Ciena (CIEN) 10-K 20 Dec 19 2019 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Billions	12 Months Ended
	Oct. 31, 2019	Dec. 16, 2019	May 03, 2019
Cover page.
Document Type	10-K
Document Annual Report	true
Document Period End Date	Oct. 31, 2019
Document Transition Report	false
Entity File Number	001-36250
Entity Registrant Name	Ciena Corp
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	23-2725311
Entity Address, Address Line One	7035 Ridge Road
Entity Address, City or Town	Hanover
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	21076
City Area Code	410
Local Phone Number	694-5700
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	CIEN
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 6
Entity Common Stock, Shares Outstanding		154,054,072
Entity Central Index Key	0000936395
Current Fiscal Year End Date	--10-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Oct. 31, 2019	Oct. 31, 2018
Current assets:
Cash and cash equivalents	$ 904,045	$ 745,423
Short-term investments	109,940	148,981
Accounts receivable, net	724,854	786,502
Inventories, net	345,049	262,751
Prepaid expenses and other	297,914	198,945
Total current assets	2,381,802	2,142,602
Long-term investments	10,014	58,970
Equipment, building, furniture and fixtures, net	286,884	292,067
Goodwill	297,937	297,968
Other intangible assets, net	112,781	148,225
Deferred tax asset, net	714,942	745,039
Other long-term assets	88,986	71,652
Total assets	3,893,346	3,756,523
Current liabilities:
Accounts payable	344,819	340,582
Accrued liabilities and other short-term obligations	382,740	340,075
Deferred revenue	111,381	111,134
Current portion of long-term debt	7,000	7,000
Debt conversion liability	0	164,212
Total current liabilities	845,940	963,003
Long-term deferred revenue	45,492	58,323
Other long-term obligations	148,747	119,413
Long-term debt, net	680,406	686,450
Total liabilities	1,720,585	1,827,189
Commitments and contingencies (Note 25)
Stockholders’ equity:
Preferred stock — par value $0.01; 20,000,000 shares authorized; zero shares issued and outstanding	0	0
Common stock — par value $0.01; 290,000,000 shares authorized; 154,403,850 and 154,318,531 shares issued and outstanding	1,544	1,543
Additional paid-in capital	6,837,714	6,881,223
Accumulated other comprehensive loss	(22,084)	(5,780)
Accumulated deficit	(4,644,413)	(4,947,652)
Total stockholders’ equity	2,172,761	1,929,334
Total liabilities and stockholders’ equity	$ 3,893,346	$ 3,756,523

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Oct. 31, 2019	Oct. 31, 2018
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	290,000,000	290,000,000
Common stock, shares issued (in shares)	154,403,850	154,318,531
Common stock, shares outstanding (in shares)	154,403,850	154,318,531

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Revenue:
Total revenue	$ 3,572,131	$ 3,094,286	$ 2,801,687
Cost of goods sold:
Total cost of goods sold	2,030,065	1,779,596	1,555,901
Gross profit	1,542,066	1,314,690	1,245,786
Operating expenses:
Research and development	548,139	491,564	475,329
Selling and marketing	423,046	394,060	356,169
General and administrative	174,399	160,133	142,604
Amortization of intangible assets	21,808	15,737	33,029
Acquisition and integration costs	3,370	5,111	0
Significant asset impairments and restructuring costs	24,538	18,139	23,933
Total operating expenses	1,195,300	1,084,744	1,031,064
Income from operations	346,766	229,946	214,722
Interest and other income (loss), net	3,876	(12,029)	913
Interest expense	(37,452)	(55,249)	(55,852)
Loss on extinguishment and modification of debt	0	(13,887)	(3,657)
Income before income taxes	313,190	148,781	156,126
Provision (benefit) for income taxes	59,756	493,471	(1,105,827)
Net income (loss)	$ 253,434	$ (344,690)	$ 1,261,953
Basic net income (loss) per common share (in dollars per share)	$ 1.63	$ (2.40)	$ 8.89
Diluted net income (loss) per potential common share (in dollars per share)	$ 1.61	$ (2.49)	$ 7.53
Weighted average basic common shares outstanding (in shares)	155,720	143,738	141,997
Weighted average diluted potential common shares outstanding (in shares)	157,612	143,738	169,919
Products
Revenue:
Total revenue	$ 2,983,815	$ 2,565,460	$ 2,318,581
Cost of goods sold:
Total cost of goods sold	1,716,358	1,507,157	1,308,295
Services
Revenue:
Total revenue	588,316	528,826	483,106
Cost of goods sold:
Total cost of goods sold	$ 313,707	$ 272,439	$ 247,606

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Net income (loss)	$ 253,434	$ (344,690)	$ 1,261,953
Other Comprehensive Income (Loss)
Change in unrealized gain (loss) on available-for-sale securities, net of tax	577	26	(590)
Change in accumulated translation adjustments	(763)	686	8,012
Other comprehensive income (loss)	(16,304)	5,237	13,312
Total comprehensive income (loss)	237,130	(339,453)	1,275,265
Foreign Currency Forward Contracts
Other Comprehensive Income (Loss)
Change in unrealized gain (loss) on derivatives	3,985	(1,674)	(295)
Forward starting interest rate swaps
Other Comprehensive Income (Loss)
Change in unrealized gain (loss) on derivatives	$ (20,103)	$ 6,199	$ 6,185

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in-Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance at Oct. 31, 2016	$ 766,341	$ 1,398	$ 6,715,478	$ (24,329)	$ (5,926,206)
Beginning balance (in shares) at Oct. 31, 2016		139,767,627
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,261,953				1,261,953
Other comprehensive loss	13,312			13,312
Issuance of shares from employee equity plans	20,412	$ 32	20,380
Issuance of shares from employee equity plans (in shares)		3,275,600
Share-based compensation expense	48,360		48,360
Reversal of deferred tax asset valuation allowance	25,964		25,964
Ending balance at Oct. 31, 2017	2,136,342	$ 1,430	6,810,182	(11,017)	(4,664,253)
Ending balance (in shares) at Oct. 31, 2017		143,043,227
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(344,690)				(344,690)
Other comprehensive loss	5,237			5,237
Reclassification of cash conversion feature	(152,142)		(152,142)
Conversion of convertible notes into common shares	262,103	$ 122	261,981
Conversion of convertible notes into common shares (in shares)		12,236,146
Repurchases of common stock - repurchase program	(110,981)	$ (44)	(110,937)
Repurchases of common stock - repurchase program (in shares)		(4,290,801)
Issuance of shares from employee equity plans	23,127	$ 37	23,090
Issuance of shares from employee equity plans (in shares)		3,484,018
Share-based compensation expense	52,972		52,972
Shares repurchased for tax withholdings on vesting of restricted stock units	(4,757)	$ (2)	(4,755)
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)		(154,059)
Ending balance at Oct. 31, 2018	$ 1,929,334	$ 1,543	6,881,223	(5,780)	(4,947,652)
Ending balance (in shares) at Oct. 31, 2018	154,318,531	154,318,531
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 253,434				253,434
Other comprehensive loss	(16,304)			(16,304)
Conversion of convertible notes into common shares	52,944	$ 16	52,928
Conversion of convertible notes into common shares (in shares)		1,585,140
Repurchases of common stock - repurchase program	$ (150,076)	$ (38)	(150,038)
Repurchases of common stock - repurchase program (in shares)	(3,838,466,000)	(3,838,466)
Issuance of shares from employee equity plans	$ 22,947	$ 31	22,916
Issuance of shares from employee equity plans (in shares)	50,000	3,112,916
Share-based compensation expense	$ 59,736		59,736
Shares repurchased for tax withholdings on vesting of restricted stock units	(29,059)	$ (8)	(29,051)
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)		(774,271)
Ending balance at Oct. 31, 2019	$ 2,172,761	$ 1,544	$ 6,837,714	$ (22,084)	$ (4,644,413)
Ending balance (in shares) at Oct. 31, 2019	154,403,850	154,403,850

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Cash flows from operating activities:
Net income (loss)	$ 253,434	$ (344,690)	$ 1,261,953
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Loss on extinguishment of debt	0	10,039	0
Loss on fair value of debt conversion liability	0	12,070	0
Depreciation of equipment, building, furniture and fixtures, and amortization of leasehold improvements	87,576	84,214	77,189
Share-based compensation costs	59,736	52,972	48,360
Amortization of intangible assets	35,136	25,806	45,713
Deferred taxes	19,865	463,631	(1,126,732)
Provision for doubtful accounts	6,740	2,700	18,221
Provision for inventory excess and obsolescence	28,085	30,615	35,459
Provision for warranty	23,105	20,992	7,965
Other	(910)	21,685	22,417
Changes in assets and liabilities:
Accounts receivable	65,712	(168,357)	(66,123)
Inventories	(112,941)	(27,445)	(91,567)
Prepaid expenses and other	(96,618)	(21,425)	(33,834)
Accounts payable, accruals and other obligations	27,740	85,798	33,897
Deferred revenue	16,480	(19,344)	1,964
Net cash provided by operating activities	413,140	229,261	234,882
Cash flows used in investing activities:
Payments for equipment, furniture, fixtures and intellectual property	(62,579)	(67,616)	(94,600)
Purchase of available for sale securities	(158,074)	(286,824)	(299,038)
Proceeds from maturities of available for sale securities	248,748	410,109	335,075
Purchase of equity investment	(2,667)	(1,767)	0
Settlement of foreign currency forward contracts, net	(1,351)	9,385	(2,810)
Acquisition of businesses, net of cash acquired	0	(82,670)	0
Net cash used in investing activities	24,077	(19,383)	(61,373)
Cash flows from financing activities:
Proceeds from issuance of long-term debt, net	0	305,125	0
Payment of long-term debt	(7,000)	(292,730)	(233,554)
Payment for debt conversion liability	(111,268)	0	0
Payment for make-whole provision upon conversion of long-term debt	0	(13,453)	0
Payment for modification of term loans	0	0	(93,625)
Payment of debt issuance costs	(1,191)	(1,936)	(722)
Payment of capital lease obligations	(3,319)	(3,624)	(3,562)
Shares repurchased for tax withholdings on vesting of restricted stock units	(29,059)	(4,757)	0
Repurchases of common stock - repurchase program	(150,076)	(110,981)	0
Proceeds from issuance of common stock	22,947	23,127	20,412
Net cash used in financing activities	(278,966)	(99,229)	(311,051)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	476	(5,856)	494
Net increase (decrease) in cash, cash equivalents and restricted cash	158,727	104,793	(137,048)
Cash, cash equivalents and restricted cash at beginning of fiscal year	745,434	640,641	777,689
Cash, cash equivalents and restricted cash at end of fiscal year	904,161	745,434	640,641
Supplemental disclosure of cash flow information
Cash paid during the fiscal year for interest	39,579	44,750	47,235
Cash paid during the fiscal year for income taxes, net	33,570	26,900	22,136
Non-cash investing and financing activities
Purchase of equipment in accounts payable	16,549	5,118	6,214
Equipment acquired under and building subject to capital lease	0	0	50,370
Contingent consideration for acquisition of business	0	10,900	0
3.75% Convertible Senior Notes due October 15, 2018
Non-cash investing and financing activities
Conversion of convertible senior notes	0	61,270	0
4.0% Convertible Senior Notes due March 15, 2015
Non-cash investing and financing activities
Conversion of convertible senior notes	0	214,286	0
3.75% Convertible Senior Notes due October 15, 2018 (New)
Non-cash investing and financing activities
Conversion of convertible senior notes	$ 52,944	$ 0	$ 0

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - shares	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
3.75% Convertible Senior Notes due October 15, 2018
Interest rate on convertible notes	3.75%	3.75%
Debt conversion, shares issued (in shares)		3,038,208
4.0% Convertible Senior Notes due March 15, 2015
Interest rate on convertible notes		4.00%
Debt conversion, shares issued (in shares)		9,197,943
3.75% Convertible Senior Notes due October 15, 2018 (New)
Interest rate on convertible notes	3.75%
Debt conversion, shares issued (in shares)	1,585,140

Ciena Corporation and Significa

Ciena Corporation and Significant Accounting Policies and Estimates	12 Months Ended
	Oct. 31, 2019
Accounting Policies [Abstract]
CIENA CORPORATION AND SIGNIFICANT ACCOUNTING POLICIES AND ESTIMATES	CIENA CORPORATION AND SIGNIFICANT ACCOUNTING POLICIES AND ESTIMATES Description of Business Ciena Corporation (“Ciena” or the “Company”) is a networking systems, services and software company, providing solutions that enable a wide range of network operators to deploy and manage next-generation networks that deliver services to businesses and consumers. Ciena provides hardware, software and services that support the transport, switching, aggregation, service delivery and management of video, data and voice traffic on communications networks. Ciena’s solutions are used by communications service providers, cable and multiservice operators, Web-scale providers, submarine network operators, governments, enterprises, research and education institutions and other emerging network operators. Ciena’s solutions include a portfolio of Networking Platforms, including Ciena’s Converged Packet Optical and Packet Networking products, that can be applied from the network core to end user access points, and that allow network operators to scale capacity, increase transmission speeds, allocate traffic and adapt dynamically to changing end-user service demands. Ciena offers Platform Software that provides management and domain control of Ciena’s hardware solutions and automates network lifecycle operations, including provisioning equipment and services. Through its Blue Planet Automation Software, Ciena enables network providers to use network data, analytics and policy-based assurance to achieve closed loop automation across multi-vendor and multi-domain network environments, streamlining key business and network processes. To complement its hardware and software products, Ciena offers a broad range of services that help its customers build, operate and improve their networks and associated operational environments. Ciena refers to its complete portfolio vision as the Adaptive Network. The Adaptive Network emphasizes a programmable network infrastructure, software control and automation capabilities, and network analytics and intelligence. By transforming network infrastructures into a dynamic, programmable environment driven by automation and analytics, network operators can realize greater business agility, dynamically adapt to changing end user service demands and rapidly introduce new revenue-generating services. They can also gain valuable real-time network insights, allowing them to optimize network operation and maximize the return on their network infrastructure investment. Basis of Presentation The accompanying consolidated financial statements include the accounts of Ciena and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Ciena has a 52 or 53 week fiscal year, which ends on the Saturday nearest to the last day of October in each year ( November 2, 2019 , November 3, 2018 and October 28, 2017 for the periods reported). Fiscal 2019 and fiscal 2017 each consisted of a 52-week fiscal year and fiscal 2018 consisted of a 53-week fiscal year. For purposes of financial statement presentation, each fiscal year is described as having ended on October 31. Business Combinations Ciena records acquisitions using the purchase method of accounting. All of the assets acquired, liabilities assumed, contractual contingencies and contingent consideration are recognized at their fair value as of the acquisition date. The excess of the purchase price over the estimated fair values of the net tangible and net intangible assets acquired is recorded as goodwill. The application of the purchase method of accounting for business combinations requires management to make significant estimates and assumptions in the determination of the fair value of assets acquired and liabilities assumed, in order to properly allocate purchase price consideration between assets that are depreciated and amortized from goodwill. These assumptions and estimates include a market participant’s use of the asset and the appropriate discount rates for a market participant. Ciena’s estimates are based on historical experience, information obtained from the management of the acquired companies and, when appropriate, include assistance from independent third-party appraisal firms. Significant assumptions and estimates can include, but are not limited to, the cash flows that an asset is expected to generate in the future, the appropriate weighted-average cost of capital and the cost savings expected to be derived from acquiring an asset. These estimates are inherently uncertain and unpredictable. In addition, unanticipated events and circumstances may occur which may affect the accuracy or validity of such estimates. Use of Estimates The preparation of the financial statements and related disclosures in conformity with Generally Accepted Accounting Principles (“GAAP”) requires management to make estimates and judgments that affect the amounts reported in the consolidated financial statements and accompanying notes. Estimates are used for selling prices for multiple element arrangements, shared-based compensation, bad debts, valuation of inventories and investments, recoverability of intangible assets, other long-lived assets and goodwill, income taxes, warranty obligations, restructuring liabilities, derivatives, contingencies and litigation. Ciena bases its estimates on historical experience and assumptions that it believes are reasonable. Actual results may differ materially from management’s estimates. Cash and Cash Equivalents Ciena considers all highly liquid investments purchased with original maturities of three months or less to be cash equivalents. Any restricted cash collateralizing letters of credit is included in other current assets and other long-term assets depending on the duration of the restriction. Investments Ciena’s investments in debt securities are classified as available-for-sale and reported at fair value, with unrealized gains and losses recorded in accumulated other comprehensive income (loss). Ciena recognizes losses in the income statement when it determines that declines in the fair value of its investments below their cost basis are other-than-temporary. In determining whether a decline in fair value is other-than-temporary, Ciena considers various factors, including market price (when available), investment ratings, the financial condition and near-term prospects of the investee, the length of time and the extent to which the fair value has been less than Ciena’s cost basis, and Ciena’s intent and ability to hold the investment until maturity or for a period of time sufficient to allow for any anticipated recovery in market value. Ciena considers all marketable debt securities that it expects to convert to cash within one year or less to be short-term investments, with all others considered to be long-term investments. Ciena has minority equity investments in privately held technology companies that are classified in other long-term assets. These investments are carried at cost because Ciena owns less than 20% of the voting equity and does not have the ability to exercise significant influence over the company. Ciena monitors these investments for impairment and makes appropriate reductions to the carrying value when necessary. As of October 31, 2019 , the combined carrying value of these investments was $10.7 million . Ciena elects to estimate the fair value at cost minus impairment, if any, plus or minus observable price changes in orderly transactions for identical or similar investments of the same issuer. Ciena has not evaluated these investments for impairment or observable price changes as there have not been any events or changes in circumstances that Ciena believes would have had a significant effect on the fair value of these investments. Inventories Inventories are stated at the lower of cost or market, with cost computed using standard cost, which approximates actual cost, on a first-in, first-out basis. Ciena records a provision for excess and obsolete inventory when an impairment has been identified. Segment Reporting Ciena’s chief operating decision maker, its chief executive officer, evaluates the Company’s performance and allocates resources based on multiple factors, including measures of segment profit (loss). Operating segments are defined as components of an enterprise that engage in business activities that may earn revenue and incur expense, for which discrete financial information is available, and for which such information is evaluated regularly by the chief operating decision maker for purposes of allocating resources and assessing performance. During fiscal 2019, we separated our previous Software and Software-Related Services segment into two stand-alone operating segments. Ciena has the following operating segments for reporting purposes: (i) Networking Platforms; (ii) Platform Software and Services; (iii) Blue Planet Automation Software and Services; and (iv) Global Services. See Note 23 below. Goodwill Goodwill is the excess of the purchase price over the fair values assigned to the net assets acquired in a business combination. Ciena tests goodwill for impairment on an annual basis, which it has determined to be the last business day of fiscal September each year. Ciena also tests goodwill for impairment between annual tests if an event occurs or circumstances change that would, more likely than not, reduce the fair value of the reporting unit below its carrying value. Ciena tests goodwill impairment by comparing the fair value of the reporting unit with the unit’s carrying amount, including goodwill. If this test indicates that the fair value is less than the carrying value, then an impairment loss is recognized limited to the total amount of goodwill allocated to that reporting unit. A non-cash goodwill impairment charge would have the effect of decreasing earnings or increasing losses in such period. If Ciena is required to take a substantial impairment charge, its operating results would be materially adversely affected in such period. Long-lived Assets Long-lived assets include: equipment, building, furniture and fixtures; finite-lived intangible assets; and maintenance spares. Ciena tests long-lived assets for impairment whenever triggering events or changes in circumstances indicate that the asset’s carrying amount is not recoverable from its undiscounted cash flows. An impairment loss is measured as the amount by which the carrying amount of the asset or asset group exceeds its fair value. Ciena’s long-lived assets are assigned to asset groups that represent the lowest level for which cash flows can be identified. Equipment, Building, Furniture and Fixtures and Internal Use Software Equipment, building, furniture and fixtures are recorded at cost. Depreciation and amortization are computed using the straight-line method over useful lives of two years to five years for equipment and furniture and fixtures and the shorter of useful life or lease term for leasehold improvements. Qualifying internal use software and website development costs incurred during the application development stage, which consist primarily of outside services and purchased software license costs, are capitalized and amortized straight-line over the estimated useful lives of two years to five years . Intangible Assets Ciena has recorded finite-lived intangible assets as a result of several acquisitions. Finite-lived intangible assets are carried at cost less accumulated amortization. Amortization is computed using the straight-line method over the expected economic lives of the respective assets, up to seven years , which approximates the use of intangible assets. Maintenance Spares Maintenance spares are recorded at cost. Spares usage cost is expensed ratably over four years . Concentrations Substantially all of Ciena’s cash and cash equivalents are maintained at a small number of major U.S. financial institutions. The majority of Ciena’s cash equivalents consist of money market funds. Deposits held with banks may exceed the amount of insurance provided on such deposits. Because these deposits generally may be redeemed upon demand, management believes that they bear minimal risk. Historically, a significant percentage of Ciena’s revenue has been concentrated among sales to a small number of large communications service providers and Web-scale providers. Consolidation among Ciena’s customers has increased this concentration. Consequently, Ciena’s accounts receivable are concentrated among these customers. See Note 23 below. Additionally, Ciena’s access to certain materials or components is dependent on sole or limited source suppliers. The inability of any of these suppliers to fulfill Ciena’s supply requirements, or significant changes in supply cost, could affect future results. Ciena relies on a small number of contract manufacturers to perform the majority of the manufacturing for its products. If Ciena cannot effectively manage these manufacturers or forecast future demand, or if these manufacturers fail to deliver products or components on time, Ciena’s business and results of operations may suffer. Revenue Recognition Ciena recognizes revenue when control of the promised products or services is transferred to its customer, in an amount that reflects the consideration to which Ciena expects to be entitled in exchange for those products or services. Ciena determines revenue recognition by applying the following five-step approach: • identification of the contract, or contracts, with a customer; • identification of the performance obligations in the contract; • determination of the transaction price; • allocation of the transaction price to the performance obligations in the contract; and • recognition of revenue when, or as, Ciena satisfies a performance obligation. Generally, Ciena makes sales pursuant to purchase orders placed by customers under framework agreements that govern the general commercial terms and conditions of the sale of Ciena’s products and services. These purchase orders under framework agreements are used to determine the identification of the contract or contracts with this customer. Purchase orders typically include the description, quantity, and price of each product or service purchased. Purchase orders may include one-line bundled pricing for both products and services. Accordingly, purchase orders can include various combinations of products and services that are generally distinct and accounted for as separate performance obligations. Ciena evaluates each promised product and service offering to determine whether it represents a distinct performance obligation. In doing so, Ciena considers, among other things, customary business practices, whether the customer can benefit from the product or service on its own or together with other resources that are readily available, and whether Ciena’s commitment to transfer the product or service to the customer is separately identifiable from other obligations in the purchase order. For transactions where Ciena delivers the product or services, Ciena is typically the principal and records revenue and costs of goods sold on a gross basis. Purchase orders are invoiced based on the terms set forth either in the purchase order or the framework agreement, as applicable. Generally, sales of products and software licenses are invoiced upon shipment or delivery. Maintenance and software subscription services are invoiced quarterly or annually in advance of the service term. Ciena’s other service offerings are generally invoiced upon completion of the service. Payment terms and cash received typically range from 30 to 90 days from the invoicing date. Historically, Ciena has not provided any material financing arrangements to its customers. As a practical expedient, Ciena does not adjust the amount of consideration it will receive for the effects of a significant financing component as it expects, at contract inception, that the period between Ciena transfer of the products or services to the customer, and customer payment for the products or services will be one year or less. Shipping and handling fees invoiced to customers are included in revenue, with the associated expense included in product cost of goods sold. Ciena records revenue net of any associated sales taxes. Ciena recognizes revenue upon the transfer of control of promised products or services to a customer. Transfer of control occurs once the customer has the contractual right to use the product, generally upon shipment or delivery to the customer. Transfer of control can also occur over time for services such as software subscription, maintenance, installation, and various professional services as the customer receives the benefit over the contract term. Significant Judgments Revenue is allocated among performance obligations based on standalone selling price (“SSP”). SSP reflects the price at which Ciena would expect to sell that product or service on a stand-alone basis at contract inception and that Ciena would expect to be entitled to receive for the promised products or services. SSP is estimated for each distinct performance obligation, and judgment may be required in its determination. The best evidence of SSP is the observable price of a product or service when Ciena sells the products separately in similar circumstances and to similar customers. In instances where SSP is not directly observable, Ciena determines SSP using information that may include market conditions and other observable inputs. Ciena applies judgment in determining the transaction price, as Ciena may be required to estimate variable consideration when determining the amount of revenue to recognize. Variable consideration can include various rebate, cooperative marketing, and other incentive programs that Ciena offers to its distributors, partners and customers. When determining the amount of revenue to recognize, Ciena estimates the expected usage of these programs, applying the expected value or most likely estimate and updates the estimate at each reporting period as actual utilization data becomes available. Ciena also considers any customer right of return and any actual or potential payment of liquidated damages, contractual or similar penalties, or other claims for performance failures or delays in determining the transaction price, where applicable. When transfer of control is judged to be over time for installation and professional service arrangements, Ciena applies the input method to determine the amount of revenue to be recognized in a given period. Utilizing the input method, Ciena recognizes revenue based on the ratio of actual costs incurred to date to the total estimated costs expected to be incurred. Revenue for software subscription and maintenance is recognized ratably over the period during which the services are performed. Capitalized Contract Acquisition Costs Ciena has considered the impact of the guidance in Accounting Standards Codification (“ASC”) 340-40, Other Assets and Deferred Costs; Contracts with Customers , and the interpretations of the Financial Accounting Standards Board (“FASB”) Transition Resource Group for Revenue Recognition with respect to capitalization and amortization of incremental costs of obtaining a contract. In conjunction with this interpretation, Ciena considers each customer purchase in combination with the corresponding framework agreement, if applicable, as a contract. Ciena has elected to implement the practical expedient, which allows for incremental costs to be recognized as an expense when incurred if the period of the asset recognition is one year or less. If the period of the asset recognition is greater than one year, Ciena amortizes these costs over the period of performance. Ciena considers sales commissions incurred upon receipt of purchase orders placed by customers as incremental costs to obtain such purchase orders. The practical expedient method is applied to the purchase order as a whole and thus the capitalized costs of obtaining a purchase order is applied even if the purchase order contains more than one performance obligation. In cases where a purchase order includes various distinct products or services with both short-term (one year or less) and long-term (more than a year) performance periods, the cost of commissions incurred for the total value of the purchase order is capitalized and subsequently amortized as each performance obligation is recognized. For the additional disclosures required as part of ASC 606 see Note 2 below. Warranty Accruals Ciena provides for the estimated costs to fulfill customer warranty obligations upon recognition of the related revenue. Estimated warranty costs include estimates for material costs, technical support labor costs and associated overhead. Warranty is included in cost of goods sold and is determined based on actual warranty cost experience, estimates of component failure rates and management’s industry experience. Ciena’s sales contracts do not permit the right of return of the product by the customer after the product has been accepted. Accounts Receivable, Net Ciena’s allowance for doubtful accounts is based on its assessment, on a specific identification basis, of the collectibility of customer accounts. Ciena performs ongoing credit evaluations of its customers and generally has not required collateral or other forms of security from them. In determining the appropriate balance for Ciena’s allowance for doubtful accounts, management considers each individual customer account receivable in order to determine collectibility. In doing so, management considers creditworthiness, payment history, account activity and communication with the customer. If a customer’s financial condition changes, Ciena may be required to record an allowance for doubtful accounts for that customer, which could negatively affect its results of operations. Research and Development Ciena charges all research and development costs to expense as incurred. Types of expense incurred in research and development include employee compensation, prototype equipment, consulting and third-party services, depreciation, facility costs and information technology. Government Grants Ciena accounts for proceeds from government grants as a reduction of expense when there is reasonable assurance that Ciena has met the required conditions associated with the grant and that grant proceeds will be received. Grant benefits are recorded to the particular line item of the Consolidated Statement of Operations to which the grant activity relates. See Note 25 below. Advertising Costs Ciena expenses all advertising costs as incurred. Legal Costs Ciena expenses legal costs associated with litigation as incurred. Share-Based Compensation Expense Ciena measures and recognizes compensation expense for share-based awards based on estimated fair values on the date of grant. Ciena estimates the fair value of each option-based award on the date of grant using the Black-Scholes option-pricing model. This model is affected by Ciena’s stock price as well as estimates regarding a number of variables, including expected stock price volatility over the expected term of the award and projected employee stock option exercise behaviors. Ciena recognizes the estimated fair value of restricted stock units subject only to service-based vesting conditions by multiplying the number of shares underlying the award by the closing price per share of Ciena common stock on the grant date. In each case, Ciena only recognizes expense in its Consolidated Statement of Operations for those stock options or restricted stock units that are expected ultimately to vest. Awards with performance-based vesting conditions (i) require the achievement of certain operational, financial or other performance criteria or targets or (ii) vest based on Ciena’s total shareholder return as compared to an index of peer companies, in whole or in part. Ciena recognizes the estimated fair value of restricted stock units subject to performance-based vesting conditions other than total shareholder return by assuming the satisfaction of any performance-based objectives at the “target” level and multiplying the corresponding number of shares earned based upon such achievement by the closing price per share of Ciena common stock on the grant date. Ciena recognizes the estimated fair value of performance based awards subject to total shareholder return as compared to an index of peer companies using a Monte Carlo simulation valuation model on the date of grant. At the end of each reporting period, Ciena reassesses the probability of achieving the performance targets and the performance period required to meet those targets. See Note 22 below. Stock Repurchase Plan Shares repurchased pursuant to Ciena’s share repurchase program are immediately retired upon purchase. Repurchased common stock is reflected as a reduction of stockholders’ equity. Ciena’s accounting policy related to its share repurchases is to reduce its common stock based on the par value of the shares and to reduce its capital surplus for the excess of the repurchase price over the par value. Since the inception of its share repurchase program in December 2018, Ciena has had an accumulated deficit balance; therefore, the excess over the par value has been applied to additional paid-in capital. Once Ciena has retained earnings, the excess will be charged entirely to retained earnings. Income Taxes Ciena accounts for income taxes using an asset and liability approach. This approach recognizes deferred tax assets and liabilities (“DTA”) for the expected future tax consequences attributable to differences between the carrying amounts of assets and liabilities for financial reporting purposes and their respective tax bases, and for operating loss and tax credit carryforwards. In estimating future tax consequences, Ciena considers all expected future events other than the enactment of changes in tax laws or rates. Valuation allowances are provided if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. In the ordinary course of business, transactions occur for which the ultimate outcome may be uncertain. In addition, tax authorities periodically audit Ciena’s income tax returns. These audits examine significant tax filing positions, including the timing and amounts of deductions and the allocation of income tax expenses among tax jurisdictions. Ciena is currently under audit in India for 2012 and 2014 through 2018, and in Canada for 2011 through 2015. Management does not expect the outcome of these audits to have a material adverse effect on Ciena’s consolidated financial position, results of operations or cash flows. Ciena’s major tax jurisdictions and the earliest open tax years are as follows: United States (2016), United Kingdom (2016), Canada (2011), and India (2012). Limited adjustments can be made to Federal U.S. tax returns in earlier years in order to reduce net operating loss carryforwards. Ciena classifies interest and penalties related to uncertain tax positions as a component of income tax expense. Ciena has not provided for U.S. deferred income taxes on the cumulative unremitted earnings of its non-U.S. affiliates, as it plans to indefinitely reinvest these foreign earnings outside the U.S. As of October 31, 2019, the cumulative amount of such temporary differences for which a deferred tax liability has not been recognized totaled approximately $372.0 million . If these earnings were distributed to the U.S. in the form of dividends, or otherwise, or if the shares of the relevant foreign subsidiaries were sold or otherwise transferred, Ciena would be subject to additional U.S. income taxes (subject to an adjustment for foreign tax credits) and foreign withholding taxes. Ciena is required to record excess tax benefits or tax deficiencies related to stock-based compensation as income tax benefit or expense when share-based awards vest or are settled. Ciena adopted ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, in the first quarter of fiscal 2018. In connection with the adoption of this guidance, Ciena recognized approximately $62.1 million of deferred tax assets related to previously unrecognized tax benefits. This was recorded as a cumulative-effect adjustment to retained earnings as of the beginning of the first quarter of fiscal 2018. The Tax Cuts and Jobs Act (the “Tax Act”) includes provisions that affect Ciena in fiscal 2019, including a provision designed to tax global intangible low-taxed income (“GILTI”). An accounting policy choice is allowed to either treat taxes due on future U.S. inclusions related to GILTI in taxable income as a current-period expense when incurred (the “period cost method”) or factor such amounts into the measurement of deferred taxes (the “deferred method”). The calculation of the deferred balance with respect to the new GILTI tax provisions will depend, in part, on analyzing global income to determine whether future U.S. inclusions in taxable income are expected related to GILTI and, if so, what the impact is expected to be. Ciena is electing to use the period cost method for future GILTI inclusions. Additionally, Ciena is electing to use the incremental cash tax savings approach when determining whether a valuation allowance needs to be recorded against the U.S. net operating loss (“NOL”) due to the GILTI inclusions. The Tax Act also introduced an alternative tax known as the base erosion and anti-abuse tax (“BEAT”). An accounting policy choice has been made to consider BEAT as a period cost when incurred. Loss Contingencies Ciena is subject to the possibility of various losses arising in the ordinary course of business. These may relate to disputes, litigation and other legal actions. Ciena considers the likelihood of loss or the incurrence of a liability, as well as Ciena’s ability to estimate the amount of loss reasonably, in determining loss contingencies. An estimated loss contingency is accrued when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. Ciena regularly evaluates current information available to it in order to determine whether any accruals should be adjusted and whether new accruals are required. Fair Value of Financial Instruments The carrying value of Ciena’s cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximates fair market value due to the relatively short period of time to maturity. For information related to the fair value of Ciena’s term loan, see Note 17 below. Fair value for the measurement of financial assets and liabilities is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. Ciena utilizes a valuation hierarchy for disclosure of the inputs for fair value measurement. This hierarchy prioritizes the inputs into three broad levels as follows: • Level 1 inputs are unadjusted quoted prices in active markets for identical assets or liabilities; • Level 2 inputs are quoted prices for identical or similar assets or liabilities in less active markets or model-derived valuations in which significant inputs are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument; and • Level 3 inputs are unobservable inputs based on Ciena’s assumptions used to measure assets and liabilities at fair value. The fair values are determined based on model-based techniques using inputs Ciena could not corroborated with market data. By distinguishing between inputs that are observable in the marketplace, and therefore more objective, and those that are unobservable, and therefore more subjective, the hierarchy is designed to indicate the relative reliability of the fair value measurements. A financial asset’s or liability’s classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. Restructuring From time to time, Ciena takes actions to better align its workforce, facilities and operating costs with perceived market opportunities, business strategies and changes in market and business conditions. Ciena recognizes a

Business Combinations

Business Combinations	12 Months Ended
	Oct. 31, 2019
Business Combinations [Abstract]
BUSINESS COMBINATIONS	BUSINESS COMBINATIONS DonRiver Acquisition On October 1, 2018 , Ciena acquired DonRiver, a global software and services company specializing in federated network and service inventory management solutions within the service provider Operational Support Systems (OSS) environment. This transaction has been accounted for as the acquisition of a business. During fiscal 2019 and fiscal 2018, Ciena incurred approximately $2.4 million and $3.5 million of acquisition-related costs associated with this transaction, respectively. These costs and expenses include fees associated with financial, legal and accounting advisors and other employment-related costs, including the contingent compensation portion of the three year earn-out agreement as described below. These costs were recorded in acquisition and integration costs in the Consolidated Statement of Operations. The following table summarizes the purchase price for the acquisition (in thousands): Amount Cash $ 43,283 Contingent consideration 10,900 Total purchase price $ 54,183 The following table summarizes the final purchase price allocation related to the acquisition based on the estimated fair value of the acquired assets and assumed liabilities (in thousands): Amount Cash and cash equivalents $ 1,025 Accounts receivable 4,790 Prepaid expenses and other long term assets 372 Goodwill 10,453 Customer relationships and contracts 37,700 Developed technology 9,700 Deferred revenue (193 ) Other current and long term liabilities (9,664 ) Total purchase price $ 54,183 The acquisition of DonRiver includes a $ 28.5 million three -year earn-out arrangement that consists of both a contingent consideration element and a contingent compensation element. The contingent consideration element requires additional cash consideration to be paid based on the future revenues generally derived from the DonRiver business over a 25 -month period from the acquisition date through October 31, 2020. The undiscounted amounts potentially payable by Ciena under the contingent consideration element range from $ 0.0 million to $ 15.0 million in the aggregate over the period. Any remaining amounts earned under the contingent consideration element are payable in the first quarters of fiscal 2020 and 2021. The $10.9 million fair value of the contingent consideration element as of the acquisition date was estimated by applying the income approach based on a discounted cash flow technique using Monte Carlo simulations. See Note 7 below. The contingent compensation element of the earn-out arrangement includes an employment condition for the selling shareholders who became employees of Ciena upon the completion of the acquisition. The range of amounts that Ciena could pay under the contingent compensation element is between $ 0.0 million and $ 13.5 million in the aggregate over the period. Any amounts earned under the contingent compensation element are payable in the first quarters of fiscal 2021 and fiscal 2022. These amounts are accrued over the period earned and recorded as expense in the acquisition and integration costs line item in the Consolidated Statement of Operations. During fiscal 2019 and fiscal 2018, Ciena recorded $5.1 million and $0.4 million , of contingent compensation associated with the earn-out arrangement, respectively. The contingent consideration liability established at closing had an acquisition date fair value of $10.9 million . As of October 31, 2019 , the fair value of the contingent consideration liability was $8.1 million . A decrease of $2.8 million was recorded as a reduction to expense in the acquisitions and integrations costs line item in the Consolidated Statement of Operations. During fiscal 2019, $4.4 million of the total contingent consideration liability was earned. This payment is due during the first quarter of fiscal 2020 and is included in accrued liabilities and other short-term obligations. The remainder of the contingent consideration liability is included in Other long-term obligations on the Consolidated Balance Sheet as of October 31, 2019 . Customer relationships and contracts represent agreements with existing DonRiver customers. Customer relationships and contracts are amortized on a straight line basis over their estimated useful life of seven years . Fair value was determined using the multi-period excess earnings method based on the present value of the incremental after-tax cash flows (or “excess earnings”) attributable to customer relationships for a discrete projection period. Developed technology represents purchased technology that had reached technological feasibility and for which DonRiver had substantially completed development as of the date of acquisition. Fair value was determined using future discounted cash flows related to the projected income stream of the developed technology for a discrete projection period. Cash flows were discounted to their present value as of the closing date. Developed technology is amortized on a straight line basis over its estimated useful life of seven years . The goodwill generated from the acquisition of DonRiver is primarily related to expected synergies. The total goodwill amount was recorded in the previous Software and Software-Related Services segment. The goodwill related to this acquisition is not deductible for tax purposes. Pro forma disclosures have not been included due to immateriality. Packet Design Acquisition On July 2, 2018 , Ciena acquired Packet Design, a provider of network performance management software focused on Layer 3 network optimization, topology and route analytics, in a cash transaction for approximately $41.1 million in cash. This transaction has been accounted for as the acquisition of a business. During fiscal 2018, Ciena incurred approximately $1.6 million of acquisition-related costs associated with this transaction. There were minimal acquisition-related costs associated with this transaction during fiscal 2019. These costs and expenses include fees associated with financial, legal and accounting advisors and severance and other employment-related costs, including payments to certain former Packet Design employees. The following table summarizes the final purchase price allocation related to the acquisition based on the estimated fair value of the acquired assets and assumed liabilities (in thousands): Amount Cash and cash equivalents $ 642 Accounts receivable 1,525 Prepaid expenses and other 450 Equipment, furniture and fixtures 31 Goodwill 20,304 Customer relationships and contracts 2,200 Developed technology 21,900 Accounts payable (165 ) Accrued liabilities (657 ) Deferred revenue (5,176 ) Total purchase price $ 41,054 Customer relationships and contracts represent agreements with existing Packet Design customers. Customer relationships and contracts are amortized on a straight line basis over their estimated useful life of three years . Developed technology represents purchased technology that had reached technological feasibility and for which Packet Design had substantially completed development as of the date of acquisition. Fair value was determined using future discounted cash flows related to the projected income stream of the developed technology for a discrete projection period. Cash flows were discounted to their present value as of the closing date. Developed technology is amortized on a straight line basis over its estimated useful life of five years . The goodwill generated from the acquisition of Packet Design is primarily related to expected synergies. The total goodwill amount was recorded in the previous Software and Software-Related Services segment. The goodwill related to this acquisition is not deductible for tax purposes. Pro forma disclosures have not been included due to immateriality.

Revenue

Revenue	12 Months Ended
	Oct. 31, 2019
Revenue from Contract with Customer [Abstract]
REVENUE	REVENUE Disaggregation of Revenue Ciena’s disaggregated revenue represents similar groups that depict the nature, amount, and timing of revenue and cash flows for Ciena’s various offerings. The sales cycle, contractual obligations, customer requirements, and go-to-market strategies may differ for each of its product categories, resulting in different economic risk profiles for each category. The tables below (in thousands) set forth Ciena’s disaggregated revenue for the respective period: Year Ended October 31, 2019 Networking Platforms Platform Software and Services Blue Planet Automation Software and Services Global Services Total Product lines: Converged Packet Optical $ 2,562,841 $ — $ — $ — $ 2,562,841 Packet Networking 348,477 — — — 348,477 Platform Software and Services — 155,376 — — 155,376 Blue Planet Automation Software and Services — — 54,555 — 54,555 Maintenance Support and Training — — — 261,337 261,337 Installation and Deployment — — — 148,233 148,233 Consulting and Network Design — — — 41,312 41,312 Total revenue by product line $ 2,911,318 $ 155,376 $ 54,555 $ 450,882 $ 3,572,131 Timing of revenue recognition: Products and services at a point in time $ 2,911,318 $ 55,530 $ 17,697 $ 18,802 $ 3,003,347 Products and services transferred over time — 99,846 36,858 432,080 568,784 Total revenue by timing of revenue recognition $ 2,911,318 $ 155,376 $ 54,555 $ 450,882 $ 3,572,131 Year Ended October 31, 2019 Geographic Distribution: North America $ 2,351,260 EMEA 566,718 CALA 152,653 APAC 501,500 Total revenue by geographic distribution $ 3,572,131 • Networking Platforms reflects sales of Ciena’s Converged Packet Optical and Packet Networking product lines . • Converged Packet Optical - includes the 6500 Packet-Optical Platform, 5430 Reconfigurable Switching System, Waveserver® stackable interconnect system, the family of CoreDirector® Multiservice Optical Switches and the OTN configuration for the 5410 Reconfigurable Switching System. This product line also includes sales of the Z-Series Packet-Optical Platform. • Packet Networking - includes the 3000 family of service delivery switches and service aggregation switches and the 5000 family of service aggregation switches. This product line also includes the 8700 Packetwave Platform, the Ethernet packet configuration for the 5410 Service Aggregation Switch, and the 6500 Packet Transport System (PTS), which combines packet switching, control plane operation, and integrated optics. The Networking Platforms segment also includes sales of operating system software and enhanced software features embedded in each of the product lines above. Revenue from this segment is included in product revenue on the Consolidated Statements of Operations. Ciena’s hardware with the embedded operating system software and enhanced software features are considered distinct performance obligations for which the revenue is generally recognized upfront at a point in time upon transfer of control. • Platform Software and Services provides analytics, data, and planning tools to assist customers in managing Ciena’s Networking Platforms products in their networks. Ciena’s platform software includes its Manage, Control and Plan (MCP) domain controller solution, OneControl Unified Management System, ON-Center® Network and Service Management Suite, Ethernet Services Manager, Optical Suite Release and Planet Operate. Platform software-related services revenue includes sales of subscription, installation, support, and consulting services related to Ciena’s software platforms, operating system software and enhanced software features embedded in each of the Networking Platforms product lines above. Revenue from the software portion of this segment is included in product revenue on the Consolidated Statements of Operations. Revenue from services portions of this segment is included in services revenue on the Consolidated Statements of Operations. • Blue Planet Automation Software and Services which is a comprehensive, open software suite that allows customers to use enhanced knowledge about their networks to drive adaptive optimization of their services and operations. Ciena’s Blue Planet Automation Platform includes multi-domain service orchestration (MDSO), network function virtualization (NFV), management and orchestration (NFV MANO), analytics, network health predictor (NHP), route optimization and assurance (ROA), inventory management and Ciena’s SDN Multilayer Controller and virtual wide area network (V-WAN) application. Ciena acquired the NHP and ROA software solutions as a part of its acquisition of Packet Design, LLC (“Packet Design”). Ciena acquired the inventory management software solution as a part of its acquisition of DonRiver Holdings, LLC (“DonRiver”). Services revenue includes sales of subscription, installation, support, consulting and design services related to Ciena’s Blue Planet Automation Platform. Revenue from the software portion of this segment is included in product revenue on the Consolidated Statements of Operations. Revenue from services portions of this segment is included in services revenue on the Consolidated Statements of Operations. Ciena’s software platform revenue typically reflects either perpetual or term-based software licenses, and these sales are considered a distinct performance obligation where revenue is generally recognized upfront at a point in time upon transfer of control. Revenue from software subscription and support are recognized ratably over the period during which the services are performed. Revenue from professional services for solution customization, software and solution support services, consulting and design, and build-operate-transfer services relating to Ciena’s software offerings are recognized over time with Ciena applying the input method to determine the amount of revenue to be recognized in a given period. • Global Services reflects sales of a broad range of Ciena’s services for maintenance support and training, installation and deployment, and consulting and network design activities. Revenue from this segment is included in services revenue on the Consolidated Statements of Operations. Ciena’s Global Services are considered a distinct performance obligation where revenue is generally recognized over time. Revenue from maintenance support is recognized ratably over the period during which the services are performed. Revenue from installation and deployment services and consulting and network design services are recognized over time with Ciena applying the input method to determine the amount of revenue to be recognized in a given period. Revenue from training services is generally recognized at a point in time upon completion of the service. Contract Balances The following table provides information about receivables, contract assets and contract liabilities (deferred revenue) from contracts with customers (in thousands): Balance at October 31, 2019 Adjusted Balance at November 1, 2018 Accounts receivable, net $ 724,854 $ 799,011 Contract assets $ 84,046 $ 31,380 Deferred revenue $ 156,873 $ 140,704 Our contract assets represent unbilled accounts receivable where transfer of a product or service has occurred but invoicing is conditional on completion of future performance obligations. These amounts are primarily related to installation and deployment and professional services arrangements where transfer of control has occurred but Ciena has not yet invoiced the customer. Contract assets are included in prepaid expenses and other current assets in the Consolidated Balance Sheets, see Note 10 below. Contract liabilities consist of deferred revenue and represent advanced payments against non-cancelable customer orders received prior to revenue recognition. Ciena recognized approximately $95.1 million of revenue during fiscal 2019 that was included in the deferred revenue balance at November 1, 2018 . Revenue recognized due to changes in transaction price from performance obligations satisfied or partially satisfied in previous periods was immaterial during fiscal 2019 . Capitalized Contract Acquisition Costs Capitalized contract acquisition costs consist of deferred sales commissions and were $15.7 million and $13.6 million as of October 31, 2019 and November 1, 2018 , respectively, and were included in other current assets and other assets. The amortization expense associated with these costs was $18.6 million during fiscal 2019 and was included in sales and marketing expense. Remaining Performance Obligations Remaining Performance Obligations (“RPO”) are comprised of non-cancelable customer purchase orders for products and services that are awaiting transfer of control for revenue recognition under the applicable contract terms. As of October 31, 2019 , the aggregate amount of RPO was $950.0 million . As of October 31, 2019 , Ciena expects approximately 83% of the RPO to be recognized as revenue within the next twelve months

Restructuring Costs

Restructuring Costs	12 Months Ended
	Oct. 31, 2019
Restructuring and Related Activities [Abstract]
RESTRUCTURING COSTS	RESTRUCTURING COSTS Ciena has undertaken a number of restructuring activities intended to reduce expense and better align its workforce and costs with market opportunities, product development and business strategies. The following table sets forth the restructuring activity and balance of the restructuring liability accounts for the fiscal years indicated (in thousands): Workforce reduction Consolidation of excess facilities Total Balance at October 31, 2016 $ 868 $ 1,970 $ 2,838 Additional liability recorded 5,883 (1) 5,432 (4) 11,315 Adjustment to previous estimates — (1,048 ) (1,048 ) Cash payments (5,460 ) (4,706 ) (10,166 ) Balance at October 31, 2017 1,291 1,648 2,939 Additional liability recorded 14,853 (2) 3,890 (5) 18,743 Cash payments (14,036 ) (3,799 ) (17,835 ) Balance at October 31, 2018 2,108 1,739 3,847 Additional liability recorded 13,779 (3) 10,759 (6) 24,538 Cash payments (11,904 ) (1,338 ) (13,242 ) Balance at October 31, 2019 $ 3,983 $ 11,160 $ 15,143 Current restructuring liabilities $ 3,983 $ 1,484 $ 5,467 Non-current restructuring liabilities $ — $ 9,676 $ 9,676 _________________________________ (1) During fiscal 2017, Ciena recorded a charge of $5.9 million of severance and other employee-related costs associated with a workforce reduction of approximately 100 employees. (2) During fiscal 2018, Ciena recorded a charge of $14.9 million of severance and other employee-related costs associated with a workforce reduction of approximately 240 employees. (3) During fiscal 2019, Ciena recorded a charge of $13.8 million of severance and other employee-related costs associated with a workforce reduction of approximately 283 employees. (4) Reflects unfavorable lease commitments and relocation costs incurred in connection with Ciena’s research and development center facility transitions in Ottawa, Canada. (5) Reflects unfavorable lease commitments in connection with a portion of facilities located in Petaluma, California and in Gurgaon, India. (6) Reflects unfavorable lease commitments in connection with a portion of facilities located in Alpharetta, Georgia, Spokane, Washington, Durham, North Carolina and Hanover, Maryland.

Interest and Other Income (Loss

Interest and Other Income (Loss), Net	12 Months Ended
	Oct. 31, 2019
Other Income and Expenses [Abstract]
INTEREST AND OTHER INCOME (LOSS), NET	INTEREST AND OTHER INCOME (LOSS), NET The components of interest and other income (loss), net, were as follows (in thousands): Year Ended October 31, 2019 2018 2017 Interest income $ 14,410 $ 13,703 $ 6,579 Gain (loss) on non-hedge designated foreign currency forward contracts 3 6,791 (1,198 ) Foreign currency exchange losses (9,800 ) (19,434 ) (4,376 ) Loss on fair value of debt conversion liability — (12,070 ) — Other (737 ) (1,019 ) (92 ) Interest and other income (loss), net $ 3,876 $ (12,029 ) $ 913 Ciena Corporation, as the U.S. parent entity, uses the U.S. Dollar as its functional currency; however, some of its foreign branch offices and subsidiaries use the local currency as their functional currency. During fiscal 2019 , 2018 and 2017 , Ciena recorded $9.8 million , $19.4 million and $4.4 million , respectively, in exchange rate losses, as a result of monetary assets and liabilities that were transacted in a currency other than the entity’s functional currency, and the re-measurement adjustments were recorded in interest and other income (loss), net. For fiscal 2019 , the majority of the foreign currency exchange rate losses relate to fluctuations in the Brazilian and Argentine exchange rates. From time to time, Ciena uses foreign currency forwards to hedge these balance sheet exposures. These forwards are not designated as hedges for accounting purposes, and any net gain or loss associated with these derivatives is also reported in interest and other income (loss), net. During fiscal 2019 , Ciena recorded minimal gains from non-hedge designated foreign currency forward contracts. For fiscal 2018 and fiscal 2017 , Ciena recorded a gain of $6.8 million , and a loss of $1.2 million

Short-Term and Long-Term Invest

Short-Term and Long-Term Investments	12 Months Ended
	Oct. 31, 2019
Investments, Debt and Equity Securities [Abstract]
SHORT-TERM AND LONG-TERM INVESTMENTS	SHORT-TERM AND LONG-TERM INVESTMENTS As of October 31, 2019 , investments are comprised of the following (in thousands): October 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. government obligations: Included in short-term investments $ 109,715 $ 225 $ — $ 109,940 Included in long-term investments 10,017 — (3 ) 10,014 $ 119,732 $ 225 $ (3 ) $ 119,954 As of October 31, 2018 , investments are comprised of the following (in thousands): October 31, 2018 Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair U.S. government obligations: Included in short-term investments $ 139,365 $ — $ (347 ) $ 139,018 Included in long-term investments 59,029 — (59 ) 58,970 $ 198,394 $ — $ (406 ) $ 197,988 Commercial paper: Included in short-term investments $ 9,963 $ — $ — $ 9,963 $ 9,963 $ — $ — $ 9,963 The following table summarizes the legal maturities of debt investments at October 31, 2019 : October 31, 2019 Amortized Cost Estimated Fair Less than one year $ 109,715 $ 109,940 Due in 1-2 years 10,017 10,014 $ 119,732 $ 119,954

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Oct. 31, 2019
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS As of the dates indicated, the following tables summarize the fair value of assets and liabilities that were recorded at fair value on a recurring basis (in thousands): October 31, 2019 Level 1 Level 2 Level 3 Total Assets: Money market funds $ 759,114 $ — $ — $ 759,114 U.S. government obligations — 119,954 — 119,954 Foreign currency forward contracts — 1,570 — 1,570 Total assets measured at fair value $ 759,114 $ 121,524 $ — $ 880,638 Liabilities: Foreign currency forward contracts $ — $ 35 $ — $ 35 Forward starting interest rate swaps — 21,093 — 21,093 Contingent consideration — — 3,705 3,705 Total liabilities measured at fair value $ — $ 21,128 $ 3,705 $ 24,833 October 31, 2018 Level 1 Level 2 Level 3 Total Assets: Money market funds $ 590,684 $ — $ — $ 590,684 U.S. government obligations — 197,988 — 197,988 Commercial paper — 69,888 — 69,888 Foreign currency forward contracts — 133 — 133 Forward starting interest rate swaps — 779 — 779 Total assets measured at fair value $ 590,684 $ 268,788 $ — $ 859,472 Liabilities: Foreign currency forward contracts $ — $ 3,231 $ — $ 3,231 Debt conversion liability — 164,212 — 164,212 Contingent consideration — — 10,900 10,900 Total liabilities measured at fair value $ — $ 167,443 $ 10,900 $ 178,343 As of the dates indicated, the assets and liabilities above were presented on Ciena’s Consolidated Balance Sheet as follows (in thousands): October 31, 2019 Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 759,114 $ — $ — $ 759,114 Short-term investments — 109,940 — 109,940 Prepaid expenses and other — 1,570 — 1,570 Long-term investments — 10,014 — 10,014 Total assets measured at fair value $ 759,114 $ 121,524 $ — $ 880,638 Liabilities: Accrued liabilities $ — $ 35 $ — $ 35 Other long-term obligations — 21,093 3,705 24,798 Total liabilities measured at fair value $ — $ 21,128 $ 3,705 $ 24,833 October 31, 2018 Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 590,684 $ 59,925 $ — $ 650,609 Short-term investments — 148,981 — 148,981 Prepaid expenses and other — 133 — 133 Long-term investments — 58,970 — 58,970 Other long-term assets — 779 — 779 Total assets measured at fair value $ 590,684 $ 268,788 $ — $ 859,472 Liabilities: Accrued liabilities $ — $ 3,231 $ — $ 3,231 Debt conversion liability — 164,212 — 164,212 Other long-term obligations — — 10,900 10,900 Total liabilities measured at fair value $ — $ 167,443 $ 10,900 $ 178,343 Ciena did not have any transfers between Level 1 and Level 2 fair value measurements during the periods presented. Ciena’s Level 3 liability includes $3.7 million in other long-term obligations as of October 31, 2019 . This reflects a contingent consideration element of a three -year payout arrangement associated with Ciena’s purchase of DonRiver in the fourth quarter of fiscal 2018. See Note 3

Accounts Receivable

Accounts Receivable	12 Months Ended
	Oct. 31, 2019
Receivables [Abstract]
ACCOUNTS RECEIVABLE	ACCOUNTS RECEIVABLE As of October 31, 2019 , one customer accounted for 12.0% of net accounts receivable. As of October 31, 2018 , one customer accounted for 10.0% of net accounts receivable. Ciena has not historically experienced a significant amount of bad debt expense. During fiscal 2017, Ciena’s allowance for doubtful accounts includes a provision for a significant asset impairment of $13.7 million for a trade receivable related to a single customer in the APAC region. The following table summarizes the activity in Ciena’s allowance for doubtful accounts for the fiscal years indicated (in thousands): Year ended Beginning Net Ending October 31, Balance Provisions Deductions Balance 2017 $ 3,963 $ 18,221 $ 4,604 $ 17,580 2018 $ 17,580 $ 2,700 $ 2,902 $ 17,378 2019 $ 17,378 $ 6,740 $ 4,017 $ 20,101

Inventories

Inventories	12 Months Ended
	Oct. 31, 2019
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES As of the dates indicated, inventories are comprised of the following (in thousands): October 31, 2019 2018 Raw materials $ 99,041 $ 67,468 Work-in-process 13,657 9,589 Finished goods 226,622 188,575 Deferred cost of goods sold 53,051 48,057 392,371 313,689 Reserve for excess and obsolescence (47,322 ) (50,938 ) $ 345,049 $ 262,751 Ciena writes down its inventory for estimated obsolescence or unmarketable inventory by an amount equal to the difference between the cost of inventory and the estimated net realizable value based on assumptions about future demand, which are affected by changes in Ciena’s strategic direction, discontinuance of a product or introduction of newer versions of products, declines in the sales of or forecasted demand for certain products, and general market conditions. During fiscal 2019 , fiscal 2018 and fiscal 2017 , Ciena recorded a provision for excess and obsolescence of $28.1 million , $30.6 million , and $35.5 million , respectively, primarily related to the decrease in the forecasted demand for certain Converged Packet Optical products. Deductions from the provision for excess and obsolete inventory relate to disposal activities. The following table summarizes the activity in Ciena’s reserve for excess and obsolete inventory for the fiscal years indicated (in thousands): Year ended Beginning Ending October 31, Balance Provisions Disposals Balance 2017 $ 62,503 $ 35,459 $ 46,756 $ 51,206 2018 $ 51,206 $ 30,615 $ 30,883 $ 50,938 2019 $ 50,938 $ 28,085 $ 31,701 $ 47,322

Prepaid Expenses and Other

Prepaid Expenses and Other	12 Months Ended
	Oct. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
PREPAID EXPENSES AND OTHER	PREPAID EXPENSES AND OTHER As of the dates indicated, prepaid expenses and other are comprised of the following (in thousands): October 31, 2019 2018 Prepaid VAT and other taxes $ 84,706 $ 82,518 Contract assets 84,046 — Prepaid expenses 48,680 32,987 Product demonstration equipment, net 38,900 37,623 Other non-trade receivables 28,136 25,716 Capitalized contract acquisition costs 11,677 — Derivative assets 1,570 133 Deferred deployment expense 125 19,342 Restricted cash 74 — Financing receivable — 626 $ 297,914 $ 198,945 Depreciation of product demonstration equipment was $8.8 million , $9.0 million and $10.0 million for fiscal 2019 , 2018 and 2017 , respectively. For further discussion on contract assets and capitalized contract acquisition costs, see Note 2 above.

Equipment, Building, Furniture

Equipment, Building, Furniture and Fixtures	12 Months Ended
	Oct. 31, 2019
Property, Plant and Equipment [Abstract]
EQUIPMENT, BUILDING, FURNITURE AND FIXTURES	EQUIPMENT, BUILDING, FURNITURE AND FIXTURES As of the dates indicated, equipment, building, furniture and fixtures are comprised of the following (in thousands): October 31, 2019 2018 Equipment, furniture and fixtures $ 544,012 $ 504,714 Building subject to capital lease 71,760 71,968 Leasehold improvements 94,626 94,195 710,398 670,877 Accumulated depreciation and amortization (423,514 ) (378,810 ) $ 286,884 $ 292,067 During fiscal 2019 , fiscal 2018 and fiscal 2017 , Ciena recorded depreciation of equipment, building, furniture and fixtures, and amortization of leasehold improvements of $78.8 million , $75.3 million and $67.2 million

Intangible Assets

Intangible Assets	12 Months Ended
	Oct. 31, 2019
Intangible Assets, Net (Excluding Goodwill) [Abstract]
INTANGIBLE ASSETS	INTANGIBLE ASSETS As of the dates indicated, intangible assets are comprised of the following (in thousands): October 31, 2019 2018 Gross Intangible Accumulated Amortization Net Intangible Gross Intangible Accumulated Amortization Net Intangible Developed technology $ 373,526 $ (308,261 ) $ 65,265 $ 373,581 $ (285,233 ) $ 88,348 Patents and licenses 3,565 (2,244 ) 1,321 3,565 (1,958 ) 1,607 Customer relationships, covenants not to compete, outstanding purchase orders and contracts 374,381 (328,186 ) 46,195 374,620 (316,350 ) 58,270 Total intangible assets $ 751,472 $ (638,691 ) $ 112,781 $ 751,766 $ (603,541 ) $ 148,225 The aggregate amortization expense of intangible assets was $35.1 million , $25.8 million and $45.7 million for fiscal 2019 , fiscal 2018 and fiscal 2017 , respectively. Expected future amortization of intangible assets for the fiscal years indicated is as follows (in thousands): Year Ended October 31, 2020 $ 34,008 2021 30,830 2022 24,809 2023 10,000 2024 6,948 Thereafter 6,186 $ 112,781

Goodwill

Goodwill	12 Months Ended
	Oct. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL	GOODWILL During fiscal 2019, Ciena separated its previous Software and Software-Related Services segment into two stand-alone operating segments: Blue Planet Automation Software and Services and Platform Software and Services. Ciena was required to separate this operating segment as a result of an internal realignment to support its corporate strategy to further promote customer adoption of its Blue Planet Automation Software and Services, and corresponding changes by management to the evaluation of resource allocation for and measurement of performance of this business. Accordingly, as of the end of fiscal 2019, for reporting purposes, our results of operations are presented based on the following operating segments: (i) Networking Platforms; (ii) Platform Software and Services; (iii) Blue Planet Automation Software and Services; and (iv) Global Services. As a result of the separation of Platform Software and Services and Blue Planet Automation Software and Services into separate operating segments, Ciena allocated the $232.2 million of goodwill previously allocated to the combined Software and Software Related-Services segment to the two separate operating segments based on each operating segments relative fair value using a discounted cash flow model. The following table presents the goodwill allocated to Ciena’s operating segments as of October 31, 2019 and October 31, 2018 , as well as the changes to goodwill during fiscal 2019 (in thousands): Balance at October 31, 2018 Reallocation Acquisitions Impairments Translation Balance at October 31, 2019 Software and Software Related Services $ 232,185 $ (232,185 ) $ — $ — $ — $ — Platform Software and Services — 156,191 — — — 156,191 Blue Planet Automation Software and Services — 75,994 — — — 75,994 Networking Platforms 65,783 — — — (31 ) 65,752 Total $ 297,968 $ — $ — $ — $ (31 ) $ 297,937

Other Balance Sheet Details

Other Balance Sheet Details	12 Months Ended
	Oct. 31, 2019
Balance Sheet Related Disclosures [Abstract]
OTHER BALANCE SHEET DETAILS	OTHER BALANCE SHEET DETAILS As of the dates indicated, other long-term assets are comprised of the following (in thousands): October 31, 2019 2018 Maintenance spares inventory, net $ 55,482 $ 45,679 Cost method investments 10,727 8,056 Capitalized contract acquisition costs 3,994 — Deferred debt issuance costs, net (1) 1,609 720 Restricted cash 42 11 Forward starting interest rate swaps — 779 Other 17,132 16,407 $ 88,986 $ 71,652 (1) Deferred debt issuance costs relate to Ciena’s senior secured asset-based revolving credit facility (the “ABL Credit Facility”) entered into during fiscal 2019 and its predecessor credit facility (described in Note 18 below). The amortization of deferred debt issuance costs for the ABL Credit Facility and its predecessor is included in interest expense, and was $0.3 million , $0.3 million and $0.3 million for fiscal 2019 , fiscal 2018 and fiscal 2017 , respectively. As of the dates indicated, accrued liabilities and other short-term obligations are comprised of the following (in thousands): October 31, 2019 2018 Compensation, payroll related tax and benefits $ 182,363 $ 140,277 Warranty 48,498 44,740 Vacation (1) 22,290 42,507 Contingent Consideration 4,372 — Capital lease obligations 2,764 3,547 Interest payable 1,007 1,072 Other 121,446 107,932 $ 382,740 $ 340,075 (1) Reduction is primarily due to the payout of North America vacation accruals in conjunction with Ciena’s adoption of a new vacation policy during fiscal 2019. The following table summarizes the activity in Ciena’s accrued warranty for the fiscal years indicated (in thousands): Year ended Beginning Current Year Ending October 31, Balance Provisions (1) Settlements Balance 2017 $ 52,324 $ 7,965 $ 17,833 $ 42,456 2018 $ 42,456 $ 20,992 $ 18,708 $ 44,740 2019 $ 44,740 $ 23,105 $ 19,347 $ 48,498 (1) As a result of actual failure rates lower than expected, Ciena adjusted its fiscal 2017 provisions for warranty. These adjustments for previous fiscal year provisions had the effect of reducing warranty provisions by $9.7 million for fiscal 2017 . During fiscal 2018 and fiscal 2019 , Ciena determined that failure rates for prior estimates remained unchanged, and accordingly did not make any adjustments for previous fiscal year provisions not yet settled. As a result, Ciena’s warranty provision for fiscal 2018 and fiscal 2019 increased as compared to fiscal 2017. As of the dates indicated, deferred revenue is comprised of the following (in thousands): October 31, 2019 2018 Products $ 27,366 $ 42,474 Services 129,507 126,983 156,873 169,457 Less current portion (111,381 ) (111,134 ) Long-term deferred revenue $ 45,492 $ 58,323 As of the dates indicated, other long-term obligations are comprised of the following (in thousands): October 31, 2019 2018 Capital lease obligations $ 65,284 $ 68,245 Income tax liability 20,546 15,894 Interest rate swap liability 21,093 — Deferred tenant allowance 6,248 7,244 Straight-line rent 5,434 6,750 Contingent consideration 3,705 10,900 Other 26,437 10,380 $ 148,747 $ 119,413 The following is a schedule by fiscal years of future minimum lease payments under capital leases and the present value of minimum lease payments as of October 31, 2019 (in thousands): Year Ending October 31, Amount 2020 $ 7,652 2021 7,547 2022 7,860 2023 8,067 2024 8,067 Thereafter 67,126 Net minimum capital lease payments 106,319 Less: Amount representing interest (38,271 ) Present value of minimum lease payments 68,048 Less: Current portion of present value of minimum lease payments (2,764 ) Long-term portion of present value of minimum lease payments $ 65,284

Derivative Instruments

Derivative Instruments	12 Months Ended
	Oct. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS	DERIVATIVE INSTRUMENTS Foreign Currency Derivatives During fiscal 2019 and fiscal 2018 , Ciena entered into forward contracts to hedge its foreign exchange exposure from its forecasted cash flows in order to reduce the variability in its Canadian Dollar and Indian Rupee denominated expense, which principally relates to research and development activities. The notional amount of these contracts was approximately $197.4 million and $163.2 million as of October 31, 2019 and October 31, 2018 , respectively. These foreign exchange contracts have maturities of 24 months or less and have been designated as cash flow hedges. During fiscal 2019 and fiscal 2018 , in order to hedge its foreign exchange exposure from certain balance sheet items, Ciena entered into forward contracts to mitigate risk due to volatility in the Brazilian Real, Canadian Dollar, Euro, Australian Dollar, British Pound Sterling, Mexican Peso, and Japanese Yen. The notional amount of these contracts was approximately $206.0 million and $162.6 million as of October 31, 2019 and October 31, 2018 . These foreign exchange contracts have maturities of 12 months or less and have not been designated as hedges for accounting purposes. Interest Rate Derivatives Ciena is exposed to floating rates of LIBOR interest on its term loan borrowings (see Note 17 below) and has hedged such risk by entering into floating to fixed interest rate swap arrangements (“interest rate swaps”). During the fourth quarter of fiscal 2018, Ciena refinanced its previous term loan in the aggregate principal amount of $394.0 million , maturing on January 30, 2022 (the “2022 Term Loan”), into a new term loan due September 28, 2025 (the “2025 Term Loan”), increasing the aggregate outstanding principal to $700.0 million and extending the maturity to September 2025 (see Note 17 below). In conjunction with the refinancing, Ciena unwound its then-existing interest rate swaps for a cash gain of $ 6.8 million , which was recorded in Other Comprehensive Income, and entered into new floating-to-fixed interest rate swaps. The interest rate swaps fix the LIBOR rate of approximately $350.0 million of the principal amount of the 2025 Term Loan at 2.957% through September 2023. The total notional amount of these interest rate swaps in effect as of October 31, 2019 was $350.0 million . Ciena expects the variable rate payments to be received under the terms of the interest rate swaps to offset exactly the forecasted variable rate payments on the equivalent notional amounts of the term loan. These derivative contracts have been designated as cash flow hedges. Other information regarding Ciena’s derivatives is immaterial for separate financial statement presentation. See Notes 5 and 7 above. Debt Conversion Liability Associated With the New Notes The New Notes provided Ciena the option, at its election, to settle conversions of such notes for cash, shares of its common stock, or a combination of cash and shares equal to the aggregate amount due upon conversion. On August 30, 2018, Ciena notified the noteholders that it had elected to settle conversion of the New Notes in a combination of cash and shares, provided that the cash portion would not exceed an aggregate amount of $400.0 million . Ciena became obligated to settle a portion of the conversion feature in cash and reclassified the cash conversion feature from equity to a derivative liability at its current fair value of $152.1 million . As of October 31, 2018, Ciena recorded a loss of approximately $12.1 million related to the change in fair value of the embedded conversion feature. On November 15, 2018, Ciena paid approximately $111.3 million in cash and issued 1.6 million shares in settlement of this embedded conversion feature.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Oct. 31, 2019
Statement of Comprehensive Income [Abstract]
ACCUMULATED OTHER COMPREHENSIVE INCOME	ACCUMULATED OTHER COMPREHENSIVE INCOME The following table summarizes the changes in accumulated balances of other comprehensive income (“AOCI”): Unrealized Gain/(Loss) on Available-for-Sale Securities Unrealized Gain/(Loss) on Foreign Currency Forward Contracts Unrealized Gain/(Loss) on Forward Starting Interest Rate Swaps Cumulative Foreign Currency Translation Adjustment Total Balance at October 31, 2016 $ 139 $ (1,091 ) $ (5,967 ) $ (17,410 ) $ (24,329 ) Other comprehensive gain (loss) before reclassifications (590 ) 1,290 3,669 8,012 12,381 Amounts reclassified from AOCI — (1,585 ) 2,516 — 931 Balance at October 31, 2017 (451 ) (1,386 ) 218 (9,398 ) (11,017 ) Other comprehensive gain (loss) before reclassifications 26 (3,242 ) 6,011 686 3,481 Amounts reclassified from AOCI — 1,568 188 — 1,756 Balance at October 31, 2018 (425 ) (3,060 ) 6,417 (8,712 ) (5,780 ) Other comprehensive gain (loss) before reclassifications 577 14 (18,948 ) (763 ) (19,120 ) Amounts reclassified from AOCI — 3,971 (1,155 ) — 2,816 Balance at October 31, 2019 $ 152 $ 925 $ (13,686 ) $ (9,475 ) $ (22,084 ) All amounts reclassified from AOCI related to settlement (gains) losses on foreign currency forward contracts designated as cash flow hedges impacted revenue, research and development expense or sales and marketing expense on the Consolidated Statements of Operations. All amounts reclassified from AOCI related to settlement (gains) losses on forward starting interest rate swaps designated as cash flow hedges impacted interest and other income (loss), net on the Consolidated Statements of Operations.

Short-Term and Long-Term Debt

Short-Term and Long-Term Debt	12 Months Ended
	Oct. 31, 2019
Debt Disclosure [Abstract]
SHORT-TERM AND LONG-TERM DEBT	SHORT-TERM AND LONG-TERM DEBT 2025 Term Loan The net carrying values of Ciena’s term loan were comprised of the following for the fiscal periods indicated (in thousands): October 31, 2019 October 31, 2018 Principal Balance Unamortized Discount Deferred Debt Issuance Costs Net Carrying Value Net Carrying Value Term Loan Payable due September 28, 2025 $ 693,000 $ (1,958 ) $ (3,636 ) $ 687,406 $ 693,450 Deferred debt issuance costs deducted from the carrying amount of the term loan totaled $3.6 million at October 31, 2019 and $4.3 million at October 31, 2018 . Deferred debt issuance costs are amortized using the straight-line method, which approximates the effect of the effective interest rate method, through the maturity of the term loan. The amortization of deferred debt issuance costs for this term loan is included in interest expense, and was $0.6 million and $0.7 million during fiscal 2019 and fiscal 2018 , respectively. As of October 31, 2019 , the estimated fair value of the term loan was $694.7 million . Ciena’s term loan is categorized as Level 2 in the fair value hierarchy. Ciena estimated the fair value of its term loan using a market approach based on observable inputs, such as current market transactions involving comparable securities. On September 28, 2018, Ciena, as borrower, and Ciena Communications, Inc. and Ciena Government Solutions, Inc., as guarantors, entered into an Increase Joinder and Refinancing Amendment to Credit Agreement with the lenders party thereto and the Administrative Agent (the “Refinancing Agreement”), pursuant to which Ciena refinanced its the 2022 Term Loan into the 2025 Term Loan. In connection with the transaction, Ciena received a loan in the amount of $699.1 million , net of original discount, from the 2025 Term Loan and simultaneously repaid $394.0 million of outstanding principal under the 2022 Term Loan, resulting in proceeds of $305.1 million . The 2025 Term Loan requires Ciena to make installment payments of $1.75 million on a quarterly basis. Based on the continuation of existing lenders and the addition of new lenders, this arrangement was primarily accounted for as a modification of debt and, as such, $3.8 million of debt issuance costs associated with the 2025 Term Loan were expensed. The aggregate balance of $2.4 million of debt issuance costs and approximately $1.4 million of original discount from the 2022 Term Loan, $1.9 million of debt issuance costs associated with new lenders for the 2025 Term Loan, and approximately $0.9 million of original discount from the 2025 Term Loan, were included in the carrying value of the 2025 Term Loan. The Refinancing Agreement amends Ciena’s credit agreement, dated July 15, 2014, as amended (the “Credit Agreement”) and provides that the 2025 Term Loan will, among other things: • amortize in equal quarterly installments in aggregate amounts equal to 0.25% of the principal amount of the 2025 Term Loan as of September 28, 2018, with the balance payable at maturity; • be subject to mandatory prepayment provisions upon the occurrence of certain specified events substantially similar to the 2022 Term Loan, including certain asset sales, debt issuances and receipt of annual Excess Cash Flow (as defined in the Credit Agreement); • bear interest, at Ciena’s election, at a per annum rate equal to (a) LIBOR (subject to a floor of 0.00% ) plus an applicable margin of 2.00% , or (b) a base rate (subject to a floor of 1.00% ) plus an applicable margin of 1.00% ; and • be repayable at any time at Ciena’s election, provided that repayment of the 2025 Term Loan with proceeds of certain indebtedness prior to March 28, 2019 will require a prepayment premium of 1.00% of the aggregate principal amount of such prepayment.

ABL Credit Facility

ABL Credit Facility	12 Months Ended
	Oct. 31, 2019
Line of Credit Facility [Abstract]
ABL CREDIT FACILITY	ABL CREDIT FACILITY Ciena Corporation and certain of its subsidiaries are parties to the ABL Credit Facility, which provides for a total commitment of $300 million with a maturity date of October 28, 2024. The ABL Credit Facility was entered into on October 28, 2019 and replaced a predecessor senior secured asset-based revolving credit facility. Ciena principally uses the ABL Credit Facility to support the issuance of letters of credit that arise in the ordinary course of its business and thereby to reduce its use of cash required to collateralize these instruments. As of October 31, 2019 , letters of credit totaling $72.9 million were outstanding under the ABL Credit Facility. There were no borrowings outstanding under the ABL Credit Facility as of October 31, 2019 .

Earnings (Loss) Per Share Calcu

Earnings (Loss) Per Share Calculation	12 Months Ended
	Oct. 31, 2019
Earnings Per Share [Abstract]
EARNINGS (LOSS) PER SHARE CALCULATION	EARNINGS (LOSS) PER SHARE CALCULATION The following tables (in thousands except per share amounts) show a reconciliation of the numerator and denominator of the Basic EPS and the Diluted EPS. Basic EPS is computed using the weighted average number of common shares outstanding. Diluted EPS is computed using the weighted average number of the following, in each case, to the extent the effect is not anti-dilutive: (i) common shares outstanding, (ii) shares issuable upon vesting of restricted stock units and (iii) shares issuable under Ciena’s employee stock purchase plan and upon exercise of outstanding stock options, using the treasury stock method. Numerator Year Ended October 31, 2019 2018 2017 Net income (loss) $ 253,434 $ (344,690 ) $ 1,261,953 Less: Loss on fair value of debt conversion liability (12,894 ) — Add: Interest expense associated with 0.875% Convertible Senior Notes due 2017 — — 853 Add: Interest expense associated with 3.75% Convertible Senior Notes due 2018 (Original Notes) — — 7,224 Add: Interest expense associated with 4.0% Convertible Senior Notes due 2020 — — 8,691 Net income (loss) used to calculate Diluted EPS $ 253,434 $ (357,584 ) $ 1,278,721 Denominator Year Ended October 31, 2019 2018 2017 Basic weighted average shares outstanding 155,720 143,738 141,997 Add: Shares underlying outstanding stock options, employee stock purchase plan and restricted stock units 1,892 — 1,354 Add: Shares underlying 3.75% Convertible Senior Notes due 2018 (New Notes) — — 404 Add: Shares underlying 0.875% Convertible Senior Notes due 2017 — — 3,032 Add: Shares underlying 3.75% Convertible Senior Notes due 2018 (Original Notes) — — 13,934 Add: Shares underlying 4.0% Convertible Senior Notes due 2020 — — 9,198 Diluted weighted average shares outstanding 157,612 143,738 169,919 EPS Year Ended October 31, 2019 2018 2017 Basic EPS $ 1.63 $ (2.40 ) $ 8.89 Diluted EPS $ 1.61 $ (2.49 ) $ 7.53 The following table summarizes the weighted average shares excluded from the calculation of the denominator for Diluted EPS due to their anti-dilutive effect for the fiscal years indicated (in thousands): Year Ended October 31, 2019 2018 2017 Shares underlying stock options and restricted stock units 234 2,235 958 Add: Shares underlying 3.75% Convertible Senior Notes due 2018 (New Notes) — 1,780 — — 3.75% Convertible Senior Notes due October 15, 2018 (Original Notes) — 2,883 — 4.0% Convertible Senior Notes due December 15, 2020 — 9,123 — Total shares excluded due to anti-dilutive effect 234 16,021 958

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Oct. 31, 2019
Equity [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS’ EQUITY Stock Repurchase Program On December 13, 2018, Ciena announced that its Board of Directors authorized a program to repurchase up to $500 million of Ciena’s common stock. The amount and timing of repurchases are subject to a variety of factors including liquidity, cash flow, stock price, and general business and market conditions. The program may be modified, suspended, or discontinued at any time. The following table summarizes activity of the stock repurchase program, reported based on trade date: Shares Repurchased Weighted-Average Price per Share Amount Repurchased (in thousands) Cumulative balance at October 31, 2018 — $ — $ — Repurchase of common stock under the stock repurchase program 3,838,466 $ 39.10 150,076 Cumulative balance at October 31, 2019 3,838,466 $ 39.10 $ 150,076 The purchase price for the shares of Ciena’s stock repurchased is reflected as a reduction of common stock and additional paid-in capital. Stock Repurchases Related to Restricted Stock Unit Tax Withholdings Ciena repurchases shares of common stock to satisfy employee tax withholding obligations due upon vesting of stock unit awards. The purchase price of $29.1 million for the shares of Ciena’s stock repurchased is reflected as a reduction to stockholders’ equity. Ciena is required to allocate the purchase price of the repurchased shares as a reduction of common stock and additional paid-in capital.

Income Taxes

Income Taxes	12 Months Ended
	Oct. 31, 2019
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES For the fiscal periods indicated, the provision (benefit) for income taxes consists of the following (in thousands): Year Ended October 31, 2019 2018 2017 Provision (benefit) for income taxes: Current: Federal $ 13,143 $ 8,327 $ — State 16,945 8,219 6,342 Foreign 9,816 13,294 14,563 Total current 39,904 29,840 20,905 Deferred: Federal 31,872 475,951 (1 ) (1,047,699 ) (1 ) State (9,159 ) (8,202 ) (77,429 ) (1 ) Foreign (2,861 ) (4,118 ) (1,604 ) Total deferred 19,852 463,631 (1,126,732 ) Provision (benefit) for income taxes $ 59,756 $ 493,471 $ (1,105,827 ) _________________________________ (1) The income tax expense for 2018 includes the impact of the remeasurement of the net deferred tax assets and the federal transition tax. See further discussion below. The income tax benefit for fiscal 2017 includes the reversal of a significant portion of the valuation allowance on Ciena’s deferred tax assets in the U.S. For the fiscal periods indicated, income before provision for income taxes consists of the following (in thousands): Year Ended October 31, 2019 2018 2017 United States $ 256,461 $ 106,972 $ 114,242 Foreign 56,729 41,809 41,884 Total $ 313,190 $ 148,781 $ 156,126 Ciena’s foreign income tax as a percentage of foreign income may appear disproportionate compared to the expected tax based on the U.S. federal statutory rate and is dependent on the mix of earnings and tax rates in foreign jurisdictions. For the periods indicated, the tax provision (benefit) reconciles to the amount computed by multiplying income before income taxes by the U.S. federal statutory rate of 21% for fiscal 2019, 23.41% for fiscal 2018 (see note below), and 35% for fiscal 2017 as follows: Year Ended October 31, 2019 2018 2017 Provision at statutory rate 21.00 % 23.41 % 35.00 % Deferred tax assets remeasurement — % 294.56 % — % Base Erosion and Anti-Abuse Tax 3.60 % — % — % State taxes 2.18 % (0.16 )% 2.29 % Foreign taxes (0.37 )% 1.22 % (0.35 )% Research and development credit (7.53 )% (8.80 )% (15.38 )% Non-deductible compensation 1.01 % 3.39 % 3.45 % Fair value of debt conversion liability — % 1.90 % — % Transition tax 0.29 % 23.23 % — % Valuation allowance (2.13 )% (11.95 )% (739.97 )% Other 1.03 % 4.88 % 6.67 % Effective income tax rate 19.08 % 331.68 % (708.29 )% On December 22, 2017, the Tax Act was enacted. The Tax Act significantly revises the U.S. corporate income tax by, among other things, lowering the statutory corporate income tax rate (“federal tax rate”) from 35% to 21% effective January 1, 2018, implementing a modified territorial tax system, and imposing a mandatory one-time transition tax on accumulated earnings of foreign subsidiaries. As a result of the decrease in the federal tax rate from 35% to 21% effective January 1, 2018, Ciena computed its income tax expense for the October 31, 2018 fiscal year using a blended federal tax rate of 23.41% . Ciena remeasured its DTA using the federal tax rate that will apply when the related temporary differences are expected to reverse. In December 2017, the SEC issued Staff Accounting Bulletin No. 118, which addresses how a company recognizes provisional amounts when it does not have the necessary information available, prepared or analyzed (including computations) in reasonable detail to complete its accounting for the effect of the changes due to the Tax Act. The measurement period ends when a company has obtained, prepared and analyzed the information necessary to finalize its accounting, but cannot extend beyond one year. The final impact of the Tax Act may differ from the above amounts to the extent they are provisional due to changes in interpretations of the Tax Act, legislative action to address questions that arise because of the Tax Act, changes in accounting standards for income taxes and related interpretations in response to the Tax Act, and any updates or changes to estimates used in the provisional amounts. The enactment of the Tax Act resulted in Ciena recording a provisional tax expense of $472.8 million in fiscal 2018. In the first quarter of fiscal 2019, the measurement period under the Tax Act concluded, which resulted in immaterial adjustments to our provisional estimates. Ciena is also required to make accounting policy elections as a result of the Tax Act. These include whether a valuation allowance is recorded for the estimated effect of the application of GILTI and BEAT or if these will be treated as period costs when incurred. Ciena had made the incremental cash tax cost policy election with respect to analyzing the impact of GILTI on the assessment of the realizability of net operating losses. Ciena’s analysis of the new BEAT rules, as well as the very recent regulatory guidance and how they may impact the company, continue to progress. The realizability of U.S. tax carryforwards is not impacted by the BEAT, and the BEAT is a period cost when incurred. Ciena is also required to elect to either treat taxes due on future GILTI inclusions in U.S. taxable income as a current period expense when incurred or reflect such portion of the future GILTI inclusions in U.S. taxable income that relate to existing basis differences in Ciena’s current measurement of deferred taxes. Ciena’s accounting policy election is to treat the taxes due on future U.S. inclusions in taxable income under GILTI as a period cost when incurred. The significant components of DTA are as follows (in thousands): October 31, 2019 2018 Deferred tax assets: Reserves and accrued liabilities $ 54,183 $ 40,959 Depreciation and amortization 455,007 353,838 NOL and credit carry forward 302,325 483,495 Other 39,405 9,397 Gross deferred tax assets 850,920 887,689 Valuation allowance (135,978 ) (142,650 ) Deferred tax asset, net of valuation allowance $ 714,942 $ 745,039 A reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding interest and penalties, is as follows (in thousands): Amount Unrecognized tax benefits at October 31, 2016 $ 30,668 Increase related to positions taken in prior period 122 Increase related to positions taken in current period 111,412 Reductions related to expiration of statute of limitations (620 ) Unrecognized tax benefits at October 31, 2017 141,582 Decrease related to positions taken in prior period (46,400 ) Increase related to positions taken in current period 2,482 Reductions related to expiration of statute of limitations (1,301 ) Unrecognized tax benefits at October 31, 2018 96,363 Increase related to positions taken in prior period 1,959 Reductions related to settlements with taxing authorities (1,224 ) Reductions related to expiration of statute of limitations (2,494 ) Unrecognized tax benefits at October 31, 2019 $ 94,604 As of October 31, 2019 and 2018 , Ciena had accrued $3.0 million and $3.5 million of interest and penalties, respectively, related to unrecognized tax benefits within other long-term liabilities in the Consolidated Balance Sheets. Interest and penalties of $1.0 million and $0.6 million were recorded as a net benefit to the provision for income taxes during fiscal 2019 and fiscal 2017 , respectively. During fiscal 2019, Ciena recorded a net benefit primarily as a result of a settlement with a taxing authority. During fiscal 2017, Ciena recorded a net benefit primarily as a result of recognizing a portion of previously unrecognized tax benefits. During fiscal 2018, Ciena recorded a provision for interest and penalties in its provision for income taxes of $1.1 million . If recognized, the entire balance of unrecognized tax benefits would impact the effective tax rate. Over the next 12 months, Ciena does not estimate any material changes in unrecognized income tax benefits. Ciena has not provided for U.S. deferred income taxes on the cumulative unremitted earnings of its non-U.S. affiliates, as it plans to indefinitely reinvest these foreign earnings outside the U.S. As of October 31, 2019, the cumulative amount of such temporary differences for which a deferred tax liability has not been recognized is an estimated $372.0 million . If these earnings were distributed to the U.S., Ciena would be subject to additional foreign withholding taxes of approximately $31.0 million . Additionally, there are no other significant temporary differences for which a deferred tax liability has not been recognized. As of October 31, 2019 , Ciena continues to maintain a valuation allowance against net deferred tax assets of $136.0 million primarily related to state and foreign net operating losses and credits that Ciena estimates it will not be able to use. The following table summarizes the activity in Ciena’s valuation allowance against its gross deferred tax assets (in thousands): Year ended Beginning Ending October 31, Balance Additions Deductions Balance 2017 $ 1,489,780 $ — $ 1,303,882 $ 185,898 2018 $ 185,898 $ 23,720 $ 66,968 $ 142,650 2019 $ 142,650 $ 27,459 $ 34,131 $ 135,978 As of October 31, 2019 , Ciena had a $391.0 million net operating loss carry forward and a $62.0 million income tax credit carry forward which begin to expire in fiscal 2029 and fiscal 2021, respectively. Ciena’s ability to use net operating losses and credit carry forwards is subject to limitations pursuant to the ownership change rules of the Internal Revenue Code Section 382. Ciena adopted ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, in the first quarter of fiscal 2018. In connection with the adoption of this guidance, Ciena recognized approximately $62.1 million of deferred tax assets related to previously unrecognized tax benefits. This was recorded as a cumulative-effect adjustment to retained earnings as of the beginning of the first quarter of fiscal 2018.

Share-Based Compensation Expens

Share-Based Compensation Expense	12 Months Ended
	Oct. 31, 2019
Share-based Payment Arrangement [Abstract]
SHARE-BASED COMPENSATION EXPENSE	SHARE-BASED COMPENSATION EXPENSE Ciena has outstanding equity awards issued under its 2017 Omnibus Incentive Plan (the “2017 Plan”), its 2008 Omnibus Incentive Plan, and certain legacy equity plans and equity plans assumed as a result of previous acquisitions. All equity awards granted on or after March 23, 2017 are made exclusively from the 2017 Plan. Ciena also makes shares of its common stock available for purchase under its Amended and Restated 2003 Employee Stock Purchase Plan (the “ESPP”). Each of the 2017 Plan and the ESPP are described below. 2017 Plan The 2017 Plan has a ten -year term and authorizes the issuance of awards including stock options, restricted stock units (RSUs), restricted stock, unrestricted stock, stock appreciation rights (SARs) and other equity and/or cash performance incentive awards to employees, directors and consultants of Ciena. Subject to certain restrictions, the Compensation Committee of the Board of Directors has broad discretion to establish the terms and conditions for awards under the 2017 Plan, including the number of shares, vesting conditions, and the required service or performance criteria. Options and SARs have a maximum term of ten years , and their exercise price may not be less than 100% of fair market value on the date of grant. Repricing of stock options and SARs is prohibited without stockholder approval. Certain change in control transactions may cause awards granted under the 2017 Plan to vest, unless the awards are continued or substituted for in connection with the transaction. The 2017 Plan authorizes and reserves 8.9 million shares for issuance. In addition, any shares that remained available for issuance under the 2008 Plan as of March 23, 2017 were added to the 2017 Plan and are available for issuance thereunder. The number of shares available under the 2017 Plan will also be increased from time to time by: (i) the number of shares subject to outstanding awards granted under Ciena’s prior equity compensation plans that are forfeited, expire or are canceled without delivery of common stock following the effective date of the 2017 Plan, and (ii) the number of shares subject to awards assumed or substituted in connection with the acquisition of another company. As of October 31, 2019 , the total number of shares authorized for issuance under the 2017 Plan is 8.9 million and approximately 5.0 million shares remained available for issuance thereunder. Stock Options There were no stock options granted by Ciena during fiscal 2019 , fiscal 2018 or fiscal 2017. Outstanding stock option awards granted to employees in prior periods are generally subject to service-based vesting conditions and vest over a four -year period. The following table is a summary of Ciena’s stock option activity for the periods indicated (shares in thousands): Shares Underlying Options Outstanding Weighted Average Exercise Price Balance as of October 31, 2018 276 $ 33.52 Granted — — Exercised (50 ) $ 24.13 Canceled (6 ) $ 37.03 Balance as of October 31, 2019 220 $ 35.54 The total intrinsic value of options exercised during fiscal 2019 , fiscal 2018 and fiscal 2017 was $0.8 million , $2.2 million and $3.1 million , respectively. The following table summarizes information with respect to stock options outstanding at October 31, 2019 , based on Ciena’s closing stock price on the last trading day of Ciena’s fiscal 2019 (shares and intrinsic value in thousands): Options Outstanding and Vested at October 31, 2019 Number Weighted Average Remaining Weighted Range of of Contractual Average Aggregate Exercise Underlying Life Exercise Intrinsic Price Shares (Years) Price Value $ 6.43 — $ 10.50 4 0.81 $ 8.42 $ 117 $ 11.34 — $ 15.67 49 2.79 $ 13.51 1,123 $ 17.50 — $ 19.25 11 4.6 $ 18.17 202 $ 32.06 — $ 37.10 31 3.27 $ 36.04 28 $ 41.52 — $ 55.63 125 3.48 $ 46.47 — $ 6.43 — $ 55.63 220 3.30 $ 35.54 $ 1,470 Assumptions for Option-Based Awards Ciena recognizes the fair value of stock options as share-based compensation expense on a straight-line basis over the requisite service period. Ciena did not grant any option-based awards during fiscal 2019, fiscal 2018, or fiscal 2017. Restricted Stock Units A restricted stock unit is a stock award that entitles the holder to receive shares of Ciena common stock as the unit vests. Ciena’s outstanding restricted stock unit awards are subject to service-based vesting conditions and/or performance-based vesting conditions. Awards subject to service-based conditions typically vest in increments over a three or four -year period. However, the 2017 Plan permits Ciena to grant service-based stock awards with a minimum one -year vesting period. Awards with performance-based vesting conditions (i) require the achievement of certain operational, financial or other performance criteria or targets or (ii) vest based on Ciena’s total shareholder return as compared to an index of peer companies, in whole or in part. Assumptions for Restricted Stock Unit Awards Ciena recognizes the estimated fair value of performance-based awards as share-based compensation expense over the performance period, using graded vesting, which considers each performance period or tranche separately, based on Ciena’s determination of whether it is probable that the performance targets will be achieved. At the end of each reporting period, Ciena reassesses the probability of achieving the performance targets and the performance period required to meet those targets. Ciena recognizes the estimated fair value of restricted stock units subject only to service-based vesting conditions by multiplying the number of shares underlying the award by the closing price per share of Ciena common stock on the grant date. Ciena recognizes the estimated fair value of restricted stock units subject to performance-based vesting conditions other than total shareholder return by assuming the satisfaction of any performance-based objectives at the “target” level and multiplying the corresponding number of shares earned based upon such achievement by the closing price per share of Ciena common stock on the grant date. Ciena recognizes the estimated fair value of performance based awards subject to total shareholder return as compared to an index of peer companies using a Monte Carlo simulation valuation model. Assumptions for awards granted during fiscal 2019 and fiscal 2018 included the following: Year Ended October 31, 2019 2018 Expected volatility of Ciena common stock, which is a weighted average of implied volatility and historical volatility 34.10% 34.93% Historical volatility of Ciena common stock 36.80% 38.24% Historical volatility of S&P Networking Index 17.39% 17.14% Correlation coefficient 0.6251 0.6597 Expected life in years 2.87 2.89 Risk-free interest rate 2.62% 1.94% Expected dividend yield 0.0% 0.0% The following table is a summary of Ciena’s restricted stock unit activity for the period indicated, with the aggregate fair value of the balance outstanding at the end of each period, based on Ciena’s closing stock price on the last trading day of the relevant period (shares and aggregate fair value in thousands): Restricted Stock Units Outstanding Weighted Average Grant Date Fair Value Per Share Aggregate Fair Value Balance as of October 31, 2018 4,402 $ 22.26 $ 140,943 Granted 2,057 Vested (2,101 ) Canceled or forfeited (348 ) Balance as of October 31, 2019 4,010 $ 27.94 $ 146,091 As of October 31, 2019 and 2018, 0.3 million and 0.2 million of the total restricted stock units outstanding are performance based awards subject to total shareholder return, respectively. The total fair value of restricted stock units that vested and were converted into common stock during fiscal 2019 , fiscal 2018 and fiscal 2017 was $79.2 million , $54.3 million and $49.5 million , respectively. The weighted average fair value of each restricted stock unit granted by Ciena during fiscal 2019 , fiscal 2018 and fiscal 2017 was $34.53 , $22.46 and $23.29 , respectively. The fair value of each restricted stock unit award is based on the closing price on the date of grant. Share-based expense for service-based restricted stock unit awards is recognized ratably over the vesting period on a straight-line basis. Share-based expense for performance-based restricted stock unit awards is recognized ratably over the performance period based on Ciena’s determination of whether it is probable that the performance targets will be achieved. At each reporting period, Ciena reassesses the probability of achieving the performance targets and the performance period required to meet those targets. The estimation of whether the performance targets will be achieved involves judgment, and the estimate of expense is revised periodically based on the probability of achieving the performance targets. Revisions are reflected in the period in which the estimate is changed. If any performance goals are not met, no compensation cost is ultimately recognized against that goal and, to the extent previously recognized, compensation expense is reversed. Share-based compensation expense is recognized only for those awards that are ultimately expected to vest. In the event of a forfeiture of an award, the expense related to the unvested portion of that award is reversed. Reversal of share-based compensation expense based on forfeitures can materially affect the measurement of estimated fair value of Ciena’s share-based compensation. Amended and Restated ESPP Under the ESPP, eligible employees may enroll in a twelve -month offer period that begins in December and June of each year. Each offer period includes two six -month purchase periods. Employees may purchase a limited number of shares of Ciena common stock at 85% of the fair market value on either the day immediately preceding the offer date or the purchase date, whichever is lower. The ESPP is considered compensatory for purposes of share-based compensation expense. Pursuant to the ESPP’s “evergreen” provision, on December 31 of each year, the number of shares available under the ESPP increases by up to 0.6 million shares, provided that the total number of shares available at that time shall not exceed 8.2 million . Unless earlier terminated, the ESPP will terminate on January 24, 2023 . During fiscal 2019 , fiscal 2018 and fiscal 2017 , Ciena issued 1.0 million , 1.1 million and 1.0 million shares under the ESPP, respectively. At October 31, 2019 , 4.5 million shares remained available for issuance under the ESPP. Share-Based Compensation Expense The following table summarizes share-based compensation expense for the periods indicated (in thousands): Year Ended October 31, 2019 2018 2017 Product cost of goods sold $ 2,868 $ 2,984 $ 2,672 Service cost of goods sold 3,175 2,616 2,487 Share-based compensation expense included in cost of goods sold 6,043 5,600 5,159 Research and development 14,321 13,518 12,957 Sales and marketing 16,474 14,246 12,846 General and administrative 22,841 19,709 17,321 Share-based compensation expense included in operating expense 53,636 47,473 43,124 Share-based compensation expense capitalized in inventory, net 57 (101 ) 77 Total share-based compensation $ 59,736 $ 52,972 $ 48,360 As of October 31, 2019 , total unrecognized share-based compensation expense was $88.2 million which relates to unvested restricted stock units and is expected to be recognized over a weighted-average period of 1.45 years.

Segment and Entity Wide Disclos

Segment and Entity Wide Disclosures	12 Months Ended
	Oct. 31, 2019
Segment Reporting [Abstract]
SEGMENT AND ENTITY WIDE DISCLOSURES	SEGMENT AND ENTITY WIDE DISCLOSURES Segment Reporting Ciena has the following operating segments for reporting purposes: (i) Networking Platforms; (ii) Platform Software and Services; (iii) Blue Planet Automation Software and Services; and (iv) Global Services. During fiscal 2019, we separated our previous Software and Software-Related Services segment into two stand-alone operating segments. Because Ciena previously disclosed its Platform Software and Services and Blue Planet Automation Software and Services as distinct product lines in its presentation of segment revenue for Software and Software-Related Services, there is no significant change to our presentation of segment revenues as a result of this separation. Comparative periods have been retrospectively adjusted to disclose segment profit for Platform Software and Services and Blue Planet Automation Software and Services. Ciena’s long-lived assets, including equipment, building, furniture and fixtures, finite-lived intangible assets, and maintenance spares, are not reviewed by the chief operating decision maker for purposes of evaluating performance and allocating resources. As of October 31, 2019 , equipment, building, furniture and fixtures totaling $286.9 million primarily supports asset groups within Ciena’s Networking Platforms, Platform Software and Services and Blue Planet Automation Software and Services segments and Ciena’s unallocated selling and general and administrative activities. As of October 31, 2019 , $20.3 million of Ciena’s intangible assets were assigned to asset groups within Ciena’s Networking Platforms segment and $92.5 million of Ciena’s intangible assets were assigned to asset groups within Ciena’s Blue Planet Automation Software and Services segment. As of October 31, 2019 , all of the maintenance spares totaling $55.5 million were assigned to asset groups within Ciena’s Global Services segment. Segment Revenue The table below (in thousands, except percentage data) sets forth Ciena’s segment revenue for the respective periods indicated: Year Ended October 31, 2019 2018 2017 Revenue: Networking Platforms Converged Packet Optical $ 2,562,841 $ 2,194,519 $ 1,939,621 Packet Networking 348,477 283,499 313,089 Total Networking Platforms 2,911,318 2,478,018 2,252,710 Platform Software and Services 155,376 173,949 145,009 Blue Planet Automation Software and Services 54,555 26,764 16,110 Global Services Maintenance Support and Training 261,337 245,161 227,400 Installation and Deployment 148,233 128,829 117,524 Consulting and Network Design 41,312 41,565 42,934 Total Global Services 450,882 415,555 387,858 Total revenue $ 3,572,131 $ 3,094,286 $ 2,801,687 Segment Profit (Loss) The presentation of segment profit (loss) for fiscal 2018 and 2017 reflects the change in Ciena’s software operating segments as described above. Segment profit (loss) is determined based on internal performance measures used by Ciena’s chief executive officer to assess the performance of each operating segment in a given period. In connection with that assessment, the chief executive officer excludes the following items: selling and marketing costs; general and administrative costs; amortization of intangible assets; acquisition and integration costs; significant asset impairments and restructuring costs, interest and other income (loss), net; interest expense; loss on extinguishment and modification of debt; and provision (benefit) for income taxes. The table below (in thousands) sets forth Ciena’s segment profit (loss) and the reconciliation to consolidated net income (loss) during the respective periods indicated: Year Ended October 31, 2019 2018 2017 Segment profit (loss): Networking Platforms $ 759,244 $ 581,113 $ 578,039 Platform Software and Services 64,210 78,048 47,353 Blue Planet Automation Software and Services (17,769 ) (8,240 ) (14,817 ) Global Services 188,242 172,205 159,882 Total segment profit 993,927 823,126 770,457 Less: non-performance operating expenses Selling and marketing 423,046 394,060 356,169 General and administrative 174,399 160,133 142,604 Amortization of intangible assets 21,808 15,737 33,029 Acquisition and integration costs 3,370 5,111 — Significant asset impairments and restructuring costs 24,538 18,139 23,933 Add: other non-performance financial items Interest and other income (loss), net 3,876 (12,029 ) 913 Interest expense (37,452 ) (55,249 ) (55,852 ) Loss on extinguishment and modification of debt — (13,887 ) (3,657 ) Less: Provision (benefit) for income taxes 59,756 493,471 (1,105,827 ) Total net income (loss) $ 253,434 $ (344,690 ) $ 1,261,953 Entity Wide Reporting Ciena’s operating segments each engage in business across four geographic regions: North America; Europe, Middle East and Africa (“EMEA”); Asia-Pacific, Japan and India (“APAC”); and Caribbean and Latin America (“CALA”). North America includes only activities in the United States and Canada. The following table reflects Ciena’s geographic distribution of revenue principally based on the relevant location for Ciena’s delivery of products and performance of services. For the periods below, Ciena’s geographic distribution of revenue was as follows (in thousands): Year Ended October 31, 2019 2018 2017 North America $ 2,351,260 $ 1,886,450 $ 1,736,047 EMEA 566,718 464,876 404,099 CALA 152,653 140,177 164,308 APAC 501,500 602,783 497,233 Total $ 3,572,131 $ 3,094,286 $ 2,801,687 North America includes $2.25 billion , $1.77 billion and $1.63 billion of United States revenue for fiscal years ended October 31, 2019 , 2018 and 2017 , respectively. No other country accounted for at least 10% of total revenue for the periods presented above. The following table reflects Ciena’s geographic distribution of equipment, building, furniture and fixtures, net, with any country accounting for at least 10% of total equipment, building, furniture and fixtures, net, specifically identified. Equipment, building, furniture and fixtures, net, attributable to geographic regions outside of the United States and Canada are reflected as “Other International.” For the periods below, Ciena’s geographic distribution of equipment, building, furniture and fixtures, net, was as follows (in thousands): October 31, 2019 2018 Canada $ 211,901 $ 198,028 United States 58,119 75,479 Other International 16,864 18,560 Total $ 286,884 $ 292,067 While Ciena has benefited from the diversification of its business and customer base, its ten largest customers contributed 59.3% of fiscal 2019 revenue, 56.5% of fiscal 2018 revenue and 55.6% of fiscal 2017 revenue. For the periods below, customers accounting for at least 10% of Ciena’s revenue were as follows (in thousands): October 31, 2019 2018 2017 Verizon $ 459,787 $ 318,013 $ 288,048 AT&T 388,704 374,576 448,943 Web-scale provider 370,577 n/a n/a Total $ 1,219,068 $ 692,589 $ 736,991 ________________________________ n/a Denotes revenue representing less than 10% of total revenue for the period The Web-scale provider noted above contributed greater than 10% of total revenue for the first time in fiscal 2019 and purchased products from each of Ciena’s operating segments excluding Blue Planet Automation Software and Services. The other customers identified above purchased products and services from each of Ciena’s operating segments.

Other Employee Benefit Plans

Other Employee Benefit Plans	12 Months Ended
	Oct. 31, 2019
Retirement Benefits [Abstract]
OTHER EMPLOYEE BENEFIT PLANS	OTHER EMPLOYEE BENEFIT PLANS Ciena has a Defined Contribution Pension Plan that covers a majority of its Canada-based employees. The plan covers all Canada-based employees who are not part of an excluded group. Total contributions (employee and employer) cannot exceed the lesser of 18% of participant earnings and an annual dollar limit (CAD $27,230 (approximately $20,725 ) for 2019 ). This plan includes a required employer contribution of 1% for all participants and a 50% matching of participant contributions up to a total annual maximum of CAD $3,000 (approximately $2,283 ) per employee. During fiscal 2019 , 2018 and 2017 , Ciena made matching contributions of approximately CAD $5.2 million (approximately $4.0 million ), CAD $5.1 million (approximately $3.9 million ) and CAD $4.7 million (approximately $3.6 million ), respectively. Ciena has a 401(k) defined contribution profit sharing plan. Participants may contribute up to 60% of pre-tax compensation, subject to certain limitations. The plan includes an employer matching contribution equal to 50% of the first 6% an employee contributes each pay period. Ciena may also make discretionary annual profit contributions up to the IRS regulated limit. Ciena has made no profit sharing contributions to date. During fiscal 2019 , 2018 and 2017 , Ciena made matching contributions of approximately $5.9 million , $5.8 million and $5.7 million , respectively.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Oct. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Government Grant During fiscal 2018, Ciena entered into agreements related to the Evolution of Networking Services through a Corridor in Quebec and Ontario for Research and Innovation project with the Canadian federal government, the government of the province of Ontario and the government of the province of Quebec to develop a 5G technology corridor between Quebec and Ontario to promote research and development, small business enterprises and entrepreneurs in Canada. Under these agreements, Ciena can receive up to an aggregate CAD $57.6 million (approximately $43.8 million ) in reimbursement from the three Canadian government entities for eligible costs over a period commencing on February 20, 2017 and ending on March 31, 2022. Ciena anticipates receiving recurring disbursements over this period. Amounts received under the agreements are subject to recoupment in the event that Ciena fails to achieve certain minimum investment, employment and project milestones. As of October 31, 2019 , Ciena has recorded CAD $28.9 million (approximately $22.0 million ) in cumulative benefits as a reduction in research and development expense of which CAD $12.3 million (approximately $9.2 million ) was recorded in fiscal 2019. As of October 31, 2019 , amounts receivable from this grant were CAD $10.4 million (approximately $7.9 million ). Tax Contingencies Ciena is subject to various tax liabilities arising in the ordinary course of business. Ciena does not expect that the ultimate settlement of these tax liabilities will have a material effect on its results of operations, financial position or cash flows. Litigation Ciena is subject to various legal proceedings, claims and other matters arising in the ordinary course of business, including those that relate to employment, commercial, tax and other regulatory matters. Ciena is also subject to intellectual property related claims, including claims against third parties that may involve contractual indemnification obligations on the part of Ciena. Ciena does not expect that the ultimate costs to resolve such matters will have a material effect on its results of operations, financial position or cash flows. Lease Commitments Ciena has certain minimum obligations under non-cancelable leases expiring on various dates through 2032 for equipment and facilities. The following table summarizes Ciena’s future annual minimum lease commitments under non-cancelable leases that are not recorded on the balance sheet as of October 31, 2019 (in thousands): 2020 2021 2022 2023 2024 Thereafter Total Operating leases $ 28,776 $ 24,184 $ 16,767 $ 13,393 $ 10,632 $ 26,110 $ 119,862 Rental expense for fiscal 2019 , fiscal 2018 and fiscal 2017 was approximately $22.0 million , $24.1 million and $30.9 million , respectively. In addition, Ciena paid approximately $1.3 million , $1.9 million and $2.7 million during fiscal 2019 , fiscal 2018 and fiscal 2017 , respectively, related to rent costs for restructured facilities and unfavorable lease commitments, which were offset against Ciena’s restructuring liabilities and unfavorable lease obligations. The amount for operating lease commitments above does not include variable expenses relating to insurance, taxes, maintenance and other costs required by the applicable operating lease. These costs are not expected to have a material impact on Ciena’s financial condition, results of operations or cash flows.

Subsequent Events

Subsequent Events	12 Months Ended
	Oct. 31, 2019
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS Stock Repurchase Program From the end of the fourth quarter of fiscal 2019 through December 16, 2019, Ciena repurchased an additional 737,474 shares of its common stock, for an aggregate purchase price of $27.4 million at an average price of $37.21 per share, inclusive of repurchases pending settlement. As of December 16, 2019, Ciena has repurchased an aggregate of 4,575,940 shares and has an aggregate of $322.5 million of authorized funds remaining under its Stock Repurchase Program. Centina Acquisition On October 3, 2019, Ciena entered into a definitive agreement to acquire privately-held Centina Systems, Inc., a provider of service assurance analytics and network performance management solutions. The transaction closed during Ciena’s first quarter of fiscal 2020. Tax Regulations On December 2, 2019, the U.S. Department of the Treasury released final regulations and proposed regulations under Section 59A, BEAT. BEAT, which requires certain U.S. corporations to pay a minimum tax associated with deductible payments to non-U.S. related parties, was enacted by the Tax Act. In addition, on December 2, 2019, the U.S. Department of the Treasury also released final regulations that provide additional guidance with respect to the foreign tax credit regime under the Tax Act. For the year ended October 31, 2019, Ciena recorded $11.3 million of BEAT and a benefit of $0.9 million attributable to such foreign tax credits. Ciena is in the process of reviewing these regulations and does not anticipate the impact of the new regulations will be material. Any tax effect will be recorded in Ciena’s fiscal 2020 results.

Ciena Corporation and Signifi_2

Ciena Corporation and Significant Accounting Policies and Estimates (Policies)	12 Months Ended
	Oct. 31, 2019
Accounting Policies [Abstract]
Principles of Consolidation	The accompanying consolidated financial statements include the accounts of Ciena and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Fiscal Year	Ciena has a 52 or 53 week fiscal year, which ends on the Saturday nearest to the last day of October in each year ( November 2, 2019 , November 3, 2018 and October 28, 2017 for the periods reported). Fiscal 2019 and fiscal 2017 each consisted of a 52-week fiscal year and fiscal 2018 consisted of a 53-week fiscal year. For purposes of financial statement presentation, each fiscal year is described as having ended on October 31.
Business Combinations	Ciena records acquisitions using the purchase method of accounting. All of the assets acquired, liabilities assumed, contractual contingencies and contingent consideration are recognized at their fair value as of the acquisition date. The excess of the purchase price over the estimated fair values of the net tangible and net intangible assets acquired is recorded as goodwill. The application of the purchase method of accounting for business combinations requires management to make significant estimates and assumptions in the determination of the fair value of assets acquired and liabilities assumed, in order to properly allocate purchase price consideration between assets that are depreciated and amortized from goodwill. These assumptions and estimates include a market participant’s use of the asset and the appropriate discount rates for a market participant. Ciena’s estimates are based on historical experience, information obtained from the management of the acquired companies and, when appropriate, include assistance from independent third-party appraisal firms. Significant assumptions and estimates can include, but are not limited to, the cash flows that an asset is expected to generate in the future, the appropriate weighted-average cost of capital and the cost savings expected to be derived from acquiring an asset. These estimates are inherently uncertain and unpredictable. In addition, unanticipated events and circumstances may occur which may affect the accuracy or validity of such estimates.
Use of Estimates	The preparation of the financial statements and related disclosures in conformity with Generally Accepted Accounting Principles (“GAAP”) requires management to make estimates and judgments that affect the amounts reported in the consolidated financial statements and accompanying notes. Estimates are used for selling prices for multiple element arrangements, shared-based compensation, bad debts, valuation of inventories and investments, recoverability of intangible assets, other long-lived assets and goodwill, income taxes, warranty obligations, restructuring liabilities, derivatives, contingencies and litigation. Ciena bases its estimates on historical experience and assumptions that it believes are reasonable. Actual results may differ materially from management’s estimates.
Cash and Cash Equivalents	Ciena considers all highly liquid investments purchased with original maturities of three months or less to be cash equivalents. Any restricted cash collateralizing letters of credit is included in other current assets and other long-term assets depending on the duration of the restriction.
Investments	Ciena’s investments in debt securities are classified as available-for-sale and reported at fair value, with unrealized gains and losses recorded in accumulated other comprehensive income (loss). Ciena recognizes losses in the income statement when it determines that declines in the fair value of its investments below their cost basis are other-than-temporary. In determining whether a decline in fair value is other-than-temporary, Ciena considers various factors, including market price (when available), investment ratings, the financial condition and near-term prospects of the investee, the length of time and the extent to which the fair value has been less than Ciena’s cost basis, and Ciena’s intent and ability to hold the investment until maturity or for a period of time sufficient to allow for any anticipated recovery in market value. Ciena considers all marketable debt securities that it expects to convert to cash within one year or less to be short-term investments, with all others considered to be long-term investments. Ciena has minority equity investments in privately held technology companies that are classified in other long-term assets. These investments are carried at cost because Ciena owns less than 20% of the voting equity and does not have the ability to exercise significant influence over the company. Ciena monitors these investments for impairment and makes appropriate reductions to the carrying value when necessary. As of October 31, 2019 , the combined carrying value of these investments was $10.7 million . Ciena elects to estimate the fair value at cost minus impairment, if any, plus or minus observable price changes in orderly transactions for identical or similar investments of the same issuer. Ciena has not evaluated these investments for impairment or observable price changes as there have not been any events or changes in circumstances that Ciena believes would have had a significant effect on the fair value of these investments.
Inventories	Inventories are stated at the lower of cost or market, with cost computed using standard cost, which approximates actual cost, on a first-in, first-out basis. Ciena records a provision for excess and obsolete inventory when an impairment has been identified.
Segment Reporting	Ciena’s chief operating decision maker, its chief executive officer, evaluates the Company’s performance and allocates resources based on multiple factors, including measures of segment profit (loss). Operating segments are defined as components of an enterprise that engage in business activities that may earn revenue and incur expense, for which discrete financial information is available, and for which such information is evaluated regularly by the chief operating decision maker for purposes of allocating resources and assessing performance. During fiscal 2019, we separated our previous Software and Software-Related Services segment into two
Goodwill	Goodwill is the excess of the purchase price over the fair values assigned to the net assets acquired in a business combination. Ciena tests goodwill for impairment on an annual basis, which it has determined to be the last business day of fiscal September each year. Ciena also tests goodwill for impairment between annual tests if an event occurs or circumstances change that would, more likely than not, reduce the fair value of the reporting unit below its carrying value. Ciena tests goodwill impairment by comparing the fair value of the reporting unit with the unit’s carrying amount, including goodwill. If this test indicates that the fair value is less than the carrying value, then an impairment loss is recognized limited to the total amount of goodwill allocated to that reporting unit. A non-cash goodwill impairment charge would have the effect of decreasing earnings or increasing losses in such period. If Ciena is required to take a substantial impairment charge, its operating results would be materially adversely affected in such period.
Long-lived Assets	Long-lived assets include: equipment, building, furniture and fixtures; finite-lived intangible assets; and maintenance spares. Ciena tests long-lived assets for impairment whenever triggering events or changes in circumstances indicate that the asset’s carrying amount is not recoverable from its undiscounted cash flows. An impairment loss is measured as the amount by which the carrying amount of the asset or asset group exceeds its fair value. Ciena’s long-lived assets are assigned to asset groups that represent the lowest level for which cash flows can be identified.
Equipment, Building, Furniture and Fixtures and Internal Use Software	Equipment, building, furniture and fixtures are recorded at cost. Depreciation and amortization are computed using the straight-line method over useful lives of two years to five years for equipment and furniture and fixtures and the shorter of useful life or lease term for leasehold improvements. Qualifying internal use software and website development costs incurred during the application development stage, which consist primarily of outside services and purchased software license costs, are capitalized and amortized straight-line over the estimated useful lives of two years to five years .
Intangible Assets	Ciena has recorded finite-lived intangible assets as a result of several acquisitions. Finite-lived intangible assets are carried at cost less accumulated amortization. Amortization is computed using the straight-line method over the expected economic lives of the respective assets, up to seven years , which approximates the use of intangible assets.
Maintenance Spares	Maintenance spares are recorded at cost. Spares usage cost is expensed ratably over four years .
Concentrations	Substantially all of Ciena’s cash and cash equivalents are maintained at a small number of major U.S. financial institutions. The majority of Ciena’s cash equivalents consist of money market funds. Deposits held with banks may exceed the amount of insurance provided on such deposits. Because these deposits generally may be redeemed upon demand, management believes that they bear minimal risk. Historically, a significant percentage of Ciena’s revenue has been concentrated among sales to a small number of large communications service providers and Web-scale providers. Consolidation among Ciena’s customers has increased this concentration. Consequently, Ciena’s accounts receivable are concentrated among these customers. See Note 23 below. Additionally, Ciena’s access to certain materials or components is dependent on sole or limited source suppliers. The inability of any of these suppliers to fulfill Ciena’s supply requirements, or significant changes in supply cost, could affect future results. Ciena relies on a small number of contract manufacturers to perform the majority of the manufacturing for its products. If Ciena cannot effectively manage these manufacturers or forecast future demand, or if these manufacturers fail to deliver products or components on time, Ciena’s business and results of operations may suffer.
Revenue Recognition	Ciena recognizes revenue when control of the promised products or services is transferred to its customer, in an amount that reflects the consideration to which Ciena expects to be entitled in exchange for those products or services. Ciena determines revenue recognition by applying the following five-step approach: • identification of the contract, or contracts, with a customer; • identification of the performance obligations in the contract; • determination of the transaction price; • allocation of the transaction price to the performance obligations in the contract; and • recognition of revenue when, or as, Ciena satisfies a performance obligation. Generally, Ciena makes sales pursuant to purchase orders placed by customers under framework agreements that govern the general commercial terms and conditions of the sale of Ciena’s products and services. These purchase orders under framework agreements are used to determine the identification of the contract or contracts with this customer. Purchase orders typically include the description, quantity, and price of each product or service purchased. Purchase orders may include one-line bundled pricing for both products and services. Accordingly, purchase orders can include various combinations of products and services that are generally distinct and accounted for as separate performance obligations. Ciena evaluates each promised product and service offering to determine whether it represents a distinct performance obligation. In doing so, Ciena considers, among other things, customary business practices, whether the customer can benefit from the product or service on its own or together with other resources that are readily available, and whether Ciena’s commitment to transfer the product or service to the customer is separately identifiable from other obligations in the purchase order. For transactions where Ciena delivers the product or services, Ciena is typically the principal and records revenue and costs of goods sold on a gross basis. Purchase orders are invoiced based on the terms set forth either in the purchase order or the framework agreement, as applicable. Generally, sales of products and software licenses are invoiced upon shipment or delivery. Maintenance and software subscription services are invoiced quarterly or annually in advance of the service term. Ciena’s other service offerings are generally invoiced upon completion of the service. Payment terms and cash received typically range from 30 to 90 days from the invoicing date. Historically, Ciena has not provided any material financing arrangements to its customers. As a practical expedient, Ciena does not adjust the amount of consideration it will receive for the effects of a significant financing component as it expects, at contract inception, that the period between Ciena transfer of the products or services to the customer, and customer payment for the products or services will be one year or less. Shipping and handling fees invoiced to customers are included in revenue, with the associated expense included in product cost of goods sold. Ciena records revenue net of any associated sales taxes. Ciena recognizes revenue upon the transfer of control of promised products or services to a customer. Transfer of control occurs once the customer has the contractual right to use the product, generally upon shipment or delivery to the customer. Transfer of control can also occur over time for services such as software subscription, maintenance, installation, and various professional services as the customer receives the benefit over the contract term. Significant Judgments Revenue is allocated among performance obligations based on standalone selling price (“SSP”). SSP reflects the price at which Ciena would expect to sell that product or service on a stand-alone basis at contract inception and that Ciena would expect to be entitled to receive for the promised products or services. SSP is estimated for each distinct performance obligation, and judgment may be required in its determination. The best evidence of SSP is the observable price of a product or service when Ciena sells the products separately in similar circumstances and to similar customers. In instances where SSP is not directly observable, Ciena determines SSP using information that may include market conditions and other observable inputs. Ciena applies judgment in determining the transaction price, as Ciena may be required to estimate variable consideration when determining the amount of revenue to recognize. Variable consideration can include various rebate, cooperative marketing, and other incentive programs that Ciena offers to its distributors, partners and customers. When determining the amount of revenue to recognize, Ciena estimates the expected usage of these programs, applying the expected value or most likely estimate and updates the estimate at each reporting period as actual utilization data becomes available. Ciena also considers any customer right of return and any actual or potential payment of liquidated damages, contractual or similar penalties, or other claims for performance failures or delays in determining the transaction price, where applicable. When transfer of control is judged to be over time for installation and professional service arrangements, Ciena applies the input method to determine the amount of revenue to be recognized in a given period. Utilizing the input method, Ciena recognizes revenue based on the ratio of actual costs incurred to date to the total estimated costs expected to be incurred. Revenue for software subscription and maintenance is recognized ratably over the period during which the services are performed. Capitalized Contract Acquisition Costs Ciena has considered the impact of the guidance in Accounting Standards Codification (“ASC”) 340-40, Other Assets and Deferred Costs; Contracts with Customers , and the interpretations of the Financial Accounting Standards Board (“FASB”) Transition Resource Group for Revenue Recognition with respect to capitalization and amortization of incremental costs of obtaining a contract. In conjunction with this interpretation, Ciena considers each customer purchase in combination with the corresponding framework agreement, if applicable, as a contract. Ciena has elected to implement the practical expedient, which allows for incremental costs to be recognized as an expense when incurred if the period of the asset recognition is one year or less. If the period of the asset recognition is greater than one year, Ciena amortizes these costs over the period of performance. Ciena considers sales commissions incurred upon receipt of purchase orders placed by customers as incremental costs to obtain such purchase orders. The practical expedient method is applied to the purchase order as a whole and thus the capitalized costs of obtaining a purchase order is applied even if the purchase order contains more than one performance obligation. In cases where a purchase order includes various distinct products or services with both short-term (one year or less) and long-term (more than a year) performance periods, the cost of commissions incurred for the total value of the purchase order is capitalized and subsequently amortized as each performance obligation is recognized.
Warranty Accruals	Ciena provides for the estimated costs to fulfill customer warranty obligations upon recognition of the related revenue. Estimated warranty costs include estimates for material costs, technical support labor costs and associated overhead. Warranty is included in cost of goods sold and is determined based on actual warranty cost experience, estimates of component failure rates and management’s industry experience. Ciena’s sales contracts do not permit the right of return of the product by the customer after the product has been accepted.
Accounts Receivable, Net
Research and Development	Ciena charges all research and development costs to expense as incurred. Types of expense incurred in research and development include employee compensation, prototype equipment, consulting and third-party services, depreciation, facility costs and information technology.
Government Grants	Ciena accounts for proceeds from government grants as a reduction of expense when there is reasonable assurance that Ciena has met the required conditions associated with the grant and that grant proceeds will be received. Grant benefits are recorded to the particular line item of the Consolidated Statement of Operations to which the grant activity relates.
Advertising Costs	Ciena expenses all advertising costs as incurred.
Legal Costs	Ciena expenses legal costs associated with litigation as incurred.
Share-Based Compensation Expense	Ciena measures and recognizes compensation expense for share-based awards based on estimated fair values on the date of grant. Ciena estimates the fair value of each option-based award on the date of grant using the Black-Scholes option-pricing model. This model is affected by Ciena’s stock price as well as estimates regarding a number of variables, including expected stock price volatility over the expected term of the award and projected employee stock option exercise behaviors. Ciena recognizes the estimated fair value of restricted stock units subject only to service-based vesting conditions by multiplying the number of shares underlying the award by the closing price per share of Ciena common stock on the grant date. In each case, Ciena only recognizes expense in its Consolidated Statement of Operations for those stock options or restricted stock units that are expected ultimately to vest. Awards with performance-based vesting conditions (i) require the achievement of certain operational, financial or other performance criteria or targets or (ii) vest based on Ciena’s total shareholder return as compared to an index of peer companies, in whole or in part.
Stock Repurchase Plan	Shares repurchased pursuant to Ciena’s share repurchase program are immediately retired upon purchase. Repurchased common stock is reflected as a reduction of stockholders’ equity. Ciena’s accounting policy related to its share repurchases is to reduce its common stock based on the par value of the shares and to reduce its capital surplus for the excess of the repurchase price over the par value. Since the inception of its share repurchase program in December 2018, Ciena has had an accumulated deficit balance; therefore, the excess over the par value has been applied to additional paid-in capital. Once Ciena has retained earnings, the excess will be charged entirely to retained earnings.
Income Taxes	Ciena accounts for income taxes using an asset and liability approach. This approach recognizes deferred tax assets and liabilities (“DTA”) for the expected future tax consequences attributable to differences between the carrying amounts of assets and liabilities for financial reporting purposes and their respective tax bases, and for operating loss and tax credit carryforwards. In estimating future tax consequences, Ciena considers all expected future events other than the enactment of changes in tax laws or rates. Valuation allowances are provided if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. In the ordinary course of business, transactions occur for which the ultimate outcome may be uncertain. In addition, tax authorities periodically audit Ciena’s income tax returns. These audits examine significant tax filing positions, including the timing and amounts of deductions and the allocation of income tax expenses among tax jurisdictions. Ciena is currently under audit in India for 2012 and 2014 through 2018, and in Canada for 2011 through 2015. Management does not expect the outcome of these audits to have a material adverse effect on Ciena’s consolidated financial position, results of operations or cash flows. Ciena’s major tax jurisdictions and the earliest open tax years are as follows: United States (2016), United Kingdom (2016), Canada (2011), and India (2012). Limited adjustments can be made to Federal U.S. tax returns in earlier years in order to reduce net operating loss carryforwards. Ciena classifies interest and penalties related to uncertain tax positions as a component of income tax expense. Ciena has not provided for U.S. deferred income taxes on the cumulative unremitted earnings of its non-U.S. affiliates, as it plans to indefinitely reinvest these foreign earnings outside the U.S. As of October 31, 2019, the cumulative amount of such temporary differences for which a deferred tax liability has not been recognized totaled approximately $372.0 million . If these earnings were distributed to the U.S. in the form of dividends, or otherwise, or if the shares of the relevant foreign subsidiaries were sold or otherwise transferred, Ciena would be subject to additional U.S. income taxes (subject to an adjustment for foreign tax credits) and foreign withholding taxes. Ciena is required to record excess tax benefits or tax deficiencies related to stock-based compensation as income tax benefit or expense when share-based awards vest or are settled. Ciena adopted ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, in the first quarter of fiscal 2018. In connection with the adoption of this guidance, Ciena recognized approximately $62.1 million of deferred tax assets related to previously unrecognized tax benefits. This was recorded as a cumulative-effect adjustment to retained earnings as of the beginning of the first quarter of fiscal 2018. The Tax Cuts and Jobs Act (the “Tax Act”) includes provisions that affect Ciena in fiscal 2019, including a provision designed to tax global intangible low-taxed income (“GILTI”). An accounting policy choice is allowed to either treat taxes due on future U.S. inclusions related to GILTI in taxable income as a current-period expense when incurred (the “period cost method”) or factor such amounts into the measurement of deferred taxes (the “deferred method”). The calculation of the deferred balance with respect to the new GILTI tax provisions will depend, in part, on analyzing global income to determine whether future U.S. inclusions in taxable income are expected related to GILTI and, if so, what the impact is expected to be. Ciena is electing to use the period cost method for future GILTI inclusions. Additionally, Ciena is electing to use the incremental cash tax savings approach when determining whether a valuation allowance needs to be recorded against the U.S. net operating loss (“NOL”) due to the GILTI inclusions. The Tax Act also introduced an alternative tax known as the base erosion and anti-abuse tax (“BEAT”). An accounting policy choice has been made to consider BEAT as a period cost when incurred.
Loss Contingencies	Ciena is subject to the possibility of various losses arising in the ordinary course of business. These may relate to disputes, litigation and other legal actions. Ciena considers the likelihood of loss or the incurrence of a liability, as well as Ciena’s ability to estimate the amount of loss reasonably, in determining loss contingencies. An estimated loss contingency is accrued when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. Ciena regularly evaluates current information available to it in order to determine whether any accruals should be adjusted and whether new accruals are required.
Fair Value of Financial Instruments	The carrying value of Ciena’s cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximates fair market value due to the relatively short period of time to maturity. For information related to the fair value of Ciena’s term loan, see Note 17 below. Fair value for the measurement of financial assets and liabilities is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. Ciena utilizes a valuation hierarchy for disclosure of the inputs for fair value measurement. This hierarchy prioritizes the inputs into three broad levels as follows: • Level 1 inputs are unadjusted quoted prices in active markets for identical assets or liabilities; • Level 2 inputs are quoted prices for identical or similar assets or liabilities in less active markets or model-derived valuations in which significant inputs are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument; and • Level 3 inputs are unobservable inputs based on Ciena’s assumptions used to measure assets and liabilities at fair value. The fair values are determined based on model-based techniques using inputs Ciena could not corroborated with market data. By distinguishing between inputs that are observable in the marketplace, and therefore more objective, and those that are unobservable, and therefore more subjective, the hierarchy is designed to indicate the relative reliability of the fair value measurements. A financial asset’s or liability’s classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement.
Restructuring	From time to time, Ciena takes actions to better align its workforce, facilities and operating costs with perceived market opportunities, business strategies and changes in market and business conditions. Ciena recognizes a liability for the cost associated with an exit or disposal activity in the period in which the liability is incurred, except for one-time employee termination benefits related to a service period, typically of more than 60 days
Foreign Currency	Certain of Ciena’s foreign branch offices and subsidiaries use the U.S. Dollar as their functional currency because Ciena Corporation, as the U.S. parent entity, exclusively funds the operations of these branch offices and subsidiaries. For those subsidiaries using the local currency as their functional currency, assets and liabilities are translated at exchange rates in effect at the balance sheet date, and the statement of operations is translated at a monthly average rate. Resulting translation adjustments are recorded directly to a separate component of stockholders’ equity. Where the monetary assets and liabilities are transacted in a currency other than the entity’s functional currency, re-measurement adjustments are recorded in interest and other income (loss), net on the Consolidated Statement of Operations.
Derivatives	Ciena’s 3.75% Convertible Senior Notes due October 15, 2018 (the “New Notes”) included a conversion feature that was accounted for as a separate embedded derivative. The embedded conversion feature was recorded at fair value using the underlying stock price, time to maturity and expected volatility of Ciena’s stock and conversion price. These changes are included in interest and other income (loss), net on the Consolidated Statement of Operations. On November 15, 2018, Ciena settled this embedded conversion feature. From time to time, Ciena uses foreign currency forward contracts to reduce variability in certain forecasted non-U.S. Dollar denominated cash flows. Generally, these derivatives have maturities of 24 months or less. Ciena also has interest rate swap arrangements to reduce variability in certain forecasted interest expense associated with its term loan. All of these derivatives are designated as cash flow hedges. At the inception of the cash flow hedge, and on an ongoing basis, Ciena assesses whether the derivative has been effective in offsetting changes in cash flows attributable to the hedged risk during the hedging period. The derivative’s net gain or loss is initially reported as a component of accumulated other comprehensive income (loss), and, upon occurrence of the forecasted transaction, is subsequently reclassified to the line item in the Consolidated Statement of Operations to which the hedged transaction relates. Ciena records derivative instruments in the Consolidated Statements of Cash Flows within operating, investing, or financing activities consistent with the cash flows of the hedged items. From time to time, Ciena uses foreign currency forward contracts to hedge certain balance sheet foreign exchange exposures. These forward contracts are not designated as hedges for accounting purposes, and any net gain or loss associated with these derivatives is reported in interest and other income (loss), net on the Consolidated Statement of Operations.
Computation of Net Income (Loss) per Share	Ciena calculates basic earnings per share by dividing earnings attributable to common stock by the weighted average number of common shares outstanding for the period. Diluted net income (loss) per potential common share (“Diluted EPS”) includes other potential dilutive shares that would be outstanding if securities or other contracts to issue common stock were exercised or converted into common stock. Ciena uses a dual presentation of basic net income (loss) per common share (“Basic EPS”) and Diluted EPS on the face of its income statement. A reconciliation of the numerator and denominator used for the Basic EPS and Diluted EPS computations is set forth in Note 19 below.
Software Development Costs	Ciena develops software for sale to its customers. GAAP requires the capitalization of certain software development costs that are incurred subsequent to the date technological feasibility is established and prior to the date the product is generally available for sale. The capitalized cost is then amortized using the straight-line method over the estimated life of the product. Ciena defines technological feasibility as being attained at the time a working model is completed. To date, the period between Ciena achieving technological feasibility and the general availability of such software has been short, and software development costs qualifying for capitalization have been insignificant. Accordingly, Ciena has not capitalized any software development costs.
Newly Issued Accounting Standards - Effective and Not Yet Effective	Revenue Recognition In May 2014, FASB issued Accounting Standards Codification ASC 606, Revenue from Contracts with Customers , a new accounting standard related to revenue recognition. ASC 606 supersedes nearly all U.S. GAAP standards on revenue recognition and eliminates industry-specific guidance. The underlying principle of ASC 606 is to recognize revenue when a customer obtains control of the promised products or services at an amount that reflects the consideration that is expected to be received in exchange for those products or services. ASC 606 also requires additional disclosures regarding the nature, amount, timing, and uncertainty of revenues and cash flows related to contracts with customers. ASC 606 allows two methods of adoption: (i) retrospectively to each prior period presented (“full retrospective method”), or (ii) retrospectively with the cumulative effect recognized in retained earnings as of the date of adoption (“modified retrospective method”). Effective upon the start of its first quarter of fiscal 2019, Ciena adopted ASC 606 using the modified retrospective method and accordingly recognized the cumulative effect in accumulated deficit for those contracts that were not completed as of October 31, 2018. Accordingly, results for the reporting periods after October 31, 2018 are presented under ASC 606, while prior periods have not been adjusted and continue to be reported in accordance with Ciena’s historical revenue recognition practices. Refer to Opening Balance Adjustments below for the impact of ASC 606 adoption on Ciena’s Consolidated Financial Statements. In connection with its adoption of ASC 606, Ciena has implemented new accounting policies and processes, and incorporated such into its existing internal control environment as necessary to support the requirements of ASC 606. Revenue Recognition Timing Differences The adoption of ASC 606 requires Ciena to recognize revenue when the customer obtains control of promised products or services in an amount that reflects the consideration that Ciena would expect to receive in exchange for those products or services. Under the prior revenue standard, the timing of revenue recognition for delivered products or services was limited to such amount not contingent on future delivery of products or service or future performance obligations, or subject to customer-specified return or privileges. In the case of multiple element software arrangements for which vendor-specific objective evidence of undelivered maintenance did not exist, under the prior revenue standard, Ciena recognized revenue for the entire arrangement over the maintenance term. The adoption of ASC 606 requires Ciena to determine the stand-alone selling price for each of the software and software-related deliverables of such multiple element arrangements at contract inception. Consequently, under ASC 606, certain software deliverables will be recognized at a point in time rather than over a period of time. In addition, under ASC 606, certain installation and deployment, and consulting and network design services, will be recognized over a period of time rather than at a point in time. Impact of ASC 606 Adoption The following table summarizes the impact of adopting ASC 606 on Ciena’s Consolidated Statement of Operations (in millions): Year Ended October 31, 2019 As Reported Adjustments Balances without adoption of ASC 606 Total revenue $ 3,572,131 $ (28,838 ) $ 3,543,293 Total cost of goods sold $ 2,030,065 $ (21,330 ) $ 2,008,735 Net income $ 253,434 $ (7,776 ) $ 245,658 Diluted net income per potential common share $ 1.61 $ (0.05 ) $ 1.56 During fiscal 2019 , the increase in revenue from adoption of ASC 606 was primarily the result of installation and deployment services revenue that was recognized over a period of time rather than at a point in time under the prior revenue recognition standard. The adoption of ASC 606 did not have a material impact to Ciena’s Consolidated Balance Sheets or any impact on net cash provided by operating activities as of October 31, 2019 . See “ Revenue Recognition Timing Differences” above . For additional information regarding ASC 606, see Note 2 below. Opening Balance Adjustments The following table summarizes the cumulative effect of the changes made to Ciena’s Consolidated Balance Sheets in connection with the adoption of ASC 606 (in millions): Balance at October 31, 2018 New Revenue Recognition Standard Adjusted Balance at November 1, 2018 ASSETS: Accounts receivable, net $ 786,502 $ 12,509 (1) $ 799,011 Inventories $ 262,751 (2,486 ) (2) $ 260,265 Prepaid expenses and other $ 198,945 21,470 (3) $ 220,415 Deferred tax asset, net $ 745,039 (14,439 ) (4) $ 730,600 Other long-term assets $ 71,652 3,998 (5) $ 75,650 Total assets $ 3,756,523 $ 21,052 $ 3,777,575 LIABILITIES AND STOCKHOLDERS’ EQUITY: Deferred revenue $ 111,134 $ (14,403 ) (6) $ 96,731 Long-term deferred revenue $ 58,323 (14,350 ) (7) $ 43,973 Accumulated deficit $ (4,947,652 ) 49,805 (8) $ (4,897,847 ) Total liabilities and stockholders’ equity $ 3,756,523 $ 21,052 $ 3,777,575 (1) Unpaid accounts receivable and related deferred revenue related to rights and obligations in a contract are interdependent and therefore recorded net within Ciena’s balance sheet. This represents an increase of $12.5 million from the reversal of certain net unpaid accounts receivable and related deferred revenue. (2) Represents a decrease of $2.5 million in deferred costs of goods sold due to change in revenue recognition for certain product sales. (3) Represents increases of $27.5 million in unbilled accounts receivable for change in recognizing revenue for installation services, $3.9 million in unbilled accounts receivable from change in recognizing revenue for certain product sales and $9.6 million related to short-term capitalized acquisition costs (e.g., commissions) and a decrease of $19.5 million related to prepaid cost of installation services. (4) Represents a decrease of $14.4 million in deferred tax asset, net, related to the unrecognized income tax effects of the net adjustments from the new revenue recognition standard. (5) Represents an increase of $4.0 million related to long-term capitalized acquisition costs (e.g., commissions). (6) Represents decreases of $23.6 million in deferred revenue, primarily due to a change in revenue recognition for certain multiple-element software arrangements and $1.7 million in deferred revenue, primarily due to a change in revenue recognition for certain product sales, and increases of $2.7 million for a change in revenue recognition from certain maintenance services and $8.2 million from the reversal of balance sheet netting for certain unpaid invoices included in accounts receivable, net and deferred revenue. (7) Represents a decrease of $18.6 million in long-term deferred revenue, primarily due to a change in revenue recognition for certain multiple-element software arrangements and an increase of $4.3 million from the reversal of balance sheet netting for certain unpaid invoices included in accounts receivable, net and long-term deferred revenue. (8) Accumulated deficit impact from the adjustments noted above. Intangibles In August 2018, the FASB issued ASU No. 2018-15 ( “ASU 2018-15” ), Intangibles - Goodwill and Other-Internal-Use Software , which aligns 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. Ciena adopted ASU 2018-15 during the first quarter of fiscal 2019. The application of this accounting standard did not have a material impact on Ciena’s Consolidated Financial Statements. Restricted Cash in Statement of Cash Flows In November 2016, the FASB issued ASU 2016-18 (“ASU 2016-18”), Statement of Cash Flows (Topic 230): Restricted Cash , which broadens the classification and presentation of changes in restricted cash in the statement of cash flows. Ciena adopted ASU 2016-18 during the first quarter of fiscal 2019. The application of this accounting standard update did not have a material impact on Ciena’s Consolidated Statements of Cash Flows. Prior period information has been retrospectively adjusted due to the adoption of ASU 2016-18, Statement of Cash Flows, Restricted Cash at the beginning of the first quarter of fiscal 2019. Newly Issued Accounting Standards - Not Yet Effective In February 2016, the FASB issued ASU No. 2016-02 (“ASU 2016-02”), Leases , which requires an entity to recognize assets and liabilities on the balance sheet for the rights and obligations created by leased assets and to provide additional disclosures. Under current GAAP, the majority of Ciena’s leases for its properties are considered operating leases, and Ciena expects that the adoption of this ASU will require these leases to be recognized as assets and liabilities on Ciena’s balance sheet. ASU 2016-02 is effective for Ciena beginning in the first quarter of fiscal 2020. Ciena is continuing to evaluate other possible impacts of the adoption of ASU 2016-02 on its Consolidated Financial Statements and disclosures. Ciena will adopt this guidance on a modified retrospective basis on its effective date, November 1, 2019. This adoption will include the election of the related practical expedients. Ciena is continuing to evaluate other possible impacts of the adoption of ASU 2016-02 on its Consolidated Financial Statements and disclosures. In June 2016, the FASB issued ASU No. 2016-13 (“ASU 2016-13”), Financial Instruments - Credit Losses , which requires measurement and recognition of expected credit losses for financial assets held based on historical experience, current conditions, and reasonable and supportable forecasts that affect the collectibility of the reported amount. ASU 2016-13 is effective for Ciena beginning in the first quarter of fiscal 2021 and early adoption is permitted. Ciena is currently evaluating the impact of this accounting standard update on its Consolidated Financial Statements and disclosures. In August 2018, the FASB issued ASU No. 2018-13 ( “ASU 2018-13” ), Fair Value Measurement (Topic 820): Disclosure Framework which modifies the disclosure requirements on fair value measurements. ASU 2018-13 is effective for Ciena beginning in the first quarter of fiscal year 2020, early adoption is permitted. Adoption of ASU 2018-13 will not have a material effect on Ciena’s financial position or results of operations.

Ciena Corporation and Signifi_3

Ciena Corporation and Significant Accounting Policies and Estimates (Tables)	12 Months Ended
	Oct. 31, 2019
Accounting Policies [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The following table summarizes the cumulative effect of the changes made to Ciena’s Consolidated Balance Sheets in connection with the adoption of ASC 606 (in millions): Balance at October 31, 2018 New Revenue Recognition Standard Adjusted Balance at November 1, 2018 ASSETS: Accounts receivable, net $ 786,502 $ 12,509 (1) $ 799,011 Inventories $ 262,751 (2,486 ) (2) $ 260,265 Prepaid expenses and other $ 198,945 21,470 (3) $ 220,415 Deferred tax asset, net $ 745,039 (14,439 ) (4) $ 730,600 Other long-term assets $ 71,652 3,998 (5) $ 75,650 Total assets $ 3,756,523 $ 21,052 $ 3,777,575 LIABILITIES AND STOCKHOLDERS’ EQUITY: Deferred revenue $ 111,134 $ (14,403 ) (6) $ 96,731 Long-term deferred revenue $ 58,323 (14,350 ) (7) $ 43,973 Accumulated deficit $ (4,947,652 ) 49,805 (8) $ (4,897,847 ) Total liabilities and stockholders’ equity $ 3,756,523 $ 21,052 $ 3,777,575 (1) Unpaid accounts receivable and related deferred revenue related to rights and obligations in a contract are interdependent and therefore recorded net within Ciena’s balance sheet. This represents an increase of $12.5 million from the reversal of certain net unpaid accounts receivable and related deferred revenue. (2) Represents a decrease of $2.5 million in deferred costs of goods sold due to change in revenue recognition for certain product sales. (3) Represents increases of $27.5 million in unbilled accounts receivable for change in recognizing revenue for installation services, $3.9 million in unbilled accounts receivable from change in recognizing revenue for certain product sales and $9.6 million related to short-term capitalized acquisition costs (e.g., commissions) and a decrease of $19.5 million related to prepaid cost of installation services. (4) Represents a decrease of $14.4 million in deferred tax asset, net, related to the unrecognized income tax effects of the net adjustments from the new revenue recognition standard. (5) Represents an increase of $4.0 million related to long-term capitalized acquisition costs (e.g., commissions). (6) Represents decreases of $23.6 million in deferred revenue, primarily due to a change in revenue recognition for certain multiple-element software arrangements and $1.7 million in deferred revenue, primarily due to a change in revenue recognition for certain product sales, and increases of $2.7 million for a change in revenue recognition from certain maintenance services and $8.2 million from the reversal of balance sheet netting for certain unpaid invoices included in accounts receivable, net and deferred revenue. (7) Represents a decrease of $18.6 million in long-term deferred revenue, primarily due to a change in revenue recognition for certain multiple-element software arrangements and an increase of $4.3 million from the reversal of balance sheet netting for certain unpaid invoices included in accounts receivable, net and long-term deferred revenue. (8) Accumulated deficit impact from the adjustments noted above. The following table summarizes the impact of adopting ASC 606 on Ciena’s Consolidated Statement of Operations (in millions): Year Ended October 31, 2019 As Reported Adjustments Balances without adoption of ASC 606 Total revenue $ 3,572,131 $ (28,838 ) $ 3,543,293 Total cost of goods sold $ 2,030,065 $ (21,330 ) $ 2,008,735 Net income $ 253,434 $ (7,776 ) $ 245,658 Diluted net income per potential common share $ 1.61 $ (0.05 ) $ 1.56

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Oct. 31, 2019
Business Combinations [Abstract]
Schedule of purchase price for acquisition	The following table summarizes the purchase price for the acquisition (in thousands): Amount Cash $ 43,283 Contingent consideration 10,900 Total purchase price $ 54,183
Schedule of acquired assets and assumed liabilities	The following table summarizes the final purchase price allocation related to the acquisition based on the estimated fair value of the acquired assets and assumed liabilities (in thousands): Amount Cash and cash equivalents $ 1,025 Accounts receivable 4,790 Prepaid expenses and other long term assets 372 Goodwill 10,453 Customer relationships and contracts 37,700 Developed technology 9,700 Deferred revenue (193 ) Other current and long term liabilities (9,664 ) Total purchase price $ 54,183 The following table summarizes the final purchase price allocation related to the acquisition based on the estimated fair value of the acquired assets and assumed liabilities (in thousands): Amount Cash and cash equivalents $ 642 Accounts receivable 1,525 Prepaid expenses and other 450 Equipment, furniture and fixtures 31 Goodwill 20,304 Customer relationships and contracts 2,200 Developed technology 21,900 Accounts payable (165 ) Accrued liabilities (657 ) Deferred revenue (5,176 ) Total purchase price $ 41,054

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Oct. 31, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The tables below (in thousands) set forth Ciena’s disaggregated revenue for the respective period: Year Ended October 31, 2019 Networking Platforms Platform Software and Services Blue Planet Automation Software and Services Global Services Total Product lines: Converged Packet Optical $ 2,562,841 $ — $ — $ — $ 2,562,841 Packet Networking 348,477 — — — 348,477 Platform Software and Services — 155,376 — — 155,376 Blue Planet Automation Software and Services — — 54,555 — 54,555 Maintenance Support and Training — — — 261,337 261,337 Installation and Deployment — — — 148,233 148,233 Consulting and Network Design — — — 41,312 41,312 Total revenue by product line $ 2,911,318 $ 155,376 $ 54,555 $ 450,882 $ 3,572,131 Timing of revenue recognition: Products and services at a point in time $ 2,911,318 $ 55,530 $ 17,697 $ 18,802 $ 3,003,347 Products and services transferred over time — 99,846 36,858 432,080 568,784 Total revenue by timing of revenue recognition $ 2,911,318 $ 155,376 $ 54,555 $ 450,882 $ 3,572,131 Year Ended October 31, 2019 Geographic Distribution: North America $ 2,351,260 EMEA 566,718 CALA 152,653 APAC 501,500 Total revenue by geographic distribution $ 3,572,131
Contract Balances	The following table provides information about receivables, contract assets and contract liabilities (deferred revenue) from contracts with customers (in thousands): Balance at October 31, 2019 Adjusted Balance at November 1, 2018 Accounts receivable, net $ 724,854 $ 799,011 Contract assets $ 84,046 $ 31,380 Deferred revenue $ 156,873 $ 140,704 As of the dates indicated, deferred revenue is comprised of the following (in thousands): October 31, 2019 2018 Products $ 27,366 $ 42,474 Services 129,507 126,983 156,873 169,457 Less current portion (111,381 ) (111,134 ) Long-term deferred revenue $ 45,492 $ 58,323

Restructuring Costs (Tables)

Restructuring Costs (Tables)	12 Months Ended
	Oct. 31, 2019
Restructuring and Related Activities [Abstract]
Activity and balance of the restructuring liability accounts	The following table sets forth the restructuring activity and balance of the restructuring liability accounts for the fiscal years indicated (in thousands): Workforce reduction Consolidation of excess facilities Total Balance at October 31, 2016 $ 868 $ 1,970 $ 2,838 Additional liability recorded 5,883 (1) 5,432 (4) 11,315 Adjustment to previous estimates — (1,048 ) (1,048 ) Cash payments (5,460 ) (4,706 ) (10,166 ) Balance at October 31, 2017 1,291 1,648 2,939 Additional liability recorded 14,853 (2) 3,890 (5) 18,743 Cash payments (14,036 ) (3,799 ) (17,835 ) Balance at October 31, 2018 2,108 1,739 3,847 Additional liability recorded 13,779 (3) 10,759 (6) 24,538 Cash payments (11,904 ) (1,338 ) (13,242 ) Balance at October 31, 2019 $ 3,983 $ 11,160 $ 15,143 Current restructuring liabilities $ 3,983 $ 1,484 $ 5,467 Non-current restructuring liabilities $ — $ 9,676 $ 9,676 _________________________________ (1) During fiscal 2017, Ciena recorded a charge of $5.9 million of severance and other employee-related costs associated with a workforce reduction of approximately 100 employees. (2) During fiscal 2018, Ciena recorded a charge of $14.9 million of severance and other employee-related costs associated with a workforce reduction of approximately 240 employees. (3) During fiscal 2019, Ciena recorded a charge of $13.8 million of severance and other employee-related costs associated with a workforce reduction of approximately 283 employees. (4) Reflects unfavorable lease commitments and relocation costs incurred in connection with Ciena’s research and development center facility transitions in Ottawa, Canada. (5) Reflects unfavorable lease commitments in connection with a portion of facilities located in Petaluma, California and in Gurgaon, India. (6) Reflects unfavorable lease commitments in connection with a portion of facilities located in Alpharetta, Georgia, Spokane, Washington, Durham, North Carolina and Hanover, Maryland.

Interest and Other Income (Lo_2

Interest and Other Income (Loss), Net (Tables)	12 Months Ended
	Oct. 31, 2019
Other Income and Expenses [Abstract]
Schedule of Interest and Other Income (Loss)	The components of interest and other income (loss), net, were as follows (in thousands): Year Ended October 31, 2019 2018 2017 Interest income $ 14,410 $ 13,703 $ 6,579 Gain (loss) on non-hedge designated foreign currency forward contracts 3 6,791 (1,198 ) Foreign currency exchange losses (9,800 ) (19,434 ) (4,376 ) Loss on fair value of debt conversion liability — (12,070 ) — Other (737 ) (1,019 ) (92 ) Interest and other income (loss), net $ 3,876 $ (12,029 ) $ 913

Short-Term and Long-Term Inve_2

Short-Term and Long-Term Investments (Tables)	12 Months Ended
	Oct. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Short-term and long-term investments	As of October 31, 2019 , investments are comprised of the following (in thousands): October 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. government obligations: Included in short-term investments $ 109,715 $ 225 $ — $ 109,940 Included in long-term investments 10,017 — (3 ) 10,014 $ 119,732 $ 225 $ (3 ) $ 119,954 As of October 31, 2018 , investments are comprised of the following (in thousands): October 31, 2018 Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair U.S. government obligations: Included in short-term investments $ 139,365 $ — $ (347 ) $ 139,018 Included in long-term investments 59,029 — (59 ) 58,970 $ 198,394 $ — $ (406 ) $ 197,988 Commercial paper: Included in short-term investments $ 9,963 $ — $ — $ 9,963 $ 9,963 $ — $ — $ 9,963
Legal maturities of debt investments	The following table summarizes the legal maturities of debt investments at October 31, 2019 : October 31, 2019 Amortized Cost Estimated Fair Less than one year $ 109,715 $ 109,940 Due in 1-2 years 10,017 10,014 $ 119,732 $ 119,954

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Oct. 31, 2019
Fair Value Disclosures [Abstract]
Summary of the fair value of assets and liabilities recorded on a recurring basis	As of the dates indicated, the following tables summarize the fair value of assets and liabilities that were recorded at fair value on a recurring basis (in thousands): October 31, 2019 Level 1 Level 2 Level 3 Total Assets: Money market funds $ 759,114 $ — $ — $ 759,114 U.S. government obligations — 119,954 — 119,954 Foreign currency forward contracts — 1,570 — 1,570 Total assets measured at fair value $ 759,114 $ 121,524 $ — $ 880,638 Liabilities: Foreign currency forward contracts $ — $ 35 $ — $ 35 Forward starting interest rate swaps — 21,093 — 21,093 Contingent consideration — — 3,705 3,705 Total liabilities measured at fair value $ — $ 21,128 $ 3,705 $ 24,833 October 31, 2018 Level 1 Level 2 Level 3 Total Assets: Money market funds $ 590,684 $ — $ — $ 590,684 U.S. government obligations — 197,988 — 197,988 Commercial paper — 69,888 — 69,888 Foreign currency forward contracts — 133 — 133 Forward starting interest rate swaps — 779 — 779 Total assets measured at fair value $ 590,684 $ 268,788 $ — $ 859,472 Liabilities: Foreign currency forward contracts $ — $ 3,231 $ — $ 3,231 Debt conversion liability — 164,212 — 164,212 Contingent consideration — — 10,900 10,900 Total liabilities measured at fair value $ — $ 167,443 $ 10,900 $ 178,343
Assets and liabilities are presented on Ciena's Condensed Consolidated Balance Sheet	As of the dates indicated, the assets and liabilities above were presented on Ciena’s Consolidated Balance Sheet as follows (in thousands): October 31, 2019 Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 759,114 $ — $ — $ 759,114 Short-term investments — 109,940 — 109,940 Prepaid expenses and other — 1,570 — 1,570 Long-term investments — 10,014 — 10,014 Total assets measured at fair value $ 759,114 $ 121,524 $ — $ 880,638 Liabilities: Accrued liabilities $ — $ 35 $ — $ 35 Other long-term obligations — 21,093 3,705 24,798 Total liabilities measured at fair value $ — $ 21,128 $ 3,705 $ 24,833 October 31, 2018 Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 590,684 $ 59,925 $ — $ 650,609 Short-term investments — 148,981 — 148,981 Prepaid expenses and other — 133 — 133 Long-term investments — 58,970 — 58,970 Other long-term assets — 779 — 779 Total assets measured at fair value $ 590,684 $ 268,788 $ — $ 859,472 Liabilities: Accrued liabilities $ — $ 3,231 $ — $ 3,231 Debt conversion liability — 164,212 — 164,212 Other long-term obligations — — 10,900 10,900 Total liabilities measured at fair value $ — $ 167,443 $ 10,900 $ 178,343

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
	Oct. 31, 2019
Receivables [Abstract]
Activity in allowance for doubtful accounts	The following table summarizes the activity in Ciena’s allowance for doubtful accounts for the fiscal years indicated (in thousands): Year ended Beginning Net Ending October 31, Balance Provisions Deductions Balance 2017 $ 3,963 $ 18,221 $ 4,604 $ 17,580 2018 $ 17,580 $ 2,700 $ 2,902 $ 17,378 2019 $ 17,378 $ 6,740 $ 4,017 $ 20,101

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Oct. 31, 2019
Inventory Disclosure [Abstract]
Inventories	As of the dates indicated, inventories are comprised of the following (in thousands): October 31, 2019 2018 Raw materials $ 99,041 $ 67,468 Work-in-process 13,657 9,589 Finished goods 226,622 188,575 Deferred cost of goods sold 53,051 48,057 392,371 313,689 Reserve for excess and obsolescence (47,322 ) (50,938 ) $ 345,049 $ 262,751
Activity in reserve for excess and obsolete inventory	The following table summarizes the activity in Ciena’s reserve for excess and obsolete inventory for the fiscal years indicated (in thousands): Year ended Beginning Ending October 31, Balance Provisions Disposals Balance 2017 $ 62,503 $ 35,459 $ 46,756 $ 51,206 2018 $ 51,206 $ 30,615 $ 30,883 $ 50,938 2019 $ 50,938 $ 28,085 $ 31,701 $ 47,322

Prepaid Expenses and Other (Tab

Prepaid Expenses and Other (Tables)	12 Months Ended
	Oct. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid expenses and other	As of the dates indicated, prepaid expenses and other are comprised of the following (in thousands): October 31, 2019 2018 Prepaid VAT and other taxes $ 84,706 $ 82,518 Contract assets 84,046 — Prepaid expenses 48,680 32,987 Product demonstration equipment, net 38,900 37,623 Other non-trade receivables 28,136 25,716 Capitalized contract acquisition costs 11,677 — Derivative assets 1,570 133 Deferred deployment expense 125 19,342 Restricted cash 74 — Financing receivable — 626 $ 297,914 $ 198,945

Equipment, Building, Furnitur_2

Equipment, Building, Furniture and Fixtures (Tables)	12 Months Ended
	Oct. 31, 2019
Property, Plant and Equipment [Abstract]
Equipment, building, furniture and fixtures	As of the dates indicated, equipment, building, furniture and fixtures are comprised of the following (in thousands): October 31, 2019 2018 Equipment, furniture and fixtures $ 544,012 $ 504,714 Building subject to capital lease 71,760 71,968 Leasehold improvements 94,626 94,195 710,398 670,877 Accumulated depreciation and amortization (423,514 ) (378,810 ) $ 286,884 $ 292,067

Intangible Assets (Tables)

Intangible Assets (Tables)	12 Months Ended
	Oct. 31, 2019
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Intangible assets	As of the dates indicated, intangible assets are comprised of the following (in thousands): October 31, 2019 2018 Gross Intangible Accumulated Amortization Net Intangible Gross Intangible Accumulated Amortization Net Intangible Developed technology $ 373,526 $ (308,261 ) $ 65,265 $ 373,581 $ (285,233 ) $ 88,348 Patents and licenses 3,565 (2,244 ) 1,321 3,565 (1,958 ) 1,607 Customer relationships, covenants not to compete, outstanding purchase orders and contracts 374,381 (328,186 ) 46,195 374,620 (316,350 ) 58,270 Total intangible assets $ 751,472 $ (638,691 ) $ 112,781 $ 751,766 $ (603,541 ) $ 148,225
Expected future amortization of finite-lived intangible assets	Expected future amortization of intangible assets for the fiscal years indicated is as follows (in thousands): Year Ended October 31, 2020 $ 34,008 2021 30,830 2022 24,809 2023 10,000 2024 6,948 Thereafter 6,186 $ 112,781

Goodwill (Tables)

Goodwill (Tables)	12 Months Ended
	Oct. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill Allocated by Reportable Segments	The following table presents the goodwill allocated to Ciena’s operating segments as of October 31, 2019 and October 31, 2018 , as well as the changes to goodwill during fiscal 2019 (in thousands): Balance at October 31, 2018 Reallocation Acquisitions Impairments Translation Balance at October 31, 2019 Software and Software Related Services $ 232,185 $ (232,185 ) $ — $ — $ — $ — Platform Software and Services — 156,191 — — — 156,191 Blue Planet Automation Software and Services — 75,994 — — — 75,994 Networking Platforms 65,783 — — — (31 ) 65,752 Total $ 297,968 $ — $ — $ — $ (31 ) $ 297,937

Other Balance Sheet Details (Ta

Other Balance Sheet Details (Tables)	12 Months Ended
	Oct. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Other long-term assets	As of the dates indicated, other long-term assets are comprised of the following (in thousands): October 31, 2019 2018 Maintenance spares inventory, net $ 55,482 $ 45,679 Cost method investments 10,727 8,056 Capitalized contract acquisition costs 3,994 — Deferred debt issuance costs, net (1) 1,609 720 Restricted cash 42 11 Forward starting interest rate swaps — 779 Other 17,132 16,407 $ 88,986 $ 71,652 (1) Deferred debt issuance costs relate to Ciena’s senior secured asset-based revolving credit facility (the “ABL Credit Facility”) entered into during fiscal 2019 and its predecessor credit facility (described in Note 18 below). The amortization of deferred debt issuance costs for the ABL Credit Facility and its predecessor is included in interest expense, and was $0.3 million , $0.3 million and $0.3 million for fiscal 2019 , fiscal 2018 and fiscal 2017 , respectively.
Accrued liabilities	As of the dates indicated, accrued liabilities and other short-term obligations are comprised of the following (in thousands): October 31, 2019 2018 Compensation, payroll related tax and benefits $ 182,363 $ 140,277 Warranty 48,498 44,740 Vacation (1) 22,290 42,507 Contingent Consideration 4,372 — Capital lease obligations 2,764 3,547 Interest payable 1,007 1,072 Other 121,446 107,932 $ 382,740 $ 340,075 (1) Reduction is primarily due to the payout of North America vacation accruals in conjunction with Ciena’s adoption of a new vacation policy during fiscal 2019.
Accrued warranty	The following table summarizes the activity in Ciena’s accrued warranty for the fiscal years indicated (in thousands): Year ended Beginning Current Year Ending October 31, Balance Provisions (1) Settlements Balance 2017 $ 52,324 $ 7,965 $ 17,833 $ 42,456 2018 $ 42,456 $ 20,992 $ 18,708 $ 44,740 2019 $ 44,740 $ 23,105 $ 19,347 $ 48,498 (1) As a result of actual failure rates lower than expected, Ciena adjusted its fiscal 2017 provisions for warranty. These adjustments for previous fiscal year provisions had the effect of reducing warranty provisions by $9.7 million for fiscal 2017 . During fiscal 2018 and fiscal 2019 , Ciena determined that failure rates for prior estimates remained unchanged, and accordingly did not make any adjustments for previous fiscal year provisions not yet settled. As a result, Ciena’s warranty provision for fiscal 2018 and fiscal 2019 increased as compared to fiscal 2017.
Deferred revenue	The following table provides information about receivables, contract assets and contract liabilities (deferred revenue) from contracts with customers (in thousands): Balance at October 31, 2019 Adjusted Balance at November 1, 2018 Accounts receivable, net $ 724,854 $ 799,011 Contract assets $ 84,046 $ 31,380 Deferred revenue $ 156,873 $ 140,704 As of the dates indicated, deferred revenue is comprised of the following (in thousands): October 31, 2019 2018 Products $ 27,366 $ 42,474 Services 129,507 126,983 156,873 169,457 Less current portion (111,381 ) (111,134 ) Long-term deferred revenue $ 45,492 $ 58,323
Other liabilities	As of the dates indicated, other long-term obligations are comprised of the following (in thousands): October 31, 2019 2018 Capital lease obligations $ 65,284 $ 68,245 Income tax liability 20,546 15,894 Interest rate swap liability 21,093 — Deferred tenant allowance 6,248 7,244 Straight-line rent 5,434 6,750 Contingent consideration 3,705 10,900 Other 26,437 10,380 $ 148,747 $ 119,413
Future minimum lease payments under capital leases	The following is a schedule by fiscal years of future minimum lease payments under capital leases and the present value of minimum lease payments as of October 31, 2019 (in thousands): Year Ending October 31, Amount 2020 $ 7,652 2021 7,547 2022 7,860 2023 8,067 2024 8,067 Thereafter 67,126 Net minimum capital lease payments 106,319 Less: Amount representing interest (38,271 ) Present value of minimum lease payments 68,048 Less: Current portion of present value of minimum lease payments (2,764 ) Long-term portion of present value of minimum lease payments $ 65,284

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Oct. 31, 2019
Statement of Comprehensive Income [Abstract]
Accumulated Other Comprehensive Income	The following table summarizes the changes in accumulated balances of other comprehensive income (“AOCI”): Unrealized Gain/(Loss) on Available-for-Sale Securities Unrealized Gain/(Loss) on Foreign Currency Forward Contracts Unrealized Gain/(Loss) on Forward Starting Interest Rate Swaps Cumulative Foreign Currency Translation Adjustment Total Balance at October 31, 2016 $ 139 $ (1,091 ) $ (5,967 ) $ (17,410 ) $ (24,329 ) Other comprehensive gain (loss) before reclassifications (590 ) 1,290 3,669 8,012 12,381 Amounts reclassified from AOCI — (1,585 ) 2,516 — 931 Balance at October 31, 2017 (451 ) (1,386 ) 218 (9,398 ) (11,017 ) Other comprehensive gain (loss) before reclassifications 26 (3,242 ) 6,011 686 3,481 Amounts reclassified from AOCI — 1,568 188 — 1,756 Balance at October 31, 2018 (425 ) (3,060 ) 6,417 (8,712 ) (5,780 ) Other comprehensive gain (loss) before reclassifications 577 14 (18,948 ) (763 ) (19,120 ) Amounts reclassified from AOCI — 3,971 (1,155 ) — 2,816 Balance at October 31, 2019 $ 152 $ 925 $ (13,686 ) $ (9,475 ) $ (22,084 )

Short-Term and Long-Term Debt (

Short-Term and Long-Term Debt (Tables)	12 Months Ended
	Oct. 31, 2019
Debt Disclosure [Abstract]
Schedule of carrying values and estimated fair values of debt instruments	The net carrying values of Ciena’s term loan were comprised of the following for the fiscal periods indicated (in thousands): October 31, 2019 October 31, 2018 Principal Balance Unamortized Discount Deferred Debt Issuance Costs Net Carrying Value Net Carrying Value Term Loan Payable due September 28, 2025 $ 693,000 $ (1,958 ) $ (3,636 ) $ 687,406 $ 693,450

Earnings (Loss) Per Share Cal_2

Earnings (Loss) Per Share Calculation (Tables)	12 Months Ended
	Oct. 31, 2019
Earnings Per Share [Abstract]
Reconciliation of numerator and denominator of Basic and Diluted Earnings Per Share	The following tables (in thousands except per share amounts) show a reconciliation of the numerator and denominator of the Basic EPS and the Diluted EPS. Basic EPS is computed using the weighted average number of common shares outstanding. Diluted EPS is computed using the weighted average number of the following, in each case, to the extent the effect is not anti-dilutive: (i) common shares outstanding, (ii) shares issuable upon vesting of restricted stock units and (iii) shares issuable under Ciena’s employee stock purchase plan and upon exercise of outstanding stock options, using the treasury stock method. Numerator Year Ended October 31, 2019 2018 2017 Net income (loss) $ 253,434 $ (344,690 ) $ 1,261,953 Less: Loss on fair value of debt conversion liability (12,894 ) — Add: Interest expense associated with 0.875% Convertible Senior Notes due 2017 — — 853 Add: Interest expense associated with 3.75% Convertible Senior Notes due 2018 (Original Notes) — — 7,224 Add: Interest expense associated with 4.0% Convertible Senior Notes due 2020 — — 8,691 Net income (loss) used to calculate Diluted EPS $ 253,434 $ (357,584 ) $ 1,278,721 Denominator Year Ended October 31, 2019 2018 2017 Basic weighted average shares outstanding 155,720 143,738 141,997 Add: Shares underlying outstanding stock options, employee stock purchase plan and restricted stock units 1,892 — 1,354 Add: Shares underlying 3.75% Convertible Senior Notes due 2018 (New Notes) — — 404 Add: Shares underlying 0.875% Convertible Senior Notes due 2017 — — 3,032 Add: Shares underlying 3.75% Convertible Senior Notes due 2018 (Original Notes) — — 13,934 Add: Shares underlying 4.0% Convertible Senior Notes due 2020 — — 9,198 Diluted weighted average shares outstanding 157,612 143,738 169,919 EPS Year Ended October 31, 2019 2018 2017 Basic EPS $ 1.63 $ (2.40 ) $ 8.89 Diluted EPS $ 1.61 $ (2.49 ) $ 7.53
Weighted average shares excluded from calculation of denominator for Basic and Diluted EPS	The following table summarizes the weighted average shares excluded from the calculation of the denominator for Diluted EPS due to their anti-dilutive effect for the fiscal years indicated (in thousands): Year Ended October 31, 2019 2018 2017 Shares underlying stock options and restricted stock units 234 2,235 958 Add: Shares underlying 3.75% Convertible Senior Notes due 2018 (New Notes) — 1,780 — — 3.75% Convertible Senior Notes due October 15, 2018 (Original Notes) — 2,883 — 4.0% Convertible Senior Notes due December 15, 2020 — 9,123 — Total shares excluded due to anti-dilutive effect 234 16,021 958

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Oct. 31, 2019
Equity [Abstract]
Summary of stock repurchase program	The following table summarizes activity of the stock repurchase program, reported based on trade date: Shares Repurchased Weighted-Average Price per Share Amount Repurchased (in thousands) Cumulative balance at October 31, 2018 — $ — $ — Repurchase of common stock under the stock repurchase program 3,838,466 $ 39.10 150,076 Cumulative balance at October 31, 2019 3,838,466 $ 39.10 $ 150,076

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Oct. 31, 2019
Income Tax Disclosure [Abstract]
Provision (benefit) for income taxes	For the fiscal periods indicated, the provision (benefit) for income taxes consists of the following (in thousands): Year Ended October 31, 2019 2018 2017 Provision (benefit) for income taxes: Current: Federal $ 13,143 $ 8,327 $ — State 16,945 8,219 6,342 Foreign 9,816 13,294 14,563 Total current 39,904 29,840 20,905 Deferred: Federal 31,872 475,951 (1 ) (1,047,699 ) (1 ) State (9,159 ) (8,202 ) (77,429 ) (1 ) Foreign (2,861 ) (4,118 ) (1,604 ) Total deferred 19,852 463,631 (1,126,732 ) Provision (benefit) for income taxes $ 59,756 $ 493,471 $ (1,105,827 ) _________________________________ (1) The income tax expense for 2018 includes the impact of the remeasurement of the net deferred tax assets and the federal transition tax. See further discussion below. The income tax benefit for fiscal 2017 includes the reversal of a significant portion of the valuation allowance on Ciena’s deferred tax assets in the U.S.
Income before provision (benefit) for income taxes	For the fiscal periods indicated, income before provision for income taxes consists of the following (in thousands): Year Ended October 31, 2019 2018 2017 United States $ 256,461 $ 106,972 $ 114,242 Foreign 56,729 41,809 41,884 Total $ 313,190 $ 148,781 $ 156,126
Tax provision (benefit) reconciles to the amount computed by multiplying income or loss before income taxes by the U.S. federal statutory rate of 35%	For the periods indicated, the tax provision (benefit) reconciles to the amount computed by multiplying income before income taxes by the U.S. federal statutory rate of 21% for fiscal 2019, 23.41% for fiscal 2018 (see note below), and 35% for fiscal 2017 as follows: Year Ended October 31, 2019 2018 2017 Provision at statutory rate 21.00 % 23.41 % 35.00 % Deferred tax assets remeasurement — % 294.56 % — % Base Erosion and Anti-Abuse Tax 3.60 % — % — % State taxes 2.18 % (0.16 )% 2.29 % Foreign taxes (0.37 )% 1.22 % (0.35 )% Research and development credit (7.53 )% (8.80 )% (15.38 )% Non-deductible compensation 1.01 % 3.39 % 3.45 % Fair value of debt conversion liability — % 1.90 % — % Transition tax 0.29 % 23.23 % — % Valuation allowance (2.13 )% (11.95 )% (739.97 )% Other 1.03 % 4.88 % 6.67 % Effective income tax rate 19.08 % 331.68 % (708.29 )%
Significant components of deferred tax assets and liabilities	The significant components of DTA are as follows (in thousands): October 31, 2019 2018 Deferred tax assets: Reserves and accrued liabilities $ 54,183 $ 40,959 Depreciation and amortization 455,007 353,838 NOL and credit carry forward 302,325 483,495 Other 39,405 9,397 Gross deferred tax assets 850,920 887,689 Valuation allowance (135,978 ) (142,650 ) Deferred tax asset, net of valuation allowance $ 714,942 $ 745,039
Reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding interest and penalties	A reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding interest and penalties, is as follows (in thousands): Amount Unrecognized tax benefits at October 31, 2016 $ 30,668 Increase related to positions taken in prior period 122 Increase related to positions taken in current period 111,412 Reductions related to expiration of statute of limitations (620 ) Unrecognized tax benefits at October 31, 2017 141,582 Decrease related to positions taken in prior period (46,400 ) Increase related to positions taken in current period 2,482 Reductions related to expiration of statute of limitations (1,301 ) Unrecognized tax benefits at October 31, 2018 96,363 Increase related to positions taken in prior period 1,959 Reductions related to settlements with taxing authorities (1,224 ) Reductions related to expiration of statute of limitations (2,494 ) Unrecognized tax benefits at October 31, 2019 $ 94,604
Summary of valuation allowance against the gross deferred tax assets	The following table summarizes the activity in Ciena’s valuation allowance against its gross deferred tax assets (in thousands): Year ended Beginning Ending October 31, Balance Additions Deductions Balance 2017 $ 1,489,780 $ — $ 1,303,882 $ 185,898 2018 $ 185,898 $ 23,720 $ 66,968 $ 142,650 2019 $ 142,650 $ 27,459 $ 34,131 $ 135,978

Share-Based Compensation Expe_2

Share-Based Compensation Expense (Tables)	12 Months Ended
	Oct. 31, 2019
Share-based Payment Arrangement [Abstract]
Summary of stock option activity	The following table is a summary of Ciena’s stock option activity for the periods indicated (shares in thousands): Shares Underlying Options Outstanding Weighted Average Exercise Price Balance as of October 31, 2018 276 $ 33.52 Granted — — Exercised (50 ) $ 24.13 Canceled (6 ) $ 37.03 Balance as of October 31, 2019 220 $ 35.54
Assumptions for awards granted	Assumptions for awards granted during fiscal 2019 and fiscal 2018 included the following: Year Ended October 31, 2019 2018 Expected volatility of Ciena common stock, which is a weighted average of implied volatility and historical volatility 34.10% 34.93% Historical volatility of Ciena common stock 36.80% 38.24% Historical volatility of S&P Networking Index 17.39% 17.14% Correlation coefficient 0.6251 0.6597 Expected life in years 2.87 2.89 Risk-free interest rate 2.62% 1.94% Expected dividend yield 0.0% 0.0%
Summarizes information with respect to stock options outstanding	The following table summarizes information with respect to stock options outstanding at October 31, 2019 , based on Ciena’s closing stock price on the last trading day of Ciena’s fiscal 2019 (shares and intrinsic value in thousands): Options Outstanding and Vested at October 31, 2019 Number Weighted Average Remaining Weighted Range of of Contractual Average Aggregate Exercise Underlying Life Exercise Intrinsic Price Shares (Years) Price Value $ 6.43 — $ 10.50 4 0.81 $ 8.42 $ 117 $ 11.34 — $ 15.67 49 2.79 $ 13.51 1,123 $ 17.50 — $ 19.25 11 4.6 $ 18.17 202 $ 32.06 — $ 37.10 31 3.27 $ 36.04 28 $ 41.52 — $ 55.63 125 3.48 $ 46.47 — $ 6.43 — $ 55.63 220 3.30 $ 35.54 $ 1,470
Summary of restricted stock unit activity	The following table is a summary of Ciena’s restricted stock unit activity for the period indicated, with the aggregate fair value of the balance outstanding at the end of each period, based on Ciena’s closing stock price on the last trading day of the relevant period (shares and aggregate fair value in thousands): Restricted Stock Units Outstanding Weighted Average Grant Date Fair Value Per Share Aggregate Fair Value Balance as of October 31, 2018 4,402 $ 22.26 $ 140,943 Granted 2,057 Vested (2,101 ) Canceled or forfeited (348 ) Balance as of October 31, 2019 4,010 $ 27.94 $ 146,091
Share-based compensation expense	The following table summarizes share-based compensation expense for the periods indicated (in thousands): Year Ended October 31, 2019 2018 2017 Product cost of goods sold $ 2,868 $ 2,984 $ 2,672 Service cost of goods sold 3,175 2,616 2,487 Share-based compensation expense included in cost of goods sold 6,043 5,600 5,159 Research and development 14,321 13,518 12,957 Sales and marketing 16,474 14,246 12,846 General and administrative 22,841 19,709 17,321 Share-based compensation expense included in operating expense 53,636 47,473 43,124 Share-based compensation expense capitalized in inventory, net 57 (101 ) 77 Total share-based compensation $ 59,736 $ 52,972 $ 48,360

Segment and Entity Wide Discl_2

Segment and Entity Wide Disclosures (Tables)	12 Months Ended
	Oct. 31, 2019
Segment Reporting [Abstract]
Segment revenue	The table below (in thousands, except percentage data) sets forth Ciena’s segment revenue for the respective periods indicated: Year Ended October 31, 2019 2018 2017 Revenue: Networking Platforms Converged Packet Optical $ 2,562,841 $ 2,194,519 $ 1,939,621 Packet Networking 348,477 283,499 313,089 Total Networking Platforms 2,911,318 2,478,018 2,252,710 Platform Software and Services 155,376 173,949 145,009 Blue Planet Automation Software and Services 54,555 26,764 16,110 Global Services Maintenance Support and Training 261,337 245,161 227,400 Installation and Deployment 148,233 128,829 117,524 Consulting and Network Design 41,312 41,565 42,934 Total Global Services 450,882 415,555 387,858 Total revenue $ 3,572,131 $ 3,094,286 $ 2,801,687
Segment profit (loss) and the reconciliation to consolidated net income (loss)	The table below (in thousands) sets forth Ciena’s segment profit (loss) and the reconciliation to consolidated net income (loss) during the respective periods indicated: Year Ended October 31, 2019 2018 2017 Segment profit (loss): Networking Platforms $ 759,244 $ 581,113 $ 578,039 Platform Software and Services 64,210 78,048 47,353 Blue Planet Automation Software and Services (17,769 ) (8,240 ) (14,817 ) Global Services 188,242 172,205 159,882 Total segment profit 993,927 823,126 770,457 Less: non-performance operating expenses Selling and marketing 423,046 394,060 356,169 General and administrative 174,399 160,133 142,604 Amortization of intangible assets 21,808 15,737 33,029 Acquisition and integration costs 3,370 5,111 — Significant asset impairments and restructuring costs 24,538 18,139 23,933 Add: other non-performance financial items Interest and other income (loss), net 3,876 (12,029 ) 913 Interest expense (37,452 ) (55,249 ) (55,852 ) Loss on extinguishment and modification of debt — (13,887 ) (3,657 ) Less: Provision (benefit) for income taxes 59,756 493,471 (1,105,827 ) Total net income (loss) $ 253,434 $ (344,690 ) $ 1,261,953
Ciena's geographic distribution of revenue and long-lived assets	For the periods below, Ciena’s geographic distribution of equipment, building, furniture and fixtures, net, was as follows (in thousands): October 31, 2019 2018 Canada $ 211,901 $ 198,028 United States 58,119 75,479 Other International 16,864 18,560 Total $ 286,884 $ 292,067 Year Ended October 31, 2019 2018 2017 North America $ 2,351,260 $ 1,886,450 $ 1,736,047 EMEA 566,718 464,876 404,099 CALA 152,653 140,177 164,308 APAC 501,500 602,783 497,233 Total $ 3,572,131 $ 3,094,286 $ 2,801,687
Schedule of revenue by major customers by reporting segments	For the periods below, customers accounting for at least 10% of Ciena’s revenue were as follows (in thousands): October 31, 2019 2018 2017 Verizon $ 459,787 $ 318,013 $ 288,048 AT&T 388,704 374,576 448,943 Web-scale provider 370,577 n/a n/a Total $ 1,219,068 $ 692,589 $ 736,991 ________________________________ n/a Denotes revenue representing less than 10% of total revenue for the period

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Oct. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Future annual minimum lease commitments under non-cancelable operating leases	The following table summarizes Ciena’s future annual minimum lease commitments under non-cancelable leases that are not recorded on the balance sheet as of October 31, 2019 (in thousands): 2020 2021 2022 2023 2024 Thereafter Total Operating leases $ 28,776 $ 24,184 $ 16,767 $ 13,393 $ 10,632 $ 26,110 $ 119,862

Ciena Corporation and Signifi_4

Ciena Corporation and Significant Accounting Policies and Estimates (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Nov. 01, 2018	Oct. 31, 2018	Nov. 01, 2017
Significant Accounting Policies [Line Items]
Cost method investments	$ 10,727		$ 8,056
Expected economic lives of finite-lived intangible assets (in years)	7 years
Expected number of years Spares usage cost is expensed	4 years
Cumulative amount of temporary differences for unremitted foreign earnings for which a deferred tax liability has not been recognized	$ 372,000
Cumulative-effect adjustment		$ 49,805		$ 62,123
One-time employee termination benefits related to service period (in days)	60 days
Minimum
Significant Accounting Policies [Line Items]
Payment terms and cash received	30 days
Maximum
Significant Accounting Policies [Line Items]
Payment terms and cash received	90 days
Foreign exchange contract maturities	24 months
Equipment, furniture and fixtures | Minimum
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line (in years)	2 years
Equipment, furniture and fixtures | Maximum
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line (in years)	5 years
Software and website development | Minimum
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line (in years)	2 years
Software and website development | Maximum
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line (in years)	5 years
3.75% Convertible Senior Notes due October 15, 2018 (New)
Significant Accounting Policies [Line Items]
Interest rate on convertible notes	3.75%
Retained Earnings
Significant Accounting Policies [Line Items]
Cumulative-effect adjustment		$ 49,805		61,291
Retained Earnings | Accounting Standards Update 2016-09
Significant Accounting Policies [Line Items]
Cumulative-effect adjustment				$ 62,100

Ciena Corporation and Signifi_5

Ciena Corporation and Significant Accounting Policies and Estimates - Impact of Adopting ASC 606 on Condensed Consolidated Statement of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	$ 3,572,131	$ 3,094,286	$ 2,801,687
Total cost of goods sold	2,030,065	1,779,596	1,555,901
Net income	$ 253,434	$ (344,690)	$ 1,261,953
Diluted net income (loss) per potential common share (in dollars per share)	$ 1.61	$ (2.49)	$ 7.53
Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	$ (28,838)
Total cost of goods sold	(21,330)
Net income	$ (7,776)
Diluted net income (loss) per potential common share (in dollars per share)	$ (0.05)
Balances without adoption of ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	$ 3,543,293
Total cost of goods sold	2,008,735
Net income	$ 245,658
Diluted net income (loss) per potential common share (in dollars per share)	$ 1.56

Ciena Corporation and Signifi_6

Ciena Corporation and Significant Accounting Policies and Estimates - Cumulative Effect of the Changes Made to Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Nov. 01, 2018	Oct. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ 724,854	$ 799,011	$ 786,502
Inventories	345,049	260,265	262,751
Prepaid expenses and other	297,914	220,415	198,945
Deferred tax asset, net	714,942	730,600	745,039
Other long-term assets	88,986	75,650	71,652
Total assets	3,893,346	3,777,575	3,756,523
Deferred revenue	111,381	96,731	111,134
Long-term deferred revenue	45,492	43,973	58,323
Accumulated deficit	(4,644,413)	(4,897,847)	(4,947,652)
Total liabilities and stockholders’ equity	3,893,346	3,777,575	3,756,523
Capitalized contract acquisition costs	11,677		0
Capitalized acquisition costs, long term	$ 3,994		$ 0
Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net		12,509
Inventories		(2,486)
Prepaid expenses and other		21,470
Deferred tax asset, net		(14,439)
Other long-term assets		3,998
Total assets		21,052
Deferred revenue		(14,403)
Long-term deferred revenue		(14,350)
Accumulated deficit		49,805
Total liabilities and stockholders’ equity		21,052
Installation | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Unbilled receivables		27,500
Products | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Unbilled receivables		3,900
Multiple Element Software Arrangements | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenue		(23,600)
Long-term deferred revenue		(18,600)
Product Sales Other Than Multiple Element Software Arrangements | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenue		(1,700)
Maintenance Services Other Than Multiple Element Software Arrangements | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenue		2,700
Products and Services With Unpaid Invoices | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenue		8,200
Long-term deferred revenue		4,300
Capitalized Contract Acquisition Costs | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Capitalized contract acquisition costs		9,600
Capitalized acquisition costs, long term		4,000
Prepaid Costs of Installation Services | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Capitalized contract acquisition costs		$ (19,500)

Business Combinations (Details)

Business Combinations (Details) - USD ($)	Oct. 01, 2018	Jul. 02, 2018	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2019
Business Acquisition [Line Items]
Acquisition-related costs			$ 3,370,000	$ 5,111,000	$ 0
Contingent consideration			4,372,000	0		$ 4,372,000
DonRiver
Business Acquisition [Line Items]
Acquisition-related costs			2,400,000	3,500,000
Undiscounted contingent consideration, maximum	$ 28,500,000
Contingent consideration agreement term	3 years
Contingent consideration revenue measurement term	25 months
Change in contingent consideration						(2,800,000)
Contingent consideration	$ 10,900,000		8,100,000			8,100,000
Short term contingent consideration			4,400,000			$ 4,400,000
Acquisition of business, net of cash acquired	$ 43,283,000
DonRiver | Customer relationships and contracts
Business Acquisition [Line Items]
Intangible assets, useful life	7 years
DonRiver | Developed technology
Business Acquisition [Line Items]
Intangible assets, useful life	7 years
Packet Design
Business Acquisition [Line Items]
Acquisition-related costs				1,600,000
Acquisition of business, net of cash acquired		$ 41,100,000
Packet Design | Customer relationships and contracts
Business Acquisition [Line Items]
Intangible assets, useful life		3 years
Packet Design | Developed technology
Business Acquisition [Line Items]
Intangible assets, useful life		5 years
Contingent Consideration | DonRiver
Business Acquisition [Line Items]
Undiscounted contingent consideration, maximum	$ 15,000,000
Undiscounted contingent consideration, minimum	0
Contingent Compensation | DonRiver
Business Acquisition [Line Items]
Undiscounted contingent consideration, maximum	13,500,000
Undiscounted contingent consideration, minimum	$ 0
Change in contingent consideration			$ (5,100,000)	$ (400,000)

Revenue - Disaggregation of Re

Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Disaggregation of Revenue [Line Items]
Total revenue	$ 3,572,131	$ 3,094,286	$ 2,801,687
Products and services at a point in time
Disaggregation of Revenue [Line Items]
Total revenue	3,003,347
Products and services transferred over time
Disaggregation of Revenue [Line Items]
Total revenue	568,784
Converged Packet Optical
Disaggregation of Revenue [Line Items]
Total revenue	2,562,841
Packet Networking
Disaggregation of Revenue [Line Items]
Total revenue	348,477
Platform Software and Services
Disaggregation of Revenue [Line Items]
Total revenue	155,376
Blue Planet Automation Software and Services
Disaggregation of Revenue [Line Items]
Total revenue	54,555
Maintenance Support and Training
Disaggregation of Revenue [Line Items]
Total revenue	261,337
Installation and Deployment
Disaggregation of Revenue [Line Items]
Total revenue	148,233
Consulting and Network Design
Disaggregation of Revenue [Line Items]
Total revenue	41,312
Operating Segments
Disaggregation of Revenue [Line Items]
Total revenue	3,572,131	3,094,286	2,801,687
Networking Platforms
Disaggregation of Revenue [Line Items]
Total revenue	2,911,318
Networking Platforms | Products and services at a point in time
Disaggregation of Revenue [Line Items]
Total revenue	2,911,318
Networking Platforms | Products and services transferred over time
Disaggregation of Revenue [Line Items]
Total revenue	0
Networking Platforms | Operating Segments
Disaggregation of Revenue [Line Items]
Total revenue	2,911,318	2,478,018	2,252,710
Networking Platforms | Operating Segments | Converged Packet Optical
Disaggregation of Revenue [Line Items]
Total revenue	2,562,841	2,194,519	1,939,621
Networking Platforms | Operating Segments | Packet Networking
Disaggregation of Revenue [Line Items]
Total revenue	348,477	283,499	313,089
Networking Platforms | Operating Segments | Platform Software and Services
Disaggregation of Revenue [Line Items]
Total revenue	0
Networking Platforms | Operating Segments | Blue Planet Automation Software and Services
Disaggregation of Revenue [Line Items]
Total revenue	0
Networking Platforms | Operating Segments | Maintenance Support and Training
Disaggregation of Revenue [Line Items]
Total revenue	0
Networking Platforms | Operating Segments | Installation and Deployment
Disaggregation of Revenue [Line Items]
Total revenue	0
Networking Platforms | Operating Segments | Consulting and Network Design
Disaggregation of Revenue [Line Items]
Total revenue	0
Platform Software and Services
Disaggregation of Revenue [Line Items]
Total revenue	155,376
Platform Software and Services | Products and services at a point in time
Disaggregation of Revenue [Line Items]
Total revenue	55,530
Platform Software and Services | Products and services transferred over time
Disaggregation of Revenue [Line Items]
Total revenue	99,846
Platform Software and Services | Operating Segments
Disaggregation of Revenue [Line Items]
Total revenue	155,376
Platform Software and Services | Operating Segments | Converged Packet Optical
Disaggregation of Revenue [Line Items]
Total revenue	0
Platform Software and Services | Operating Segments | Packet Networking
Disaggregation of Revenue [Line Items]
Total revenue	0
Platform Software and Services | Operating Segments | Platform Software and Services
Disaggregation of Revenue [Line Items]
Total revenue	155,376	173,949	145,009
Platform Software and Services | Operating Segments | Blue Planet Automation Software and Services
Disaggregation of Revenue [Line Items]
Total revenue	0
Platform Software and Services | Operating Segments | Maintenance Support and Training
Disaggregation of Revenue [Line Items]
Total revenue	0
Platform Software and Services | Operating Segments | Installation and Deployment
Disaggregation of Revenue [Line Items]
Total revenue	0
Platform Software and Services | Operating Segments | Consulting and Network Design
Disaggregation of Revenue [Line Items]
Total revenue	0
Blue Planet Automation Software and Services
Disaggregation of Revenue [Line Items]
Total revenue	54,555
Blue Planet Automation Software and Services | Products and services at a point in time
Disaggregation of Revenue [Line Items]
Total revenue	17,697
Blue Planet Automation Software and Services | Products and services transferred over time
Disaggregation of Revenue [Line Items]
Total revenue	36,858
Blue Planet Automation Software and Services | Operating Segments
Disaggregation of Revenue [Line Items]
Total revenue	54,555
Blue Planet Automation Software and Services | Operating Segments | Converged Packet Optical
Disaggregation of Revenue [Line Items]
Total revenue	0
Blue Planet Automation Software and Services | Operating Segments | Packet Networking
Disaggregation of Revenue [Line Items]
Total revenue	0
Blue Planet Automation Software and Services | Operating Segments | Platform Software and Services
Disaggregation of Revenue [Line Items]
Total revenue	0
Blue Planet Automation Software and Services | Operating Segments | Blue Planet Automation Software and Services
Disaggregation of Revenue [Line Items]
Total revenue	54,555	26,764	16,110
Blue Planet Automation Software and Services | Operating Segments | Maintenance Support and Training
Disaggregation of Revenue [Line Items]
Total revenue	0
Blue Planet Automation Software and Services | Operating Segments | Installation and Deployment
Disaggregation of Revenue [Line Items]
Total revenue	0
Blue Planet Automation Software and Services | Operating Segments | Consulting and Network Design
Disaggregation of Revenue [Line Items]
Total revenue	0
Global Services
Disaggregation of Revenue [Line Items]
Total revenue	450,882
Global Services | Products and services at a point in time
Disaggregation of Revenue [Line Items]
Total revenue	18,802
Global Services | Products and services transferred over time
Disaggregation of Revenue [Line Items]
Total revenue	432,080
Global Services | Operating Segments
Disaggregation of Revenue [Line Items]
Total revenue	450,882	415,555	387,858
Global Services | Operating Segments | Converged Packet Optical
Disaggregation of Revenue [Line Items]
Total revenue	0
Global Services | Operating Segments | Packet Networking
Disaggregation of Revenue [Line Items]
Total revenue	0
Global Services | Operating Segments | Platform Software and Services
Disaggregation of Revenue [Line Items]
Total revenue	0
Global Services | Operating Segments | Blue Planet Automation Software and Services
Disaggregation of Revenue [Line Items]
Total revenue	0
Global Services | Operating Segments | Maintenance Support and Training
Disaggregation of Revenue [Line Items]
Total revenue	261,337	245,161	227,400
Global Services | Operating Segments | Installation and Deployment
Disaggregation of Revenue [Line Items]
Total revenue	148,233	128,829	117,524
Global Services | Operating Segments | Consulting and Network Design
Disaggregation of Revenue [Line Items]
Total revenue	$ 41,312	$ 41,565	$ 42,934

Business Combinations - Conside

Business Combinations - Consideration Transferred (Details) - DonRiver $ in Thousands	Oct. 01, 2018USD ($)
Business Acquisition [Line Items]
Cash	$ 43,283
Contingent consideration	10,900
Total purchase price	$ 54,183

Revenue Revenue - Geographical

Revenue Revenue - Geographical Distribution of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Disaggregation of Revenue [Line Items]
Total revenue	$ 3,572,131	$ 3,094,286	$ 2,801,687
North America
Disaggregation of Revenue [Line Items]
Total revenue	2,351,260	1,886,450	1,736,047
EMEA
Disaggregation of Revenue [Line Items]
Total revenue	566,718	464,876	404,099
CALA
Disaggregation of Revenue [Line Items]
Total revenue	152,653	140,177	164,308
APAC
Disaggregation of Revenue [Line Items]
Total revenue	$ 501,500	$ 602,783	$ 497,233

Business Combinations - Purchas

Business Combinations - Purchase Price Allocation (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Oct. 31, 2018	Oct. 01, 2018	Jul. 02, 2018
Business Acquisition [Line Items]
Goodwill	$ 297,937	$ 297,968
DonRiver
Business Acquisition [Line Items]
Cash and cash equivalents			$ 1,025
Accounts receivable			4,790
Prepaid expenses and other long term assets			372
Goodwill			10,453
Deferred revenue			(193)
Other current and long term liabilities			(9,664)
Total purchase price			54,183
DonRiver | Customer relationships and contracts
Business Acquisition [Line Items]
Intangible assets acquired			37,700
DonRiver | Developed technology
Business Acquisition [Line Items]
Intangible assets acquired			$ 9,700
Packet Design
Business Acquisition [Line Items]
Cash and cash equivalents				$ 642
Accounts receivable				1,525
Prepaid expenses and other long term assets				450
Equipment, furniture and fixtures				31
Goodwill				20,304
Accounts payable				(165)
Accrued liabilities				(657)
Deferred revenue				(5,176)
Total purchase price				41,054
Packet Design | Customer relationships and contracts
Business Acquisition [Line Items]
Intangible assets acquired				2,200
Packet Design | Developed technology
Business Acquisition [Line Items]
Intangible assets acquired				$ 21,900

Revenue - Contract Balances (De

Revenue - Contract Balances (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Nov. 01, 2018	Oct. 31, 2018
Revenue from Contract with Customer [Abstract]
Accounts receivable, net	$ 724,854	$ 799,011	$ 786,502
Contract assets	84,046	31,380
Deferred revenue	$ 156,873	$ 140,704	$ 169,457

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2019	Nov. 01, 2018
Revenue from Contract with Customer [Abstract]
Revenue recognized that was previously deferred	$ 95.1
Capitalized contract acquisition costs	15.7	$ 13.6
Amortization of capitalized contract acquisition costs	18.6
Remaining performance obligation	$ 950

Revenue - Performance Obligatio

Revenue - Performance Obligation (Details) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-11-01	Oct. 31, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percentage of remaining performance obligation	83.00%
Period of remaining performance obligation	12 months

Restructuring Costs (Details)

Restructuring Costs (Details) $ in Thousands	12 Months Ended
	Oct. 31, 2019USD ($)employee	Oct. 31, 2018USD ($)employee	Oct. 31, 2017USD ($)employee
Activity and balance of the restructuring liability accounts
Balance at beginning of period	$ 3,847	$ 2,939	$ 2,838
Additional liability recorded	24,538	18,743	11,315
Adjustment to previous estimates			(1,048)
Cash payments	(13,242)	(17,835)	(10,166)
Balance at end of period	15,143	3,847	2,939
Current restructuring liabilities	5,467
Non-current restructuring liabilities	9,676
Workforce reduction
Activity and balance of the restructuring liability accounts
Balance at beginning of period	2,108	1,291	868
Additional liability recorded	13,779	14,853	5,883
Adjustment to previous estimates			0
Cash payments	(11,904)	(14,036)	(5,460)
Balance at end of period	3,983	$ 2,108	$ 1,291
Current restructuring liabilities	3,983
Non-current restructuring liabilities	$ 0
Restructuring and Related Cost, Positions Eliminated [Abstract]
Number of employees in workforce reduction | employee	283	240	100
Consolidation of excess facilities
Activity and balance of the restructuring liability accounts
Balance at beginning of period	$ 1,739	$ 1,648	$ 1,970
Additional liability recorded	10,759	3,890	5,432
Adjustment to previous estimates			(1,048)
Cash payments	(1,338)	(3,799)	(4,706)
Balance at end of period	11,160	$ 1,739	$ 1,648
Current restructuring liabilities	1,484
Non-current restructuring liabilities	$ 9,676

Interest and Other Income (Lo_3

Interest and Other Income (Loss), Net (Details) - USD ($) $ in Thousands	2 Months Ended	12 Months Ended
	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Other Income and Expenses [Abstract]
Interest income		$ 14,410	$ 13,703	$ 6,579
Gain (loss) on non-hedge designated foreign currency forward contracts		3	6,791	(1,198)
Foreign currency exchange losses		(9,800)	(19,434)	(4,376)
Loss on fair value of debt conversion liability	$ (12,100)	0	(12,070)	0
Other		(737)	(1,019)	(92)
Interest and other income (loss), net		$ 3,876	$ (12,029)	$ 913

Short-Term and Long-Term Inve_3

Short-Term and Long-Term Investments (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Oct. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 119,732
Estimated Fair Value	119,954
U.S. government obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	119,732	$ 198,394
Gross Unrealized Gains	225	0
Gross Unrealized Losses	(3)	(406)
Estimated Fair Value	119,954	197,988
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		9,963
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Estimated Fair Value		9,963
Short-term Investments | U.S. government obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	109,715	139,365
Gross Unrealized Gains	225	0
Gross Unrealized Losses	0	(347)
Estimated Fair Value	109,940	139,018
Short-term Investments | Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		9,963
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Estimated Fair Value		9,963
Other Long-term Investments | U.S. government obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	10,017	59,029
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(3)	(59)
Estimated Fair Value	$ 10,014	$ 58,970

Short-Term and Long-Term Inve_4

Short-Term and Long-Term Investments - Legal Maturities of Debt Investments (Details) $ in Thousands	Oct. 31, 2019USD ($)
Investments, Debt and Equity Securities [Abstract]
Amortized Cost, Less than one year	$ 109,715
Amortized Cost, Due in 1-2 years	10,017
Amortized Cost	119,732
Estimated Fair Value, Less than one year	109,940
Estimated Fair Value, Due in 1-2 years	10,014
Estimated Fair Value	$ 119,954

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Oct. 31, 2018	Aug. 30, 2018
Assets:
U.S. government obligations	$ 119,954
Liabilities:
Debt conversion liability	0	$ 164,212	$ 152,100
Contingent Consideration	4,372	0
Fair Value, Measurements, Recurring
Assets:
Money market funds	759,114	590,684
U.S. government obligations	119,954	197,988
Commercial paper		69,888
Foreign currency forward contracts	1,570	133
Forward starting interest rate swaps		779
Total assets measured at fair value	880,638	859,472
Liabilities:
Debt conversion liability		164,212
Contingent Consideration	3,705	10,900
Total liabilities measured at fair value	24,833	178,343
Level 1 | Fair Value, Measurements, Recurring
Assets:
Money market funds	759,114	590,684
U.S. government obligations	0	0
Commercial paper		0
Foreign currency forward contracts	0	0
Forward starting interest rate swaps		0
Total assets measured at fair value	759,114	590,684
Liabilities:
Debt conversion liability		0
Contingent Consideration	0	0
Total liabilities measured at fair value	0	0
Level 2 | Fair Value, Measurements, Recurring
Assets:
Money market funds	0	0
U.S. government obligations	119,954	197,988
Commercial paper		69,888
Foreign currency forward contracts	1,570	133
Forward starting interest rate swaps		779
Total assets measured at fair value	121,524	268,788
Liabilities:
Debt conversion liability		164,212
Contingent Consideration	0	0
Total liabilities measured at fair value	21,128	167,443
Level 3 | Fair Value, Measurements, Recurring
Assets:
Money market funds	0	0
U.S. government obligations	0	0
Commercial paper		0
Foreign currency forward contracts	0	0
Total assets measured at fair value	0	0
Liabilities:
Debt conversion liability		0
Contingent Consideration	3,705	10,900
Total liabilities measured at fair value	3,705	10,900
Foreign currency forward contracts | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	35	3,231
Foreign currency forward contracts | Level 1 | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	0	0
Foreign currency forward contracts | Level 2 | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	35	3,231
Foreign currency forward contracts | Level 3 | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	0	$ 0
Forward starting interest rate swaps | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	21,093
Forward starting interest rate swaps | Level 1 | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	0
Forward starting interest rate swaps | Level 2 | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	21,093
Forward starting interest rate swaps | Level 3 | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	$ 0

Fair Value Measurements - Balan

Fair Value Measurements - Balance Sheet Items (Details) - USD ($) $ in Thousands	Oct. 01, 2018	Oct. 31, 2019	Oct. 31, 2018	Aug. 30, 2018
Liabilities:
Debt conversion liability		$ 0	$ 164,212	$ 152,100
Fair Value, Measurements, Recurring
Assets:
Total assets measured at fair value		880,638	859,472
Liabilities:
Debt conversion liability			164,212
Total liabilities measured at fair value		24,833	178,343
Fair Value, Measurements, Recurring | Cash equivalents
Assets:
Cash equivalents		759,114	650,609
Fair Value, Measurements, Recurring | Short-term investments
Assets:
Short-term investments		109,940	148,981
Fair Value, Measurements, Recurring | Prepaid expenses and other
Assets:
Prepaid expenses and other		1,570	133
Fair Value, Measurements, Recurring | Long-term investments
Assets:
Long-term investments		10,014	58,970
Fair Value, Measurements, Recurring | Other long-term assets
Assets:
Other long-term assets			779
Fair Value, Measurements, Recurring | Accrued liabilities
Liabilities:
Accrued liabilities		35	3,231
Fair Value, Measurements, Recurring | Debt conversion liability
Liabilities:
Debt conversion liability			164,212
Fair Value, Measurements, Recurring | Other long-term obligations
Liabilities:
Other long-term obligations		24,798	10,900
Fair Value, Measurements, Recurring | Level 1
Assets:
Total assets measured at fair value		759,114	590,684
Liabilities:
Debt conversion liability			0
Total liabilities measured at fair value		0	0
Fair Value, Measurements, Recurring | Level 1 | Cash equivalents
Assets:
Cash equivalents		759,114	590,684
Fair Value, Measurements, Recurring | Level 1 | Short-term investments
Assets:
Short-term investments		0	0
Fair Value, Measurements, Recurring | Level 1 | Prepaid expenses and other
Assets:
Prepaid expenses and other		0	0
Fair Value, Measurements, Recurring | Level 1 | Long-term investments
Assets:
Long-term investments		0	0
Fair Value, Measurements, Recurring | Level 1 | Other long-term assets
Assets:
Other long-term assets			0
Fair Value, Measurements, Recurring | Level 1 | Accrued liabilities
Liabilities:
Accrued liabilities		0	0
Fair Value, Measurements, Recurring | Level 1 | Debt conversion liability
Liabilities:
Debt conversion liability			0
Fair Value, Measurements, Recurring | Level 1 | Other long-term obligations
Liabilities:
Other long-term obligations		0	0
Fair Value, Measurements, Recurring | Level 2
Assets:
Total assets measured at fair value		121,524	268,788
Liabilities:
Debt conversion liability			164,212
Total liabilities measured at fair value		21,128	167,443
Fair Value, Measurements, Recurring | Level 2 | Cash equivalents
Assets:
Cash equivalents		0	59,925
Fair Value, Measurements, Recurring | Level 2 | Short-term investments
Assets:
Short-term investments		109,940	148,981
Fair Value, Measurements, Recurring | Level 2 | Prepaid expenses and other
Assets:
Prepaid expenses and other		1,570	133
Fair Value, Measurements, Recurring | Level 2 | Long-term investments
Assets:
Long-term investments		10,014	58,970
Fair Value, Measurements, Recurring | Level 2 | Other long-term assets
Assets:
Other long-term assets			779
Fair Value, Measurements, Recurring | Level 2 | Accrued liabilities
Liabilities:
Accrued liabilities		35	3,231
Fair Value, Measurements, Recurring | Level 2 | Debt conversion liability
Liabilities:
Debt conversion liability			164,212
Fair Value, Measurements, Recurring | Level 2 | Other long-term obligations
Liabilities:
Other long-term obligations		21,093	0
Fair Value, Measurements, Recurring | Level 3
Assets:
Total assets measured at fair value		0	0
Liabilities:
Debt conversion liability			0
Total liabilities measured at fair value		3,705	10,900
Fair Value, Measurements, Recurring | Level 3 | Cash equivalents
Assets:
Cash equivalents		0	0
Fair Value, Measurements, Recurring | Level 3 | Short-term investments
Assets:
Short-term investments		0	0
Fair Value, Measurements, Recurring | Level 3 | Prepaid expenses and other
Assets:
Prepaid expenses and other		0	0
Fair Value, Measurements, Recurring | Level 3 | Long-term investments
Assets:
Long-term investments		0	0
Fair Value, Measurements, Recurring | Level 3 | Other long-term assets
Assets:
Other long-term assets			0
Fair Value, Measurements, Recurring | Level 3 | Accrued liabilities
Liabilities:
Accrued liabilities		0	0
Fair Value, Measurements, Recurring | Level 3 | Debt conversion liability
Liabilities:
Debt conversion liability			0
Fair Value, Measurements, Recurring | Level 3 | Other long-term obligations
Liabilities:
Other long-term obligations		$ 3,705	$ 10,900
DonRiver
Liabilities:
Contingent consideration agreement term	3 years

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 17,378	$ 17,580	$ 3,963
Provisions	6,740	2,700	18,221
Net Deductions	4,017	2,902	4,604
Balance at end of period	$ 20,101	$ 17,378	17,580
One Unidentified Customer | Customer Concentration Risk | Accounts Receivable
Concentration Risk [Line Items]
Net accounts receivable percentage	12.00%
Two Unidentified Customers | Customer Concentration Risk | Accounts Receivable
Concentration Risk [Line Items]
Net accounts receivable percentage		10.00%
APC Region Customer
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Provisions			$ 13,700

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2019	Nov. 01, 2018	Oct. 31, 2018
Inventories
Raw materials				$ 99,041		$ 67,468
Work-in-process				13,657		9,589
Finished goods				226,622		188,575
Deferred cost of goods sold				53,051		48,057
Inventories before provision				392,371		313,689
Reserve for excess and obsolescence	$ (47,322)	$ (51,206)	$ (51,206)	(47,322)		(50,938)
Total inventories				$ 345,049	$ 260,265	$ 262,751
Reserve for excess and obsolete inventory [Roll Forward]
Valuation allowance, beginning balance	50,938	51,206	62,503
Provisions	28,085	30,615	35,459
Disposals	31,701	30,883	46,756
Valuation allowance, ending balance	$ 47,322	$ 50,938	$ 51,206

Prepaid Expenses and Other (Det

Prepaid Expenses and Other (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017	Nov. 01, 2018
Prepaid expenses and other
Prepaid VAT and other taxes	$ 84,706	$ 82,518
Contract assets	84,046			$ 0
Prepaid expenses	48,680	32,987
Product demonstration equipment, net	38,900	37,623
Other non-trade receivables	28,136	25,716
Capitalized contract acquisition costs	11,677	0
Derivative assets	1,570	133
Deferred deployment expense	125	19,342
Restricted cash	74	0
Financing receivable	0	626
Prepaid expenses and other	297,914	198,945		$ 220,415
Depreciation of product demonstration equipment	$ 8,800	$ 9,000	$ 10,000

Equipment, Building, Furnitur_3

Equipment, Building, Furniture and Fixtures (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Property, Plant and Equipment, Net [Abstract]
Equipment, building, furniture and fixtures, gross	$ 710,398	$ 670,877
Accumulated depreciation and amortization	(423,514)	(378,810)
Equipment, building, furniture and fixtures, net	286,884	292,067
Equipment Furniture Fixtures And Leasehold Improvements
Equipment, furniture and fixtures (Textuals) [Abstract]
Depreciation of equipment, furniture and fixtures, and amortization of leasehold improvements	78,800	75,300	$ 67,200
Equipment, furniture and fixtures
Property, Plant and Equipment, Net [Abstract]
Equipment, building, furniture and fixtures, gross	544,012	504,714
Building subject to capital lease
Property, Plant and Equipment, Net [Abstract]
Equipment, building, furniture and fixtures, gross	71,760	71,968
Leasehold improvements
Property, Plant and Equipment, Net [Abstract]
Equipment, building, furniture and fixtures, gross	$ 94,626	$ 94,195

Intangible Assets (Details)

Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Intangible Assets
Gross Intangible	$ 751,472	$ 751,766
Accumulated Amortization	(638,691)	(603,541)
Net Intangible	112,781	148,225
Amortization of intangible assets	35,136	25,806	$ 45,713
Expected future amortization of finite-lived intangible assets
2020	34,008
2021	30,830
2022	24,809
2023	10,000
2024	6,948
Thereafter	6,186
Net Intangible	112,781	148,225
Developed technology
Intangible Assets
Gross Intangible	373,526	373,581
Accumulated Amortization	(308,261)	(285,233)
Net Intangible	65,265	88,348
Expected future amortization of finite-lived intangible assets
Net Intangible	65,265	88,348
Patents and licenses
Intangible Assets
Gross Intangible	3,565	3,565
Accumulated Amortization	(2,244)	(1,958)
Net Intangible	1,321	1,607
Expected future amortization of finite-lived intangible assets
Net Intangible	1,321	1,607
Customer relationships, covenants not to compete, outstanding purchase orders and contracts
Intangible Assets
Gross Intangible	374,381	374,620
Accumulated Amortization	(328,186)	(316,350)
Net Intangible	46,195	58,270
Expected future amortization of finite-lived intangible assets
Net Intangible	$ 46,195	$ 58,270

Goodwill (Details)

Goodwill (Details) $ in Thousands	12 Months Ended
	Oct. 31, 2019USD ($)segment
Goodwill [Roll Forward]
Goodwill beginning balance	$ 297,968
Reallocation	0
Acquisitions	0
Impairments	0
Translation	(31)
Goodwill ending balance	$ 297,937
Platform and Blue Planet Automation Software and Services Segments
Goodwill [Line Items]
Number of operating segments | segment	2
Software and Software Related Services
Goodwill [Roll Forward]
Goodwill beginning balance	$ 232,200
Operating Segments | Software and Software Related Services
Goodwill [Roll Forward]
Goodwill beginning balance	232,185
Reallocation	(232,185)
Acquisitions	0
Impairments	0
Translation	0
Goodwill ending balance	0
Operating Segments | Platform Software and Services
Goodwill [Roll Forward]
Goodwill beginning balance	0
Reallocation	156,191
Acquisitions	0
Impairments	0
Translation	0
Goodwill ending balance	156,191
Operating Segments | Blue Planet Automation Software and Services
Goodwill [Roll Forward]
Goodwill beginning balance	0
Reallocation	75,994
Acquisitions	0
Impairments	0
Translation	0
Goodwill ending balance	75,994
Operating Segments | Networking Platforms
Goodwill [Roll Forward]
Goodwill beginning balance	65,783
Reallocation	0
Acquisitions	0
Impairments	0
Translation	(31)
Goodwill ending balance	$ 65,752

Other Balance Sheet Details -

Other Balance Sheet Details - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017	Nov. 01, 2018
Other long-term assets
Maintenance spares inventory, net	$ 55,482	$ 45,679
Cost method investments	10,727	8,056
Capitalized contract acquisition costs	3,994	0
Deferred debt issuance costs, net	1,609	720
Restricted cash	42	11
Forward starting interest rate swaps	0	779
Other	17,132	16,407
Total	88,986	71,652		$ 75,650
Revolving Credit Facility
Other long-term assets
Amortization of debt issuance costs included in interest expense	$ 300	$ 300	$ 300

Other Balance Sheet Details - A

Other Balance Sheet Details - Accrued Liabilities (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Accrued liabilities
Compensation, payroll related tax and benefits	$ 182,363	$ 140,277
Warranty	48,498	44,740	$ 42,456	$ 52,324
Vacation	22,290	42,507
Contingent Consideration	4,372	0
Capital lease obligations	2,764	3,547
Interest payable	1,007	1,072
Other	121,446	107,932
Total	$ 382,740	$ 340,075

Other Balance Sheet Details -_2

Other Balance Sheet Details - Accrued Warranty (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	$ 44,740	$ 42,456	$ 52,324
Current Year Provisions	23,105	20,992	7,965
Settlements	19,347	18,708	17,833
Balance at end of period	$ 48,498	$ 44,740	42,456
Adjustment on prior year provisions			$ (9,700)

Other Balance Sheet Details - D

Other Balance Sheet Details - Deferred Revenue (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Nov. 01, 2018	Oct. 31, 2018
Deferred Revenue Arrangement [Line Items]
Total	$ 156,873	$ 140,704	$ 169,457
Less current portion	(111,381)	(96,731)	(111,134)
Long-term deferred revenue	45,492	$ 43,973	58,323
Products
Deferred Revenue Arrangement [Line Items]
Total	27,366		42,474
Services
Deferred Revenue Arrangement [Line Items]
Total	$ 129,507		$ 126,983

Other Balance Sheet Details - O

Other Balance Sheet Details - Other Long-Term Obligations (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Oct. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Capital lease obligations	$ 65,284	$ 68,245
Income tax liability	20,546	15,894
Interest rate swap liability	21,093	0
Deferred tenant allowance	6,248	7,244
Straight-line rent	5,434	6,750
Contingent consideration	3,705	10,900
Other	26,437	10,380
Other long-term obligations	$ 148,747	$ 119,413

Other Balance Sheet Details - F

Other Balance Sheet Details - Future Minimum Capital Lease Payments (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Oct. 31, 2018
Balance Sheet Related Disclosures [Abstract]
2020	$ 7,652
2021	7,547
2022	7,860
2023	8,067
2024	8,067
Thereafter	67,126
Net minimum capital lease payments	106,319
Less: Amount representing interest	(38,271)
Present value of minimum lease payments	68,048
Less: Current portion of present value of minimum lease payments	(2,764)	$ (3,547)
Long-term portion of present value of minimum lease payments	$ 65,284	$ 68,245

Derivative Instruments (Details

Derivative Instruments (Details) - USD ($) shares in Millions	Nov. 15, 2018	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017	Sep. 28, 2018	Aug. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Embedded conversion feature		$ 164,212,000	$ 0	$ 0	$ 164,212,000			$ 152,100,000
Loss on fair value of debt conversion liability		12,100,000		0	12,070,000	$ 0
Cash paid for embedded conversion feature				111,268,000	0	0
Term Loan Payable due January 30, 2022 | Secured Debt
Derivative Instruments, Gain (Loss) [Line Items]
Aggregate principal amount of debt repurchased							$ 394,000,000
Term Loan Payable due September 28, 2025 | Secured Debt
Derivative Instruments, Gain (Loss) [Line Items]
Term loan principal amount			700,000,000	$ 700,000,000
3.75% Convertible Senior Notes due October 15, 2018 (New) | Convertible Notes Payable
Derivative Instruments, Gain (Loss) [Line Items]
Maximum cash settlement of convertible debt								$ 400,000,000
Cash paid for embedded conversion feature	$ 111,300,000
Shares issued for embedded conversion feature (in shares)	1.6
Maximum
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange contract maturities				24 months
Foreign Currency Forward Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain on unwounding of interest rate swaps				$ 3,985,000	(1,674,000)	(295,000)
Forward starting interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain on unwounding of interest rate swaps				(20,103,000)	6,199,000	$ 6,185,000
Designated as Hedging Instrument | Foreign Currency Forward Contracts | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Notional principal of contract		163,200,000	197,400,000	$ 197,400,000	163,200,000
Designated as Hedging Instrument | Foreign Currency Forward Contracts | Cash Flow Hedging | Maximum
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange contract maturities				24 months
Designated as Hedging Instrument | Forward starting interest rate swaps | Cash Flow Hedging | Term Loan Payable due January 30, 2022 | Secured Debt
Derivative Instruments, Gain (Loss) [Line Items]
Gain on unwounding of interest rate swaps			6,800,000
Designated as Hedging Instrument | Forward starting interest rate swaps | Cash Flow Hedging | Term Loan Payable due September 28, 2025 | Secured Debt
Derivative Instruments, Gain (Loss) [Line Items]
Notional principal of contract			$ 350,000,000	$ 350,000,000
Fixed interest amount resulting from interest rate swap			2.957%	2.957%
Not Designated as Hedging Instrument | Foreign Currency Forward Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional principal of contract		$ 162,600,000	$ 206,000,000	$ 206,000,000	$ 162,600,000
Not Designated as Hedging Instrument | Foreign Currency Forward Contracts | Maximum
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange contract maturities				12 months

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	$ 1,929,334
Other comprehensive gain (loss) before reclassifications	(19,120)	$ 3,481	$ 12,381
Amounts reclassified from AOCI	2,816	1,756	931
Balance at end of the period	2,172,761	1,929,334
AOCI Attributable to Parent
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(5,780)	(11,017)	(24,329)
Balance at end of the period	(22,084)	(5,780)	(11,017)
Unrealized Gain/(Loss) on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(425)	(451)	139
Other comprehensive gain (loss) before reclassifications	577	26	(590)
Amounts reclassified from AOCI	0	0	0
Balance at end of the period	152	(425)	(451)
Unrealized Gain/Losses on Derivative Instruments | Foreign Currency Forward Contracts
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(3,060)	(1,386)	(1,091)
Other comprehensive gain (loss) before reclassifications	14	(3,242)	1,290
Amounts reclassified from AOCI	3,971	1,568	(1,585)
Balance at end of the period	925	(3,060)	(1,386)
Unrealized Gain/Losses on Derivative Instruments | Forward starting interest rate swaps
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	6,417	218	(5,967)
Other comprehensive gain (loss) before reclassifications	(18,948)	6,011	3,669
Amounts reclassified from AOCI	(1,155)	188	2,516
Balance at end of the period	(13,686)	6,417	218
Cumulative Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(8,712)	(9,398)	(17,410)
Other comprehensive gain (loss) before reclassifications	(763)	686	8,012
Amounts reclassified from AOCI	0	0	0
Balance at end of the period	$ (9,475)	$ (8,712)	$ (9,398)

Short-Term and Long-Term Debt -

Short-Term and Long-Term Debt - Net Carrying Values of Term Loans (Details) - Secured Debt - Term Loan Payable due September 28, 2025 - USD ($) $ in Thousands	Oct. 31, 2019	Oct. 31, 2018	Sep. 28, 2018
Debt Instrument [Line Items]
Principal Balance	$ 693,000		$ 699,100
Unamortized Discount	(1,958)		(900)
Deferred Debt Issuance Costs	(3,636)	$ (4,300)	$ (1,900)
Net Carrying Value	$ 687,406	$ 693,450

Short-Term and Long-Term Debt_2

Short-Term and Long-Term Debt (Details) - Secured Debt - USD ($)	Sep. 28, 2018	Oct. 31, 2019	Oct. 31, 2018
Term Loan Payable due September 28, 2025
Debt Instrument [Line Items]
Deferred debt issuance costs	$ 1,900,000	$ 3,636,000	$ 4,300,000
Amortization of debt issuance costs included in interest expense		600,000	$ 700,000
Fair value of debt		694,700,000
Aggregate principal amount		700,000,000
Principal Balance	699,100,000	693,000,000
Installment payment	1,750,000
Debt issuance costs expensed	3,800,000
Debt discount	$ 900,000	$ 1,958,000
Installment payment, percentage	0.25%
Prepayment premium	1.00%
Term Loan Payable due September 28, 2025 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
LIBOR interest floor	0.00%
Basis spread on variable rate	2.00%
Term Loan Payable due September 28, 2025 | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
Interest rate floor	1.00%
Term Loan Payable due January 30, 2022
Debt Instrument [Line Items]
Deferred debt issuance costs	$ 2,400,000
Aggregate principal amount of debt repurchased	394,000,000
Proceeds from term loan	305,100,000
Debt discount	$ 1,400,000

ABL Credit Facility (Details)

ABL Credit Facility (Details)	Oct. 31, 2019USD ($)
Letter of Credit
Line of Credit Facility [Line Items]
Letters of credit collateralized by the credit facility	$ 72,900,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Current borrowing capacity	300,000,000
Line of credit outstanding	$ 0

Earnings (Loss) Per Share Cal_3

Earnings (Loss) Per Share Calculation - Reconciliation of Numerator and Denominator of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Numerator
Net income (loss)	$ 253,434	$ (344,690)	$ 1,261,953
Less: Loss on fair value of debt conversion liability		(12,894)	0
Net income (loss) used to calculate Diluted EPS	$ 253,434	$ (357,584)	$ 1,278,721
Denominator
Basic weighted average shares outstanding (in shares)	155,720	143,738	141,997
Add: Shares underlying outstanding stock options, employee stock purchase plan and restricted stock units (in shares)	1,892	0	1,354
Diluted weighted average shares outstanding (in shares)	157,612	143,738	169,919
Earning Per Share [Abstract]
Basic EPS (in dollars per share)	$ 1.63	$ (2.40)	$ 8.89
Diluted EPS (in dollars per share)	$ 1.61	$ (2.49)	$ 7.53
3.75% Convertible Senior Notes due October 15, 2018 (New)
Denominator
Add: Shares underlying Convertible Senior Notes (in shares)	0	0	404
Earning Per Share [Abstract]
Interest rate on convertible notes	3.75%
0.875% Convertible Senior Notes due June 15, 2017
Numerator
Interest expense associated with Convertible Senior Notes due	$ 0	$ 0	$ 853
Denominator
Add: Shares underlying Convertible Senior Notes (in shares)	0	0	3,032
Earning Per Share [Abstract]
Interest rate on convertible notes	0.875%
3.75% Convertible Senior Notes due October 15, 2018 (Original)
Numerator
Interest expense associated with Convertible Senior Notes due	$ 0	$ 0	$ 7,224
Denominator
Add: Shares underlying Convertible Senior Notes (in shares)	0	0	13,934
Earning Per Share [Abstract]
Interest rate on convertible notes	3.75%	3.75%
4.0% Convertible Senior Notes due December 15, 2020
Numerator
Interest expense associated with Convertible Senior Notes due	$ 0	$ 0	$ 8,691
Denominator
Add: Shares underlying Convertible Senior Notes (in shares)	0	0	9,198
Earning Per Share [Abstract]
Interest rate on convertible notes	4.00%

Earnings (Loss) Per Share Cal_4

Earnings (Loss) Per Share Calculation - Weighted Average Shares Excluded from Calculation of Denominator for Basic and Diluted EPS (Details) - shares shares in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect (in shares)	234	16,021	958
3.75% Convertible Senior Notes due October 15, 2018 (New)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Interest rate on convertible notes	3.75%
3.75% Convertible Senior Notes due October 15, 2018 (Original)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Interest rate on convertible notes	3.75%	3.75%
4.0% Convertible Senior Notes due December 15, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Interest rate on convertible notes	4.00%
Shares underlying stock options and restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect (in shares)	234	2,235	958
Convertible Senior Notes | 3.75% Convertible Senior Notes due October 15, 2018 (New)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect (in shares)	0	1,780	0
Convertible Senior Notes | 3.75% Convertible Senior Notes due October 15, 2018 (Original)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect (in shares)	0	2,883	0
Convertible Senior Notes | 4.0% Convertible Senior Notes due December 15, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect (in shares)	0	9,123	0

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($)	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Dec. 13, 2018
Equity [Abstract]
Stock repurchase program authorized amount			$ 500,000,000
Shares repurchased for tax withholdings on vesting of restricted stock units	$ 29,059,000	$ 4,757,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Repurchase Program (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
Shares Repurchased
Beginning balance (in shares)	0
Repurchase of common stock under the stock repurchase program (in shares)	3,838,466,000
Ending balance (in shares)	3,838,466,000	0
Weighted-Average Price per Share
Beginning balance (in USD per share)	$ 0
Repurchase of common stock under the stock repurchase program (in USD per share)	39.10
Ending balance (in USD per share)	$ 39.10	$ 0
Amount Repurchased (in thousands)
Beginning balance	$ 0
Repurchase of common stock under the stock repurchase program	150,076	$ 110,981
Ending balance	$ 150,076	$ 0

Income Taxes - Provision (Benef

Income Taxes - Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Current:
Federal	$ 13,143	$ 8,327	$ 0
State	16,945	8,219	6,342
Foreign	9,816	13,294	14,563
Total current	39,904	29,840	20,905
Deferred:
Federal	31,872	475,951	(1,047,699)
State	(9,159)	(8,202)	(77,429)
Foreign	(2,861)	(4,118)	(1,604)
Total deferred	19,852	463,631	(1,126,732)
Provision (benefit) for income taxes	$ 59,756	$ 493,471	$ (1,105,827)

Income Taxes - Income before Pr

Income Taxes - Income before Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Income (loss) before provision (benefit) for income taxes:
United States	$ 256,461	$ 106,972	$ 114,242
Foreign	56,729	41,809	41,884
Income before income taxes	$ 313,190	$ 148,781	$ 156,126

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017	Nov. 01, 2018	Nov. 01, 2017	Oct. 31, 2016
Valuation Allowance [Line Items]
Provision at statutory rate	21.00%	23.41%	35.00%
Provisional tax expense from enactment of the Tax Act		$ 472,800
Unrecognized tax benefits, interest and penalties accrued	$ 3,000	3,500
Interest and penalties expense (benefit)	(1,000)	1,100	$ (600)
Cumulative unremitted earnings of non-U.S. affiliates	372,000
Cumulative amount of temporary differences for unremitted foreign earnings for which a deferred tax liability has not been recognized	31,000
Valuation allowance	135,978	$ 142,650	$ 185,898			$ 1,489,780
Operating loss carryforwards	391,000
Income tax credit carryforwards subject to expiration	$ 62,000
Effect of adoption of new accounting standard (Note 1)				$ 49,805	$ 62,123
Retained Earnings
Valuation Allowance [Line Items]
Effect of adoption of new accounting standard (Note 1)				$ 49,805	61,291
Retained Earnings | Accounting Standards Update 2016-09
Valuation Allowance [Line Items]
Effect of adoption of new accounting standard (Note 1)					$ 62,100

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate (Details)	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Income tax rate reconciliation:
Provision at statutory rate	21.00%	23.41%	35.00%
Deferred tax assets remeasurement	0.00%	294.56%	0.00%
Base Erosion and Anti-Abuse Tax	3.60%	0.00%	0.00%
State taxes	2.18%	(0.16%)	2.29%
Foreign taxes	(0.37%)	1.22%	(0.35%)
Research and development credit	(7.53%)	(8.80%)	(15.38%)
Non-deductible compensation	1.01%	3.39%	3.45%
Fair value of debt conversion liability	0.00%	1.90%	0.00%
Transition tax	0.29%	23.23%	0.00%
Valuation allowance	(2.13%)	(11.95%)	(739.97%)
Other	1.03%	4.88%	6.67%
Effective income tax rate	19.08%	331.68%	(708.29%)

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Deferred tax assets:
Reserves and accrued liabilities	$ 54,183	$ 40,959
Depreciation and amortization	455,007	353,838
NOL and credit carry forward	302,325	483,495
Other	39,405	9,397
Gross deferred tax assets	850,920	887,689
Valuation allowance	(135,978)	(142,650)	$ (185,898)	$ (1,489,780)
Deferred tax asset, net of valuation allowance	$ 714,942	$ 745,039

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding interest and penalties
Unrecognized tax benefits, beginning balance	$ 96,363	$ 141,582	$ 30,668
Increase related to positions taken in prior period	1,959		122
Decrease related to positions taken in prior period		(46,400)
Increase related to positions taken in current period		2,482	111,412
Reductions related to settlements with taxing authorities	(1,224)
Reductions related to expiration of statute of limitations	(2,494)	(1,301)	(620)
Unrecognized tax benefits, ending balance	$ 94,604	$ 96,363	$ 141,582

Income Taxes - Valuation Allowa

Income Taxes - Valuation Allowance of Gross Deferred Tax Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Valuation allowance against gross deferred tax assets:
Valuation allowance, beginning balance	$ 142,650	$ 185,898	$ 1,489,780
Additions	27,459	23,720	0
Deductions	34,131	66,968	1,303,882
Valuation allowance, ending balance	$ 135,978	$ 142,650	$ 185,898

Share-Based Compensation Expe_3

Share-Based Compensation Expense (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Oct. 31, 2019USD ($)period$ / sharesshares	Oct. 31, 2018USD ($)$ / sharesshares	Oct. 31, 2017USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted during the period (in shares)	0	0	0
Unrecognized share-based compensation | $	$ 88.2
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of service-based awards (in years)	4 years
Intrinsic value of option exercised | $	$ 0.8	$ 2.2	$ 3.1
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards outstanding (in shares)	4,010,000	4,402,000
Total fair value of restricted stock units vested and converted into common stock | $	$ 79.2	$ 54.3	$ 49.5
Weighted average fair value of each restricted stock unit granted (per share) | $ / shares	$ 34.53	$ 22.46	$ 23.29
Nonvested award compensation cost not yet recognized, period for recognition	1 year 5 months 12 days
Restricted Stock Units (RSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of service-based awards (in years)	3 years
Restricted Stock Units (RSUs) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of service-based awards (in years)	4 years
Performance Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards outstanding (in shares)	300,000	200,000
2017 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum expiration period of incentive awards (in years)	10 years
Number of shares authorized (in shares)	8,900,000
Remaining authorized shares available for issuance (in shares)	5,000,000
2017 Omnibus Incentive Plan | Employee Stock Options and Stock Appreciation Rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum expiration period of incentive awards (in years)	10 years
Minimum exercise price, percentage of fair market value on grant date (as a percent)	100.00%
2017 Omnibus Incentive Plan | Restricted Stock Units (RSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of service-based awards (in years)	1 year
Employee Stock Purchase Plan | Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining authorized shares available for issuance (in shares)	4,500,000
Offer period for ESPP (in years)	12 months
Number of purchase periods in offer period | period	2
Purchase period	6 months
ESPP discount percentage purchase date	85.00%
Maximum number of shares increase under ESPP (in shares)	600,000
Shares issued under ESPP (in shares)	1,000,000	1,100,000	1,000,000
Employee Stock Purchase Plan | Employee Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	8,200,000

Share-Based Compensation Expe_4

Share-Based Compensation Expense - Summary of Stock Option Activity (Details) - $ / shares	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Shares Underlying Options Outstanding
Beginning Balance (in shares)	276,000
Granted (in shares)	0	0	0
Exercised (in shares)	(50,000)
Canceled (in shares)	(6,000)
Ending Balance (in shares)	220,000	276,000
Weighted Average Exercise Price
Beginning Balance (in dollars per share)	$ 33.52
Granted (in dollars per share)	0
Exercised (in dollars per share)	24.13
Canceled (in dollars per share)	37.03
Ending Balance (in dollars per share)	$ 35.54	$ 33.52

Share-Based Compensation Expe_5

Share-Based Compensation Expense - Stock Options Outstanding (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
Summarizes information with respect to stock options outstanding
Weighted average exercise price, (in dollars per share)	$ 35.54	$ 33.52
$6.43 to $10.50
Summarizes information with respect to stock options outstanding
Range of exercise price, lower (in dollars per share)	6.43
Range of exercise price, upper (in dollars per share)	$ 10.50
Number of underlying shares (in shares)	4
Weighted average remaining contractual life (in years)	24 days
Weighted average exercise price, (in dollars per share)	$ 8.42
Aggregate intrinsic value	$ 117
$11.34 to $15.67
Summarizes information with respect to stock options outstanding
Range of exercise price, lower (in dollars per share)	$ 11.34
Range of exercise price, upper (in dollars per share)	$ 15.67
Number of underlying shares (in shares)	49
Weighted average remaining contractual life (in years)	2 years 9 months 14 days
Weighted average exercise price, (in dollars per share)	$ 13.51
Aggregate intrinsic value	$ 1,123
$17.50 to $19.25
Summarizes information with respect to stock options outstanding
Range of exercise price, lower (in dollars per share)	$ 17.50
Range of exercise price, upper (in dollars per share)	$ 19.25
Number of underlying shares (in shares)	11
Weighted average remaining contractual life (in years)	4 years 7 months 6 days
Weighted average exercise price, (in dollars per share)	$ 18.17
Aggregate intrinsic value	$ 202
$32.06 to $37.10
Summarizes information with respect to stock options outstanding
Range of exercise price, lower (in dollars per share)	$ 32.06
Range of exercise price, upper (in dollars per share)	$ 37.10
Number of underlying shares (in shares)	31
Weighted average remaining contractual life (in years)	3 years 3 months 7 days
Weighted average exercise price, (in dollars per share)	$ 36.04
Aggregate intrinsic value	$ 28
$41.52 to $55.63
Summarizes information with respect to stock options outstanding
Range of exercise price, lower (in dollars per share)	$ 41.52
Range of exercise price, upper (in dollars per share)	$ 55.63
Number of underlying shares (in shares)	125
Weighted average remaining contractual life (in years)	3 years 5 months 23 days
Weighted average exercise price, (in dollars per share)	$ 46.47
Aggregate intrinsic value	$ 0
$6.43 to $55.63
Summarizes information with respect to stock options outstanding
Range of exercise price, lower (in dollars per share)	$ 6.43
Range of exercise price, upper (in dollars per share)	$ 55.63
Number of underlying shares (in shares)	220
Weighted average remaining contractual life (in years)	3 years 3 months 18 days
Weighted average exercise price, (in dollars per share)	$ 35.54
Aggregate intrinsic value	$ 1,470

Share-Based Compensation Expe_6

Share-Based Compensation Expense - Assumptions for Awards Granted (Details) - Performance Based Awards	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility of Ciena common stock, which is a weighted average of implied volatility and historical volatility	34.10%	34.93%
Historical volatility of Ciena common stock	36.80%	38.24%
Historical volatility of S&P Networking Index	17.39%	17.14%
Correlation coefficient	0.6251	0.6597
Expected life in years	2 years 10 months 13 days	2 years 10 months 20 days
Risk-free interest rate	2.62%	1.94%
Expected dividend yield	0.00%	0.00%

Share-Based Compensation Expe_7

Share-Based Compensation Expense - Restricted Stock Units (Details) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
Summary of Restricted Stock Unit Activity
Restricted shares outstanding, Beginning balance (in shares)	4,402
Restricted stock units outstanding, granted (in shares)	2,057
Restricted stock units outstanding, vested (in shares)	(2,101)
Restricted stock units outstanding, canceled or forfeited (in shares)	(348)
Restricted shares outstanding, Ending balance (in shares)	4,010
Weighted average grant date fair value per share (in dollars per share)	$ 27.94	$ 22.26
Aggregate fair value	$ 146,091	$ 140,943

Share-Based Compensation Expe_8

Share-Based Compensation Expense - Components of Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Share-based compensation expense
Share-based compensation expense capitalized in inventory, net	$ (57)	$ 101	$ (77)
Total share-based compensation	59,736	52,972	48,360
Share-based compensation expense included in cost of goods sold
Share-based compensation expense
Share-based compensation expense included in operating expense	6,043	5,600	5,159
Product cost of goods sold
Share-based compensation expense
Share-based compensation expense included in operating expense	2,868	2,984	2,672
Service cost of goods sold
Share-based compensation expense
Share-based compensation expense included in operating expense	3,175	2,616	2,487
Share-based compensation expense included in operating expense
Share-based compensation expense
Share-based compensation expense included in operating expense	53,636	47,473	43,124
Research and development
Share-based compensation expense
Share-based compensation expense included in operating expense	14,321	13,518	12,957
Sales and marketing
Share-based compensation expense
Share-based compensation expense included in operating expense	16,474	14,246	12,846
General and administrative
Share-based compensation expense
Share-based compensation expense included in operating expense	$ 22,841	$ 19,709	$ 17,321

Segment and Entity Wide Discl_3

Segment and Entity Wide Disclosures (Details) $ in Thousands	12 Months Ended
	Oct. 31, 2019USD ($)segment	Oct. 31, 2018USD ($)
Segment Reporting Information [Line Items]
Property, plant and equipment, net	$ 286,884	$ 292,067
Net intangible	112,781	148,225
Maintenance spares inventory net non current	$ 55,482	$ 45,679
Platform and Blue Planet Automation Software and Services Segments
Segment Reporting Information [Line Items]
Number of operating segments | segment	2
Operating Segments
Segment Reporting Information [Line Items]
Maintenance spares inventory net non current	$ 55,500
Operating Segments | Networking Platforms
Segment Reporting Information [Line Items]
Net intangible	20,300
Operating Segments | Blue Planet Automation Software and Services
Segment Reporting Information [Line Items]
Net intangible	$ 92,500

Segment and Entity Wide Discl_4

Segment and Entity Wide Disclosures - Segment Revenue, Profit (loss) and the reconciliation to consolidated net income (loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Revenue:
Revenues	$ 3,572,131	$ 3,094,286	$ 2,801,687
Less: non-performance operating expenses
Selling and marketing	423,046	394,060	356,169
General and administrative	174,399	160,133	142,604
Amortization of intangible assets	21,808	15,737	33,029
Acquisition and integration costs	3,370	5,111	0
Significant asset impairments and restructuring costs	24,538	18,139	23,933
Add: other non-performance financial items
Interest and other income (loss), net	3,876	(12,029)	913
Interest expense	(37,452)	(55,249)	(55,852)
Loss on extinguishment and modification of debt	0	(13,887)	(3,657)
Provision (benefit) for income taxes	59,756	493,471	(1,105,827)
Net income (loss)	253,434	(344,690)	1,261,953
Networking Platforms
Revenue:
Revenues	2,911,318
Platform Software and Services
Revenue:
Revenues	155,376
Blue Planet Automation Software and Services
Revenue:
Revenues	54,555
Global Services
Revenue:
Revenues	450,882
Converged Packet Optical
Revenue:
Revenues	2,562,841
Packet Networking
Revenue:
Revenues	348,477
Platform Software and Services
Revenue:
Revenues	155,376
Blue Planet Automation Software and Services
Revenue:
Revenues	54,555
Maintenance Support and Training
Revenue:
Revenues	261,337
Installation and Deployment
Revenue:
Revenues	148,233
Consulting and Network Design
Revenue:
Revenues	41,312
Operating Segments
Revenue:
Revenues	3,572,131	3,094,286	2,801,687
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Gross profit	993,927	823,126	770,457
Operating Segments | Networking Platforms
Revenue:
Revenues	2,911,318	2,478,018	2,252,710
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Gross profit	759,244	581,113	578,039
Operating Segments | Platform Software and Services
Revenue:
Revenues	155,376
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Gross profit	64,210	78,048	47,353
Operating Segments | Blue Planet Automation Software and Services
Revenue:
Revenues	54,555
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Gross profit	(17,769)	(8,240)	(14,817)
Operating Segments | Global Services
Revenue:
Revenues	450,882	415,555	387,858
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Gross profit	188,242	172,205	159,882
Operating Segments | Converged Packet Optical | Networking Platforms
Revenue:
Revenues	2,562,841	2,194,519	1,939,621
Operating Segments | Converged Packet Optical | Platform Software and Services
Revenue:
Revenues	0
Operating Segments | Converged Packet Optical | Blue Planet Automation Software and Services
Revenue:
Revenues	0
Operating Segments | Converged Packet Optical | Global Services
Revenue:
Revenues	0
Operating Segments | Packet Networking | Networking Platforms
Revenue:
Revenues	348,477	283,499	313,089
Operating Segments | Packet Networking | Platform Software and Services
Revenue:
Revenues	0
Operating Segments | Packet Networking | Blue Planet Automation Software and Services
Revenue:
Revenues	0
Operating Segments | Packet Networking | Global Services
Revenue:
Revenues	0
Operating Segments | Platform Software and Services | Networking Platforms
Revenue:
Revenues	0
Operating Segments | Platform Software and Services | Platform Software and Services
Revenue:
Revenues	155,376	173,949	145,009
Operating Segments | Platform Software and Services | Blue Planet Automation Software and Services
Revenue:
Revenues	0
Operating Segments | Platform Software and Services | Global Services
Revenue:
Revenues	0
Operating Segments | Blue Planet Automation Software and Services | Networking Platforms
Revenue:
Revenues	0
Operating Segments | Blue Planet Automation Software and Services | Platform Software and Services
Revenue:
Revenues	0
Operating Segments | Blue Planet Automation Software and Services | Blue Planet Automation Software and Services
Revenue:
Revenues	54,555	26,764	16,110
Operating Segments | Blue Planet Automation Software and Services | Global Services
Revenue:
Revenues	0
Operating Segments | Maintenance Support and Training | Networking Platforms
Revenue:
Revenues	0
Operating Segments | Maintenance Support and Training | Platform Software and Services
Revenue:
Revenues	0
Operating Segments | Maintenance Support and Training | Blue Planet Automation Software and Services
Revenue:
Revenues	0
Operating Segments | Maintenance Support and Training | Global Services
Revenue:
Revenues	261,337	245,161	227,400
Operating Segments | Installation and Deployment | Networking Platforms
Revenue:
Revenues	0
Operating Segments | Installation and Deployment | Platform Software and Services
Revenue:
Revenues	0
Operating Segments | Installation and Deployment | Blue Planet Automation Software and Services
Revenue:
Revenues	0
Operating Segments | Installation and Deployment | Global Services
Revenue:
Revenues	148,233	128,829	117,524
Operating Segments | Consulting and Network Design | Networking Platforms
Revenue:
Revenues	0
Operating Segments | Consulting and Network Design | Platform Software and Services
Revenue:
Revenues	0
Operating Segments | Consulting and Network Design | Blue Planet Automation Software and Services
Revenue:
Revenues	0
Operating Segments | Consulting and Network Design | Global Services
Revenue:
Revenues	$ 41,312	$ 41,565	$ 42,934

Segment and Entity Wide Discl_5

Segment and Entity Wide Disclosures - Entity Wide Reporting (Details) $ in Thousands	12 Months Ended
	Oct. 31, 2019USD ($)region	Oct. 31, 2018USD ($)	Oct. 31, 2017USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of geographic regions | region	4
Ciena's geographic distribution of revenue
Revenues	$ 3,572,131	$ 3,094,286	$ 2,801,687
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	286,884	292,067
North America
Ciena's geographic distribution of revenue
Revenues	2,351,260	1,886,450	1,736,047
Canada
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	211,901	198,028
UNITED STATES
Ciena's geographic distribution of revenue
Revenues	2,250,000	1,770,000	1,630,000
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	58,119	75,479
EMEA
Ciena's geographic distribution of revenue
Revenues	566,718	464,876	404,099
CALA
Ciena's geographic distribution of revenue
Revenues	152,653	140,177	164,308
APAC
Ciena's geographic distribution of revenue
Revenues	501,500	602,783	$ 497,233
Other International
Ciena's geographic distribution of equipment, furniture and fixtures
Equipment, building, furniture and fixtures, net	$ 16,864	$ 18,560

Segment and Entity Wide Discl_6

Segment and Entity Wide Disclosures - Customer Concentration (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Revenue, Major Customer [Line Items]
Revenues	$ 3,572,131	$ 3,094,286	$ 2,801,687
Revenue
Revenue, Major Customer [Line Items]
Percent of revenue	59.30%	56.50%	55.60%
Customer Concentration Risk | Revenue
Revenue, Major Customer [Line Items]
Revenues	$ 1,219,068	$ 692,589	$ 736,991
Customer Concentration Risk | Revenue | Verizon
Revenue, Major Customer [Line Items]
Revenues	459,787	318,013	288,048
Customer Concentration Risk | Revenue | AT&T
Revenue, Major Customer [Line Items]
Revenues	388,704	$ 374,576	$ 448,943
Customer Concentration Risk | Revenue | Web-scale provider
Revenue, Major Customer [Line Items]
Revenues	$ 370,577

Other Employee Benefit Plans (D

Other Employee Benefit Plans (Details)	12 Months Ended
	Oct. 31, 2019USD ($)	Oct. 31, 2019CAD ($)	Oct. 31, 2018USD ($)	Oct. 31, 2018CAD ($)	Oct. 31, 2017USD ($)	Oct. 31, 2017CAD ($)
Defined Contribution Pension Plan Canada
Schedule of Defined Contribution Pension And Other Postretirement Plans Disclosure [Line Items]
Maximum total employee and employer contribution percentage	18.00%	18.00%
Maximum total employee and employer contribution amount	$ 20,725	$ 27,230
Required employer contribution percent	1.00%	1.00%
Employer matching percentage for eligible employee contribution	50.00%	50.00%
Maximum employer annual contribution amount per employee	$ 2,283	$ 3,000
Employer matching contributions	$ 4,000,000	$ 5,200,000	$ 3,900,000	$ 5,100,000	$ 3,600,000	$ 4,700,000
Defined Contribution Profit Sharing Plan
Schedule of Defined Contribution Pension And Other Postretirement Plans Disclosure [Line Items]
Employer matching percentage for eligible employee contribution	50.00%	50.00%
Employer matching contributions	$ 5,900,000		$ 5,800,000		$ 5,700,000
Maximum employee contribution percentage of pre-tax compensation	60.00%	60.00%
Percentage of employee contribution with 50% employer matching contribution	6.00%	6.00%
Employer discretionary contribution amount	$ 0

Commitments and Contingencies_2

Commitments and Contingencies (Details) $ in Thousands, $ in Millions	12 Months Ended				32 Months Ended
	Oct. 31, 2019USD ($)government_entity	Oct. 31, 2019CAD ($)government_entity	Oct. 31, 2018USD ($)	Oct. 31, 2017USD ($)	Oct. 31, 2019USD ($)	Oct. 31, 2019CAD ($)	Oct. 31, 2019CAD ($)	Oct. 31, 2018CAD ($)
Operating Leased Assets [Line Items]
Maximum amount of Canadian grant			$ 43,800					$ 57.6
Number of Canadian government entities | government_entity	3	3
Total revenue	$ 3,572,131		3,094,286	$ 2,801,687
Amounts receivable from grant	7,900				$ 7,900		$ 10.4
Leases
2020	28,776				28,776
2021	24,184				24,184
2022	16,767				16,767
2023	13,393				13,393
2024	10,632				10,632
Thereafter	26,110				26,110
Total	119,862				119,862
Operating lease, rental expense
Rental expense	22,000		24,100	30,900
Restructured facilities and unfavorable lease
Operating lease, rental expense
Rental expense	1,300		$ 1,900	$ 2,700
Grant
Operating Leased Assets [Line Items]
Total revenue	$ 9,200	$ 12.3			$ 22,000	$ 28.9

Subsequent Events (Details)

Subsequent Events (Details) - USD ($)	2 Months Ended	12 Months Ended
	Dec. 16, 2019	Oct. 31, 2019	Dec. 13, 2018	Oct. 31, 2018
Subsequent Event [Line Items]
Authorized funds remaining under stock repurchase program			$ 500,000,000
Aggregate shares repurchased (in shares)		3,838,466,000		0
BEAT tax expense		$ 11,300,000
FTC tax benefit		$ 900,000
Subsequent Event
Subsequent Event [Line Items]
Stock repurchased (in shares)	737,474
Stock repurchases	$ 27,400,000
Average price of shares repurchased (in dollars per share)	$ 37.21
Aggregate shares repurchased (in shares)	4,575,940
Authorized funds remaining under stock repurchase program	$ 322,500,000

Uncategorized Items - a20191031

Label	Element	Value
Additional Paid-in Capital [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 832,000