Basis of Presentation and Recently Issued Accounting Pronouncements Basis of Presentation and Recently Issued Accounting Pronouncements (Notes)	3 Months Ended
Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Significant Accounting Policies [Text Block]	Basis of Presentation and Recently Issued Accounting Pronouncements Basis of Presentation The Company prepares its condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP"). In the opinion of management, the condensed consolidated financial statements reflect all adjustments of a normal recurring nature that are necessary for a fair statement of the results for the interim periods presented. Interim results are not necessarily indicative of results for a full year. The year-end condensed consolidated balance sheet data was derived from audited financial statements, however, these condensed consolidated financial statements do not include all of the disclosures required for complete annual financial statements and, accordingly, certain information, footnotes and disclosures normally included in annual financial statements, prepared in accordance with U.S. GAAP, have been condensed or omitted in accordance with Securities and Exchange Commission ("SEC") rules and regulations. The Company believes that the disclosures made are adequate to make the information not misleading. Accordingly, the condensed consolidated financial statements should be read in conjunction with the Company's audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018, filed with the SEC on February 28, 2019. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and footnotes. Actual results could differ materially from those estimates. Significant estimates inherent in the preparation of the condensed consolidated financial statements include receivables allowances, depreciation of rental equipment, the recoverability of long-lived assets, useful lives and impairment of long-lived tangible and intangible assets including goodwill and trade name, pension and postretirement benefits, valuation of stock-based compensation, reserves for litigation and other contingencies and accounting for income taxes, among others. Principles of Consolidation The condensed consolidated financial statements include the accounts of Herc Holdings and its wholly owned subsidiaries. In the event that the Company is a primary beneficiary of a variable interest entity, the assets, liabilities and results of operations of the variable interest entity are included in the Company's condensed consolidated financial statements. The Company accounts for its investments in joint ventures using the equity method when it has significant influence but not control and is not the primary beneficiary. All significant intercompany transactions have been eliminated in consolidation. Recently Issued Accounting Pronouncements Adopted Leases In February 2016, the Financial Accounting Standards Board ("FASB") issued new leasing guidance ("Topic 842") that replaced the existing lease guidance ("Topic 840"). Topic 842 established a right-of-use (“ROU”) model that requires a lessee to record a ROU asset and lease liability on the balance sheet for all leases with terms longer than 12 months. Leases are classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. This guidance also expanded the requirements for lessees to record leases embedded in other arrangements and the required quantitative and qualitative disclosures surrounding leases. Accounting guidance for lessors is largely unchanged. The Company adopted Topic 842 on its effective date of January 1, 2019 using a modified retrospective transition approach; as such, Topic 842 will not be applied to periods prior and the adoption had no impact on the Company's previously reported results. The Company recognized operating lease liabilities of $165.3 million upon adoption, with corresponding ROU assets on its balance sheet. This guidance did not have a material impact on its results of operations and cash flows. The Company took advantage of the transition package of practical expedients permitted within Topic 842 which allowed the Company not to reassess (i) whether any expired or existing lease contracts are or contain leases, (ii) the historical lease classification for any expired or existing leases and (iii) initial direct costs for any existing leases. The Company has elected not to combine lease and non-lease components for its real estate leases and allocates the consideration in the contract based on relative stand-alone prices of each component. Additionally, as discussed in Note 3, "Revenue Recognition," most of the Company's equipment rental revenues were accounted for under Topic 840 until the adoption of Topic 842. The Company recognized a cumulative-effect adjustment to the opening balance of retained earnings related to these items of $7.6 million. The adoption of Topic 842 will not have a significant impact on future revenues. The Company also elected the practical expedient that allows lessors to treat the lease and non-lease components as a single lease component where the non-lease component would otherwise be accounted for under Accounting Standards Codification ("ASC") Topic 606, Revenue from Contracts with Customers (“Topic 606”), as timing and pattern of transfer for the lease component and non-lease components associated with that lease component are the same. Not Yet Adopted Compensation - Retirement Benefits In August 2018, the FASB issued guidance that adds, removes, and modifies disclosure requirements related to defined benefit pension and other postretirement plans in order to improve the disclosure effectiveness. The guidance is effective for fiscal years beginning after December 15, 2020 and should be applied on a retrospective basis to all periods presented, with early adoption permitted. The Company expects to adopt the new and modified disclosures requirements of this new guidance on its effective date. Fair Value Measurement In August 2018, the FASB issued new guidance that modifies disclosure requirements on fair value measurements, removing and modifying certain disclosures, while adding other disclosures. The guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted. The Company expects to adopt the new guidance on its effective date and adoption is not expected to have a material impact on the Company's financial statement disclosures.

Basis of Presentation and Recently Issued Accounting Pronouncements

Basis of Presentation

The Company prepares its condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP"). In the opinion of management, the condensed consolidated financial statements reflect all adjustments of a normal recurring nature that are necessary for a fair statement of the results for the interim periods presented. Interim results are not necessarily indicative of results for a full year. The year-end condensed consolidated balance sheet data was derived from audited financial statements, however, these condensed consolidated financial statements do not include all of the disclosures required for complete annual financial statements and, accordingly, certain information, footnotes and disclosures normally included in annual financial statements, prepared in accordance with U.S. GAAP, have been condensed or omitted in accordance with Securities and Exchange Commission ("SEC") rules and regulations. The Company believes that the disclosures made are adequate to make the information not misleading. Accordingly, the condensed consolidated financial statements should be read in conjunction with the Company's audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018, filed with the SEC on February 28, 2019.

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and footnotes. Actual results could differ materially from those estimates.

Significant estimates inherent in the preparation of the condensed consolidated financial statements include receivables allowances, depreciation of rental equipment, the recoverability of long-lived assets, useful lives and impairment of long-lived tangible and intangible assets including goodwill and trade name, pension and postretirement benefits, valuation of stock-based compensation, reserves for litigation and other contingencies and accounting for income taxes, among others.

Principles of Consolidation

The condensed consolidated financial statements include the accounts of Herc Holdings and its wholly owned subsidiaries. In the event that the Company is a primary beneficiary of a variable interest entity, the assets, liabilities and results of operations of the variable interest entity are included in the Company's condensed consolidated financial statements. The Company accounts for its investments in joint ventures using the equity method when it has significant influence but not control and is not the primary beneficiary. All significant intercompany transactions have been eliminated in consolidation.

Recently Issued Accounting Pronouncements

Adopted

Leases

In February 2016, the Financial Accounting Standards Board ("FASB") issued new leasing guidance ("Topic 842") that replaced the existing lease guidance ("Topic 840"). Topic 842 established a right-of-use (“ROU”) model that requires a lessee to record a ROU asset and lease liability on the balance sheet for all leases with terms longer than 12 months. Leases are classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. This guidance also expanded the requirements for lessees to record leases embedded in other arrangements and the required quantitative and qualitative disclosures surrounding leases. Accounting guidance for lessors is largely unchanged.

The Company adopted Topic 842 on its effective date of January 1, 2019 using a modified retrospective transition approach; as such, Topic 842 will not be applied to periods prior and the adoption had no impact on the Company's previously reported results. The Company recognized operating lease liabilities of $165.3 million upon adoption, with corresponding ROU assets on its balance sheet. This guidance did not have a material impact on its results of operations and cash flows.

The Company took advantage of the transition package of practical expedients permitted within Topic 842 which allowed the Company not to reassess (i) whether any expired or existing lease contracts are or contain leases, (ii) the historical lease classification for any expired or existing leases and (iii) initial direct costs for any existing leases. The Company has elected not to combine lease and non-lease components for its real estate leases and allocates the consideration in the contract based on relative stand-alone prices of each component.

Additionally, as discussed in Note 3, "Revenue Recognition," most of the Company's equipment rental revenues were accounted for under Topic 840 until the adoption of Topic 842. The Company recognized a cumulative-effect adjustment to the opening balance of retained earnings related to these items of $7.6 million. The adoption of Topic 842 will not have a significant impact on future revenues. The Company also elected the practical expedient that allows lessors to treat the lease and non-lease components as a single lease component where the non-lease component would otherwise be accounted for under Accounting Standards Codification ("ASC") Topic 606, Revenue from Contracts with Customers (“Topic 606”), as timing and pattern of transfer for the lease component and non-lease components associated with that lease component are the same.

Not Yet Adopted

Compensation - Retirement Benefits

In August 2018, the FASB issued guidance that adds, removes, and modifies disclosure requirements related to defined benefit pension and other postretirement plans in order to improve the disclosure effectiveness. The guidance is effective for fiscal years beginning after December 15, 2020 and should be applied on a retrospective basis to all periods presented, with early adoption permitted. The Company expects to adopt the new and modified disclosures requirements of this new guidance on its effective date.

Fair Value Measurement

In August 2018, the FASB issued new guidance that modifies disclosure requirements on fair value measurements, removing and modifying certain disclosures, while adding other disclosures. The guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted. The Company expects to adopt the new guidance on its effective date and adoption is not expected to have a material impact on the Company's financial statement disclosures.