Organization and Basis of Presentation	3 Months Ended
Mar. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Basis of Presentation	NOTE 1: ORGANIZATION AND BASIS OF PRESENTATION Organization. NovoCure Limited (including its consolidated subsidiaries, the “Company”) was incorporated in the Bailiwick of Jersey and is principally engaged in the development, manufacture and commercialization of Optune for the treatment of solid tumors. The Company has regulatory approvals and clearances in certain countries for Optune to treat adult patients with glioblastoma (“GBM”). Financial statement preparation. The accompanying consolidated financial statements include the accounts of the Company and intercompany accounts and transactions have been eliminated. In the opinion of the Company’s management, the consolidated financial statements reflect all adjustments, which are normal and recurring in nature, necessary for fair financial statement presentation for the periods presented. The preparation of these consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in these consolidated financial statements and accompanying notes. Actual results could differ materially from those estimates. These consolidated financial statements and accompanying notes should be read in conjunction with the Company’s annual consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018 (the “2018 10-K”) filed with the Securities and Exchange Commission on February 28, 2019. The significant accounting policies applied in the audited annual consolidated financial statements of the Company as disclosed in the 2018 10-K are applied consistently in these unaudited interim consolidated financial statements, except as noted below: Recently Adopted Accounting Pronouncements. In 2016, the FASB issued ASU No. 2016-02, "Leases (Topic 842)", which amends the existing standards for lease accounting, requiring lessees to recognize most leases on their balance sheets. The new standard establishes a right-of-use model that requires a lessee to recognize a right-of-use asset and lease liability on the balance sheet for all leases with a term longer than 12 months. Leases will be classified as finance or operating. The standard is effective for interim and annual reporting periods beginning after December 15, 2018. The provisions of ASU 2016-02 are to be applied using a modified retrospective approach. In July 2018, the FASB issued ASU No. 2018-11, "Targeted Improvements - Leases (Topic 842)." This update provides an additional (and optional) transition method to adopt the new leases standard. Under this method, an entity initially applies the new leases standard at the adoption date and recognizes a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Consequently, the prior comparative period’s financials will remain the same as those previously presented. The Company adopted the new standard as of January 1, 2019 and it has also elected to adopt the package of practical expedients permitted in ASC 842. The consolidated financial statements for the three months ended March 31, 2019 are presented under the new standard, while comparative year and periods presented are not adjusted and continue to be reported in accordance with Topic 840, Leases.

Organization and Basis of Presentation

3 Months Ended

Mar. 31, 2019

Organization Consolidation And Presentation Of Financial Statements [Abstract]

NOTE 1: ORGANIZATION AND BASIS OF PRESENTATION

Organization. NovoCure Limited (including its consolidated subsidiaries, the “Company”) was incorporated in the Bailiwick of Jersey and is principally engaged in the development, manufacture and commercialization of Optune for the treatment of solid tumors. The Company has regulatory approvals and clearances in certain countries for Optune to treat adult patients with glioblastoma (“GBM”).

Financial statement preparation. The accompanying consolidated financial statements include the accounts of the Company and intercompany accounts and transactions have been eliminated. In the opinion of the Company’s management, the consolidated financial statements reflect all adjustments, which are normal and recurring in nature, necessary for fair financial statement presentation for the periods presented. The preparation of these consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in these consolidated financial statements and accompanying notes. Actual results could differ materially from those estimates. These consolidated financial statements and accompanying notes should be read in conjunction with the Company’s annual consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018 (the “2018 10-K”) filed with the Securities and Exchange Commission on February 28, 2019.

The significant accounting policies applied in the audited annual consolidated financial statements of the Company as disclosed in the 2018 10-K are applied consistently in these unaudited interim consolidated financial statements, except as noted below:

Recently Adopted Accounting Pronouncements. In 2016, the FASB issued ASU No. 2016-02, "Leases (Topic 842)", which amends the existing standards for lease accounting, requiring lessees to recognize most leases on their balance sheets. The new standard establishes a right-of-use model that requires a lessee to recognize a right-of-use asset and lease liability on the balance sheet for all leases with a term longer than 12 months. Leases will be classified as finance or operating. The standard is effective for interim and annual reporting periods beginning after December 15, 2018.

The provisions of ASU 2016-02 are to be applied using a modified retrospective approach. In July 2018, the FASB issued ASU No. 2018-11, "Targeted Improvements - Leases (Topic 842)." This update provides an additional (and optional) transition method to adopt the new leases standard. Under this method, an entity initially applies the new leases standard at the adoption date and recognizes a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Consequently, the prior comparative period’s financials will remain the same as those previously presented. The Company adopted the new standard as of January 1, 2019 and it has also elected to adopt the package of practical expedients permitted in ASC 842.

The consolidated financial statements for the three months ended March 31, 2019 are presented under the new standard, while comparative year and periods presented are not adjusted and continue to be reported in accordance with Topic 840, Leases.