Income Taxes	3 Months Ended
Income Taxes	Jan. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES On December 2, 2019, the U.S. Department of the Treasury released final regulations and proposed regulations under Section 59A of the Internal Revenue Code, the Base Erosion and Anti-Abuse Tax (“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 as part of the Tax Cuts and Jobs Act (the “Tax Act”). Also, on December 2, 2019, the U.S. Department of the Treasury released final regulations that provide additional guidance with respect to the foreign tax credit regime under the Tax Act. The effective tax rate for the three months ended January 30, 2021 was higher than the effective tax rate for the three months ended February 1, 2020, primarily due to the BEAT reduction in fiscal 2020 and the effect of the final regulations released on December 2, 2019. Our future income tax provisions and deferred tax balances may be affected by the amount of pre-tax income, the jurisdictions where it is earned, the existence and utilizability of tax attributes and changes in tax laws and business reorganizations. Ciena continues to monitor these items and will adopt strategies to address their impact as appropriate.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.