SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The member owners' interest in Premier LP is reflected as redeemable limited partners' capital in the Company's accompanying Condensed Consolidated Balance Sheets, and the limited partners' proportionate share of income in Premier LP is reflected within net income attributable to non-controlling interest in Premier LP in the Company's accompanying Condensed Consolidated Statements of Income and within comprehensive income attributable to non-controlling interest in Premier LP in the Company's accompanying Condensed Consolidated Statements of Comprehensive Income.
Principles of Consolidation	Principles of Consolidation The accompanying condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC and in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and include the assets, liabilities, revenues and expenses of all majority-owned subsidiaries over which the Company exercised control and when applicable, entities for which the Company had a controlling financial interest or was the primary beneficiary. All intercompany transactions have been eliminated upon consolidation. Accordingly, certain information and disclosures normally included in annual financial statements have been condensed or omitted. The accompanying condensed consolidated financial statements reflect all adjustments that, in the opinion of management, are necessary for a fair presentation of results of operations and financial condition for the interim periods shown, including normal recurring adjustments. The Company believes that the disclosures are adequate to make the information presented not misleading and should be read in conjunction with the audited consolidated financial statements and related footnotes contained in the 2019 Annual Report.
Variable Interest Entities	Variable Interest Entities Premier LP is a variable interest entity ("VIE") as the limited partners do not have the ability to exercise a substantive removal right with respect to the general partner. The Company, through Premier GP, has the exclusive power and authority to manage the business and affairs of Premier LP, to make all decisions with respect to driving the economic performance of Premier LP, and has both an obligation to absorb losses and a right to receive benefits. As such, the Company is the primary beneficiary of the VIE and consolidates the operations of Premier LP under the Variable Interest Model.
Use of Estimates in the Preparation of Financial Statements	Use of Estimates in the Preparation of Financial Statements The preparation of the Company's condensed consolidated financial statements in accordance with GAAP requires management to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses and related disclosure of contingent assets and liabilities. Significant estimates are evaluated on an ongoing basis, including estimates for net administrative fees revenue, other services and support revenue, contract assets, deferred revenue, contract costs, allowances for doubtful accounts, useful lives of property and equipment, stock-based compensation, payables under tax receivable agreements ("TRA"), deferred tax balances including valuation allowances on deferred tax assets, uncertain tax positions, values of investments not publicly traded, projected future cash flows used in the evaluation of asset impairments, values of put and call rights, values of earn-out liabilities and the allocation of purchase prices. These estimates are based on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates.
Recently Adopted Accounting Standards and Recently Issued Accounting Standards Not Yet Adopted	Recently Adopted Accounting Standards In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which increases transparency and comparability by requiring the recognition of lease assets and lease liabilities on the balance sheet, as well as requiring the disclosure of key information about leasing arrangements. The Company adopted ASU No. 2016-02, Leases (ASC Topic 842), on July 1, 2019 on a modified retrospective basis under the optional transition method. Therefore, comparative periods are presented in accordance with ASC Topic 840. Additionally, the Company elected the package of practical expedients permitted under the transition guidance within the new standard, which allowed us to carry forward (1) historical lease classification and assessments for expired and existing leases, and (2) historical accounting for initial direct costs for existing leases. The Company elected not to recognize any operating lease right-of-use assets or operating lease liabilities for any lease whose term is 12 months or less and does not include a purchase option that the Company is reasonably certain to exercise. The Company also elected to account for the non-lease components within its leases as part of the single lease component to which they are related. Refer to "Adoption of Topic 842" for additional information on the impact of the adoption of ASC 842. Recently Issued Accounting Standards Not Yet Adopted In August 2018, the FASB issued ASU 2018-15, Intangibles- Goodwill and Other- Internal Use Software (Topic 350): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract, which requires customers in a cloud computing arrangement (i.e., hosting arrangement) that is a service contract to follow the internal use software guidance in ASC 350-40 to determine which implementation costs to capitalize as assets or expense as incurred. The standard is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The new standard will be effective for the Company for the fiscal year beginning July 1, 2020. Early adoption is permitted including adoption in any interim periods. The Company does not believe this guidance will have a material impact on its consolidated financial statements and related disclosures. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework- Changes to the Disclosure Requirements for Fair Value Measurement, which improves the effectiveness of fair value measurement disclosures by eliminating, adding and modifying certain disclosure requirements for fair value measurements as part of its disclosure framework project. More specifically, entities will no longer be required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, but public companies will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. The standard is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The new standard will be effective for the Company for the fiscal year beginning July 1, 2020. Early adoption is permitted. The Company is currently evaluating the impact of the adoption of the new standard on its consolidated financial statements and related disclosures. Adoption of Topic 842 As a result of adopting Topic 842, the Company's accounting policies and condensed consolidated financial statements were updated as follows: The Company enters into lease contracts in which the Company is the lessee, substantially all of which are related to office space leased in various buildings used for general corporate purposes. The terms of these non-cancelable operating leases typically require the Company to pay rent and a share of operating expenses and real estate taxes, generally with an inflation-based rent increase included. The Company's lease agreements do not contain any material residual value guarantees or material restrictive covenants. Operating lease right-of-use assets and operating lease liabilities are recognized based on the present value of future minimum lease payments over the lease term beginning at the commencement date. Operating lease right-of-use assets are adjusted for lease incentives, deferred rent and initial direct costs, if incurred. The Company's leases generally do not include an implicit rate; therefore, the Company determined the present value of future minimum lease payments using an incremental borrowing rate based on information available as of July 1, 2019, the transition date. The related lease expense is recognized on a straight-line basis over the lease term.

SIGNIFICANT ACCOUNTING POLICIES (Policies)

3 Months Ended

Sep. 30, 2019

The member owners' interest in Premier LP is reflected as redeemable limited partners' capital in the Company's accompanying Condensed Consolidated Balance Sheets, and the limited partners' proportionate share of income in Premier LP is reflected within net income attributable to non-controlling interest in Premier LP in the Company's accompanying Condensed Consolidated Statements of Income and within comprehensive income attributable to non-controlling interest in Premier LP in the Company's accompanying Condensed Consolidated Statements of Comprehensive Income.

Principles of Consolidation

The accompanying condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC and in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and include the assets, liabilities, revenues and expenses of all majority-owned subsidiaries over which the Company exercised control and when applicable, entities for which the Company had a controlling financial interest or was the primary beneficiary. All intercompany transactions have been eliminated upon consolidation. Accordingly, certain information and disclosures normally included in annual financial statements have been condensed or omitted. The accompanying condensed consolidated financial statements reflect all adjustments that, in the opinion of management, are necessary for a fair presentation of results of operations and financial condition for the interim periods shown, including normal recurring adjustments. The Company believes that the disclosures are adequate to make the information presented not misleading and should be read in conjunction with the audited consolidated financial statements and related footnotes contained in the 2019 Annual Report.

Variable Interest Entities

Premier LP is a variable interest entity ("VIE") as the limited partners do not have the ability to exercise a substantive removal right with respect to the general partner. The Company, through Premier GP, has the exclusive power and authority to manage the

business and affairs of Premier LP, to make all decisions with respect to driving the economic performance of Premier LP, and has both an obligation to absorb losses and a right to receive benefits. As such, the Company is the primary beneficiary of the VIE and consolidates the operations of Premier LP under the Variable Interest Model.

Use of Estimates in the Preparation of Financial Statements

The preparation of the Company's condensed consolidated financial statements in accordance with GAAP requires management to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses and related disclosure of contingent assets and liabilities. Significant estimates are evaluated on an ongoing basis, including estimates for net administrative fees revenue, other services and support revenue, contract assets, deferred revenue, contract costs, allowances for doubtful accounts, useful lives of property and equipment, stock-based compensation, payables under tax receivable agreements ("TRA"), deferred tax balances including valuation allowances on deferred tax assets, uncertain tax positions, values of investments not publicly traded, projected future cash flows used in the evaluation of asset impairments, values of put and call rights, values of earn-out liabilities and the allocation of purchase prices. These estimates are based on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates.

Recently Adopted Accounting Standards and Recently Issued Accounting Standards Not Yet Adopted

Recently Adopted Accounting Standards

In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which increases transparency and comparability by requiring the recognition of lease assets and lease liabilities on the balance sheet, as well as requiring the disclosure of key information about leasing arrangements. The Company adopted ASU No. 2016-02, Leases (ASC Topic 842), on July 1, 2019 on a modified retrospective basis under the optional transition method. Therefore, comparative periods are presented in accordance with ASC Topic 840. Additionally, the Company elected the package of practical expedients permitted under the transition guidance within the new standard, which allowed us to carry forward (1) historical lease classification and assessments for expired and existing leases, and (2) historical accounting for initial direct costs for existing leases. The Company elected not to recognize any operating lease right-of-use assets or operating lease liabilities for any lease whose term is 12 months or less and does not include a purchase option that the Company is reasonably certain to exercise. The Company also elected to account for the non-lease components within its leases as part of the single lease component to which they are related. Refer to "Adoption of Topic 842" for additional information on the impact of the adoption of ASC 842.

Recently Issued Accounting Standards Not Yet Adopted

In August 2018, the FASB issued ASU 2018-15, Intangibles- Goodwill and Other- Internal Use Software (Topic 350): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract, which requires customers in a cloud computing arrangement (i.e., hosting arrangement) that is a service contract to follow the internal use software guidance in ASC 350-40 to determine which implementation costs to capitalize as assets or expense as incurred. The standard is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The new standard will be effective for the Company for the fiscal year beginning July 1, 2020. Early adoption is permitted including adoption in any interim periods. The Company does not believe this guidance will have a material impact on its consolidated financial statements and related disclosures.

In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework- Changes to the Disclosure Requirements for Fair Value Measurement, which improves the effectiveness of fair value measurement disclosures by eliminating, adding and modifying certain disclosure requirements for fair value measurements as part of its disclosure framework project. More specifically, entities will no longer be required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, but public companies will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. The standard is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The new standard will be effective for the Company for the fiscal year beginning July 1, 2020. Early adoption is permitted. The Company is currently evaluating the impact of the adoption of the new standard on its consolidated financial statements and related disclosures.

Adoption of Topic 842

As a result of adopting Topic 842, the Company's accounting policies and condensed consolidated financial statements were updated as follows:

The Company enters into lease contracts in which the Company is the lessee, substantially all of which are related to office space leased in various buildings used for general corporate purposes. The terms of these non-cancelable operating leases typically require the Company to pay rent and a share of operating expenses and real estate taxes, generally with an inflation-based rent increase included. The Company's lease agreements do not contain any material residual value guarantees or material restrictive covenants.

Operating lease right-of-use assets and operating lease liabilities are recognized based on the present value of future minimum lease payments over the lease term beginning at the commencement date. Operating lease right-of-use assets are adjusted for lease incentives, deferred rent and initial direct costs, if incurred. The Company's leases generally do not include an implicit rate; therefore, the Company determined the present value of future minimum lease payments using an incremental borrowing rate based on information available as of July 1, 2019, the transition date. The related lease expense is recognized on a straight-line basis over the lease term.