 2020 2,077 2021 1,835 2022 612 2023 35 Total minimum lease payments $ 6,783

Common stock (Tables)

Common stock (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Reserved Shares for Issuance	At December 31, 2018 , the Company has 2,377,888 shares of common stock reserved for issuance under stock option plans.
Schedule of Stock Option Activity	The following table summarizes the combined stock option activity under the 2000 Plan, the 2006 Plan and the 2012 Plan and non-plan stock option agreements: Options outstanding Number of options Weighted average exercise price Weighted average remaining contractual term Aggregate intrinsic value (in years) (in thousands) Outstanding at December 31, 2017 1,332,063 $ 13.48 5.36 $ 22,298 Options granted — — Options exercised (531,788 ) 13.79 Options canceled (2,774 ) 4.97 Outstanding at December 31, 2018 797,501 $ 13.31 4.71 $ 20,767 Options vested and expected to vest as of December 31, 2018 797,501 $ 13.31 4.71 $ 20,767 Options vested and exercisable as of December 31, 2018 788,546 $ 13.35 4.69 $ 20,502
Options, Grants in Period, Wtd Avg Grant Date Fair Value	No options were granted during the years ended December 31, 2018 and 2017. Further information regarding the value of employee options vested and exercised during the years ended December 31, 2018 , 2017 and 2016 is set forth below. Years ended December 31, (in thousands) 2018 2017 2016 Intrinsic value of options exercised during period $ 10,243 $ 18,603 $ 7,816
Schedule of Valuation Assumptions for Stock Options
Schedule of Valuation Assumptions for ESPP	The Company uses the Black-Scholes option-pricing model to calculate the fair value of periodic ESPP offerings on their offer date. The following assumptions were used for each respective period for the ESPP: Years ended December 31, 2018 2017 2016 Expected term (in years) 0.5 0.5 0.5 Volatility 33.0% - 37.8% 29.0% - 32.0% 32.0% - 41.5% Risk-free interest rate 2.09% - 2.51% 0.61% - 1.39% 0.33% - 0.61% Dividend yield 0.0% 0.0% 0.0%
Summary of the restricted stock activty	A summary of the restricted stock activity for the year ended December 31, 2018 is presented below: Restricted Stock Units Number of shares Weighted Average Grant Date Fair Value per Share Outstanding at December 31, 2017 2,045,589 $ 18.84 Granted 868,956 26.29 Vested (979,074 ) 17.19 Forfeited (128,291 ) 21.45 Outstanding at December 31, 2018 1,807,180 $ 23.13
Schedule of Share-based Comp Allocation of Period Costs	The following table presents the allocation of stock-based compensation expense: Years ended December 31, (in thousands) 2018 2017 2016 Cost of revenue $ 3,614 $ 2,871 $ 1,268 Research and development 2,976 2,122 1,072 Sales and marketing 6,560 6,563 4,486 General and administrative 7,814 6,640 4,179 Total stock-based compensation $ 20,964 $ 18,196 $ 11,005

Segments (Tables)

Segments (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Summary of the operating segments	The following table presents a summary of the operating segments: Years ended December 31, (in thousands) 2018 2017 2016 * As Adjusted * As Adjusted Revenue Product $ 97,447 $ 91,585 $ 74,235 Service 82,183 74,404 57,791 Total revenue 179,630 165,989 132,026 Cost of revenue Product 27,425 27,244 22,788 Service 40,318 37,683 26,287 Total cost of revenue 67,743 64,927 49,075 Gross profit Product 70,022 64,341 51,447 Service 41,865 36,721 31,504 Total gross profit 111,887 101,062 82,951 Operating expenses 118,192 111,762 94,039 (Loss) income from operations (6,305 ) (10,700 ) (11,088 ) Interest income (expense), net and other (3,720 ) 562 217 Loss before income taxes $ (10,025 ) $ (10,138 ) $ (10,871 )
Summary of revenue by product line	The following tables present the Company’s revenue by product line, as well as revenue and long-lived assets by geographic region. Years ended December 31, * As Adjusted * As Adjusted (in thousands) 2018 2017 2016 Revenue Product Device $ 60,130 $ 61,746 $ 50,614 Software 37,317 29,839 23,621 Total product 97,447 91,585 74,235 Service Maintenance and support 62,267 52,342 43,408 Professional services and training 19,916 22,062 14,383 Total service 82,183 74,404 57,791 Total revenue $ 179,630 $ 165,989 $ 132,026
Schedule of revenue by geographic region	The Company’s revenue by geographic region, based on customer location, is summarized as follows: Years ended December 31, * As Adjusted * As Adjusted (in thousands) 2018 2017 2016 Revenue United States $ 161,338 $ 148,993 $ 118,278 International 18,292 16,996 13,748 Total revenue $ 179,630 $ 165,989 $ 132,026
Schedule of Geographic Disclosure of Long-Lived Assets	The Company’s tangible long-lived assets by geographic region, consisting of net property and equipment, are summarized as follows: December 31, (in thousands) 2018 2017 2016 Property and equipment, net United States $ 6,265 $ 4,621 $ 5,448 International 1,203 1,130 446 Total property and equipment, net $ 7,468 $ 5,751 $ 5,894

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Components of income (loss) before income tax	The components of loss before income taxes are as follows: Years ended December 31, (in thousands) 2018 2017 2016 United States $ (10,852 ) $ (10,930 ) $ (11,498 ) International 827 792 627 Total loss before income taxes $ (10,025 ) $ (10,138 ) $ (10,871 )
Components of the provision (benefit) for income taxes	The components of the provision for income taxes are as follows: Years ended December 31, (in thousands) 2018 2017 2016 Current Federal $ — $ (10 ) $ — State 53 54 36 Foreign 368 324 194 421 368 230 Deferred Federal (822 ) 311 334 State 99 119 26 Foreign (49 ) (39 ) (61 ) (772 ) 391 299 Total income tax provision (benefit) $ (351 ) $ 759 $ 529
Reconciliation of the provision for income taxes at the statutory rate	Reconciliation of the provision for income taxes at the statutory rate to the Company’s provision for income tax is as follows: Years ended December 31, (in thousands) 2018 2017 2016 U.S. federal (tax benefit) provision at statutory rate $ (2,105 ) $ (4,576 ) $ (5,691 ) State (tax benefit) income taxes, net of federal benefit (373 ) (437 ) (574 ) Foreign income taxes at rates other than the US rate 92 (21 ) (94 ) Stock-based compensation (3,503 ) (8,373 ) 581 Change in valuation allowance 4,710 (6,023 ) 6,657 Non-deductible executive compensation 2,418 1,624 — Rate differential impact on Tax Cuts and Jobs Act — 18,975 — Research and development credits (994 ) (602 ) (449 ) Indefinite net operating losses carryforward (1,470 ) — — Other 874 192 99 Total $ (351 ) $ 759 $ 529
Deferred tax assets and liabilities	Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The following table presents the significant components of the Company’s deferred tax assets and liabilities for the periods presented: December 31, (in thousands) 2018 2017 Deferred tax assets Net operating loss carryforward $ 29,798 $ 27,289 Research and development credits 6,840 5,826 Depreciation and amortization 3,007 2,082 Reserves and accruals 9,661 10,242 Total deferred tax assets 49,306 45,439 Valuation allowance (40,070 ) (45,255 ) Net deferred tax assets 9,236 184 Deferred tax liabilities - convertible senior notes (7,503 ) — Deferred tax liabilities - other (2,208 ) (1,437 ) Net deferred tax liabilities $ (475 ) $ (1,253 )
Valuation allowance for DTA rollforward [Table Text Block]	The following table displays by contributing factor the changes in the valuation allowance for deferred tax assets since January 1, 2017: Years Ended December 31, (in thousands) 2018 2017 2016 Balance at the beginning of the period $ 45,255 $ 42,339 $ 30,072 Net operating loss carryforwards generated (utilization) 2,509 3,050 5,049 R&D tax credit increase 1,014 1,121 1,345 Depreciation and amortization increase 925 237 1,195 Reserves and accruals increase (decrease) (581 ) (1,479 ) 4,821 Deferred tax assets decrease (increase) (9,052 ) (13 ) (143 ) Balance at the end of the period $ 40,070 $ 45,255 $ 42,339
Changes in the unrecognized tax benefits	The following table reflects changes in the unrecognized tax benefits since January 1, 2017: Years ended December 31, (in thousands) 2018 2017 Gross amount of unrecognized tax benefits as of the beginning of the period $ 1,673 $ 1,458 Decreases related to prior year tax provisions 7 — Increases related to current year tax provisions 251 215 Gross amount of unrecognized tax benefits as of the end of the period $ 1,931 $ 1,673

Business Acquisitions (Tables)

Business Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2018
Business Acquisition [Line Items]
Schedule of Finite-Lived Intangible Assets Acquired	The table below shows the valuation of the intangible assets acquired from Extension Healthcare along with their estimated useful lives: (in thousands, except for useful lives) Fair value acquired Useful life (years) Customer relationships $ 8,400 8 Developed technology 6,400 3 Trademarks 1,000 3 Backlog 1,400 3 Total intangible assets $ 17,200
Business Acquisition, Pro Forma Information	Year Ended (in thousands) December 31, 2016 Revenues $ 134,330 Net loss $ (31,787 ) Net loss per share attributable to Vocera Basic and diluted $ (1.18 )
Extension Healthcare
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	(in thousands) Fair value of net assets acquired Accounts receivable, net of allowance $ 1,569 Prepaid expenses and other current assets 774 Property and equipment, net 48 Intangibles assets, net 17,200 Goodwill 39,258 Total assets 58,849 Accounts payable (149 ) Accrued payroll and other current liabilities (1,984 ) Deferred revenue, current (2,992 ) Deferred revenue, long-term (1,224 ) Total liabilities assumed (6,349 ) Net assets acquired $ 52,500
Net assets of mVisum, Inc. [Member]
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed
Prana Technologies [Member]
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed

Quarterly results of operatio_2

Quarterly results of operations (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information [Table Text Block]	14. Quarterly results of operations (unaudited) The following tables present certain unaudited consolidated quarterly financial information for each of the eight quarters ended December 31, 2018 . This quarterly information has been prepared on the same basis as the consolidated financial statements and includes all adjustments necessary to state fairly the information for the periods presented. (In thousands, except per share data) Quarters Ended 2018 March 31, June 30, September 30, December 31, Total revenue $ 40,242 $ 42,686 $ 47,822 $ 48,880 Gross profit $ 23,901 $ 25,651 $ 31,138 $ 31,197 Net loss $ (4,770 ) $ (3,554 ) $ (249 ) $ (1,101 ) Net loss attributable to common stockholders $ (4,770 ) $ (3,554 ) $ (249 ) $ (1,101 ) Net loss per share attributable to common stockholders: Basic and diluted $ (0.24 ) $ (0.26 ) $ (0.10 ) $ (0.04 ) Weighted average shares used to compute net loss per share attributable to common stockholders: Basic and diluted 29,476 29,867 29,861 30,592 Quarters Ended 2017 March 31, June 30, September 30, December 31, Total revenue $ 36,626 $ 39,658 $ 45,585 $ 44,120 Gross profit $ 21,062 $ 22,889 $ 29,136 $ 27,975 Net income (loss) $ (6,650 ) $ (6,012 ) $ 1,391 $ 374 Net income (loss) attributable to common stockholders $ (6,650 ) $ (6,012 ) $ 1,391 $ 374 Net loss per share attributable to common stockholders: Basic $ (0.24 ) $ (0.21 ) $ 0.05 $ 0.01 Diluted $ (0.24 ) $ (0.21 ) $ 0.05 $ 0.01 Weighted average shares used to compute net loss per common share: Basic 27,751 28,422 29,130 29,317 Diluted 27,751 28,422 30,473 30,704

Convertible Senior Notes - Conv

Convertible Senior Notes - Convertible Notes and Options (Details) $ / shares in Units, shares in Millions	1 Months Ended	2 Months Ended	12 Months Ended
	May 31, 2018USD ($)day$ / sharesshares	Jun. 30, 2018USD ($)	Dec. 31, 2018USD ($)$ / shares	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2018USD ($)
Debt Instrument [Line Items]
Proceeds from issuance of convertible senior notes, net of issuance costs			$ 138,854,000	$ 0	$ 0
Net carrying amount			110,540,000	0
Total interest expense			5,241,000	0	0
Capped Calls, initial strike price (in dollars per share) | $ / shares	$ 32.25
Capped Calls, initial cap price (in dollars per share) | $ / shares	$ 38.94
Capped Calls, number of shares covered | shares	4.5
Payments To Purchase Capped Calls	$ 8,900,000		8,907,000	$ 0	$ 0
Convertible Debt | Convertible Senior Notes at 1.50%
Debt Instrument [Line Items]
Aggregate principal amount	$ 143,750,000		143,750,000
Stated interest rate	1.50%
Proceeds from issuance of convertible senior notes, net of issuance costs	$ 138,900,000
Unamortized debt discount			(29,846,000)
Unamortized issuance costs			(3,364,000)
Net carrying amount			110,540,000
Convertible Debt | Convertible Senior Notes At 1.50%, Option Portion
Debt Instrument [Line Items]
Aggregate principal amount	$ 18,750,000
Stated interest rate	1.50%
Convertible debt, conversion price (in dollars per share) | $ / shares	$ 32.25
Denominator in calculation of trading price	$ 1,000
Conditional cash repurchase, percent of principal	100.00%
Carrying amount of the equity component	$ 33,400,000		33,350,000			$ 33,350,000
Debt discount effective interest rate		7.60%
Amortization of debt issuance costs		$ 4,900,000	395,000
Amortization of debt issuance costs, liability component		3,800,000
Amortization of debt issuance costs, equity component		$ 1,100,000
Issuance costs						(1,136,000)
Net carrying amount			32,214,000
Estimated fair value of the Notes			$ 210,600,000
Denominator in closing price calculation						$ 100
If-converted value, share price (in dollars per share) | $ / shares			$ 39.35
If-converted value of the Notes			$ 175,400,000
Contractual interest expense			1,342,000
Amortization of debt discount			3,504,000
Total interest expense			$ 5,241,000
Convertible Debt | Convertible Senior Notes At 1.50%, Option Portion | Maximum
Debt Instrument [Line Items]
Convertible debt, threshold trading days | day	20
Convertible debt, threshold consecutive trading days | day	30
Percent of conversion price triggering conversion feature	130.00%
Convertible Debt | Convertible Senior Notes At 1.50%, Option Portion | Minimum
Debt Instrument [Line Items]
Convertible debt, threshold trading days | day	5
Convertible debt, threshold consecutive trading days | day	10
Percent of conversion price triggering conversion feature	98.00%

Revenue, deferred revenue, an_2

Revenue, deferred revenue, and deferred commissions - Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Other receivables	$ 4,148	$ 1,331
Deferred commissions		10,301
Deferred revenue, current	44,053	40,734
Deferred revenue, long-term	14,579	14,417
Total deferred revenue	58,632	55,151	$ 49,717
Stockholders' equity	$ 162,867	128,000
As Reported
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Other receivables		1,170
Deferred commissions		0
Deferred revenue, current		47,276
Deferred revenue, long-term		16,438
Total deferred revenue		63,714
Stockholders' equity		108,975
Accounting Standards Update 2014-09 | Impact of Adoption
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Other receivables		161
Deferred commissions		10,301
Deferred revenue, current		(6,542)
Deferred revenue, long-term		(2,021)
Total deferred revenue		(8,563)
Stockholders' equity		$ 19,025

Convertible Senior Notes - Capp

Convertible Senior Notes - Capped Calls (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	1 Months Ended	12 Months Ended
	May 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2018
Debt Instrument [Line Items]
Capped Calls, initial strike price (in dollars per share)	$ 32.25
Capped Calls, initial cap price (in dollars per share)	$ 38.94
Capped Calls, number of shares covered	4.5
Payment for purchase of capped calls	$ (8,900)	$ (8,907)	$ 0	$ 0
Issuance costs		(1,136)
Convertible Debt | Convertible Senior Notes At 1.50%, Option Portion
Debt Instrument [Line Items]
Carrying amount of the equity component	$ 33,400	33,350			$ 33,350
Carrying amount of equity component, net of capped calls		$ 23,307

Revenue, deferred revenue, an_3

Revenue, deferred revenue, and deferred commissions - Consolidated Statement of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue
Total revenue	$ 48,880	$ 47,822	$ 42,686	$ 40,242	$ 44,120	$ 45,585	$ 39,658	$ 36,626	$ 179,630	$ 165,989	$ 132,026
Gross Profit	31,197	31,138	25,651	23,901	27,975	29,136	22,889	21,062	111,887	101,062	82,951
Operating expenses									118,192	111,762	94,039
Loss from Operations									(6,305)	(10,700)	(11,088)
Net loss	$ (1,101)	$ (249)	$ (3,554)	$ (4,770)	$ 374	$ 1,391	$ (6,012)	$ (6,650)	(9,674)	$ (10,897)	$ (11,400)
Earnings Per Share, Basic and Diluted					$ 0.01	$ 0.05	$ (0.21)	$ (0.24)		$ (0.38)	$ (0.42)
Earnings Per Share, Diluted					$ 0.01	$ 0.05	$ (0.21)	$ (0.24)		$ (0.38)	$ (0.42)
As Reported
Revenue
Total revenue										$ 162,548	$ 127,696
Gross Profit										97,621	78,621
Operating expenses										111,641	95,576
Loss from Operations										(14,020)	(16,955)
Net loss										$ (14,217)	$ (17,267)
Earnings Per Share, Basic and Diluted										$ (0.50)	$ (0.64)
Earnings Per Share, Diluted										$ (0.50)	$ (0.64)
Accounting Standards Update 2014-09 | As Reported
Revenue
Total revenue										$ 3,441	$ 4,330
Accounting Standards Update 2014-09 | Impact of Adoption
Revenue
Total revenue										3,441	4,330
Gross Profit										3,441	4,330
Operating expenses										121	(1,537)
Loss from Operations										3,320	5,867
Net loss										$ 3,320	$ 5,867
Earnings Per Share, Basic and Diluted										$ 0.12	$ 0.22
Earnings Per Share, Diluted										$ 0.12	$ 0.22
Professional Services and Training [Member] | As Reported
Revenue
Total revenue										$ 21,141	$ 13,591
Professional Services and Training [Member] | Accounting Standards Update 2014-09 | As Reported
Revenue
Total revenue										921	792
Software [Member] | As Reported
Revenue
Total revenue										27,996	20,606
Software [Member] | Accounting Standards Update 2014-09 | Impact of Adoption
Revenue
Total revenue										1,843	3,015
Device [Member] | As Reported
Revenue
Total revenue										60,869	50,061
Device [Member] | Accounting Standards Update 2014-09 | Impact of Adoption
Revenue
Total revenue										877	553
Product
Revenue
Total revenue									97,447	91,585	74,235
Product | As Reported
Revenue
Total revenue										88,865	70,667
Product | Accounting Standards Update 2014-09 | Impact of Adoption
Revenue
Total revenue										2,720	3,568
Service
Revenue
Total revenue									82,183	74,404	57,791
Service | As Reported
Revenue
Total revenue										73,683	57,029
Service | Accounting Standards Update 2014-09 | As Reported
Revenue
Total revenue										721	762
Maintenance and Support [Member] | As Reported
Revenue
Total revenue										52,542	43,438
Maintenance and Support [Member] | Accounting Standards Update 2014-09 | As Reported
Revenue
Total revenue										(200)	(30)
Product Segment | Software [Member]
Revenue
Total revenue									37,317	29,839	23,621
Product Segment | Device [Member]
Revenue
Total revenue									60,130	61,746	50,614
Service Segment
Revenue
Total revenue									82,183	74,404	57,791
Service Segment | Professional Services and Training [Member]
Revenue
Total revenue									19,916	22,062	14,383
Service Segment | Maintenance and Support [Member]
Revenue
Total revenue									$ 62,267	$ 52,342	$ 43,408

The Company and Summary of Si_4

The Company and Summary of Significant Accounting Policies Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Sale of Stock [Line Items]
Revenue from Related Parties	$ 400	$ 400	$ 400
Maintenance services revenue recognition period	1 year
Accumulated deficit	$ (132,346)	(122,672)
Cash, Cash Equivalents, and Short-term Investments	221,200
Capitalized Computer Software, Additions	$ 700	$ 300	$ 0
No. of revenue customers with 10% or greater concentration	0	0	0
No of Acct Rec customers with 10% or greater concentration	0	0
Impairment of Intangibles (Excl. Goodwill)	$ 0	$ 0	$ 0
Goodwill, Impairment Loss	$ 0	0	0
No of operating segments	2
Deferred Tax Assets, Valuation Allowance	$ 40,070	45,255	42,339	$ 30,072
Maximum
Sale of Stock [Line Items]
Professional service revenue recognition period	2 months 23 days
Product Liability, Warranty Period	3 years
Minimum
Sale of Stock [Line Items]
Professional service revenue recognition period	14 days
Product Liability, Warranty Period	1 year
Restricted stock units
Sale of Stock [Line Items]
Vesting percentage on 1st anniversary of grant (percent)	33.33%
Vesting percentage on 2nd anniversary of grant (percent)	33.33%
Vesting percentage on 3rd anniversary of grant (percent)	33.34%
Sharon O'Keefe [Member] | Service | University of Chicago Medical Center [Member]
Sale of Stock [Line Items]
Related Party Transaction, Amounts of Transaction	$ 400	$ 400	$ 300
Property and Equipment, excluding LHI and major ERP [Member]
Sale of Stock [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Not major ERP implementation [Member] | Software and Software Development Costs [Member]
Sale of Stock [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Major ERP implementation [Member] | Software and Software Development Costs [Member]
Sale of Stock [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Accounts Receivable [Member]
Sale of Stock [Line Items]
Concentration Risk, Percentage	26.40%	26.30%

Revenue, deferred revenue, an_4

Revenue, deferred revenue, and deferred commissions - Cash Flows From Operating Activities (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net loss	$ (1,101)	$ (249)	$ (3,554)	$ (4,770)	$ 374	$ 1,391	$ (6,012)	$ (6,650)	$ (9,674)	$ (10,897)	$ (11,400)
Other receivables									(2,810)	(120)	120
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Deferred commissions									(2)	121	(1,538)
Deferred revenue									$ 3,482	5,434	6,863
As Reported
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net loss										(14,217)	(17,267)
Other receivables										41	120
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Deferred commissions										0	0
Deferred revenue										8,714	11,192
Impact of Adoption
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Other receivables										(161)	0
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Deferred commissions										121	(1,538)
Deferred revenue										(3,280)	(4,329)
Accounting Standards Update 2014-09 | Impact of Adoption
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net loss										$ 3,320	$ 5,867

The Company and Summary of Si_5

The Company and Summary of Significant Accounting Policies Sales type lease data (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
sales type capital leases transfered to banks	$ 400	$ 900
financing liability for future executory services on transfered leases	300	700
Capital Leases, Net Investment in Sales Type Leases	$ 724	$ 1,289

Revenue, deferred revenue, an_5

Revenue, deferred revenue, and deferred commissions - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	$ 48,880	$ 47,822	$ 42,686	$ 40,242	$ 44,120	$ 45,585	$ 39,658	$ 36,626	$ 179,630	$ 165,989	$ 132,026
Product
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue									97,447	91,585	74,235
Product Segment | Software [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue									37,317	29,839	23,621
Product Segment | Device [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue									60,130	61,746	50,614
Service Segment
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue									82,183	74,404	57,791
Service Segment | Maintenance and Support [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue									62,267	52,342	43,408
Service Segment | Professional Services and Training [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue									19,916	22,062	14,383
As Reported
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										162,548	127,696
As Reported | Software [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										27,996	20,606
As Reported | Product
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										88,865	70,667
As Reported | Device [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										60,869	50,061
As Reported | Maintenance and Support [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										52,542	43,438
As Reported | Professional Services and Training [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										21,141	13,591
As Reported | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										3,441	4,330
As Reported | Accounting Standards Update 2014-09 | Maintenance and Support [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										(200)	(30)
As Reported | Accounting Standards Update 2014-09 | Professional Services and Training [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										921	792
Impact of Adoption | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										3,441	4,330
Impact of Adoption | Accounting Standards Update 2014-09 | Software [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										1,843	3,015
Impact of Adoption | Accounting Standards Update 2014-09 | Product
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										2,720	3,568
Impact of Adoption | Accounting Standards Update 2014-09 | Device [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										877	553
United States
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue									161,338	148,993	118,278
United States | As Reported
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										145,548	114,160
United States | Impact of Adoption | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										3,445	4,118
International
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue									$ 18,292	16,996	13,748
International | As Reported
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										17,000	13,536
International | Impact of Adoption | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										$ (4)	$ 212

The Company and Summary of Si_6

The Company and Summary of Significant Accounting Policies Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in Allowance for Doubtful Accounts [Roll Forward]
Allowance—beginning of period	$ 0	$ 0	$ (451)
Provisions for bad debts	0	0	0
Allowance for Loan and Lease Loss, Recovery of Bad Debts	0	0	0
Write-offs and other	0	0	451
Allowance—end of period	$ 0	$ 0	$ 0

Revenue, deferred revenue, an_6

Revenue, deferred revenue, and deferred commissions - Significant Changes in Deferred Commissions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Change in Contract with Customer, Asset [Roll Forward]
Beginning balance	$ 10,422
Additions	8,327	$ 8,201
Commissions Recognized	(8,325)	(8,322)
Ending balance	$ 10,301	$ 10,422

Revenue, deferred revenue, an_7

Revenue, deferred revenue, and deferred commissions - Significant Changes in Deferred Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Change in Contract with Customer, Liability [Roll Forward]
Beginning balance	$ 49,717
Additions	77,969	$ 69,519
Revenue Recognized	(74,488)	(64,085)
Ending balance	$ 55,151	$ 49,717

Revenue, deferred revenue, an_8

Revenue, deferred revenue, and deferred commissions - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue from Contract with Customer [Abstract]
Deferred commissions			$ 10,301
Payment terms on invoiced amounts	30 days
Contract assets		$ 2,400	200
Deferred commissions		$ 10,303	10,301	$ 10,422
Percentage of deferred commissions to be recognized as commission expense in the next 12 months		46.60%
Revenue recognized pertaining to amounts deferred as of December 31, 2017		$ 42,600	$ 41,500
Deferred revenue and backlog		$ 120,400
Percentage of deferred revenue to be recognized over the next 12 months		62.00%

The Company and Summary of Si_7

The Company and Summary of Significant Accounting Policies Recently adopted accounting pronouncements (Details) - Subsequent Event [Member] - Accounting Standards Update 2016-02 [Member] $ in Millions	Jan. 01, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease asset	$ 5.1
Lease liability	$ 6.7

The Company and Summary of Si_8

The Company and Summary of Significant Accounting Policies Recently adopted accounting principles (Details) $ in Thousands	Dec. 31, 2017USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity component of convertible senior notes, net	$ 0

The Company and Summary of Si_9

The Company and Summary of Significant Accounting Policies - Revenue from contract with customers (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	$ 48,880	$ 47,822	$ 42,686	$ 40,242	$ 44,120	$ 45,585	$ 39,658	$ 36,626	$ 179,630	$ 165,989	$ 132,026
Prepaid expenses and other current assets	4,691				3,957				4,691	3,957
Gross Profit	31,197	31,138	25,651	23,901	27,975	29,136	22,889	21,062	111,887	101,062	82,951
Operating Expenses									118,192	111,762	94,039
Loss from Operations									(6,305)	(10,700)	(11,088)
Net loss	(1,101)	$ (249)	$ (3,554)	$ (4,770)	374	$ 1,391	$ (6,012)	$ (6,650)	$ (9,674)	$ (10,897)	$ (11,400)
Basic and diluted									$ (0.32)	$ (0.38)	$ (0.42)
Other receivables	4,148				1,331				$ 4,148	$ 1,331
Deferred commissions					10,301					10,301
Deferred revenue, current	44,053				40,734				44,053	40,734
Deferred revenue, long-term	14,579				14,417				14,579	14,417
Total deferred revenue	58,632				55,151				58,632	55,151	$ 49,717
Stockholders' equity	$ 162,867				128,000				$ 162,867	128,000
As Reported
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										162,548	127,696
Gross Profit										97,621	78,621
Operating Expenses										111,641	95,576
Loss from Operations										(14,020)	(16,955)
Net loss										(14,217)	(17,267)
Basic and diluted									$ (0.32)
Other receivables					1,170					1,170
Deferred commissions					0					0
Deferred revenue, current					47,276					47,276
Deferred revenue, long-term					16,438					16,438
Total deferred revenue					63,714					63,714
Stockholders' equity					108,975					108,975
As Reported | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										3,441	4,330
Impact of Adoption | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										3,441	4,330
Gross Profit										3,441	4,330
Operating Expenses										121	(1,537)
Loss from Operations										3,320	5,867
Net loss										3,320	5,867
Other receivables					161					161
Deferred commissions					10,301					10,301
Deferred revenue, current					(6,542)					(6,542)
Deferred revenue, long-term					(2,021)					(2,021)
Total deferred revenue					(8,563)					(8,563)
Stockholders' equity					$ 19,025					19,025
Product
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue									$ 97,447	91,585	74,235
Product | As Reported
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										88,865	70,667
Product | Impact of Adoption | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										2,720	3,568
Service
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue									$ 82,183	74,404	57,791
Service | As Reported
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										73,683	57,029
Service | As Reported | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue										$ 721	$ 762

Fair value of financial instr_3

Fair value of financial instruments Schedule of assets and liabilities measured at fair value on a recurring basis, by level (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets, Fair Value Disclosure [Abstract]
Fair value	$ 34,276	$ 28,726
Fair value	186,894	52,507
U.S. government agency securities
Assets, Fair Value Disclosure [Abstract]
Fair value	3,325	8,648
U.S. Treasury securities
Assets, Fair Value Disclosure [Abstract]
Fair value	2,730	5,561
Corporate debt securities
Assets, Fair Value Disclosure [Abstract]
Fair value	166,759	37,097
Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Total assets measured at fair value	193,121	56,172
Fair Value, Measurements, Recurring | Level 1
Assets, Fair Value Disclosure [Abstract]
Total assets measured at fair value	3,737	3,232
Fair Value, Measurements, Recurring | Level 2
Assets, Fair Value Disclosure [Abstract]
Total assets measured at fair value	189,384	52,940
Fair Value, Measurements, Recurring | U.S. government agency securities
Assets, Fair Value Disclosure [Abstract]
Fair value	3,325	8,648
Fair Value, Measurements, Recurring | U.S. government agency securities | Level 1
Assets, Fair Value Disclosure [Abstract]
Fair value	0	0
Fair Value, Measurements, Recurring | U.S. government agency securities | Level 2
Assets, Fair Value Disclosure [Abstract]
Fair value	3,325	8,648
Fair Value, Measurements, Recurring | U.S. Treasury securities
Assets, Fair Value Disclosure [Abstract]
Fair value	2,730	5,561
Fair Value, Measurements, Recurring | U.S. Treasury securities | Level 1
Assets, Fair Value Disclosure [Abstract]
Fair value	0	0
Fair Value, Measurements, Recurring | U.S. Treasury securities | Level 2
Assets, Fair Value Disclosure [Abstract]
Fair value	2,730	5,561
Fair Value, Measurements, Recurring | Corporate debt securities
Assets, Fair Value Disclosure [Abstract]
Fair value	166,759	37,530
Fair Value, Measurements, Recurring | Corporate debt securities | Level 1
Assets, Fair Value Disclosure [Abstract]
Fair value	0	0
Fair Value, Measurements, Recurring | Corporate debt securities | Level 2
Assets, Fair Value Disclosure [Abstract]
Fair value	166,759	37,530
Fair Value, Measurements, Recurring | Money Market Funds [Member]
Assets, Fair Value Disclosure [Abstract]
Fair value	3,737	3,232
Fair Value, Measurements, Recurring | Money Market Funds [Member] | Level 1
Assets, Fair Value Disclosure [Abstract]
Fair value	3,737	3,232
Fair Value, Measurements, Recurring | Money Market Funds [Member] | Level 2
Assets, Fair Value Disclosure [Abstract]
Fair value	0	0
Fair Value, Measurements, Recurring | Commercial paper
Assets, Fair Value Disclosure [Abstract]
Fair value	16,570	1,201
Fair Value, Measurements, Recurring | Commercial paper | Level 1
Assets, Fair Value Disclosure [Abstract]
Fair value	0	0
Fair Value, Measurements, Recurring | Commercial paper | Level 2
Assets, Fair Value Disclosure [Abstract]
Fair value	$ 16,570	$ 1,201

Cash, Cash Equivalents and Sh_3

Cash, Cash Equivalents and Short-term Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Cash and cash equivalents:
Amortized Cost	$ 34,277	$ 28,726
Unrealized Gains	0	0
Unrealized Losses	(1)	0
Fair value	34,276	28,726
Short-Term Investments:
Amortized Cost	187,280	52,642
Unrealized Gains	28	1
Unrealized Losses	(414)	(136)
Fair value	186,894	52,507
Cash, Cash Equivalents, and Short-term Investments:
Amortized Cost	221,557	81,368
Fair value	221,170	81,233
Cash, Cash Equivalents And Short Term Investments, Accumulated Gross Unrealized Gain	28	1
Cash, Cash Equivalents And Short Term Investments, Accumulated Gross Unrealized Loss	415	136
Amortized Cost	34,277	28,726
U.S. Treasury securities
Short-Term Investments:
Amortized Cost	2,740	5,586
Unrealized Gains	0	0
Unrealized Losses	(10)	(25)
Fair value	2,730	5,561
U.S. government agency securities
Short-Term Investments:
Amortized Cost	3,339	8,678
Unrealized Gains	0	0
Unrealized Losses	(14)	(30)
Fair value	3,325	8,648
Commercial Paper, Not Included with Cash and Cash Equivalents [Member]
Short-Term Investments:
Amortized Cost	14,091	1,202
Unrealized Gains	0	0
Unrealized Losses	(11)	(1)
Fair value	14,080	1,201
Corporate debt securities
Short-Term Investments:
Amortized Cost	167,110	37,176
Unrealized Gains	28	1
Unrealized Losses	(379)	(80)
Fair value	166,759	37,097
Demand deposis and other cash
Cash and cash equivalents:
Amortized Cost	28,049	25,061
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair value	28,049	25,061
Cash, Cash Equivalents, and Short-term Investments:
Amortized Cost	28,049	25,061
Money Market Funds [Member]
Cash and cash equivalents:
Amortized Cost	3,737	3,232
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair value	3,737	3,232
Cash, Cash Equivalents, and Short-term Investments:
Amortized Cost	3,737	3,232
Commercial paper
Cash and cash equivalents:
Amortized Cost	2,491	0
Unrealized Gains	0	0
Unrealized Losses	(1)	0
Fair value	2,490	0
Cash, Cash Equivalents, and Short-term Investments:
Amortized Cost	2,491	0
Corporate debt securities
Cash and cash equivalents:
Amortized Cost	0	433
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair value	0	433
Cash, Cash Equivalents, and Short-term Investments:
Amortized Cost	$ 0	$ 433

Cash, Cash Equivalents and Sh_4

Cash, Cash Equivalents and Short-term Investments Classification by contractual maturity of cash, cash equivalents and short-term investments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Fair value	$ 34,276	$ 28,726
Fair value	186,894	52,507
Fair value	221,170	81,233
Maturity up to one year [Member]
Debt Securities, Available-for-sale [Line Items]
Fair value	34,276	28,726
Fair value	109,451	34,750
Fair value	143,727	63,476
maturity between 1 and 2 years [Member]
Debt Securities, Available-for-sale [Line Items]
Fair value	0	0
Fair value	77,443	17,757
Fair value	$ 77,443	$ 17,757

Income (loss) per share Schedul

Income (loss) per share Schedule of the computation of basic and diluted net income (loss) per share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Numerator:
Net loss	$ (1,101)	$ (249)	$ (3,554)	$ (4,770)	$ 374	$ 1,391	$ (6,012)	$ (6,650)	$ (9,674)	$ (10,897)	$ (11,400)
Net (loss) income attributable to common stockholders	$ (1,101)	$ (249)	$ (3,554)	$ (4,770)	$ 374	$ 1,391	$ (6,012)	$ (6,650)
Net Income (Loss) Available to Common Stockholders, Diluted									$ (9,674)	$ (10,897)	$ (11,400)
Denominator:
Weighted-average shares used to compute net loss per common share - basic and diluted					29,317	29,130	28,422	27,751	30,041	28,655	26,859
Weighted average shares used to compute diluted income (loss) per common share					30,704	30,473	28,422	27,751	30,041	28,655	26,859
Net loss per share
Basic and diluted									$ (0.32)	$ (0.38)	$ (0.42)

Income (loss) per share Sched_2

Income (loss) per share Schedule of antidilutive securities excluded from computation of earnings per share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Employee stock options, including ESPP [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,085	1,365
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			2,454
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,925	2,046	2,129

Goodwill and intangible asset_2

Goodwill and intangible assets Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	$ 14,870	$ 10,373
Finite-Lived Intangible Assets, Net	9,070
Intangible Assets, Gross (Excluding Goodwill)	23,940	23,940
Intangible assets, net	9,070	13,567
Goodwill [Abstract]
Goodwill	49,246	49,246
Impairment and Amortization [Abstract]
Goodwill, Impairment Loss	0	0	$ 0
Impairment of Intangibles (Excl. Goodwill)	0	0	0
Amortization expense	4,500	4,600	$ 1,400
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	10,920	10,920
Accumulated amortization	4,645	3,469
Finite-Lived Intangible Assets, Net	6,275	7,451
Technology-Based Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	10,050	10,050
Accumulated amortization	7,731	5,302
Finite-Lived Intangible Assets, Net	2,319	4,748
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,110	1,110
Accumulated amortization	831	497
Finite-Lived Intangible Assets, Net	279	613
Backlog
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,400	1,400
Accumulated amortization	1,203	650
Finite-Lived Intangible Assets, Net	197	750
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	460	460
Accumulated amortization	460	455
Finite-Lived Intangible Assets, Net	$ 0	$ 5
Minimum [Member] | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life (years)	7 years
Minimum [Member] | Technology-Based Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life (years)	3 years
Minimum [Member] | Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life (years)	3 years
Minimum [Member] | Backlog
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life (years)	3 years
Minimum [Member] | Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life (years)	2 years
Maximum [Member] | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life (years)	9 years
Maximum [Member] | Technology-Based Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life (years)	7 years
Maximum [Member] | Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life (years)	7 years
Maximum [Member] | Backlog
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life (years)	3 years
Maximum [Member] | Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life (years)	4 years
Product Segment
Goodwill [Abstract]
Goodwill	$ 41,200
Service Segment
Goodwill [Abstract]
Goodwill	$ 8,000

Goodwill and intangible asset_3

Goodwill and intangible assets Future amortization schedule (Details) $ in Thousands	Dec. 31, 2018USD ($)
Goodwill and intangible assets [Abstract]
2,017	$ 3,717
2,018	1,251
2,019	1,127
2,020	1,050
2,021	1,050
Thereafter	875
Finite-Lived Intangible Assets, Net	$ 9,070

Balance Sheet Components Invent

Balance Sheet Components Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Inventory, Net [Abstract]
Raw materials	$ 197	$ 4
Finished goods	4,153	2,811
Total inventories	$ 4,350	$ 2,815

Balance Sheet Components Proper

Balance Sheet Components Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	$ 20,753	$ 18,171
Less: Accumulated depreciation	(13,285)	(12,420)
Property and equipment, net	7,468	5,751	$ 5,894
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	10,433	8,832
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	2,246	1,764
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	5,183	4,794
Manufacturing tools and equipment
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	2,371	2,624
Construction in process
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	$ 520	$ 157

Balance Sheet Components Deprec

Balance Sheet Components Depreciation, depletion, amortization (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property-Equipment Deepreciation and amortization [Abstract]
Depreciation and amortization	$ 3.2	$ 3	$ 2.4

Balance Sheet Components Balanc

Balance Sheet Components Balance sheet components - investment in sales type leases (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Investment in Sales Type Leases
Capital Leases, Net Investment in Sales Type Leases, Minimum Payments to be Received	$ 2,111	$ 2,758
Capital Leases, Net Investment in Sales Type Leases, Deferred Income	(1,387)	(1,469)
Capital Leases, Net Investment in Sales Type Leases	724	1,289
Capital Leases, Lessor Balance Sheet, Net Investment in Sales Type Leases, Current	(427)	(916)
Capital Leases, Lessor Balance Sheet, Net Investment in Sales Type Leases, Noncurrent	$ 297	$ 373
Minimum
Lease Term [Abstract]
Lessor, Operating Lease, Term of Contract	3 years
Maximum
Lease Term [Abstract]
Lessor, Operating Lease, Term of Contract	4 years

Balance Sheet Components Bala_2

Balance Sheet Components Balance sheet components - sales type lease Future Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Lessors schedule of future minimum lease payments [Line Items]
Capital Leases, Future Minimum Payments Due, Next Twelve Months	$ 1,145
Capital Leases, Future Minimum Payments Due in Two Years	736
Capital Leases, Future Minimum Payments Due in Three Years	205
Capital Leases, Future Minimum Payments Due in Four Years	25
Capital Leases, Net Investment in Sales Type Leases, Minimum Payments to be Received	$ 2,111	$ 2,758

Balance Sheet Components Accrue

Balance Sheet Components Accrued Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Balance Sheet Components [Abstract]
Product Warranty Accrual, Payments	$ 222	$ 296	$ 430
Accrued Liabilities, Current [Abstract]
Payroll and related expenses	7,241	9,569
Accrued payables	2,115	1,801
Deferred rent, current portion	376	271
Lease financing, current portion	956	832
Product warranty	376	353
Customer Refund Liability, Current	629	1,084
Sales and use tax payable	379	505
Other	813	274
Total accrued payroll and other current liabilities	$ 12,885	$ 14,689

Balance Sheet Components Bala_3

Balance Sheet Components Balance sheet components Product Warranties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
movement in std product warranty liability [Roll Forward]
Warranty balance at the beginning of the period	$ 353		$ 806
Warranty expense accrued for shipments during the period	468	$ 503	757
Changes in estimate related to pre-existing warranties	(223)	(450)	(537)
Warranty settlements made	(222)	(296)	(430)
Current portion of warranty balance at the end of the period		353
Product Warranty Accrual	$ 376	$ 353	$ 596

Commitments Schedule of Future

Commitments Schedule of Future Minimum Rental Payments for Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Leases, Rent Expense, Net [Abstract]
Rent expense	$ 2,700	$ 2,600	$ 2,400
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2,017	2,224
2,018	2,077
2,019	1,835
2,020	612
2,021	35
Thereafter
Total minimum lease payments	6,783
Inventories
Unrecorded Unconditional Purchase Obligation [Line Items]
Non-cancelable purchase commitment with a third party manufacturer to purchase inventory	$ 11,100	$ 4,400

Common stock (Details)

Common stock (Details) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Common stock, shares authorized	100,000,000	100,000,000
Common stock, par value	$ 0.0003	$ 0.0003

Common stock (Reserved shares f

Common stock (Reserved shares for issuance of common stock) (Details)	Dec. 31, 2018shares
Options to purchase common stock
Class of Stock [Line Items]
Common stock (in shares)	2,377,888

Common stock (Incentive stock o

Common stock (Incentive stock option plans) (Details)	Dec. 31, 2018
Class of Stock [Line Items]
Number of equity incentive plans	4

Common stock (Options outstandi

Common stock (Options outstanding) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest [Abstract]
Options vested and expected to vest (Number of options)	797,501
Options vested and expected to vest (Wtd avg exercise price)	$ 13.31
Options vested and expected to vest (Wtd avg remaining contractual term)	4 years 8 months 17 days
Options vested and expected to vest (Aggregate intrinsic value)	$ 20,767
Options vested and exercisable (Number of options)	788,546
Options vested and exercisable (Wtd avg exercise price)	$ 13.35
Options vested and exercisable (Wtd avg remaining contractual term)	4 years 8 months 9 days
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized net compensation cost related to options	$ 100
Weighted average period (in years)	2 months 25 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Options, Outstanding, Beginning balance	1,332,063
Options granted	0
Options exercised	(531,788)
Number of Options, Outstanding, Ending balance	797,501	1,332,063
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Weighted Average Exercise Price, Outstanding, Beginning balance	$ 13.48
Wtd Avg Remaining Contractual Term, Options Outstanding	4 years 8 months 17 days	5 years 4 months 10 days
Options granted	$ 0
Options exercised	13.79
Weighted Average Exercise Price, Outstanding, Ending balance	$ 13.31	$ 13.48
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period	2,774
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 4.97
Share-based Compensation Arrangement by Share-based Payment Award, Options, Aggregate Intrinsic Value [Abstract]
Aggregate Intrinsic Value, Options Outstanding	$ 20,767	$ 22,298

Common stock (Fair value option

Common stock (Fair value option pricing model) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2017
Options - intrinsic value and grant date fair value [Abstract]
Options vested and exercisable (Aggregate intrinsic value)	$ 20,502
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%
Stock options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (years)			5 years 4 months 20 days
Expected Volatility Rate			41.30%
Risk-free interest rate			1.62%
Stock options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (years)			5 years 4 months 20 days
Expected Volatility Rate			41.80%
Risk-free interest rate			1.63%

Common stock (Employee options

Common stock (Employee options vested and exercised) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, Exercises in Period, Total Intrinsic Value	$ 10,243	$ 18,603	$ 7,816

Common stock (Restricted stock

Common stock (Restricted stock awards and restricted stock units) (Details) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options	$ 0
Outstanding, Number of Shares	1,807,180	2,045,589
Outstanding, Wtd Ag Grant Date Fair Value	$ 23.13	$ 18.84
Vesting percentage on 1st anniversary of grant (percent)	33.33%
Vesting percentage on 2nd anniversary of grant (percent)	33.33%
Vesting percentage on 3rd anniversary of grant (percent)	33.34%

Common stock (Summary of restri

Common stock (Summary of restricted stock activity) (Details) - Restricted Stock Units - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period (in years)	1 year 6 months 20 days
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding, Number of Shares	2,045,589
Granted, Number of Shares	868,956
Vested, Number of Shares	979,074
Forfeited, Number of Shares	128,291
Outstanding, Number of Shares	1,807,180
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Granted, Wtd Avg Grant Date Fair Value	$ 26.29
Vested, Wtd Avg Grant Date Fair Value	17.19
Forfeitured, Wtd Avg Grant Date Fair Value	21.45
Outstanding, Wtd Ag Grant Date Fair Value	$ 23.13	$ 18.84

Common stock (Nonemployee stock

Common stock (Nonemployee stock-based compensation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 20,964	$ 18,196	$ 11,005

Common stock (Recognized expens

Common stock (Recognized expenses nonemployee stock-based compensation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Goods and Nonemployee Services Transaction [Line Items]
Stock-based compensation expense	$ 20,964	$ 18,196	$ 11,005

Common stock (Common stock) Sha

Common stock (Common stock) Share-based compensation allocated to expense captions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 20,964	$ 18,196	$ 11,005
Cost of Sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	3,614	2,871	1,268
Research and Development Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	2,976	2,122	1,072
Selling and Marketing Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	6,560	6,563	4,486
General and Administrative Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 7,814	$ 6,640	$ 4,179

Common stock Common Stock (ESPP

Common stock Common Stock (ESPP B-S-M option pricing model assumptions) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
ESPP plan details [Abstract]
Stock Shares Issued During Period, ESPP	157,426	159,532
Two Thousand Twelve Employee Stcok Purchase Plan [Member] | Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%
ESPP plan details [Abstract]
ESPP-Maximum Annual Purchase by Employee, Percent	15.00%
Share-based Compensation Arrangements by Share-based Payment Award, Offering Period, Subsequent Offers	6 months
ESPP-Discount of market Price	85.00%
Share-based Comp, Per Share Wtd Avg Price of Shares Purchased	$ 20.77	$ 17.23
Common stock (in shares) reserved for ESPP	721,303
Two Thousand Twelve Employee Stcok Purchase Plan [Member] | Employee Stock [Member] | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (years)	6 months	6 months	6 months
Expected Volatility Rate	33.00%	29.00%	32.00%
Risk-free interest rate	2.09%	0.61%	0.33%
Two Thousand Twelve Employee Stcok Purchase Plan [Member] | Employee Stock [Member] | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (years)	6 months	6 months	6 months
Expected Volatility Rate	37.80%	32.00%	41.50%
Risk-free interest rate	2.51%	1.39%	0.61%

Segments Summary of the operati

Segments Summary of the operating segments (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments									2
Revenue
Total revenue	$ 48,880	$ 47,822	$ 42,686	$ 40,242	$ 44,120	$ 45,585	$ 39,658	$ 36,626	$ 179,630	$ 165,989	$ 132,026
Cost of revenue
Total cost of revenue									67,743	64,927	49,075
Gross Profit [Abstract]
Gross Profit, Goods									70,022	64,341	51,447
Gross Profit, Services									41,865	36,721	31,504
Gross profit	$ 31,197	$ 31,138	$ 25,651	$ 23,901	$ 27,975	$ 29,136	$ 22,889	$ 21,062	111,887	101,062	82,951
Operating expenses									118,192	111,762	94,039
Interest income (expense) and other											217
Loss before income taxes									$ (10,025)	$ (10,138)	$ (10,871)

Segments Summary of revenue by

Segments Summary of revenue by product line (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue from External Customer [Line Items]
Total revenue	$ 48,880	$ 47,822	$ 42,686	$ 40,242	$ 44,120	$ 45,585	$ 39,658	$ 36,626	$ 179,630	$ 165,989	$ 132,026
Product
Revenue from External Customer [Line Items]
Total revenue									97,447	91,585	74,235
Product Segment | Device [Member]
Revenue from External Customer [Line Items]
Total revenue									60,130	61,746	50,614
Product Segment | Software [Member]
Revenue from External Customer [Line Items]
Total revenue									37,317	29,839	23,621
Service Segment
Revenue from External Customer [Line Items]
Total revenue									82,183	74,404	57,791
Service Segment | Maintenance and Support [Member]
Revenue from External Customer [Line Items]
Total revenue									62,267	52,342	43,408
Service Segment | Professional Services and Training [Member]
Revenue from External Customer [Line Items]
Total revenue									$ 19,916	$ 22,062	$ 14,383

Segments Schedule of revenue by

Segments Schedule of revenue by geographic region (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Geographic Areas, Revenues from External Customers [Abstract]
Total revenue	$ 48,880	$ 47,822	$ 42,686	$ 40,242	$ 44,120	$ 45,585	$ 39,658	$ 36,626	$ 179,630	$ 165,989	$ 132,026
Geographic Areas, Long-Lived Assets [Abstract]
Property and equipment, net	$ 7,468				$ 5,751				$ 7,468	$ 5,751	$ 5,894
Concentration Risks, Types, No Concentration Percentage [Abstract]
No. of revenue customers with 10% or greater concentration									0	0	0
No of Acct Rec customers with 10% or greater concentration	0				0				0	0
United States
Geographic Areas, Revenues from External Customers [Abstract]
Total revenue									$ 161,338	$ 148,993	$ 118,278
Geographic Areas, Long-Lived Assets [Abstract]
Property and equipment, net	$ 6,265				$ 4,621				6,265	4,621	5,448
International
Geographic Areas, Revenues from External Customers [Abstract]
Total revenue									18,292	16,996	13,748
Geographic Areas, Long-Lived Assets [Abstract]
Property and equipment, net	$ 1,203				$ 1,130				$ 1,203	$ 1,130	$ 446

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
United States	$ (10,852)	$ (10,930)	$ (11,498)
International	827	792	627
Total loss before income taxes	$ (10,025)	$ (10,138)	$ (10,871)

Income Taxes (Components of the

Income Taxes (Components of the provision (benefit) for income taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current
Federal	$ 0	$ (10)	$ 0
State	53	54	36
Foreign	368	324	194
Current Income Tax Expense (Benefit)	421	368	230
Deferred
Federal	(822)	311	334
State	99	119	26
Foreign	(49)	(39)	(61)
Deferred Income Tax Expense (Benefit)	(772)	391	299
Total income tax provision (benefit)	$ (351)	$ 759	$ 529

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of the provision for income taxes at the statutory rate to the company's provision for income tax) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
U.S. federal (tax benefit) provision at statutory rate	$ (2,105)	$ (4,576)	$ (5,691)
State (tax benefit) income taxes, net of federal benefit	(373)	(437)	(574)
Foreign income taxes at rates other than the US rate	92	(21)	(94)
Stock-based compensation	(3,503)	(8,373)	581
Change in valuation allowance	4,710	(6,023)	6,657
Non-deductible executive compensation	2,418	1,624	0
Rate differential impact on Tax Cuts and Jobs Act	0	18,975	0
Research and development credits	(994)	(602)	(449)
Indefinite net operating losses carryforward	(1,470)	0	0
Other	874	192	99
Total income tax provision (benefit)	$ (351)	$ 759	$ 529
Effective Income Tax Rate, Percent [Abstract]
Effective tax rate	(3.50%)	7.50%	4.90%

Income Taxes (Deferred tax asse

Income Taxes (Deferred tax assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Net operating loss carryforward	$ 29,798	$ 27,289
Research and development credits	6,840	5,826
Deferred Tax Assets, Property, Plant and Equipment	3,007	2,082
Reserves and accruals	9,661	10,242
Total deferred tax assets	49,306	45,439
Valuation allowance	(40,070)	(45,255)	$ (42,339)	$ (30,072)
Net deferred tax assets	9,236	184
Deferred tax liabilities - convertible senior notes	(7,503)	0
Deferred tax liabilities - other	(2,208)	(1,437)
Net deferred tax liabilities	(475)	(1,253)
Decrease in deferred tax asset due to change in tax rate	19,000
Change in valuation allowance, due to tax change	19,700
Deferred tax benefit, due to change in tax rate	(700)
GILTI inclusion	1,100
Deferred tax assets (increase) decrease	$ 5,200	$ (2,900)

Income Taxes (Tax carry forward

Income Taxes (Tax carry forwards) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Tax Credit Carryforward [Line Items]
Tax Credit Carryforward, Amount	$ 500
Research and development credits	6,840	$ 5,826
Deferred tax assets decrease	$ 5,200	$ (2,900)
Tax Credit Carryforward, Limitations on Use	600,000
Federal | Federal R&D tax credits carryforwards [Member]
Tax Credit Carryforward [Line Items]
Research and development credits	$ 3,900
State | State R&D tax credits carryforwards [Member]
Tax Credit Carryforward [Line Items]
Research and development credits	$ 5,300

Income Taxes Income Taxes (Oper

Income Taxes Income Taxes (Operating Loss Carryovers) (Details)	12 Months Ended
	Dec. 31, 2018USD ($)
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Limitations on Use	$ 11,500,000
Document Period End Date	Dec. 31, 2018
Operating Loss Carryforwards	$ 5,300,000
Federal
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	124,000,000
State
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 63,000,000

Income Taxes (income Taxes) DTA

Income Taxes (income Taxes) DTA Valuation Allowance Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes (DTA Valuation Allowance Rollforward) [Abstract]
Balance at the beginning of the period	$ 45,255	$ 42,339	$ 30,072
Net operating loss carryforwards generated (utilization)	2,509	3,050	5,049
R&D tax credit increase	1,014	1,121	1,345
Depreciation and amortization increase	925	237	1,195
Reserves and accruals increase (decrease)	(581)	(1,479)	4,821
Deferred tax assets decrease (increase)	(9,052)	(13)	(143)
Balance at the end of the period	$ 40,070	$ 45,255	$ 42,339

Income Taxes (Changes in unreco

Income Taxes (Changes in unrecognized tax benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross amount of unrecognized tax benefits as of the beginning of the period	$ 1,673	$ 1,458
Decreases related to prior year tax provisions	7	0
Increases related to current year tax provisions	251	215
Gross amount of unrecognized tax benefits as of the end of the period	$ 1,931	$ 1,673

Business Acquisitions Acquisiti

Business Acquisitions Acquisition of mVisium Net Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill	$ 49,246	$ 49,246
Minimum [Member] | Technology-Based Intangible Assets [Member]
Business Acquisition [Line Items]
Weighted average useful life (years)	3 years
Minimum [Member] | Non-compete agreements
Business Acquisition [Line Items]
Weighted average useful life (years)	2 years
Minimum [Member] | Customer relationships
Business Acquisition [Line Items]
Weighted average useful life (years)	7 years
Minimum [Member] | Trademarks and Trade Names [Member]
Business Acquisition [Line Items]
Weighted average useful life (years)	3 years
Maximum [Member] | Technology-Based Intangible Assets [Member]
Business Acquisition [Line Items]
Weighted average useful life (years)	7 years
Maximum [Member] | Non-compete agreements
Business Acquisition [Line Items]
Weighted average useful life (years)	4 years
Maximum [Member] | Customer relationships
Business Acquisition [Line Items]
Weighted average useful life (years)	9 years
Maximum [Member] | Trademarks and Trade Names [Member]
Business Acquisition [Line Items]
Weighted average useful life (years)	7 years

Business Acquisitions Acquisi_2

Business Acquisitions Acquisition of Prana Technologies assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill	$ 49,246	$ 49,246

Business Acquisitions Acquisi_3

Business Acquisitions Acquisition of Extension Healthcare (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 27, 2016	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill			$ 49,246	$ 49,246
Pro Forma Revenue					$ 134,330
Pro Forma Net Loss		$ 7,100			$ (31,787)
Pro Forma, Earnings Per Share, Basic And Diluted (in dollars per share)					$ (1,180)
Extension Healthcare
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 52,500
Business Acquisition, Transaction Costs		$ 5,800			$ 5,800
Accounts receivable, net of allowance	1,569
Prepaid expenses and other current assets	774
Property and equipment, net	48
Intangibles assets, net	17,200
Goodwill	39,258
Total assets	58,849
Accounts payable	(149)
Accrued payroll and other current liabilities	(1,984)
Deferred revenue, current	(2,992)
Deferred revenue, long-term	(1,224)
Total liabilities assumed	6,349
Net assets acquired	52,500
Recorded charge for planned redistribution of proceeds	2,600
Customer relationships | Extension Healthcare
Business Acquisition [Line Items]
Intangibles assets, net	$ 8,400
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	8 years
Developed technology | Extension Healthcare
Business Acquisition [Line Items]
Intangibles assets, net	$ 6,400
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	3 years
Trademarks | Extension Healthcare
Business Acquisition [Line Items]
Intangibles assets, net	$ 1,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	3 years
Backlog | Extension Healthcare
Business Acquisition [Line Items]
Intangibles assets, net	$ 1,400
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	3 years
Product Segment
Business Acquisition [Line Items]
Goodwill			41,200
Product Segment | Extension Healthcare
Business Acquisition [Line Items]
Goodwill	$ 31,200
Service Segment
Business Acquisition [Line Items]
Goodwill			8,000
Service Segment | Extension Healthcare
Business Acquisition [Line Items]
Goodwill	$ 8,000
Retention Bonus Plan | Extension Healthcare
Business Acquisition [Line Items]
Retention Bonus Plan, additional compensation period	2 years
Retention Bonus Plan, additional compensation	$ 2,600
Retention Bonus Plan, amounts paid			500	1,000	500
Retention Bonus Plan, amounts recorded as expense			$ 300	$ 1,000	700
Employee Severance | Extension Healthcare
Business Acquisition [Line Items]
Severance costs					500
Cost of revenue | Employee Severance | Extension Healthcare
Business Acquisition [Line Items]
Severance costs					100
Operating expense | Employee Severance | Extension Healthcare
Business Acquisition [Line Items]
Severance costs					$ 400

Quarterly results of operatio_3

Quarterly results of operations (unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Total revenue	$ 48,880	$ 47,822	$ 42,686	$ 40,242	$ 44,120	$ 45,585	$ 39,658	$ 36,626	$ 179,630	$ 165,989	$ 132,026
Gross Profit	31,197	31,138	25,651	23,901	27,975	29,136	22,889	21,062	111,887	101,062	82,951
Net loss	(1,101)	(249)	(3,554)	(4,770)	374	1,391	(6,012)	(6,650)	$ (9,674)	$ (10,897)	$ (11,400)
Net Income (Loss) Available to Common Stockholders, Basic	$ (1,101)	$ (249)	$ (3,554)	$ (4,770)	$ 374	$ 1,391	$ (6,012)	$ (6,650)
Earnings Per Share, Basic					$ 0.01	$ 0.05	$ (0.21)	$ (0.24)		$ (0.38)	$ (0.42)
Basic and diluted									$ (0.32)	(0.38)	(0.42)
Earnings Per Share, Diluted					$ 0.01	$ 0.05	$ (0.21)	$ (0.24)		$ (0.38)	$ (0.42)
Basic					29,317	29,130	28,422	27,751	30,041	28,655	26,859
Diluted					30,704	30,473	28,422	27,751	30,041	28,655	26,859