General (Policies)	6 Months Ended
General (Policies)	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of Lionsgate and all of its majority-owned and controlled subsidiaries. The unaudited condensed consolidated financial statements have been prepared in accordance with United States (“U.S.”) generally accepted accounting principles (“GAAP”) for interim financial information and the instructions to quarterly report on Form 10-Q under the Securities Exchange Act of 1934, as amended, and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of the Company’s management, all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair presentation have been reflected in these unaudited condensed consolidated financial statements. Operating results for the three and six months ended September 30, 2019 are not necessarily indicative of the results that may be expected for the fiscal year ending March 31, 2020. The balance sheet at March 31, 2019 has been derived from the audited financial statements at that date, but does not include all the information and footnotes required by U.S. GAAP for complete financial statements. The accompanying unaudited condensed consolidated financial statements should be read together with the consolidated financial statements and related notes included in the Company's Annual Report on Form 10-K for the fiscal year ended March 31, 2019. Certain amounts presented in prior periods have been reclassified to conform to the current period presentation.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the reporting period. The most significant estimates made by management in the preparation of the financial statements relate to ultimate revenue and costs used for the amortization of investment in films and television programs; estimates of sales returns and other allowances and provisions for doubtful accounts; estimates related to the revenue recognition of sales or usage-based royalties; fair value of equity-based compensation; fair value of assets and liabilities for allocation of the purchase price of companies acquired; income taxes including the assessment of valuation allowances for deferred tax assets; accruals for contingent liabilities; and impairment assessments for investment in films and television programs, property and equipment, equity investments, goodwill and intangible assets. Actual results could differ from such estimates. Change in Estimate The Company monitors its finite-lived intangible assets and changes in the underlying circumstances each reporting period for indicators of possible impairments or a change in the useful life or method of amortization of our finite-lived intangible assets. At June 30, 2019, the Company had $1.5 billion of finite live intangible assets related to customer relationships associated with U.S. MVPDs, including cable operators, satellite television providers and telecommunications companies ("Traditional Affiliate"). At September 30, 2019, the Company updated its undiscounted cash flows analysis for the Starz Traditional Affiliate customer relationships and concluded the undiscounted cash flows continue to exceed its carrying values and therefore the asset was recoverable. Due to changes in the industry related to the migration from linear to OTT and direct-to-consumer consumption, in the quarter ended September 30, 2019, the Company changed its pattern of amortization of its Traditional Affiliate customer relationship intangible assets from the straight line method over 17 years to an accelerated amortization method which reflects amortization in the proportion that current period revenues bear to management’s estimate of future revenue over the remaining estimated useful life of the asset. This method resulted in an increase to amortization expense of $11.3 million during the quarter ended September 30, 2019, with a corresponding reduction of income before income taxes, net income, net income attributable to Lions Gate Entertainment Corp. shareholders, and decreased basic and diluted net income per share by $0.05 per share. There was no tax benefit from the change due to changes in the Company’s valuation allowance on deferred taxes.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Accounting Guidance Adopted in Fiscal 2020 Accounting for Leases: In February 2016, the Financial Accounting Standards Board ("FASB") issued guidance on accounting for leases which requires lessees to recognize most leases on their balance sheets for the rights and obligations created by those leases. The new guidance also requires additional qualitative and quantitative disclosures related to the nature, timing and uncertainty of cash flows arising from leases. The Company adopted the new standard on April 1, 2019 utilizing the modified retrospective approach, and therefore, results for reporting periods beginning after April 1, 2019 are presented under the new guidance, while prior periods have not been adjusted. Additionally, the Company elected to apply practical expedients allowing it to not reassess (1) whether any expired or existing contracts previously assessed as not containing leases are, or contain, leases; (2) the lease classification for any expired or existing leases; and (3) initial direct costs for any existing leases. The Company also elected the practical expedient to not separate lease components from non-lease components for equipment. Instead, for this lease class, each separate lease component and non-lease component is accounted for as a single lease component. Upon adoption of the new guidance, the Company recognized lease liabilities on the Company's consolidated balance sheet for its operating leases of approximately $187.2 million, with a corresponding right-of-use assets balance of $157.4 million, net of existing lease incentives of $29.8 million which were previously classified in accounts payable and accrued liabilities and other liabilities, with no material impact on its consolidated statement of operations. See Note 6 for further information regarding the impact of the adoption of the new guidance on accounting for leases on the Company's financial statements. Accounting Guidance Not Yet Adopted Fair Value Measurement - Changes to Disclosure Requirements: In August 2018, the FASB issued guidance that eliminates, adds and modifies certain disclosure requirements for fair value measurements. This guidance eliminates the requirement that entities disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, but requires public companies to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements, among other changes. This guidance is effective for the Company's fiscal year beginning April 1, 2020, with early adoption permitted. The Company does not expect that the adoption of this guidance will have a material effect on its consolidated financial statements. Improvements to Accounting for Costs of Films and License Agreements for Program Materials: In March 2019, the FASB issued guidance that aligns the accounting for production costs of an episodic television series with the accounting for production costs of films by removing the content distinction for capitalization. Accordingly, the capitalization of production costs for episodic television series is no longer constrained until persuasive evidence of secondary market revenues exists. In addition, under the new guidance, a company will need to determine at the outset of production whether a film or television program is primarily monetized on its own or within a film group. A film group is defined as the lowest level at which identifiable cash flows are largely independent of the cash flows of other films and/or license agreements. In addition, under previous guidance, film and television programs accounted for under the broadcasting accounting standard were carried on the balance sheet at the lower of cost or net realizable value. The new guidance requires that an entity test a film or television program for impairment, when impairment indicators are present, at a film group level when the film or license agreement is predominantly monetized with other films and/or license agreements. The impairment would be measured as the difference between the carrying value of the film group and its fair value rather than its net realizable value. This guidance requires that an entity provide new disclosures about content that is either produced or licensed, and classify cash flows for licensed content as cash flows from operating activities in the statement of cash flows. This guidance is effective for the Company's fiscal year beginning April 1, 2020, with early adoption permitted. The Company is currently evaluating the impact that the adoption of this new guidance will have on its consolidated financial statements. Financial Instruments - Credit Losses: In June 2016, the FASB issued guidance that changes the impairment model for most financial assets and certain other instruments, including trade and other receivables, held-to-maturity debt securities and loans, from the incurred loss methodology under current U.S. GAAP to a new, forward-looking current expected credit loss model that would generally result in the earlier recognition of credit losses. This guidance is effective for the Company’s fiscal year beginning April 1, 2020, with early adoption permitted. Adoption of the standard will be applied using a modified retrospective approach through a cumulative-effect adjustment to retained earnings as of the effective date to align our credit loss methodology with the new standard. The Company is currently evaluating the impact of this standard on its consolidated financial statements, including accounting policies, processes, and systems.
Net Income (Loss) Per Share	Basic net income (loss) per share is calculated based on the weighted average common shares outstanding for the period.Diluted net income (loss) per common share reflects share purchase options, including equity-settled share appreciation rights ("SARs"), restricted share units ("RSUs") and restricted stock using the treasury stock method when dilutive, and any contingently issuable shares when dilutive.