Omnicell (OMCL) 10-Q 3 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 26, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	OMNICELL, Inc
Entity Central Index Key	0000926326
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		41,218,603
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Entity Emerging Growth Company	false
Entity Small Business	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 77,244	$ 67,192
Accounts receivable and unbilled receivables, net of allowances of $3,881 and $2,582, respectively	203,489	196,238
Inventories	103,909	100,868
Prepaid expenses	17,048	20,700
Other current assets	12,017	12,136
Total current assets	413,707	397,134
Property and equipment, net	52,039	51,500
Long-term investment in sales-type leases, net	19,469	17,082
Operating lease right-of-use assets	63,851	0
Goodwill	336,119	335,887
Intangible assets, net	138,893	143,686
Long-term deferred tax assets	32,043	15,197
Prepaid commissions	43,669	46,143
Other long-term assets	77,270	74,613
Total assets	1,177,060	1,081,242
Current liabilities:
Accounts payable	38,466	38,038
Accrued compensation	29,056	41,660
Accrued Liabilities	52,996	43,047
Deferred revenues, net	90,104	81,835
Total current liabilities	210,622	204,580
Long-term deferred revenues	10,302	10,582
Long-term deferred tax liabilities	61,405	41,484
Long-term operating lease liabilities	57,470	0
Other long-term liabilities	9,786	9,562
Long-term debt, net	96,990	135,417
Total liabilities	446,575	401,625
Commitments and contingencies (Note 11)
Stockholders’ equity:
Preferred stock, $0.001 par value, 5,000 shares authorized; no shares issued	0	0
Common stock, $0.001 par value, 100,000 shares authorized; 50,351 and 49,480 shares issued; 41,206 and 40,335 shares outstanding, respectively	50	50
Treasury stock at cost, 9,145 shares outstanding, respectively	(185,074)	(185,074)
Additional paid-in capital	725,273	678,041
Retained earnings	200,738	197,454
Accumulated other comprehensive loss	(10,502)	(10,854)
Total stockholders’ equity	730,485	679,617
Total liabilities and stockholders’ equity	$ 1,177,060	$ 1,081,242

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowances	$ 3,881	$ 2,582
Preferred stock, shares, issued (in shares)	0	0
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares, authorized (in shares)	5,000,000	5,000,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares, authorized (in shares)	100,000,000	100,000,000
Common Stock, shares, issued (in shares)	50,351,000	49,480,000
Common stock, shares, outstanding (in shares)	41,206,000	40,335,000
Treasury stock, shares (in shares)	9,145,000	9,145,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues:
Total revenues	$ 202,517	$ 182,619
Cost of revenues:
Total cost of revenues	105,400	100,164
Gross profit	97,117	82,455
Operating expenses:
Research and development	16,078	16,537
Selling, general, and administrative	68,278	65,285
Total operating expenses	84,356	81,822
Income from operations	12,761	633
Interest and other income (expense), net	(1,410)	(2,729)
Income (loss) before provision for income taxes	11,351	(2,096)
Provision for (benefit from) income taxes	8,067	(4,816)
Net income	$ 3,284	$ 2,720
Net income per share:
Net income per share - basic (in dollars per share)	$ 0.08	$ 0.07
Net income per share - diluted (in dollars per share)	$ 0.08	$ 0.07
Weighted-average shares outstanding:
Weighted-average shares outstanding — basic (in shares)	40,692	38,635
Weighted-average shares outstanding — diluted (in shares)	42,281	39,691
Product revenues
Revenues:
Total revenues	$ 145,610	$ 130,659
Cost of revenues:
Total cost of revenues	78,811	75,417
Services and other revenues
Revenues:
Total revenues	56,907	51,960
Cost of revenues:
Total cost of revenues	$ 26,589	$ 24,747

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 3,284	$ 2,720
Other comprehensive income, net of reclassification adjustments:
Unrealized gains (losses) on interest rate swap contracts	(317)	202
Foreign currency translation adjustments	669	2,472
Other comprehensive income	352	2,674
Comprehensive income	$ 3,636	$ 5,394

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Earnings	Accumulated Other Comprehensive Income (Loss)
Common Stock, Beginning of period (in shares) at Dec. 31, 2017		47,577,000
Beginning balance at Dec. 31, 2017	$ 554,339	$ 48	$ (185,074)	$ 585,756	$ 159,722	$ (6,113)
Treasury Stock, Beginning of period (in shares) at Dec. 31, 2017			(9,145,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,720				2,720
Other comprehensive income	2,674					2,674
Share-based compensation	6,528			6,528
Issuance of common stock under employee stock plans (in shares)		428,000
Issuance of common stock under employee stock plans	9,541	$ 0		9,541
Tax payments related to restricted stock units	(1,300)			(1,300)
Common Stock, End of period (in shares) at Mar. 31, 2018		48,005,000
Ending balance at Mar. 31, 2018	574,502	$ 48	$ (185,074)	600,525	162,442	(3,439)
Treasury Stock, End of period (in shares) at Mar. 31, 2018			(9,145,000)
Common Stock, Beginning of period (in shares) at Dec. 31, 2018		49,480,000
Beginning balance at Dec. 31, 2018	$ 679,617	$ 50	$ (185,074)	678,041	197,454	(10,854)
Treasury Stock, Beginning of period (in shares) at Dec. 31, 2018	(9,145,000)		(9,145,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 3,284				3,284
Other comprehensive income	352					352
At the market equity offering, net of costs ( in shares )		243,000
At the market equity offering, net of costs	20,216			20,216
Share-based compensation	8,410			8,410
Issuance of common stock under employee stock plans (in shares)		628,000
Issuance of common stock under employee stock plans	20,526	$ 0		20,526
Tax payments related to restricted stock units	(1,920)			(1,920)
Common Stock, End of period (in shares) at Mar. 31, 2019		50,351,000
Ending balance at Mar. 31, 2019	$ 730,485	$ 50	$ (185,074)	$ 725,273	$ 200,738	$ (10,502)
Treasury Stock, End of period (in shares) at Mar. 31, 2019	(9,145,000)		(9,145,000)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating Activities
Net income	$ 3,284	$ 2,720
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	12,637	12,310
Loss on disposal of fixed assets	355	0
Share-based compensation expense	8,410	6,528
Deferred income taxes	3,075	(5,128)
Amortization of operating lease right-of-use assets	2,602	0
Amortization of debt financing fees	573	573
Changes in operating assets and liabilities:
Accounts receivable and unbilled receivables	(7,251)	(632)
Inventories	(2,936)	(6,881)
Prepaid expenses	3,652	(769)
Other current assets	373	(997)
Investment in sales-type leases	(2,641)	(1,491)
Prepaid commissions	2,474	1,796
Other long-term assets	5,206	(1,673)
Accounts payable	(233)	(9,416)
Accrued compensation	(12,604)	2,391
Accrued liabilities	127	4,276
Deferred revenues	7,989	15,118
Operating lease liabilities	(2,669)	0
Other long-term liabilities	4,074	131
Net cash provided by operating activities	26,497	18,856
Investing Activities
Software development for external use	(11,717)	(5,272)
Purchases of property and equipment	(4,980)	(9,268)
Net cash used in investing activities	(16,697)	(14,540)
Financing Activities
Repayment of debt and revolving credit facility	(39,000)	(2,500)
At the market offering, net of offering costs	20,216	0
Proceeds from stock issuances under stock-based compensation plans	20,526	9,541
Employees’ taxes paid related to restricted stock units	(1,920)	(1,300)
Net cash provided by (used in) financing activities	(178)	5,741
Effect of exchange rate changes on cash and cash equivalents	430	1,292
Net increase in cash and cash equivalents	10,052	11,349
Cash and cash equivalents at beginning of period	67,192	32,424
Cash and cash equivalents at end of period	77,244	43,773
Supplemental disclosure of non-cash activities
Unpaid purchases of property and equipment	1,454	676
Property and equipment transferred to inventory	105	0
Right-of-use assets obtained in exchange for new lease liabilities	$ 431	$ 0

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Organization and Summary of Significant Accounting Policies	Organization and Summary of Significant Accounting Policies Business Omnicell, Inc. was incorporated in California in 1992 under the name Omnicell Technologies, Inc. and reincorporated in Delaware in 2001 as Omnicell, Inc. The Company’s major products are medication and supply dispensing automation solutions, central pharmacy automation solutions, analytics software, and medication adherence solutions which are sold in its principal market, which is the healthcare industry. The Company’s market is primarily located in the United States and Europe. “Omnicell” or the “Company” collectively refer to Omnicell, Inc. and its subsidiaries. Basis of Presentation The accompanying unaudited Condensed Consolidated Financial Statements reflect, in the opinion of management, all adjustments, consisting of normal recurring adjustments and accruals, necessary to present fairly the financial position of the Company as of March 31, 2019 and December 31, 2018 , and the results of operations, comprehensive income, and cash flows for the three months ended March 31, 2019 and 2018 . Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) have been condensed or omitted in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”). These unaudited Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and accompanying Notes included in the Company’s annual report on Form 10-K for the year ended December 31, 2018 filed with the SEC on February 27, 2019, except as discussed in the sections entitled “Lessor Leases”, “Lessee Leases’, and “Recently Adopted Authoritative Guidance” below. The Company’s results of operations, comprehensive income, and cash flows for the three months ended March 31, 2019 are not necessarily indicative of results that may be expected for the year ending December 31, 2019 , or for any future period. The Company reclassified $0.6 million from services and other revenues to product revenues for the three months ended March 31, 2018 related to software term-license sales to conform with current period presentation. This reclassification did not have a material impact on the condensed consolidated financial statements. Principles of Consolidation The Condensed Consolidated Financial Statements include the accounts of the Company and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Segment Reporting The Company's Chief Operating Decision Maker ("CODM") is its Chief Executive Officer. The CODM allocates resources and evaluates the performance of the Company using information about its revenues, gross profit, income from operations, and other key financial data. The Company previously operated and reported its business in two segments: Automation and Analytics, and Medication Adherence. In the fourth quarter of 2018, the Company introduced its vision of the Autonomous Pharmacy, a more fully automated and digitized system of medication management, in order to address changes in the healthcare industry as the Company executes on its plan to deliver end-to-end solutions with greater emphasis on automating manual processes for its customers. These industry changes include the continuing consolidation of healthcare systems, rising pharmaceutical costs, and increased scrutiny on controlled substances. In an effort to deliver on its strategic vision, the Company initiated a company-wide organizational realignment in the fourth quarter of 2018 to centrally manage its business operations, including the development and marketing of all of the Company’s products, sales and distribution, supply chain and inventory management, as well as regulatory and quality functions. As a result of this organizational realignment, all significant operating decisions are based upon an analysis of the Company as one operating segment. Therefore, effective January 1, 2019, the Company started reporting as only one operating segment, which is the same as the reporting segment. Accordingly, prior period information has been revised to conform with current period presentation. Use of Estimates The preparation of financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the Company’s Condensed Consolidated Financial Statements and accompanying Notes. Management bases its estimates on historical experience and various other assumptions believed to be reasonable. Although these estimates are based on management’s best knowledge of current events and actions that may impact the Company in the future, actual results may be different from the estimates. The Company’s critical accounting policies are those that affect its financial statements materially and involve difficult, subjective or complex judgments by management. Those policies are revenue recognition; accounts receivable and notes receivable from investment in sales-type leases; operating lease right-of-use assets and liabilities; inventory valuation; capitalized software development costs; impairment of goodwill; purchased intangibles and long-lived assets; share-based compensation; and accounting for income taxes. Lessor Leases The Company determines if an arrangement is a lease at inception. The transaction price is allocated to separate performance obligations, generally consisting of hardware and software products, installation, and post-installation technical support, proportionally based on the standalone selling price of each performance obligation. Standalone selling price is best evidenced by the price the Company charges for the good or service when selling it separately in similar circumstances to similar customers. Other than for the renewal of annual support services contracts, the Company’s products and services are not generally sold separately. The Company uses an amount discounted from the list price as a best estimated selling price. Sales-Type Leases The Company enters into non-cancelable sales-type lease arrangements, most of which do not have an option to extend the lease term. At the end of the lease term, the customer must either return the equipment or negotiate a new agreement, resulting in a new purchase or lease transaction. Failure of the customer to either return the equipment or negotiate a new agreement results in the contract becoming a month-to-month rental. Certain sales-type leases automatically renew for successive one year periods at the end of each lease term with written notice from the customer. The Company’s sales-type lease agreements do not contain any material residual value guarantees. For sales-type leases, the Company recognizes revenues for its hardware and software products, net of lease execution costs, post-installation product maintenance, and technical support, at the net present value of the lease payment stream upon customer acceptance. The Company recognizes service revenues associated with the sales-type leases ratably over the term of the agreement in service revenues on the Condensed Consolidated Statements of Operations. The Company recognizes interest income from sales-type leases using the effective interest method. Both hardware and software revenues, and interest income from sales-types leases are recorded in product revenues on the Condensed Consolidated Statements of Operations. The Company optimizes cash flows by selling a majority of its non-U.S. government sales-type leases to third-party leasing finance companies on a non-recourse basis. The Company has no obligation to the leasing company once the lease has been sold. Some of the Company's sales-type leases, mostly those relating to U.S. government hospitals which comprise approximately 44% of the lease receivable balance, are retained in-house. Operating Leases The Company entered into certain leasing agreements that were classified as operating leases prior to the adoption of the new lease accounting standard. Those agreements in place prior to January 1, 2019 will continue to be treated as operating leases, however any new leasing agreements entered into on or after January 1, 2019 under these programs are classified and accounted for as sales-type leases in accordance with the new lease accounting standard. The operating lease arrangements entered into prior to January 1, 2019 are non-cancelable, and most automatically renew for successive one year periods at the end of each lease term absent written notice from the customer. The Company’s operating lease agreements do not contain any material residual value guarantees. For operating leases, rental income is generally recognized on a straight-line basis over the term of the associated lease, and recorded in revenues in the Condensed Consolidated Statements of Operations. Leased assets under operating leases are carried at amortized cost net of accumulated depreciation in property and equipment, net on the Condensed Consolidated Balance Sheets. The depreciation expense of the leased assets is recognized on a straight-line basis over the contractual term of the associated lease, and recorded in cost of revenues in the Condensed Consolidated Statements of Operations. Lessee Leases The Company determines if an arrangement is a lease at inception. Operating lease right-of-use assets and liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. As most of our lease contracts do not provide an implicit rate, the Company uses its incremental borrowing rate based on information available at the commencement date in determining the present value of the lease payments. Many of the Company’s operating leases include an option to extend the lease. The specific terms and conditions of the extension options vary from lease to lease, but are consistent with standard industry practices in each area that the Company operates. The Company reviews each of its lease options at a time required by the terms of the lease contract, and notifies the lessor if it chooses to exercise the lease renewal option. Until the Company is reasonably certain that it will extend the lease contract, the renewal option periods will not be recognized as right-of-use assets or lease liabilities. Certain leases include provisions for early termination, which allows the contract parties to terminate their obligations under the lease contract. The terms and conditions of the termination options vary by contract. When the Company has made a decision to exercise an early termination option, the right-of-use assets and associated lease liabilities are remeasured in accordance with the present value of the remaining cash flows under the lease contract. Certain building lease agreements include rental payments subject to change annually based on fluctuations in various indexes (i.e. Consumer Price Index (“CPI”), Retail Price Index, and other international indexes). Certain data center lease agreements include rental payments subject to change based on usage and CPI fluctuations. The changes based on usage and indexes are treated as variable lease costs and recognized in the period in which the obligation for those payments was incurred. The Company’s operating lease agreements do not contain any material residual value guarantees, restrictions, or restriction covenants. Recently Adopted Authoritative Guidance In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, Leases (Topic 842) . The FASB amended lease accounting requirements to begin recording assets and liabilities arising from most leases on the balance sheet. The new guidance also requires significant additional disclosures about the amount and timing of cash flows from leases. The Company adopted this new guidance on January 1, 2019. In July 2018, the FASB issued amendments in ASU 2018-11, which provide a transition election to not restate comparative periods for the effects of applying the new standard. This transition election permits entities to change the date of initial application to the beginning of the year of adoption and to recognize the effects of applying the new standard as a cumulative-effect adjustment to the opening balance of retained earnings. The Company has elected this transition approach as well as elected the package of practical expedients permitted under the transition guidance within the new standard, which will allow the Company to carry forward the historical lease classification of contracts entered into prior to January 1, 2019. As a result of electing the package of practical expedients described above, existing leases and related initial direct costs have not been reassessed prior to the effective date, and therefore, adoption of the lease standard did not have an impact on the Company’s previously reported consolidated statements. The Company also elected the following practical expedients: (i) combining lease and non-lease components, (ii) leases with an initial term of 12 months or less are not recorded in the Condensed Consolidated Balance Sheets, and the associated lease payments are recognized in the Condensed Consolidated Statements of Operations on a straight-line basis over the lease term, and (iii) applying discount rates to operating leases using a portfolio approach. From a lessor perspective, certain agreements that were previously classified as operating leases are classified as sales-type leases under the new lease accounting standard. The agreements in place prior to the adoption of the new lease accounting standard on January 1, 2019 will continue to be treated as operating leases. The Company’s adoption of the new standard impacted the Condensed Consolidated Balances Sheets at the beginning of the period of adoption as follows: January 1, 2019 Pre-ASC 842 Balances ASC 842 Adoption Impact Post-ASC 842 Balances (In thousands) Operating lease right-of-use assets $ — $ 66,008 $ 66,008 Accrued liabilities (1) 43,047 10,067 53,114 Long-term operating lease liabilities — 59,791 59,791 Other long-term liabilities (2) 9,562 (3,850 ) 5,712 _________________________________________________ (1) Adjustment represents the current portion of the operating lease liabilities of $10.3 million , and reclassification of exit cost obligations and deferred rent of $0.1 million and $0.1 million , respectively, to reduce the operating lease right-of-use assets. (2) Adjustment represents the reclassification of deferred rent to reduce the operating lease right-of-use assets. Adoption of the standard did not have an impact on the Company’s stockholders’ equity, Condensed Consolidated Statements of Operations, and Condensed Consolidated Statements of Cash Flows as of January 1, 2019. In February 2018, the FASB issued ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , which permits the reclassification of the income tax effects of the Tax Cuts and Jobs Act of 2017 (the “Tax Act”) on items within accumulated other comprehensive income to retained earnings. These amounts are commonly referred to as “stranded tax effects.” ASU 2018-02 is effective for the Company beginning January 1, 2019. The adoption of this guidance did not have a material effect on the Company’s consolidated financial statements and therefore no adjustment to retained earnings was made. Recently Issued Authoritative Guidance In August 2018, the FASB issued ASU 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract , to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). ASU 2018-15 will be effective for the Company beginning January 1, 2020. The Company is currently evaluating the impact ASU 2018-15 will have on its consolidated financial statements. There was no other recently issued and effective authoritative guidance that is expected to have a material impact on the Company’s Condensed Consolidated Financial Statements through the reporting date.

Revenues

Revenues	3 Months Ended
	Mar. 31, 2019
Revenue Recognition [Abstract]
Revenues	Revenues Revenue Recognition The Company earns revenues from sales of its medication and supply dispensing automation systems, along with consumables and related services, which are sold in the healthcare industry, its principal market. The Company’s customer arrangements typically include one or more of the following performance obligations: Products. Software-enabled equipment that manages and regulates the storage and dispensing of pharmaceuticals, consumable blister cards and packaging equipment and other medical supplies. Software. Additional software applications that enable incremental functionality of the Company’s equipment or services. Installation. Installation of equipment as integrated systems at customer sites. Post-installation technical support. Phone support, on-site service, parts, and access to unspecified software updates and enhancements, if and when available. Professional services. Other customer services, such as training and consulting. A portion of the Company’s sales are made to customers who are members of Group Purchasing Organizations (“GPOs”). GPOs are often owned fully or in part by the Company’s customers, and the Company pays fees to the GPO on completed contracts. The Company considers these fees consideration paid to customers and records them as reductions to revenue. Fees to GPOs were $2.2 million and $1.9 million for the three months ended March 31, 2019 and 2018 , respectively. Disaggregation of Revenues The following table summarizes the Company’s product revenues disaggregated by revenue type for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 2018 (In thousands) Hardware and software $ 120,221 $ 107,451 Consumables 21,087 19,438 Other 4,302 3,770 Total product revenues $ 145,610 $ 130,659 The following table summarizes the Company’s revenues disaggregated by geographic region, which is determined based on customer location, for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 2018 (In thousands) United States $ 180,020 $ 158,202 Rest of world (1) 22,497 24,417 Total revenues $ 202,517 $ 182,619 _________________________________________________ (1) No individual country represented more than 10% of the respective totals. Contract Assets and Contract Liabilities The following table reflects the Company’s contract assets and contract liabilities: March 31, December 31, (In thousands) Short-term unbilled receivables - included in accounts receivable and unbilled receivables $ 8,708 $ 9,191 Long-term unbilled receivables - included in other long-term assets 11,423 16,481 Total contract assets $ 20,131 $ 25,672 Short-term deferred revenues, net $ 90,104 $ 81,835 Long-term deferred revenues 10,302 10,582 Total contract liabilities $ 100,406 $ 92,417 The portion of the transaction price allocated to the Company’s unsatisfied performance obligations is recorded as deferred revenues. Short-term deferred revenues of $90.1 million and $81.8 million include deferred revenues from product sales and service contracts, net of deferred cost of sales, of $12.2 million and $11.1 million as of March 31, 2019 and December 31, 2018 , respectively. The short-term deferred revenues from product sales relate to delivered and invoiced products, pending installation and acceptance, expected to occur within the next twelve months. During the three months ended March 31, 2019 , the Company recognized revenues of $39.3 million that were included in the corresponding gross short-term deferred revenues balance of $92.9 million as of December 31, 2018 . Long-term deferred revenues include deferred revenues from service contracts of $10.3 million and $10.6 million as of March 31, 2019 and December 31, 2018 , respectively. Remaining performance obligations primarily relate to maintenance contracts and are recognized ratably over the remaining term of the contract, generally not more than five years. Significant Customers There were no customers that accounted for more than 10% of the Company’s total revenues for the three months ended March 31, 2019 and 2018 . Also, there were no customers that accounted for more than 10% of the Company’s accounts receivable as of March 31, 2019 and December 31, 2018 .

Net Income Per Share

Net Income Per Share	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Net Income Per Share	Net Income Per Share Basic net income per share is computed by dividing net income for the period by the weighted-average number of shares outstanding during the period. In periods of net loss, all potential common shares are anti-dilutive, so diluted net loss per share equals the basic net loss per share. In periods of net income, diluted net income per share is computed by dividing net income for the period by the basic weighted-average number of shares plus any dilutive potential common stock outstanding during the period. Potential common stock includes the effect of outstanding dilutive stock options, restricted stock awards, and restricted stock units computed using the treasury stock method. Any anti-dilutive weighted-average dilutive shares related to stock award plans are excluded from the computation of the diluted net income per share. The basic and diluted net income per share calculation for the three months ended March 31, 2019 and 2018 was as follows: Three months ended March 31, 2019 2018 (In thousands, except per share data) Net income $ 3,284 $ 2,720 Weighted-average shares outstanding — basic 40,692 38,635 Effect of dilutive securities from stock award plans 1,589 1,056 Weighted-average shares outstanding — diluted 42,281 39,691 Net income per share - basic $ 0.08 $ 0.07 Net income per share - diluted $ 0.08 $ 0.07 Anti-dilutive weighted-average shares related to stock award plans 635 1,113

Cash and Cash Equivalents and F

Cash and Cash Equivalents and Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Cash and Cash Equivalents and Fair Value of Financial Instruments	Cash and Cash Equivalents and Fair Value of Financial Instruments Cash and cash equivalents of $77.2 million and $67.2 million as of March 31, 2019 and December 31, 2018 , respectively, consisted of bank accounts with major financial institutions. Fair Value Hierarchy The Company measures its financial instruments at fair value. The Company’s cash equivalents are classified within Level 1 of the fair value hierarchy as they are valued primarily using quoted market prices utilizing market observable inputs. The Company’s interest rate swap contracts are classified within Level 2 as the valuation inputs are based on quoted prices and market observable data of similar instruments. The following table represents the fair value hierarchy of the Company’s financial assets and financial liabilities measured at fair value as of March 31, 2019 : Level 1 Level 2 Level 3 Total (In thousands) Interest rate swap contracts $ — $ 136 $ — $ 136 Total financial assets $ — $ 136 $ — $ 136 The following table represents the fair value hierarchy of the Company’s financial assets and financial liabilities measured at fair value as of December 31, 2018 : Level 1 Level 2 Level 3 Total (In thousands) Interest rate swap contracts $ — $ 562 $ — $ 562 Total financial assets $ — $ 562 $ — $ 562 Interest Rate Swap Contracts The Company uses interest rate swap agreements to protect the Company against adverse fluctuations in interest rates by reducing its exposure to variability in cash flows relating to interest payments on a portion of its outstanding debt. The Company’s interest rate swaps, which are designated as cash flow hedges, involve the receipt of variable amounts from counterparties in exchange for the Company making fixed-rate payments over the life of the agreements. The Company does not hold or issue any derivative financial instruments for speculative trading purposes. During 2016, the Company entered into an interest rate swap agreement with a combined notional amount of $100.0 million with one counterparty that became effective on June 30, 2016 and is maturing on April 30, 2019. The swap agreement requires the Company to pay a fixed rate of 0.8% and provides that the Company will receive a variable rate based on the one month LIBOR rate subject to a LIBOR floor of 0.0% . Amounts payable by or due to the Company will be net settled with the respective counterparty on the last business day of each month, commencing July 31, 2016. The fair value of the interest rate swap agreements at March 31, 2019 and December 31, 2018 was $0.1 million and $0.6 million , respectively. There were no amounts reclassified into current earnings due to ineffectiveness during the periods presented.

Balance Sheet Components

Balance Sheet Components	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Balance Sheet Components Balance sheet details as of March 31, 2019 and December 31, 2018 are presented in the tables below: March 31, December 31, (In thousands) Inventories: Raw materials $ 34,552 $ 32,511 Work in process 8,876 8,726 Finished goods 60,481 59,631 Total inventories $ 103,909 $ 100,868 Other long-term assets: Capitalized software, net $ 64,682 $ 56,819 Unbilled receivables 11,423 16,481 Other assets 1,165 1,313 Total other long-term assets, net $ 77,270 $ 74,613 Accrued liabilities: Operating lease liabilities, current portion $ 10,373 $ — Advance payments from customers 9,400 8,993 Rebates and lease buyouts 8,111 11,076 Group purchasing organization fees 4,403 4,455 Taxes payable 5,996 5,885 Other accrued liabilities 14,713 12,638 Total accrued liabilities $ 52,996 $ 43,047 The following table summarizes the changes in accumulated balances of other comprehensive income (loss) for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 2018 Foreign currency translation adjustments Unrealized gain (loss) on interest rate swap hedges Total Foreign currency translation adjustments Unrealized gain (loss) on interest rate swap hedges Total (In thousands) Beginning balance $ (11,274 ) $ 420 $ (10,854 ) $ (6,954 ) $ 841 $ (6,113 ) Other comprehensive income before reclassifications 669 100 769 2,472 401 2,873 Amounts reclassified from other comprehensive income (loss), net of tax — (417 ) (417 ) — (199 ) (199 ) Net current-period other comprehensive income (loss), net of tax 669 (317 ) 352 2,472 202 2,674 Ending balance $ (10,605 ) $ 103 $ (10,502 ) $ (4,482 ) $ 1,043 $ (3,439 )

Property and Equipment (Notes)

Property and Equipment (Notes)	3 Months Ended
	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment The following table represents the property and equipment balances as of March 31, 2019 and December 31, 2018 : March 31, December 31, (In thousands) Equipment $ 76,668 $ 75,417 Furniture and fixtures 8,122 7,844 Leasehold improvements 16,381 16,274 Software 42,305 42,048 Construction in progress 11,791 10,706 Property and equipment, gross 155,267 152,289 Accumulated depreciation and amortization (103,228 ) (100,789 ) Total property and equipment, net $ 52,039 $ 51,500 Depreciation expense of property and equipment was $4.0 million and $3.5 million for the three months ended March 31, 2019 and 2018 , respectively. The geographic location of the Company's property and equipment, net, is based on the physical location in which it is located. The following table summarizes the geographic information for property and equipment, net, as of March 31, 2019 and December 31, 2018 : March 31, December 31, (In thousands) United States $ 45,656 $ 44,684 Rest of world (1) 6,383 6,816 Total property and equipment, net $ 52,039 $ 51,500 _________________________________________________ (1) No individual country represented more than 10% of the respective totals.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill The following table represents changes in the carrying amount of goodwill: December 31, Additions Foreign currency exchange rate fluctuations March 31, (In thousands) Goodwill $ 335,887 $ — $ 232 $ 336,119 Intangible Assets, Net The carrying amounts and useful lives of intangible assets as of March 31, 2019 and December 31, 2018 were as follows: March 31, 2019 Gross carrying amount (1) Accumulated amortization Foreign currency exchange rate fluctuations Net carrying amount Useful life (years) (In thousands, except for years) Customer relationships $ 135,234 $ (47,557 ) $ (1,127 ) $ 86,550 1 - 30 Acquired technology 77,142 (30,239 ) 8 46,911 3 - 20 Backlog 1,150 (575 ) — 575 1 - 4 Trade names 7,650 (4,530 ) 11 3,131 1 - 12 Patents 3,239 (1,515 ) 2 1,726 2 - 20 Total intangibles assets, net $ 224,415 $ (84,416 ) $ (1,106 ) $ 138,893 December 31, 2018 Gross carrying amount (1) Accumulated amortization Foreign currency exchange rate fluctuations Net carrying amount Useful life (years) (In thousands, except for years) Customer relationships $ 135,234 $ (45,029 ) $ (1,185 ) $ 89,020 1 - 30 Acquired technology 78,122 (29,206 ) 42 48,958 3 - 20 Backlog 21,350 (20,703 ) — 647 1 - 4 Trade names 7,650 (4,361 ) 17 3,306 1 - 12 Patents 3,239 (1,488 ) 4 1,755 2 - 20 Non-compete agreements 1,900 (1,900 ) — — 3 Total intangibles assets, net $ 247,495 $ (102,687 ) $ (1,122 ) $ 143,686 _________________________________________________ (1) The differences in gross carrying amounts between periods are due to the write-off of fully amortized intangible assets. Amortization expense of intangible assets was $4.8 million and $6.0 million for the three months ended March 31, 2019 and 2018 , respectively. The estimated future amortization expenses for amortizable intangible assets were as follows: March 31, (In thousands) Remaining nine months of 2019 $ 13,984 2020 17,618 2021 16,268 2022 14,918 2023 13,768 Thereafter 62,337 Total $ 138,893

Debt and Credit Agreements

Debt and Credit Agreements	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Debt and Credit Agreements	Debt and Credit Agreements On January 5, 2016 , the Company entered into a $400.0 million senior secured credit facility pursuant to a credit agreement with certain lenders, Wells Fargo Securities, LLC as sole lead arranger, and Wells Fargo Bank, National Association as administrative agent (the “Credit Agreement”). The Credit Agreement provides for (a) a five -year revolving credit facility of $200.0 million , which was subsequently increased pursuant to the amendment discussed below (the “Revolving Credit Facility”) and (b) a five -year $200.0 million term loan facility (the “Term Loan Facility” and together with the Revolving Credit Facility, the “Facilities”). In addition, the Credit Agreement includes a letter of credit sub-limit of up to $10.0 million and a swing line loan sub-limit of up to $10.0 million . The Credit Agreement expires on January 5, 2021, upon which date all remaining outstanding borrowings are due and payable. Loans under the Facilities bear interest, at the Company’s option, at a rate equal to either (a) the LIBOR Rate, plus an applicable margin ranging from 1.50% to 2.25% per annum based on the Company’s consolidated total net leverage ratio (as defined in the Credit Agreement), or (b) an alternate base rate equal to the highest of (i) the prime rate, (ii) the federal funds rate plus 0.50% , and (iii) LIBOR for an interest period of one month, plus an applicable margin ranging from 0.50% to 1.25% per annum based on the Company’s consolidated total net leverage ratio (as defined in the Credit Agreement). Undrawn commitments under the Revolving Credit Facility will be subject to a commitment fee ranging from 0.20% to 0.35% per annum based on the Company’s consolidated total net leverage ratio on the average daily unused portion of the Revolving Credit Facility. A letter of credit participation fee ranging from 1.50% to 2.25% per annum based on the Company’s consolidated total net leverage ratio will accrue on the average daily amount of letter of credit exposure. The Company is permitted to make voluntary prepayments at any time without payment of a premium or penalty, except for any amounts relating to the LIBOR breakage indemnity described in the Credit Agreement. The Company is required to make mandatory prepayments under the Term Loan Facility with (a) net cash proceeds from any issuances of debt (other than certain permitted debt) and (b) net cash proceeds from certain asset dispositions (other than certain asset dispositions) and insurance and condemnation events (subject to reinvestment rights and certain other exceptions). Loans under the Term Loan Facility will amortize in quarterly installments, equal to 5% per annum of the original principal amount thereof during the first two years, which shall increase to 10% per annum during the third and fourth years, and 15% per annum during the fifth year, with the remaining balance payable on January 5, 2021. The Company is required to make mandatory prepayments under the Revolving Credit Facility if at any time the aggregate outstanding principal amount of loans together with the total amount of outstanding letters of credit exceeds the aggregate commitments, with such mandatory prepayment to be equal to the amount of such excess. The Credit Agreement contains customary representations and warranties, and customary affirmative and negative covenants applicable to the Company and its subsidiaries, including, among other things, restrictions on indebtedness, liens, investments, mergers, dispositions, dividends, and other distributions. The Credit Agreement contains financial covenants that require the Company and its subsidiaries to not exceed a maximum consolidated total leverage ratio and maintain a minimum fixed charge coverage ratio. The Company’s obligations under the Credit Agreement, and any swap obligations and banking services obligations owing to a lender (or an affiliate of a lender), are guaranteed by certain of its domestic subsidiaries and secured by substantially all of its and the subsidiary guarantors’ assets. In connection with entering into the Credit Agreement, and as a condition precedent to borrowing loans thereunder, the Company and certain of the Company’s other direct and indirect subsidiaries have entered into certain ancillary agreements, including, but not limited to, a collateral agreement and subsidiary guaranty agreement. On April 11, 2017, the parties entered into the First Amendment to Credit Agreement and Collateral Agreement (the “Amended Credit Agreement”). Under this amendment, (i) the maximum capital expenditures limit in any fiscal year for property, plant, and equipment and software development increased from $35.0 million to $45.0 million , and (ii) the maximum limit for non-permitted investments increased from $10.0 million to $20.0 million . On December 26, 2017, the parties entered into an amendment (the “Amendment”) to the Amended Credit Agreement. Pursuant to the Amendment, the Revolving Credit Facility provided for under the Amended Credit Agreement, was increased from $200.0 million to $315.0 million , and certain other modifications to the Amended Credit Agreement were made, including amendments to certain negative covenants. In connection with these Facilities, the Company incurred $10.1 million of debt issuance costs. The debt issuance costs were capitalized and presented as a direct deduction from the carrying amount of that debt liability. The debt issuance costs are being amortized to interest expense using the straight line method from issuance date through 2021. Interest expense (exclusive of fees and issuance cost amortization) was approximately $1.3 million and $1.9 million for the three months ended March 31, 2019 and 2018 , respectively. Amortization expense related to fees and issuance cost was approximately $0.6 million for both the three months ended March 31, 2019 and 2018 . The Company was in compliance with all covenants as of March 31, 2019 and December 31, 2018 . During the three months ended March 31, 2019 , the Company repaid $39.0 million under these Facilities. The components of the Company’s debt obligations as of March 31, 2019 and December 31, 2018 were as follows: December 31, Borrowings Repayment / Amortization March 31, (In thousands) Term loan facility $ 140,000 $ — $ (39,000 ) $ 101,000 Revolving credit facility — — — — Total debt under the facilities 140,000 — (39,000 ) 101,000 Less: Deferred issuance cost (4,583 ) — 573 (4,010 ) Total long-term debt, net of deferred issuance cost $ 135,417 $ — $ (38,427 ) $ 96,990 As of March 31, 2019 , the carrying amount of debt of $101.0 million approximates the comparable fair value of $103.5 million . The Company’s debt facilities are classified as a Level 3 in the fair value hierarchy. The calculation of the fair value is based on a discounted cash flow model using observable market inputs and taking into consideration variables such as interest rate changes, comparable instruments and long-term credit ratings. There have been no significant changes in the assumptions used as of March 31, 2019 as compared to December 31, 2018 .

Lessor Leases

Lessor Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Lessor Leases	Lessor Leases Sales-Type Leases On a recurring basis, the Company enters into multi-year, sales-type lease agreements, with the majority varying in length from one to five years. The following table presents the Company’s income recognized from sales-type leases for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 2018 (In thousands) Sales-type lease revenues $ 11,507 $ 9,857 Interest income on sales-type lease receivables $ 409 $ 267 The receivables as a result of these types of transactions are collateralized by the underlying equipment leased and consist of the following components at March 31, 2019 and December 31, 2018 : March 31, December 31, (In thousands) Net minimum lease payments to be received $ 30,806 $ 28,295 Less: Unearned interest income portion (2,348 ) (2,477 ) Net investment in sales-type leases 28,458 25,818 Less: Current portion (1) (8,989 ) (8,736 ) Long-term net investment in sales-type leases $ 19,469 $ 17,082 _________________________________________________ (1) The current portion of the net investment in sales-type leases is included in other current assets in the Condensed Consolidated Balance Sheets. The carrying amount of the Company’s sales-type lease receivables is a reasonable estimate of fair value, as the unearned interest income is immaterial. The Company evaluates its sales-type leases individually and collectively for impairment. The allowance for credit losses was $0.2 million as of both March 31, 2019 and December 31, 2018 . The maturity schedule of future minimum lease payments under sales-type leases retained in-house and the reconciliation to the net investment in sales-type leases reported on the Condensed Consolidated Balance Sheets was as follows: March 31, (In thousands) Remaining nine months of 2019 $ 8,215 2020 8,016 2021 5,777 2022 5,081 2023 3,097 Thereafter 620 Total future minimum sales-type lease payments $ 30,806 Present value adjustment (2,348 ) Total net investment in sales-type leases $ 28,458 Operating Leases The Company entered into certain leasing agreements that were classified as operating leases prior to the adoption of the new lease accounting standard. These agreements in place prior to January 1, 2019 will continue to be treated as operating leases, however any new leasing agreements entered into on or after January 1, 2019 under these programs are classified and accounted for as sales-type leases in accordance with the new lease accounting standard. The operating lease arrangements have initial terms of one to seven years. The following table represents the Company’s income recognized from operating leases for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 2018 (In thousands) Rental income $ 3,287 $ 2,790 The net carrying value of the leased equipment under operating leases was $2.5 million and $2.6 million , which includes accumulated depreciation of $1.3 million and $1.2 million , as of March 31, 2019 and December 31, 2018 , respectively. Depreciation of the leased equipment was $0.1 million for both the three months ended March 31, 2019 and 2018 . The maturity schedule of future minimum lease payments under operating leases was as follows: March 31, (In thousands) Remaining nine months of 2019 9,124 2020 9,349 2021 7,244 2022 5,205 2023 3,026 Thereafter 1,248 Total future minimum operating lease payments $ 35,196
Lessor Leases	Lessor Leases Sales-Type Leases On a recurring basis, the Company enters into multi-year, sales-type lease agreements, with the majority varying in length from one to five years. The following table presents the Company’s income recognized from sales-type leases for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 2018 (In thousands) Sales-type lease revenues $ 11,507 $ 9,857 Interest income on sales-type lease receivables $ 409 $ 267 The receivables as a result of these types of transactions are collateralized by the underlying equipment leased and consist of the following components at March 31, 2019 and December 31, 2018 : March 31, December 31, (In thousands) Net minimum lease payments to be received $ 30,806 $ 28,295 Less: Unearned interest income portion (2,348 ) (2,477 ) Net investment in sales-type leases 28,458 25,818 Less: Current portion (1) (8,989 ) (8,736 ) Long-term net investment in sales-type leases $ 19,469 $ 17,082 _________________________________________________ (1) The current portion of the net investment in sales-type leases is included in other current assets in the Condensed Consolidated Balance Sheets. The carrying amount of the Company’s sales-type lease receivables is a reasonable estimate of fair value, as the unearned interest income is immaterial. The Company evaluates its sales-type leases individually and collectively for impairment. The allowance for credit losses was $0.2 million as of both March 31, 2019 and December 31, 2018 . The maturity schedule of future minimum lease payments under sales-type leases retained in-house and the reconciliation to the net investment in sales-type leases reported on the Condensed Consolidated Balance Sheets was as follows: March 31, (In thousands) Remaining nine months of 2019 $ 8,215 2020 8,016 2021 5,777 2022 5,081 2023 3,097 Thereafter 620 Total future minimum sales-type lease payments $ 30,806 Present value adjustment (2,348 ) Total net investment in sales-type leases $ 28,458 Operating Leases The Company entered into certain leasing agreements that were classified as operating leases prior to the adoption of the new lease accounting standard. These agreements in place prior to January 1, 2019 will continue to be treated as operating leases, however any new leasing agreements entered into on or after January 1, 2019 under these programs are classified and accounted for as sales-type leases in accordance with the new lease accounting standard. The operating lease arrangements have initial terms of one to seven years. The following table represents the Company’s income recognized from operating leases for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 2018 (In thousands) Rental income $ 3,287 $ 2,790 The net carrying value of the leased equipment under operating leases was $2.5 million and $2.6 million , which includes accumulated depreciation of $1.3 million and $1.2 million , as of March 31, 2019 and December 31, 2018 , respectively. Depreciation of the leased equipment was $0.1 million for both the three months ended March 31, 2019 and 2018 . The maturity schedule of future minimum lease payments under operating leases was as follows: March 31, (In thousands) Remaining nine months of 2019 9,124 2020 9,349 2021 7,244 2022 5,205 2023 3,026 Thereafter 1,248 Total future minimum operating lease payments $ 35,196

Lessee Leases (Notes)

Lessee Leases (Notes)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Lessee, Operating Leases [Text Block]	Lessee Leases The Company has operating leases for office buildings, data centers, office equipment, and vehicles. The Company’s leases have initial terms of one to 12 years. As of March 31, 2019 , the Company did not have any additional operating leases that were entered into, but not yet commenced. The maturity schedule of future minimum lease payments under operating leases and the reconciliation to the operating lease liabilities reported on the Condensed Consolidated Balance Sheets was as follows: March 31, (In thousands) Remaining nine months of 2019 $ 10,737 2020 13,328 2021 12,831 2022 11,799 2023 8,415 Thereafter 27,832 Total operating lease payments $ 84,942 Present value adjustment (17,099 ) Total operating lease liabilities (1) $ 67,843 _________________________________________________ (1) Amount consists of a current and long-term portion of operating lease liabilities of $10.4 million and $57.5 million , respectively. The short-term portion of the operating lease liabilities is included in accrued liabilities in the Condensed Consolidated Balance Sheets. Prior to the adoption of the new lease accounting standard, the maturity schedule of future minimum lease payments under operating leases was as follows: December 31, 2018 (In thousands) 2019 $ 14,153 2020 13,104 2021 12,729 2022 11,809 2023 8,334 Thereafter 27,289 Total minimum future lease payments $ 87,418 Operating lease costs were $3.7 million for the three months ended March 31, 2019 . Short-term lease costs and variable lease costs were immaterial for the three months ended March 31, 2019 . The following table summarizes other information related to the Company’s operating leases for the three months ended March 31, 2019 : Three months ended March 31, 2019 (Dollars in thousands) Cash paid for amounts included in the measurement of lease liabilities $ 3,761 Right-of-use assets obtained in exchange for new lease liabilities 431 Weighted-average remaining lease term, years 7.0 Weighted-average discount rate, % 6.4 %

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Purchase Obligations In the ordinary course of business, the Company issues purchase orders based on its current manufacturing needs. As of March 31, 2019 , the Company had non-cancelable purchase commitments of $71.0 million , of which $65.5 million are expected to be paid within the year ended December 31, 2019 . Legal Proceedings The Company is currently involved in various legal proceedings. As required under ASC 450, Contingencies, the Company accrues for contingencies when it believes that a loss is probable and that it can reasonably estimate the amount of any such loss. The Company has not recorded any accrual for contingent liabilities associated with the legal proceedings described below based on its belief that any potential loss, while reasonably possible, is not probable. Further, any possible range of loss in these matters cannot be reasonably estimated at this time. The Company believes that it has valid defenses with respect to legal proceedings pending against it. However, litigation is inherently unpredictable, and it is possible that cash flows or results of operations could be materially affected in any particular period by the unfavorable resolution of this contingency or because of the diversion of management’s attention and the creation of significant expenses. On January 10, 2018, a lawsuit was filed against a number of individuals, governmental agencies, and corporate entities, including the Company and one of its subsidiaries, Aesynt Incorporated (“Aesynt”), in the Circuit Court for the City of Richmond, Virginia, captioned Ruth Ann Warner, as Guardian of Jonathan James Brewster Warner v. Centra Health, Inc., et al., Case No. CL18-152-1 . The complaint seeks monetary recovery of compensatory and punitive damages in addition to certain declaratory relief based upon, as against the individuals, governmental agencies, and corporate entities other than the Company and Aesynt, allegations of the use of excessive force, unlawful detention, false imprisonment, battery, simple and gross negligence and negligent hiring, detention, and training; and, as against the Company and Aesynt, claims of product liability, negligence, and breach of implied warranties. The Company and Aesynt have not yet been served with the complaint. The Company intends to defend the lawsuit vigorously. On June 6, 2018, a class-action lawsuit was filed against a customer of the Company, the customer’s parent company and two vendors of medication dispensing systems, one of which is the Company, in the Circuit Court of Cook County, Illinois, Chancery Division, captioned Yana Mazya, individually and on behalf of all others similarly situated v. Northwestern Lake Forest Hospital, Northwestern Memorial Healthcare, Omnicell, Inc. and Becton Dickinson, Case No. 2018-CH-07161 . The complaint sought class certification, monetary damages in the form of statutory damages for willful and/or reckless or, in the alternative, negligent violation of the Illinois Biometric Information Privacy Act (“BIPA”), and certain declaratory, injunctive, and other relief based on causes of action directed to allegations of violation of BIPA and of negligence by the defendants. The complaint was served on the Company on June 15, 2018. The Company’s obligation to respond to the complaint was held in abeyance pending a decision of the Illinois Supreme Court in a separate case involving BIPA issues. The Illinois Supreme Court issued its decision in that case on January 25, 2019. On April 10, 2019, subsequent to the court’s issuance of an order granting the plaintiff leave to file an amended complaint, the plaintiff filed an amended complaint adding a second named plaintiff and an affiliate of the Company’s customer as an additional defendant and, in addition to making other modifications to the complaint, removing the separate cause of action directed to negligence. The court established a deadline of May 13, 2019 for the defendants to answer or otherwise respond to the amended complaint. The Company intends to defend the lawsuit vigorously. A declaratory judgment action was filed against the Company, on August 30, 2018, in the United States District Court for the Northern District of California, captioned Zurich American Insurance Company; American Guarantee & Liability Company v. Omnicell, Inc. and Does 1-10, inclusive, Case No. 3:18-CV-05345 . The complaint seeks a declaration that the plaintiffs have no duty to defend or indemnify the Company in connection with the underlying litigation, the Yana Mazya, et al. v. Northwestern Lake Forest Hospital, et al., Case No. 2018-CH-07161 pending in the Circuit Court of Cook County, Illinois, Chancery Division (“Underlying Action”), disclosed above, together with claims for reimbursement and unjust enrichment relating to the defense of the Underlying Action in the form of attorneys’ fees and other related costs. The Company has not responded to the complaint. On February 12, 2019, the court stayed the action pending the outcome of the Underlying Action and administratively closed the case. The Company intends to defend the lawsuit vigorously.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company generally provides for income taxes in interim periods based on the estimated annual effective tax rate for the year, adjusting for discrete items in the quarter in which they arise. The annual effective tax rate before discrete items was 23.3% and 18.3% for the three months ended March 31, 2019 and 2018 , respectively. As a result of global operational centralization activities during the three months ended March 31, 2018, the Company recognized $4.2 million of a discrete tax benefit associated with making a check-the-box election to treat Aesynt Coöperatief U.A. (Netherlands) as a US disregarded entity for the three months ended March 31, 2018. Due to continuing global operational centralization activities during the three months ended March 31, 2019, the Company recognized gain on the sale of certain intellectual property rights by Aesynt Coöperatief U.A. to Omnicell, Inc., which resulted in a discrete tax expense in the amount of $9.6 million during the three months ended March 31, 2019. The Company also recognized a discrete benefit related to equity compensation in the amount of $4.6 million and $0.9 million for the three months ended March 31, 2019 and March 31, 2018 respectively. The 2019 annual effective tax rate differed from the statutory rate of 21% primarily due to the unfavorable impact of the state income taxes, non-deductible equity charges, and non-deductible expenses, partially offset by the favorable impact of the research and development credits, foreign rate differential, and foreign derived intangible income (“FDII”) benefit deduction. The 2018 annual effective tax rate differed from the statutory rate of 21% primarily due to the favorable impact of the research and development credits and foreign rate differential, which were partially offset by the unfavorable impact of state income taxes, non-deductible expenses, and non-deductible equity charges. As of March 31, 2019 and December 31, 2018 , the Company had gross unrecognized tax benefits of $14.3 million and $10.0 million , respectively. It is the Company’s policy to classify accrued interest and penalties as part of the unrecognized tax benefits, but to record interest and penalties in other income/expense in the consolidated statements of operations. As of March 31, 2019 and December 31, 2018 , the amount of accrued interest and penalties was $1.5 million and $1.4 million , respectively. The Company files income tax returns in the United States and various states and foreign jurisdictions. In the normal course of business, the Company is subject to examination by taxing authorities, including major jurisdictions such as the United States, Germany, Italy, Netherlands, and the United Kingdom. With few exceptions, as of March 31, 2019 , the Company is no longer subject to U.S., state, and foreign examination for years before 2015, 2014, and 2014, respectively. Although the Company believes it has adequately provided for uncertain tax positions, the provisions on these positions may change as revised estimates are made or the underlying matters are settled or otherwise resolved. It is not possible at this time to reasonably estimate changes in the unrecognized tax benefits within the next twelve months.

Employee Benefits and Share-Bas

Employee Benefits and Share-Based Compensation	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Employee Benefits and Share-Based Compensation	Employee Benefits and Share-Based Compensation Stock-Based Plans For a detailed explanation of the Company's stock plans, please refer to Note 11, Employee Benefits and Share-Based Compensation , of the Company's annual report on Form 10-K for the year ended December 31, 2018 filed with the SEC on February 27, 2019. Share-Based Compensation Expense The following table sets forth the total share-based compensation expense recognized in the Company’s Condensed Consolidated Statements of Operations for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 March 31, 2018 (In thousands) Cost of product and service revenues $ 1,462 $ 1,019 Research and development 1,702 1,234 Selling, general, and administrative 5,246 4,275 Total share-based compensation expense $ 8,410 $ 6,528 In the first quarter of 2019, the Company modified the terms of its stock options by extending the post-employment exercise period for certain employees. The Company recorded share-based compensation expense related to this option modification of approximately $0.2 million during the three months ended March 31, 2019 . The Company will incur an additional $0.8 million of share-based compensation expense for the impacted options over the remaining weighted-average vesting periods of 1.9 years. Stock Options and ESPP Shares The following assumptions were used to value stock options and Employee Stock Purchase Plan (“ESPP”) shares granted pursuant to the Company’s equity incentive plans for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 March 31, 2018 Stock options Expected life, years 4.5 4.8 Expected volatility, % 33.1 % 32.2 % Risk-free interest rate, % 2.6 % 2.6 % Estimated forfeiture rate, % 7.2 % 6.9 % Dividend yield, % — % — % Three months ended March 31, 2019 March 31, 2018 Employee stock purchase plan shares Expected life, years 0.5 - 2.0 0.5 - 2.0 Expected volatility, % 28.2% - 38.4% 27.7% - 33.8% Risk-free interest rate, % 1.3% - 2.7% 0.7% - 2.3% Dividend yield, % — % — % Stock Options Activity The following table summarizes the share option activity under the Company’s equity incentive plans during the three months ended March 31, 2019 : Number of Shares Weighted-Average Exercise Price Weighted-Average Remaining Years Aggregate Intrinsic Value (In thousands, except per share data) Outstanding at December 31, 2018 3,748 $ 41.27 7.6 $ 78,365 Granted 292 76.18 Exercised (379 ) 31.83 Expired — — Forfeited (117 ) 44.18 Outstanding at March 31, 2019 3,544 $ 45.06 7.9 $ 127,007 Exercisable at March 31, 2019 1,275 $ 31.24 6.3 $ 63,241 Vested and expected to vest at March 31, 2019 and thereafter 3,544 $ 45.06 7.9 $ 127,007 The weighted-average fair value per share of options granted during the three months ended March 31, 2019 and 2018 was $24.07 and $14.22 , respectively. The intrinsic value of options exercised during the three months ended March 31, 2019 and 2018 was $17.1 million and $2.0 million , respectively. As of March 31, 2019 , total unrecognized compensation cost related to unvested stock options was $32.5 million , which is expected to be recognized over a weighted-average vesting period of 2.9 years. Employee Stock Purchase Plan Activity For the three months ended March 31, 2019 and 2018 , employees purchased approximately 210,000 and 289,000 shares of common stock, respectively, under the ESPP at weighted average prices of $40.20 and $26.30 , respectively. As of March 31, 2019 , the unrecognized compensation cost related to the shares to be purchased under the ESPP was approximately $3.9 million and is expected to be recognized over a weighted-average period of 1.5 years. Restricted Stock Units (“RSUs”) and Restricted Stock Awards (“RSAs”) Summaries of the restricted stock activity under the Company’s 2009 Equity Incentive Plan, as amended (the “2009 Plan”) are presented below for the three months ended March 31, 2019 : Number of Shares Weighted-Average Grant Date Fair Value Weighted-Average Remaining Years Aggregate Intrinsic Value (In thousands, except per share data) Restricted stock units Outstanding at December 31, 2018 538 $ 51.52 1.6 $ 32,935 Granted (Awarded) 30 78.23 Vested (Released) (36 ) 39.78 Forfeited (27 ) 44.87 Outstanding and unvested at March 31, 2019 505 $ 54.32 1.5 $ 40,813 As of March 31, 2019 , total unrecognized compensation cost related to RSUs was $23.4 million , which is expected to be recognized over the remaining weighted-average vesting period of 2.7 years. Number of Shares Weighted-Average Grant Date Fair Value (In thousands, except per share data) Restricted stock awards Outstanding at December 31, 2018 21 $ 46.60 Granted (Awarded) — — Vested (Released) — — Forfeited — — Outstanding and unvested at March 31, 2019 21 $ 46.60 As of March 31, 2019 , total unrecognized compensation cost related to RSAs was $0.1 million , which is expected to be recognized over the remaining weighted-average vesting period of 0.1 years. Performance-Based Restricted Stock Units A summary of the performance-based restricted stock activity under the 2009 Plan is presented below for the three months ended March 31, 2019 : Number of Shares Weighted-Average Grant Date Fair Value Per Unit (In thousands, except per share data) Outstanding at December 31, 2018 197 $ 34.83 Granted 61 72.02 Vested (26 ) 38.03 Forfeited (20 ) 34.37 Outstanding and unvested at March 31, 2019 212 $ 45.18 As of March 31, 2019 , total unrecognized compensation cost related to PSUs was approximately $5.3 million , which is expected to be recognized over the remaining weighted-average period of 1.3 years. Summary of Shares Reserved for Future Issuance under Equity Incentive Plans The Company had the following ordinary shares reserved for future issuance under its equity incentive plans as of March 31, 2019 : Number of Shares (In thousands) Share options outstanding 3,544 Non-vested restricted share awards 738 Shares authorized for future issuance 2,140 ESPP shares available for future issuance 1,703 Total shares reserved for future issuance 8,125 Stock Repurchase Program On August 2, 2016, the Company's Board of Directors (the “Board”) authorized a stock repurchase program providing for the repurchase of up to $50.0 million of the Company’s common stock (the “2016 Repurchase Program”). The 2016 Repurchase Program is in addition to the stock repurchase program approved by the Board on November 4, 2014 (the “2014 Repurchase Program”). As of March 31, 2019 , the maximum dollar value of shares that may yet be purchased under the two repurchase programs was $54.9 million . The stock repurchase programs do not obligate the Company to repurchase any specific number of shares, and the Company may terminate or suspend the repurchase programs at any time. During the three months ended March 31, 2019 and 2018 , the Company did not repurchase any of its outstanding common stock.

Equity Offerings

Equity Offerings	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Equity Offerings	Equity Offerings On November 3, 2017, the Company entered into a Distribution Agreement (the “Distribution Agreement”) with J.P. Morgan Securities LLC, Wells Fargo Securities, LLC, and HSBC Securities (USA) Inc., as its sales agents, pursuant to which the Company may offer and sell from time to time through the sales agents up to $125.0 million maximum aggregate offering price of the Company’s common stock. Sales of the common stock pursuant to the Distribution Agreement may be made in negotiated transactions or transactions that are deemed to be “at the market” offerings as defined in Rule 415 under the Securities Act of 1933, including sales made directly on the Nasdaq Stock Market, or sales made to or through a market maker other than on an exchange. For the three months ended March 31, 2019 , the Company received gross proceeds of $20.6 million from sales of its common stock under the Distribution Agreement and incurred issuance costs of $0.4 million on sales of approximately 243,000 shares of its common stock at an average price of approximately $84.98 per share. For the three months ended March 31, 2018 , the Company did not sell any of its common stock under the Distribution Agreement. As of March 31, 2019 , the Company had an aggregate of $49.4 million available to be offered under the Distribution Agreement.

Restructuring Expenses

Restructuring Expenses	3 Months Ended
	Mar. 31, 2019
Restructuring and Related Activities [Abstract]
Restructuring Expenses	Restructuring Expenses In the fourth quarter of 2018, the Company announced a company-wide organizational realignment initiative in order to align its organizational infrastructure for future expected growth. During the year ended December 31, 2018, the Company incurred and accrued for $1.3 million of restructuring expenses, which includes severance and consulting-related expenses. As of March 31, 2019 , the unpaid balance related to this restructuring plan was $0.1 million . On March 2, 2018, the Company initiated the realignment of its Automation and Analytics commercial group in North America and France. During the three months ended March 31, 2018 , the Company accrued $1.4 million of employee severance cost and related expenses. As of December 31, 2018 , there was no unpaid balance related to this restructuring program.

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited Condensed Consolidated Financial Statements reflect, in the opinion of management, all adjustments, consisting of normal recurring adjustments and accruals, necessary to present fairly the financial position of the Company as of March 31, 2019 and December 31, 2018 , and the results of operations, comprehensive income, and cash flows for the three months ended March 31, 2019 and 2018 . Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) have been condensed or omitted in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”). These unaudited Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and accompanying Notes included in the Company’s annual report on Form 10-K for the year ended December 31, 2018 filed with the SEC on February 27, 2019, except as discussed in the sections entitled “Lessor Leases”, “Lessee Leases’, and “Recently Adopted Authoritative Guidance” below. The Company’s results of operations, comprehensive income, and cash flows for the three months ended March 31, 2019 are not necessarily indicative of results that may be expected for the year ending December 31, 2019 , or for any future period.
Principles of Consolidation	Principles of Consolidation The Condensed Consolidated Financial Statements include the accounts of the Company and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Segment Reporting	Segment Reporting The Company's Chief Operating Decision Maker ("CODM") is its Chief Executive Officer. The CODM allocates resources and evaluates the performance of the Company using information about its revenues, gross profit, income from operations, and other key financial data. The Company previously operated and reported its business in two segments: Automation and Analytics, and Medication Adherence. In the fourth quarter of 2018, the Company introduced its vision of the Autonomous Pharmacy, a more fully automated and digitized system of medication management, in order to address changes in the healthcare industry as the Company executes on its plan to deliver end-to-end solutions with greater emphasis on automating manual processes for its customers. These industry changes include the continuing consolidation of healthcare systems, rising pharmaceutical costs, and increased scrutiny on controlled substances. In an effort to deliver on its strategic vision, the Company initiated a company-wide organizational realignment in the fourth quarter of 2018 to centrally manage its business operations, including the development and marketing of all of the Company’s products, sales and distribution, supply chain and inventory management, as well as regulatory and quality functions. As a result of this organizational realignment, all significant operating decisions are based upon an analysis of the Company as one operating segment. Therefore, effective January 1, 2019, the Company started reporting as only one operating segment, which is the same as the reporting segment. Accordingly, prior period information has been revised to conform with current period presentation.
Use of Estimates	Use of Estimates The preparation of financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the Company’s Condensed Consolidated Financial Statements and accompanying Notes. Management bases its estimates on historical experience and various other assumptions believed to be reasonable. Although these estimates are based on management’s best knowledge of current events and actions that may impact the Company in the future, actual results may be different from the estimates. The Company’s critical accounting policies are those that affect its financial statements materially and involve difficult, subjective or complex judgments by management. Those policies are revenue recognition; accounts receivable and notes receivable from investment in sales-type leases; operating lease right-of-use assets and liabilities; inventory valuation; capitalized software development costs; impairment of goodwill; purchased intangibles and long-lived assets; share-based compensation; and accounting for income taxes.
Lessor	Lessor Leases The Company determines if an arrangement is a lease at inception. The transaction price is allocated to separate performance obligations, generally consisting of hardware and software products, installation, and post-installation technical support, proportionally based on the standalone selling price of each performance obligation. Standalone selling price is best evidenced by the price the Company charges for the good or service when selling it separately in similar circumstances to similar customers. Other than for the renewal of annual support services contracts, the Company’s products and services are not generally sold separately. The Company uses an amount discounted from the list price as a best estimated selling price. Sales-Type Leases The Company enters into non-cancelable sales-type lease arrangements, most of which do not have an option to extend the lease term. At the end of the lease term, the customer must either return the equipment or negotiate a new agreement, resulting in a new purchase or lease transaction. Failure of the customer to either return the equipment or negotiate a new agreement results in the contract becoming a month-to-month rental. Certain sales-type leases automatically renew for successive one year periods at the end of each lease term with written notice from the customer. The Company’s sales-type lease agreements do not contain any material residual value guarantees. For sales-type leases, the Company recognizes revenues for its hardware and software products, net of lease execution costs, post-installation product maintenance, and technical support, at the net present value of the lease payment stream upon customer acceptance. The Company recognizes service revenues associated with the sales-type leases ratably over the term of the agreement in service revenues on the Condensed Consolidated Statements of Operations. The Company recognizes interest income from sales-type leases using the effective interest method. Both hardware and software revenues, and interest income from sales-types leases are recorded in product revenues on the Condensed Consolidated Statements of Operations. The Company optimizes cash flows by selling a majority of its non-U.S. government sales-type leases to third-party leasing finance companies on a non-recourse basis. The Company has no obligation to the leasing company once the lease has been sold. Some of the Company's sales-type leases, mostly those relating to U.S. government hospitals which comprise approximately 44% of the lease receivable balance, are retained in-house. Operating Leases The Company entered into certain leasing agreements that were classified as operating leases prior to the adoption of the new lease accounting standard. Those agreements in place prior to January 1, 2019 will continue to be treated as operating leases, however any new leasing agreements entered into on or after January 1, 2019 under these programs are classified and accounted for as sales-type leases in accordance with the new lease accounting standard. The operating lease arrangements entered into prior to January 1, 2019 are non-cancelable, and most automatically renew for successive one year periods at the end of each lease term absent written notice from the customer. The Company’s operating lease agreements do not contain any material residual value guarantees. For operating leases, rental income is generally recognized on a straight-line basis over the term of the associated lease, and recorded in revenues in the Condensed Consolidated Statements of Operations. Leased assets under operating leases are carried at amortized cost net of accumulated depreciation in property and equipment, net on the Condensed Consolidated Balance Sheets. The depreciation expense of the leased assets is recognized on a straight-line basis over the contractual term of the associated lease, and recorded in cost of revenues in the Condensed Consolidated Statements of Operations.
Lessee	Lessee Leases The Company determines if an arrangement is a lease at inception. Operating lease right-of-use assets and liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. As most of our lease contracts do not provide an implicit rate, the Company uses its incremental borrowing rate based on information available at the commencement date in determining the present value of the lease payments. Many of the Company’s operating leases include an option to extend the lease. The specific terms and conditions of the extension options vary from lease to lease, but are consistent with standard industry practices in each area that the Company operates. The Company reviews each of its lease options at a time required by the terms of the lease contract, and notifies the lessor if it chooses to exercise the lease renewal option. Until the Company is reasonably certain that it will extend the lease contract, the renewal option periods will not be recognized as right-of-use assets or lease liabilities. Certain leases include provisions for early termination, which allows the contract parties to terminate their obligations under the lease contract. The terms and conditions of the termination options vary by contract. When the Company has made a decision to exercise an early termination option, the right-of-use assets and associated lease liabilities are remeasured in accordance with the present value of the remaining cash flows under the lease contract. Certain building lease agreements include rental payments subject to change annually based on fluctuations in various indexes (i.e. Consumer Price Index (“CPI”), Retail Price Index, and other international indexes). Certain data center lease agreements include rental payments subject to change based on usage and CPI fluctuations. The changes based on usage and indexes are treated as variable lease costs and recognized in the period in which the obligation for those payments was incurred. The Company’s operating lease agreements do not contain any material residual value guarantees, restrictions, or restriction covenants.
Recently Adopted and Issued Authoritative Guidance	Recently Adopted Authoritative Guidance In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, Leases (Topic 842) . The FASB amended lease accounting requirements to begin recording assets and liabilities arising from most leases on the balance sheet. The new guidance also requires significant additional disclosures about the amount and timing of cash flows from leases. The Company adopted this new guidance on January 1, 2019. In July 2018, the FASB issued amendments in ASU 2018-11, which provide a transition election to not restate comparative periods for the effects of applying the new standard. This transition election permits entities to change the date of initial application to the beginning of the year of adoption and to recognize the effects of applying the new standard as a cumulative-effect adjustment to the opening balance of retained earnings. The Company has elected this transition approach as well as elected the package of practical expedients permitted under the transition guidance within the new standard, which will allow the Company to carry forward the historical lease classification of contracts entered into prior to January 1, 2019. As a result of electing the package of practical expedients described above, existing leases and related initial direct costs have not been reassessed prior to the effective date, and therefore, adoption of the lease standard did not have an impact on the Company’s previously reported consolidated statements. The Company also elected the following practical expedients: (i) combining lease and non-lease components, (ii) leases with an initial term of 12 months or less are not recorded in the Condensed Consolidated Balance Sheets, and the associated lease payments are recognized in the Condensed Consolidated Statements of Operations on a straight-line basis over the lease term, and (iii) applying discount rates to operating leases using a portfolio approach. From a lessor perspective, certain agreements that were previously classified as operating leases are classified as sales-type leases under the new lease accounting standard. The agreements in place prior to the adoption of the new lease accounting standard on January 1, 2019 will continue to be treated as operating leases. The Company’s adoption of the new standard impacted the Condensed Consolidated Balances Sheets at the beginning of the period of adoption as follows: January 1, 2019 Pre-ASC 842 Balances ASC 842 Adoption Impact Post-ASC 842 Balances (In thousands) Operating lease right-of-use assets $ — $ 66,008 $ 66,008 Accrued liabilities (1) 43,047 10,067 53,114 Long-term operating lease liabilities — 59,791 59,791 Other long-term liabilities (2) 9,562 (3,850 ) 5,712 _________________________________________________ (1) Adjustment represents the current portion of the operating lease liabilities of $10.3 million , and reclassification of exit cost obligations and deferred rent of $0.1 million and $0.1 million , respectively, to reduce the operating lease right-of-use assets. (2) Adjustment represents the reclassification of deferred rent to reduce the operating lease right-of-use assets. Adoption of the standard did not have an impact on the Company’s stockholders’ equity, Condensed Consolidated Statements of Operations, and Condensed Consolidated Statements of Cash Flows as of January 1, 2019. In February 2018, the FASB issued ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , which permits the reclassification of the income tax effects of the Tax Cuts and Jobs Act of 2017 (the “Tax Act”) on items within accumulated other comprehensive income to retained earnings. These amounts are commonly referred to as “stranded tax effects.” ASU 2018-02 is effective for the Company beginning January 1, 2019. The adoption of this guidance did not have a material effect on the Company’s consolidated financial statements and therefore no adjustment to retained earnings was made. Recently Issued Authoritative Guidance In August 2018, the FASB issued ASU 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract , to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). ASU 2018-15 will be effective for the Company beginning January 1, 2020. The Company is currently evaluating the impact ASU 2018-15 will have on its consolidated financial statements. There was no other recently issued and effective authoritative guidance that is expected to have a material impact on the Company’s Condensed Consolidated Financial Statements through the reporting date.

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The Company’s adoption of the new standard impacted the Condensed Consolidated Balances Sheets at the beginning of the period of adoption as follows: January 1, 2019 Pre-ASC 842 Balances ASC 842 Adoption Impact Post-ASC 842 Balances (In thousands) Operating lease right-of-use assets $ — $ 66,008 $ 66,008 Accrued liabilities (1) 43,047 10,067 53,114 Long-term operating lease liabilities — 59,791 59,791 Other long-term liabilities (2) 9,562 (3,850 ) 5,712 _________________________________________________ (1) Adjustment represents the current portion of the operating lease liabilities of $10.3 million , and reclassification of exit cost obligations and deferred rent of $0.1 million and $0.1 million , respectively, to reduce the operating lease right-of-use assets. (2) Adjustment represents the reclassification of deferred rent to reduce the operating lease right-of-use assets.

Revenues (Tables)

Revenues (Tables)	3 Months Ended
	Mar. 31, 2019
Revenue Recognition [Abstract]
Product revenue by type	The following table summarizes the Company’s product revenues disaggregated by revenue type for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 2018 (In thousands) Hardware and software $ 120,221 $ 107,451 Consumables 21,087 19,438 Other 4,302 3,770 Total product revenues $ 145,610 $ 130,659
Revenues by Geographical Location	The following table summarizes the Company’s revenues disaggregated by geographic region, which is determined based on customer location, for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 2018 (In thousands) United States $ 180,020 $ 158,202 Rest of world (1) 22,497 24,417 Total revenues $ 202,517 $ 182,619 _________________________________________________ (1) No individual country represented more than 10% of the respective totals.
Contract Asset and Liabilities	The following table reflects the Company’s contract assets and contract liabilities: March 31, December 31, (In thousands) Short-term unbilled receivables - included in accounts receivable and unbilled receivables $ 8,708 $ 9,191 Long-term unbilled receivables - included in other long-term assets 11,423 16,481 Total contract assets $ 20,131 $ 25,672 Short-term deferred revenues, net $ 90,104 $ 81,835 Long-term deferred revenues 10,302 10,582 Total contract liabilities $ 100,406 $ 92,417

Net Income Per Share (Tables)

Net Income Per Share (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Basic and Diluted Net Income Per Share	The basic and diluted net income per share calculation for the three months ended March 31, 2019 and 2018 was as follows: Three months ended March 31, 2019 2018 (In thousands, except per share data) Net income $ 3,284 $ 2,720 Weighted-average shares outstanding — basic 40,692 38,635 Effect of dilutive securities from stock award plans 1,589 1,056 Weighted-average shares outstanding — diluted 42,281 39,691 Net income per share - basic $ 0.08 $ 0.07 Net income per share - diluted $ 0.08 $ 0.07 Anti-dilutive weighted-average shares related to stock award plans 635 1,113

Cash and Cash Equivalents and_2

Cash and Cash Equivalents and Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Financial Assets Measured At Fair Value	The following table represents the fair value hierarchy of the Company’s financial assets and financial liabilities measured at fair value as of March 31, 2019 : Level 1 Level 2 Level 3 Total (In thousands) Interest rate swap contracts $ — $ 136 $ — $ 136 Total financial assets $ — $ 136 $ — $ 136 The following table represents the fair value hierarchy of the Company’s financial assets and financial liabilities measured at fair value as of December 31, 2018 : Level 1 Level 2 Level 3 Total (In thousands) Interest rate swap contracts $ — $ 562 $ — $ 562 Total financial assets $ — $ 562 $ — $ 562

Balance Sheet Components (Table

Balance Sheet Components (Tables)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Balance sheet details as of March 31, 2019 and December 31, 2018 are presented in the tables below: March 31, December 31, (In thousands) Inventories: Raw materials $ 34,552 $ 32,511 Work in process 8,876 8,726 Finished goods 60,481 59,631 Total inventories $ 103,909 $ 100,868 Other long-term assets: Capitalized software, net $ 64,682 $ 56,819 Unbilled receivables 11,423 16,481 Other assets 1,165 1,313 Total other long-term assets, net $ 77,270 $ 74,613 Accrued liabilities: Operating lease liabilities, current portion $ 10,373 $ — Advance payments from customers 9,400 8,993 Rebates and lease buyouts 8,111 11,076 Group purchasing organization fees 4,403 4,455 Taxes payable 5,996 5,885 Other accrued liabilities 14,713 12,638 Total accrued liabilities $ 52,996 $ 43,047
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes the changes in accumulated balances of other comprehensive income (loss) for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 2018 Foreign currency translation adjustments Unrealized gain (loss) on interest rate swap hedges Total Foreign currency translation adjustments Unrealized gain (loss) on interest rate swap hedges Total (In thousands) Beginning balance $ (11,274 ) $ 420 $ (10,854 ) $ (6,954 ) $ 841 $ (6,113 ) Other comprehensive income before reclassifications 669 100 769 2,472 401 2,873 Amounts reclassified from other comprehensive income (loss), net of tax — (417 ) (417 ) — (199 ) (199 ) Net current-period other comprehensive income (loss), net of tax 669 (317 ) 352 2,472 202 2,674 Ending balance $ (10,605 ) $ 103 $ (10,502 ) $ (4,482 ) $ 1,043 $ (3,439 )

Property and Equipment (Tables)

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	The following table represents the property and equipment balances as of March 31, 2019 and December 31, 2018 : March 31, December 31, (In thousands) Equipment $ 76,668 $ 75,417 Furniture and fixtures 8,122 7,844 Leasehold improvements 16,381 16,274 Software 42,305 42,048 Construction in progress 11,791 10,706 Property and equipment, gross 155,267 152,289 Accumulated depreciation and amortization (103,228 ) (100,789 ) Total property and equipment, net $ 52,039 $ 51,500
Long-Lived Assets by Geographic Areas	The following table summarizes the geographic information for property and equipment, net, as of March 31, 2019 and December 31, 2018 : March 31, December 31, (In thousands) United States $ 45,656 $ 44,684 Rest of world (1) 6,383 6,816 Total property and equipment, net $ 52,039 $ 51,500 _________________________________________________ (1) No individual country represented more than 10% of the respective totals.

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	The following table represents changes in the carrying amount of goodwill: December 31, Additions Foreign currency exchange rate fluctuations March 31, (In thousands) Goodwill $ 335,887 $ — $ 232 $ 336,119
Finite-Lived Intangible Assets	The carrying amounts and useful lives of intangible assets as of March 31, 2019 and December 31, 2018 were as follows: March 31, 2019 Gross carrying amount (1) Accumulated amortization Foreign currency exchange rate fluctuations Net carrying amount Useful life (years) (In thousands, except for years) Customer relationships $ 135,234 $ (47,557 ) $ (1,127 ) $ 86,550 1 - 30 Acquired technology 77,142 (30,239 ) 8 46,911 3 - 20 Backlog 1,150 (575 ) — 575 1 - 4 Trade names 7,650 (4,530 ) 11 3,131 1 - 12 Patents 3,239 (1,515 ) 2 1,726 2 - 20 Total intangibles assets, net $ 224,415 $ (84,416 ) $ (1,106 ) $ 138,893 December 31, 2018 Gross carrying amount (1) Accumulated amortization Foreign currency exchange rate fluctuations Net carrying amount Useful life (years) (In thousands, except for years) Customer relationships $ 135,234 $ (45,029 ) $ (1,185 ) $ 89,020 1 - 30 Acquired technology 78,122 (29,206 ) 42 48,958 3 - 20 Backlog 21,350 (20,703 ) — 647 1 - 4 Trade names 7,650 (4,361 ) 17 3,306 1 - 12 Patents 3,239 (1,488 ) 4 1,755 2 - 20 Non-compete agreements 1,900 (1,900 ) — — 3 Total intangibles assets, net $ 247,495 $ (102,687 ) $ (1,122 ) $ 143,686 _________________________________________________ (1) The differences in gross carrying amounts between periods are due to the write-off of fully amortized intangible assets.
Future Amortization Expense for Intangible Assets	The estimated future amortization expenses for amortizable intangible assets were as follows: March 31, (In thousands) Remaining nine months of 2019 $ 13,984 2020 17,618 2021 16,268 2022 14,918 2023 13,768 Thereafter 62,337 Total $ 138,893

Debt and Credit Agreements (Tab

Debt and Credit Agreements (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Debt	The components of the Company’s debt obligations as of March 31, 2019 and December 31, 2018 were as follows: December 31, Borrowings Repayment / Amortization March 31, (In thousands) Term loan facility $ 140,000 $ — $ (39,000 ) $ 101,000 Revolving credit facility — — — — Total debt under the facilities 140,000 — (39,000 ) 101,000 Less: Deferred issuance cost (4,583 ) — 573 (4,010 ) Total long-term debt, net of deferred issuance cost $ 135,417 $ — $ (38,427 ) $ 96,990

Lessor Leases (Tables)

Lessor Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Sales-type Lease Income	The receivables as a result of these types of transactions are collateralized by the underlying equipment leased and consist of the following components at March 31, 2019 and December 31, 2018 : March 31, December 31, (In thousands) Net minimum lease payments to be received $ 30,806 $ 28,295 Less: Unearned interest income portion (2,348 ) (2,477 ) Net investment in sales-type leases 28,458 25,818 Less: Current portion (1) (8,989 ) (8,736 ) Long-term net investment in sales-type leases $ 19,469 $ 17,082 _________________________________________________ (1) The current portion of the net investment in sales-type leases is included in other current assets in the Condensed Consolidated Balance Sheets. The following table presents the Company’s income recognized from sales-type leases for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 2018 (In thousands) Sales-type lease revenues $ 11,507 $ 9,857 Interest income on sales-type lease receivables $ 409 $ 267
Minimum Future Payments from Non-Cancelable Sales-Type Leases	The maturity schedule of future minimum lease payments under sales-type leases retained in-house and the reconciliation to the net investment in sales-type leases reported on the Condensed Consolidated Balance Sheets was as follows: March 31, (In thousands) Remaining nine months of 2019 $ 8,215 2020 8,016 2021 5,777 2022 5,081 2023 3,097 Thereafter 620 Total future minimum sales-type lease payments $ 30,806 Present value adjustment (2,348 ) Total net investment in sales-type leases $ 28,458
Operating Lease Income	The following table represents the Company’s income recognized from operating leases for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 2018 (In thousands) Rental income $ 3,287 $ 2,790
Payments to be Received	The maturity schedule of future minimum lease payments under operating leases was as follows: March 31, (In thousands) Remaining nine months of 2019 9,124 2020 9,349 2021 7,244 2022 5,205 2023 3,026 Thereafter 1,248 Total future minimum operating lease payments $ 35,196

Lessee Leases (Tables)

Lessee Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Minimum Future Payments on Non-Cancelable Operating Leases	The maturity schedule of future minimum lease payments under operating leases and the reconciliation to the operating lease liabilities reported on the Condensed Consolidated Balance Sheets was as follows: March 31, (In thousands) Remaining nine months of 2019 $ 10,737 2020 13,328 2021 12,831 2022 11,799 2023 8,415 Thereafter 27,832 Total operating lease payments $ 84,942 Present value adjustment (17,099 ) Total operating lease liabilities (1) $ 67,843 _________________________________________________ (1) Amount consists of a current and long-term portion of operating lease liabilities of $10.4 million and $57.5 million , respectively. The short-term portion of the operating lease liabilities is included in accrued liabilities in the Condensed Consolidated Balance Sheets.
Minimum Future Payments on Non-Cancelable Operating Leases Prior To ASC 842 Adoption	Prior to the adoption of the new lease accounting standard, the maturity schedule of future minimum lease payments under operating leases was as follows: December 31, 2018 (In thousands) 2019 $ 14,153 2020 13,104 2021 12,729 2022 11,809 2023 8,334 Thereafter 27,289 Total minimum future lease payments $ 87,418
Lease Costs	The following table summarizes other information related to the Company’s operating leases for the three months ended March 31, 2019 : Three months ended March 31, 2019 (Dollars in thousands) Cash paid for amounts included in the measurement of lease liabilities $ 3,761 Right-of-use assets obtained in exchange for new lease liabilities 431 Weighted-average remaining lease term, years 7.0 Weighted-average discount rate, % 6.4 %

Employee Benefits and Share-B_2

Employee Benefits and Share-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation Expense Recognized in Consolidated Statements of Income	The following table sets forth the total share-based compensation expense recognized in the Company’s Condensed Consolidated Statements of Operations for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 March 31, 2018 (In thousands) Cost of product and service revenues $ 1,462 $ 1,019 Research and development 1,702 1,234 Selling, general, and administrative 5,246 4,275 Total share-based compensation expense $ 8,410 $ 6,528
Stock Option Plans, Valuation Assumptions	The following assumptions were used to value stock options and Employee Stock Purchase Plan (“ESPP”) shares granted pursuant to the Company’s equity incentive plans for the three months ended March 31, 2019 and 2018 : Three months ended March 31, 2019 March 31, 2018 Stock options Expected life, years 4.5 4.8 Expected volatility, % 33.1 % 32.2 % Risk-free interest rate, % 2.6 % 2.6 % Estimated forfeiture rate, % 7.2 % 6.9 % Dividend yield, % — % — %
Employee Stock Purchase Plan, Valuation Assumptions	Three months ended March 31, 2019 March 31, 2018 Employee stock purchase plan shares Expected life, years 0.5 - 2.0 0.5 - 2.0 Expected volatility, % 28.2% - 38.4% 27.7% - 33.8% Risk-free interest rate, % 1.3% - 2.7% 0.7% - 2.3% Dividend yield, % — % — %
Stock Option Activity under the Equity Incentive Plans	The following table summarizes the share option activity under the Company’s equity incentive plans during the three months ended March 31, 2019 : Number of Shares Weighted-Average Exercise Price Weighted-Average Remaining Years Aggregate Intrinsic Value (In thousands, except per share data) Outstanding at December 31, 2018 3,748 $ 41.27 7.6 $ 78,365 Granted 292 76.18 Exercised (379 ) 31.83 Expired — — Forfeited (117 ) 44.18 Outstanding at March 31, 2019 3,544 $ 45.06 7.9 $ 127,007 Exercisable at March 31, 2019 1,275 $ 31.24 6.3 $ 63,241 Vested and expected to vest at March 31, 2019 and thereafter 3,544 $ 45.06 7.9 $ 127,007
Restricted Stock Units Activity under the Equity Incentive Plans	Summaries of the restricted stock activity under the Company’s 2009 Equity Incentive Plan, as amended (the “2009 Plan”) are presented below for the three months ended March 31, 2019 : Number of Shares Weighted-Average Grant Date Fair Value Weighted-Average Remaining Years Aggregate Intrinsic Value (In thousands, except per share data) Restricted stock units Outstanding at December 31, 2018 538 $ 51.52 1.6 $ 32,935 Granted (Awarded) 30 78.23 Vested (Released) (36 ) 39.78 Forfeited (27 ) 44.87 Outstanding and unvested at March 31, 2019 505 $ 54.32 1.5 $ 40,813
Restricted Stock Awards Activity under the Equity Incentive Plans	Number of Shares Weighted-Average Grant Date Fair Value (In thousands, except per share data) Restricted stock awards Outstanding at December 31, 2018 21 $ 46.60 Granted (Awarded) — — Vested (Released) — — Forfeited — — Outstanding and unvested at March 31, 2019 21 $ 46.60
Performance-Based Restricted Stock under the Equity Incentive Plans	A summary of the performance-based restricted stock activity under the 2009 Plan is presented below for the three months ended March 31, 2019 : Number of Shares Weighted-Average Grant Date Fair Value Per Unit (In thousands, except per share data) Outstanding at December 31, 2018 197 $ 34.83 Granted 61 72.02 Vested (26 ) 38.03 Forfeited (20 ) 34.37 Outstanding and unvested at March 31, 2019 212 $ 45.18
Shares Reserved for Future Issuance under the Equity Incentive Plans	The Company had the following ordinary shares reserved for future issuance under its equity incentive plans as of March 31, 2019 : Number of Shares (In thousands) Share options outstanding 3,544 Non-vested restricted share awards 738 Shares authorized for future issuance 2,140 ESPP shares available for future issuance 1,703 Total shares reserved for future issuance 8,125

Organization and Summary of S_4

Organization and Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	Jan. 01, 2019segment	Mar. 31, 2019USD ($)segment	Mar. 31, 2018USD ($)
Accounting Principle [Line Items]
Number of Reportable Segments | segment	1
Number of Operating Segments | segment		1
Total revenues		$ 202,517	$ 182,619
Product revenues
Accounting Principle [Line Items]
Total revenues		145,610	$ 130,659
Difference between Revenue Guidance in Effect before and after Topic 606 | Product revenues
Accounting Principle [Line Items]
Total revenues		$ 600
Lease Receivable | Customer Concentration Risk
Accounting Principle [Line Items]
Concentration risk percentage		44.00%

Organization and Summary of S_5

Organization and Summary of Significant Accounting Policies - Impact of Adopted Standard (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Mar. 31, 2019	Dec. 31, 2018
Accounting Principle [Line Items]
Operating Lease, Liability, Current	$ 10,300	$ 10,373	$ 0
Operating lease right-of-use assets	66,008	63,851	0
Accrued Liabilities	53,114	52,996	43,047
Other long-term liabilities	5,712	9,786	9,562
Long-term operating lease liabilities	59,791	$ 57,470	$ 0
Lease Exit Costs Obligations	100
Deferred Rent Credit, Current	100
Pre-Adjustment
Accounting Principle [Line Items]
Operating lease right-of-use assets	0
Other long-term liabilities	9,562
Long-term operating lease liabilities	0
Adjustment | Accounting Standards Update 2016-02
Accounting Principle [Line Items]
Operating lease right-of-use assets	66,008
Accrued Liabilities	10,067
Other long-term liabilities	(3,850)
Long-term operating lease liabilities	$ 59,791

Revenues (Details)

Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Revenue from External Customer [Line Items]
Fees to GPOs	$ 2,200	$ 1,900
Short-term deferred revenues	90,104		$ 81,835
Deferred revenues recognized	39,300
Contract with Customer, Liability, Current, Gross			92,900
Long-term deferred revenues	10,302		10,582
Deferred cost of sale,short-term
Revenue from External Customer [Line Items]
Short-term deferred revenues	$ 12,200		$ 11,100

Revenues Product revenue by typ

Revenues Product revenue by type (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue from External Customer [Line Items]
Total revenues	$ 202,517	$ 182,619
Hardware and software
Revenue from External Customer [Line Items]
Total revenues	120,221	107,451
Consumables
Revenue from External Customer [Line Items]
Total revenues	21,087	19,438
Other
Revenue from External Customer [Line Items]
Total revenues	4,302	3,770
Product revenues
Revenue from External Customer [Line Items]
Total revenues	$ 145,610	$ 130,659

Revenues Revenues by Geographic

Revenues Revenues by Geographic Location (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue from External Customer [Line Items]
Revenues	$ 202,517	$ 182,619
United States
Revenue from External Customer [Line Items]
Revenues	180,020	158,202
Rest of world
Revenue from External Customer [Line Items]
Revenues	$ 22,497	$ 24,417

Revenues Contract Asset and Lia

Revenues Contract Asset and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Contract Assets and Liabilities
Short-term unbilled receivables - included in accounts receivable and unbilled receivables	$ 8,708	$ 9,191
Total contract assets	20,131	25,672
Deferred revenues, net	90,104	81,835
Long-term deferred revenues	10,302	10,582
Total contract liabilities	100,406	92,417
Long-term unbilled receivables - included in other long-term assets
Contract Assets and Liabilities
Other long-term assets	$ 11,423	$ 16,481

Net Income Per Share (Details)

Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Net income	$ 3,284	$ 2,720
Weighted-average shares outstanding — basic (in shares)	40,692	38,635
Effect of dilutive securities from stock award plans (in shares)	1,589	1,056
Weighted-average shares outstanding — diluted (in shares)	42,281	39,691
Net income per share - basic (in dollars per share)	$ 0.08	$ 0.07
Net income per share - diluted (in dollars per share)	$ 0.08	$ 0.07
Anti-dilutive weighted-average shares related to stock award plans (in shares)	635	1,113

Cash and Cash Equivalents and_3

Cash and Cash Equivalents and Fair Value of Financial Instruments - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 77,244	$ 67,192	$ 43,773	$ 32,424
Fair value of the interest rate swap agreements	$ 136	$ 562
Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, notional amount					$ 100,000
Derivative, fixed interest rate					0.80%
London Interbank Offered Rate (LIBOR) | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, basis spread on variable rate					0.00%

Cash and Cash Equivalents and_4

Cash and Cash Equivalents and Fair Value of Financial Instruments - Schedule of Financial Assets Measured At Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap contracts	$ 136	$ 562
Total financial assets	136	562
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap contracts	0	0
Total financial assets	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap contracts	136	562
Total financial assets	136	562
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap contracts	0	0
Total financial assets	$ 0	$ 0

Balance Sheet Components - Bala

Balance Sheet Components - Balance Sheet Details (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Inventories:
Raw materials	$ 34,552		$ 32,511
Work in process	8,876		8,726
Finished goods	60,481		59,631
Total inventories	103,909		100,868
Other long-term assets:
Capitalized software, net	64,682		56,819
Unbilled receivables	11,423		16,481
Other assets	1,165		1,313
Total other long-term assets, net	77,270		74,613
Accrued liabilities:
Operating Lease, Liability, Current	10,373	$ 10,300	0
Advance payments from customers	9,400		8,993
Rebates and lease buyouts	8,111		11,076
Group purchasing organization fees	4,403		4,455
Taxes payable	5,996		5,885
Other accrued liabilities	14,713		12,638
Total accrued liabilities	$ 52,996		$ 43,047

Balance Sheet Components - Accu

Balance Sheet Components - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 679,617	$ 554,339
Other comprehensive income before reclassifications	769	2,873
Amounts reclassified from other comprehensive income (loss), net of tax	(417)	(199)
Net current-period other comprehensive income (loss), net of tax	352	2,674
Unrealized gains (losses) on interest rate swap contracts	(317)	202
Ending balance	730,485	574,502
Foreign currency translation adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(11,274)	(6,954)
Other comprehensive income before reclassifications	669	2,472
Amounts reclassified from other comprehensive income (loss), net of tax	0	0
Net current-period other comprehensive income (loss), net of tax	669	2,472
Ending balance	(10,605)	(4,482)
Unrealized gain (loss) on interest rate swap hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	420	841
Other comprehensive income before reclassifications	100	401
Amounts reclassified from other comprehensive income (loss), net of tax	(417)	(199)
Net current-period other comprehensive income (loss), net of tax	(317)	202
Ending balance	103	1,043
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(10,854)	(6,113)
Ending balance	$ (10,502)	$ (3,439)

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Property, Plant and Equipment [Abstract]
Depreciation	$ 4	$ 3.5

Property and Equipment Property

Property and Equipment Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 155,267	$ 152,289
Accumulated depreciation and amortization	103,228	100,789
Total property and equipment, net	52,039	51,500
Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	76,668	75,417
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	8,122	7,844
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	16,381	16,274
Software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	42,305	42,048
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 11,791	$ 10,706

Property and Equipment Long-liv

Property and Equipment Long-lived assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total property and equipment, net	$ 52,039	$ 51,500
United States
Property, Plant and Equipment [Line Items]
Total property and equipment, net	45,656	44,684
Rest of world
Property, Plant and Equipment [Line Items]
Total property and equipment, net	$ 6,383	$ 6,816

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Carrying Amount of Goodwill (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 335,887
Additions	0
Foreign currency exchange rate fluctuations	232
Ending balance	$ 336,119

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Intangible Assets, Net (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Intangible Assets [Line Items]
Accumulated amortization	$ (84,416)	$ (102,687)
Foreign currency exchange rate fluctuations	(1,106)	(1,122)
Total intangibles assets, gross carrying amount	224,415	247,495
Total intangible assets, net carrying amount	138,893	143,686
Customer relationships
Intangible Assets [Line Items]
Gross carrying amount	135,234	135,234
Accumulated amortization	(47,557)	(45,029)
Foreign currency exchange rate fluctuations	(1,127)	(1,185)
Total	$ 86,550	$ 89,020
Customer relationships | Minimum
Intangible Assets [Line Items]
Useful life (in years)	1 year	1 year
Customer relationships | Maximum
Intangible Assets [Line Items]
Useful life (in years)	30 years	30 years
Acquired technology
Intangible Assets [Line Items]
Gross carrying amount	$ 77,142	$ 78,122
Accumulated amortization	(30,239)	(29,206)
Foreign currency exchange rate fluctuations	8	42
Total	$ 46,911	$ 48,958
Acquired technology | Minimum
Intangible Assets [Line Items]
Useful life (in years)	3 years	3 years
Acquired technology | Maximum
Intangible Assets [Line Items]
Useful life (in years)	20 years	20 years
Backlog
Intangible Assets [Line Items]
Gross carrying amount	$ 1,150	$ 21,350
Accumulated amortization	(575)	(20,703)
Foreign currency exchange rate fluctuations	0	0
Total	$ 575	$ 647
Backlog | Minimum
Intangible Assets [Line Items]
Useful life (in years)	1 year	1 year
Backlog | Maximum
Intangible Assets [Line Items]
Useful life (in years)	4 years	4 years
Trade names
Intangible Assets [Line Items]
Gross carrying amount	$ 7,650	$ 7,650
Accumulated amortization	(4,530)	(4,361)
Foreign currency exchange rate fluctuations	11	17
Total	$ 3,131	$ 3,306
Trade names | Minimum
Intangible Assets [Line Items]
Useful life (in years)	1 year	1 year
Trade names | Maximum
Intangible Assets [Line Items]
Useful life (in years)	12 years	12 years
Patents
Intangible Assets [Line Items]
Gross carrying amount	$ 3,239	$ 3,239
Accumulated amortization	(1,515)	(1,488)
Foreign currency exchange rate fluctuations	2	4
Total	$ 1,726	$ 1,755
Patents | Minimum
Intangible Assets [Line Items]
Useful life (in years)	2 years	2 years
Patents | Maximum
Intangible Assets [Line Items]
Useful life (in years)	20 years	20 years
Non-compete agreements
Intangible Assets [Line Items]
Gross carrying amount		$ 1,900
Accumulated amortization		(1,900)
Foreign currency exchange rate fluctuations		0
Total		$ 0
Useful life (in years)	3 years	3 years

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense of intangible assets	$ 4.8	$ 6

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Future Amortization Expense for Intangible Assets (Details) $ in Thousands	Mar. 31, 2019USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Remaining nine months of 2019	$ 13,984
2020	17,618
2021	16,268
2022	14,918
2023	13,768
Thereafter	62,337
Total	$ 138,893

Debt and Credit Agreements - Ad

Debt and Credit Agreements - Additional Information (Details) - USD ($)	Jan. 05, 2016	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 26, 2017	Apr. 11, 2017
Debt Instrument [Line Items]
Repayment of debt and revolving credit facility		$ 39,000,000	$ 2,500,000
Interest expense		1,300,000	1,900,000
Amortization of debt financing fees		573,000	$ 573,000
Wells Fargo Bank, National Association
Debt Instrument [Line Items]
Proceeds from lines of credit		0
Repayment of debt and revolving credit facility		39,000,000
Amortization of debt financing fees		573,000
Carrying amount of debt		101,000,000		$ 140,000,000
Fair value of debt		103,500,000
Wells Fargo Bank, National Association | Secured Debt | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 400,000,000
Annual capital expenditure limitation per Credit Agreement	35,000,000					$ 45,000,000
Maximum allowed non-permitted investments per Credit Agreement	10,000,000					$ 20,000,000
Deferred issuance cost, gross	$ 10,100,000
Wells Fargo Bank, National Association | Secured Debt | Line of Credit | Credit Agreement, Interest Rate Option One | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Wells Fargo Bank, National Association | Secured Debt | Line of Credit | Credit Agreement, Interest Rate Option One | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	2.25%
Wells Fargo Bank, National Association | Secured Debt | Line of Credit | Credit Agreement, Interest Rate Option Two | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
Wells Fargo Bank, National Association | Secured Debt | Line of Credit | Credit Agreement, Interest Rate Option Two | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	1.25%
Wells Fargo Bank, National Association | Secured Debt | Line of Credit | Credit Agreement, Interest Rate Option Two | Federal Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
Wells Fargo Bank, National Association | Revolving credit facility
Debt Instrument [Line Items]
Proceeds from lines of credit		0
Repayment of debt and revolving credit facility		0
Carrying amount of debt		0		0
Wells Fargo Bank, National Association | Revolving credit facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 200,000,000				$ 315,000,000
Debt instrument, term (in years)	5 years
Wells Fargo Bank, National Association | Revolving credit facility | Line of Credit | Minimum
Debt Instrument [Line Items]
Commitment fee, percentage	0.20%
Wells Fargo Bank, National Association | Revolving credit facility | Line of Credit | Maximum
Debt Instrument [Line Items]
Commitment fee, percentage	0.35%
Wells Fargo Bank, National Association | Term loan facility
Debt Instrument [Line Items]
Proceeds from lines of credit		0
Repayment of debt and revolving credit facility		39,000,000
Carrying amount of debt		$ 101,000,000		$ 140,000,000
Wells Fargo Bank, National Association | Term loan facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 200,000,000
Debt instrument, term (in years)	5 years
Principal periodic payment, percent, years one and two	5.00%
Principal periodic payment, percent, years three and four	10.00%
Principal periodic payment, percent, year five	15.00%
Wells Fargo Bank, National Association | Letter of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 10,000,000
Wells Fargo Bank, National Association | Letter of Credit | Line of Credit | Minimum
Debt Instrument [Line Items]
Participation fee, percentage	1.50%
Wells Fargo Bank, National Association | Letter of Credit | Line of Credit | Maximum
Debt Instrument [Line Items]
Participation fee, percentage	2.25%
Wells Fargo Bank, National Association | Swing line loan, Sub-limit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 10,000,000

Debt and Credit Agreements - Co

Debt and Credit Agreements - Components of Debt (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Debt Borrowing, Repayment, Amortization during period [Abstract]
Repayment of debt and revolving credit facility	$ (39,000)	$ (2,500)
Amortization of deferred issuance cost	573	$ 573
Wells Fargo Bank, National Association
Components of beginning debt balance [Abstract]
Debt under credit facilities at beginning of period	140,000
Deferred issuance cost, net at beginning of period	(4,583)
Total Debt, net of deferred issuance cost at beginning of period	135,417
Debt Borrowing, Repayment, Amortization during period [Abstract]
Proceeds from lines of credit	0
Deferred issuance cost, gross	0
Increase in borrowings net of deferred issuance cost	0
Repayment of debt and revolving credit facility	(39,000)
Amortization of deferred issuance cost	573
Decrease in repayment/amortization net of deferred issuance cost	(38,427)
Components of ending debt balance [Abstract]
Debt under credit facilities at end of period	101,000
Deferred issuance cost, net at end of period	(4,010)
Total Debt, net of deferred issuance cost at end of period	96,990
Wells Fargo Bank, National Association | Term loan facility
Components of beginning debt balance [Abstract]
Debt under credit facilities at beginning of period	140,000
Debt Borrowing, Repayment, Amortization during period [Abstract]
Proceeds from lines of credit	0
Repayment of debt and revolving credit facility	(39,000)
Components of ending debt balance [Abstract]
Debt under credit facilities at end of period	101,000
Wells Fargo Bank, National Association | Revolving credit facility
Components of beginning debt balance [Abstract]
Debt under credit facilities at beginning of period	0
Debt Borrowing, Repayment, Amortization during period [Abstract]
Proceeds from lines of credit	0
Repayment of debt and revolving credit facility	0
Components of ending debt balance [Abstract]
Debt under credit facilities at end of period	$ 0

Lessor Leases Sales-type Lease

Lessor Leases Sales-type Lease Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Leases [Abstract]
Sales-type lease revenues	$ 11,507	$ 9,857
Interest income on sales-type lease receivables	$ 409	$ 267

Lessor Leases Investment in Sal

Lessor Leases Investment in Sale-Type Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Capital Leased Assets [Line Items]
Present value adjustment	$ (2,348)	$ (2,477)
Sales-type, Lease Receivable	28,458	25,818
Net Investment in Lease, Current	(8,989)	(8,736)
Net Investment in Lease, Noncurrent	19,469	17,082
Collective allowance for credit losses		200
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received	$ 30,806	$ 28,295
Minimum
Capital Leased Assets [Line Items]
Terms of sales-type leases (in years)	1 year
Maximum
Capital Leased Assets [Line Items]
Terms of sales-type leases (in years)	5 years
Sales Type Lease
Capital Leased Assets [Line Items]
Collective allowance for credit losses	$ 200

Lessor Leases Sale-Type Leases

Lessor Leases Sale-Type Leases Minimum Lease Receivables (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Remaining nine months of 2019	$ 8,215
2020	8,016
2021	5,777
2022	5,081
2023	3,097
Thereafter	620
Total future minimum sales-type lease payments	30,806	$ 28,295
Present value adjustment	(2,348)	(2,477)
Sales-type, Lease Receivable	28,458	25,818
Long-term investment in sales-type leases, net	$ 19,469	$ 17,082

Lessor Leases Operating Lease I

Lessor Leases Operating Lease Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Operating Leased Assets [Line Items]
Rental income	$ 3,287	$ 2,790
Total property and equipment, net	52,039		$ 51,500
Accumulated depreciation and amortization	103,228		100,789
Depreciation	$ 4,000	3,500
Minimum
Operating Leased Assets [Line Items]
Term of Contract ( in years )	1 year
Maximum
Operating Leased Assets [Line Items]
Term of Contract ( in years )	7 years
Equipment
Operating Leased Assets [Line Items]
Depreciation		$ 100
Equipment
Operating Leased Assets [Line Items]
Total property and equipment, net	$ 2,500		2,600
Accumulated depreciation and amortization	1,300		$ 1,200
Depreciation	$ 100

Lessor Leases Minimum Future Pa

Lessor Leases Minimum Future Payments from Non-Cancelable Sales-Type Leases (Details) $ in Thousands	Mar. 31, 2019USD ($)
Leases [Abstract]
Remaining nine months of 2019	$ 9,124
2020	9,349
2021	7,244
2022	5,205
2023	3,026
Thereafter	1,248
Total future minimum operating lease payments	$ 35,196

Lessee Leases Minimum Future Pa

Lessee Leases Minimum Future Payments on Non-Cancelable Operating Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Leased Assets [Line Items]
Weighted average remaining lease term ( in years )	6 years 11 months 27 days
Remaining nine months of 2019	$ 10,737
2020	13,328
2021	12,831
2022	11,799
2023	8,415
Thereafter	27,832
Total operating lease payments	84,942
Present value adjustment	(17,099)
Total operating lease liabilities	67,843
Operating Lease, Liability, Current	10,373	$ 10,300	$ 0
Long-term operating lease liabilities	$ 57,470	$ 59,791	$ 0
Minimum
Operating Leased Assets [Line Items]
Weighted average remaining lease term ( in years )	1 year
Maximum
Operating Leased Assets [Line Items]
Weighted average remaining lease term ( in years )	12 years

Lessee Leases Minimum Future _2

Lessee Leases Minimum Future Payments on Non-Cancelable Operating Leases Prior To ASC 842 Adoption (Details) $ in Thousands	Dec. 31, 2018USD ($)
Operating Leased Assets [Line Items]
2019	$ 14,153
2020	13,104
2021	12,729
2022	11,809
2023	8,334
Thereafter	27,289
Total operating lease payments	$ 87,418

Lessee Leases Lease Costs (Deta

Lessee Leases Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 3,671
Cash paid for amounts included in the measurement of lease liabilities	3,761
Right-of-use assets obtained in exchange for new lease liabilities	$ 431	$ 0
Term of contract ( in years )	6 years 11 months 27 days
Weighted-average discount rate ( as a percent )	6.40%
Minimum
Lessee, Lease, Description [Line Items]
Term of contract ( in years )	1 year
Maximum
Lessee, Lease, Description [Line Items]
Term of contract ( in years )	12 years

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	Mar. 31, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
Purchase Obligation	$ 71
Purchase obligation due within the remainder of the fiscal year	$ 65.5

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Income Tax Contingency [Line Items]
Annual effective tax rate ( as a percent )	23.30%	18.30%
Provision for (benefit from) income taxes	$ 8,067	$ (4,816)
Unrecognized tax benefits	14,300		$ 10,000
Accrued interest and penalties	1,500		$ 1,400
Equity Compensation
Income Tax Contingency [Line Items]
Provision for (benefit from) income taxes	(4,600)	(900)
Aesynt
Income Tax Contingency [Line Items]
Provision for (benefit from) income taxes	$ 9,600	$ (4,200)

Employee Benefits and Share-B_3

Employee Benefits and Share-Based Compensation - Shared-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 8,410	$ 6,528
Cost of product and service revenues
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	1,462	1,019
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	1,702	1,234
Selling, general, and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	5,246	$ 4,275
Forecast
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 800
Weighted-average remaining vesting period ( in years )	1 year 10 months 24 days
Equity Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 200

Employee Benefits and Share-B_4

Employee Benefits and Share-Based Compensation - Valuation of Share Based Awards, Table (Details)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
1997 Employee stock purchase plan | Employee stock purchase plan (ESPP)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield, %	0.00%	0.00%
Expected volatility, %, Min	28.20%	27.70%
Expected volatility, %, Max	38.40%	33.80%
Risk free interest rate, %, Min	1.30%	0.70%
Risk free interest rate, %, Max	2.70%	2.30%
1997 Employee stock purchase plan | Employee stock purchase plan (ESPP) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (in years)	6 months	6 months
1997 Employee stock purchase plan | Employee stock purchase plan (ESPP) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (in years)	2 years	2 years
2009 Plan | Employee stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (in years)	4 years 5 months 19 days	4 years 9 months 15 days
Expected volatility, %	33.10%	32.20%
Risk-free interest rate, %	2.60%	2.60%
Estimated forfeiture rate, %	7.20%	6.90%
Dividend yield, %	0.00%	0.00%

Employee Benefits and Share-B_5

Employee Benefits and Share-Based Compensation - Stock Option Activity (Details) - 2009 Plan - Employee stock option - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Number of Shares
Outstanding at beginning of period (in shares)	3,748
Granted (in shares)	292
Exercised (in shares)	(379)
Expired (in shares)	0
Forfeited (in shares)	(117)
Outstanding at end of period (in shares)	3,544		3,748
Exercisable at end of period (in shares)	1,275
Vested and expected to vest at end of period (in shares)	3,544
Weighted Average Exercise Price
Outstanding beginning balance (in dollars per share)	$ 41.27
Granted (in dollars per share)	76.18
Exercised (in dollars per share)	31.83
Expired (in dollars per share)	0
Forfeited (in dollars per share)	44.18
Outstanding ending balance (in dollars per share)	45.06		$ 41.27
Exercisable at end of period (in dollars per share)	31.24
Vested and expected to vest at end of period (in dollars per share)	$ 45.06
Weighted-average remaining years, outstanding	7 years 11 months 1 day		7 years 7 months 13 days
Weighted-average remaining years, exercisable at end of period	6 years 3 months 7 days
Weighted-average remaining vesting period ( in years )	7 years 11 months 1 day
Aggregate Intrinsic Value
Aggregate intrinsic value, outstanding at end of period	$ 127,007		$ 78,365
Aggregate intrinsic value, exercisable at end of period	63,241
Aggregate intrinsic value, vested and expected to vest at end of period	$ 127,007
Weighted-average fair value (in dollars per share)	$ 24.07	$ 14.22
Intrinsic value of options exercised	$ 17,100	$ 2,000
Unrecognized compensation cost of unvested stock options	$ 32,500
Weighted average period of compensation cost not yet recognized (in years)	2 years 10 months 10 days

Employee Benefits and Share-B_6

Employee Benefits and Share-Based Compensation - Employee Stock Purchase Plan (ESPP) Activity (Details) - 1997 Employee stock purchase plan - Employee stock purchase plan (ESPP) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchases under ESPP (in shares)	210	289
Exercised (in dollars per share)	$ 40.20	$ 26.30
Unrecognized compensation cost	$ 3.9
Weighted average period of compensation cost not yet recognized (in years)	1 year 6 months 4 days

Employee Benefits and Share-B_7

Employee Benefits and Share-Based Compensation - Restricted Stock Activity (Details) - 2009 Plan - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Restricted Stock Units (RSUs)
Number of Shares
Outstanding at beginning of period (in shares)	538
Granted (in shares)	30
Vested (in shares)	(36)
Forfeited (in shares)	(27)
Outstanding and unvested at end of period (in shares)	505	538
Weighted-Average Grant Date Fair Value
Outstanding and unvested (in dollars per share)	$ 51.52
Granted (in dollars per share)	78.23
Vested (in dollars per share)	39.78
Forfeited (in dollars per share)	44.87
Outstanding and unvested (in dollars per share)	$ 54.32	$ 51.52
Weighted-average remaining years, outstanding and unvested	1 year 5 months 16 days	1 year 7 months 6 days
Aggregate Intrinsic Value
Outstanding and unvested at end of period	$ 40,813	$ 32,935
Unrecognized compensation cost	$ 23,400
Weighted average period of compensation cost not yet recognized (in years)	2 years 8 months 27 days
Restricted Stock Awards (RSAs)
Number of Shares
Outstanding at beginning of period (in shares)	21
Granted (in shares)	0
Vested (in shares)	0
Forfeited (in shares)	0
Outstanding and unvested at end of period (in shares)	21	21
Weighted-Average Grant Date Fair Value
Outstanding and unvested (in dollars per share)	$ 46.60
Granted (in dollars per share)	0
Vested (in dollars per share)	0
Forfeited (in dollars per share)	0
Outstanding and unvested (in dollars per share)	$ 46.60	$ 46.60
Aggregate Intrinsic Value
Unrecognized compensation cost	$ 100
Weighted average period of compensation cost not yet recognized (in years)	1 month 13 days

Employee Benefits and Share-B_8

Employee Benefits and Share-Based Compensation - Performance Based Restricted Stock Unit Activity (Details) - 2009 Plan - Performance Shares $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)$ / sharesshares
Number of Shares
Outstanding at beginning of period (in shares) | shares	197
Granted (in shares) | shares	61
Vested (in shares) | shares	(26)
Canceled (in shares) | shares	(20)
Outstanding and unvested at end of period (in shares) | shares	212
Weighted-Average Grant Date Fair Value Per Share
Outstanding and unvested (in dollars per share) | $ / shares	$ 34.83
Granted (in dollars per share) | $ / shares	72.02
Vested (in dollars per share) | $ / shares	38.03
Canceled (in dollars per share) | $ / shares	34.37
Outstanding and unvested (in dollars per share) | $ / shares	$ 45.18
Unrecognized compensation cost | $	$ 5.3
Weighted average period of compensation cost not yet recognized (in years)	1 year 4 months 6 days

Employee Benefits and Share-B_9

Employee Benefits and Share-Based Compensation - Summary of Shares Reserved for Future Issuance Under Equity Incentive Plans (Details) shares in Thousands	Mar. 31, 2019shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance	8,125
2009 Plan | Share options outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance	3,544
2009 Plan | Non-vested restricted share awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance	738
2009 Plan | Shares authorized for future issuance
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance	2,140
1997 Employee stock purchase plan | ESPP shares available for future issuance
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance	1,703

Employee Benefits and Share-_10

Employee Benefits and Share-Based Compensation - Stock Repurchase Program (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Aug. 02, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares acquired (in shares)	0	0
The 2016 Repurchase Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase, authorized amount			$ 50,000,000
2016 and 2014 Share Repurchase Programs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase, remaining authorized repurchase amount	$ 54,900,000

Equity Offerings (Details)

Equity Offerings (Details) - Distribution Agreement - USD ($) $ / shares in Units, shares in Thousands	Nov. 03, 2017	Mar. 31, 2019
Subsidiary, Sale of Stock [Line Items]
Maximum aggregate offering price	$ 125,000,000
Consideration Received		$ 20,600,000
Payments of Stock Issuance Costs		$ 400,000
Number of Shares Issued ( in shares )		243
Average Price Per Share ( in USD per share )		$ 84.98
Available to be offered		$ 49,400,000

Restructuring Expenses (Details

Restructuring Expenses (Details) - Employee severance - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2018	Mar. 31, 2019
Q4 2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring expenses		$ 1.3
Restructuring Reserve			$ 0.1
Q1 2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 1.4