Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2019
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations. Robert Half International Inc. (the “Company”) provides specialized staffing and risk consulting services through such divisions as Accountemps^®, Robert Half^® Finance & Accounting, OfficeTeam^®, Robert Half^® Technology, Robert Half^® Management Resources, Robert Half^® Legal, The Creative Group^®, and Protiviti^®. The Company, through its Accountemps, Robert Half Finance & Accounting, and Robert Half Management Resources divisions, is a specialized provider of temporary, full-time, and senior-level project professionals in the fields of accounting and finance. OfficeTeam specializes in highly skilled temporary administrative support professionals. Robert Half Technology provides project and full-time technology professionals. Robert Half Legal provides temporary, project, and full-time staffing of lawyers, paralegals and legal support personnel. The Creative Group provides creative, digital, marketing, advertising and public relations professionals. Protiviti is a global consulting firm that helps companies solve problems in finance, technology, operations, data, analytics, governance, risk and internal audit, and is a wholly-owned subsidiary of the Company. Revenues are predominantly derived from specialized staffing services. The Company operates in North America, South America, Europe, Asia and Australia. The Company is a Delaware corporation.
Basis of Presentation	Basis of Presentation. The unaudited Condensed Consolidated Financial Statements (“Financial Statements”) of the Company are prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and the rules of the Securities and Exchange Commission (“SEC”). The comparative year-end Condensed Consolidated Statement of Financial Position data presented was derived from audited financial statements. In the opinion of management, all adjustments (consisting of only normal recurring adjustments) necessary for a fair statement of the financial position and results of operations for the periods presented have been included. These Financial Statements should be read in conjunction with the audited Consolidated Financial Statements of the Company for the year ended December 31, 2018, included in its Annual Report on Form 10-K. The results of operations for any interim period are not necessarily indicative of, nor comparable to, the results of operations for a full year.
Principles of Consolidation	Principles of Consolidation. The Financial Statements include the accounts of the Company and its subsidiaries, all of which are wholly-owned. All intercompany balances have been eliminated.
Use of Estimates	Use of Estimates. The preparation of financial statements in conformity with 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 revenues and expenses during the reporting period. As of March 31, 2019, such estimates also include allowances for uncollectible accounts receivable, sales adjustments and allowances, workers’ compensation losses, income and other taxes, and assumptions used in the Company’s goodwill impairment assessment and in the valuation of stock grants subject to market conditions. Actual results and outcomes may differ from management's estimates and assumptions.
Advertising Costs	Advertising Costs. The Company expenses all advertising costs as incurred.
Leases	Leases. The Company determines if a contractual arrangement is a lease at inception. Operating leases are included in operating lease right-of-use (“ROU”) assets, current operating lease liabilities, and noncurrent operating lease liabilities on the Company’s Condensed Consolidated Statement of Financial Position. The Company does not currently have finance leases.
Internal-use Software	Internal-use Software. The Company capitalizes direct costs incurred in the development of internal-use software. Implementation costs incurred in hosting arrangements are capitalized and reported as a component of other current assets. All other internal-use software development costs are capitalized and reported as a component of computer software within property and equipment.
New Accounting Pronouncements	Recently Adopted Accounting Pronouncements Lease Accounting. In February 2016, the Financial Accounting Standards Board (“FASB”) issued authoritative guidance which changes financial reporting as it relates to leasing transactions. Under the new guidance, lessees are required to recognize a lease liability, measured on a discounted basis; and a right-of-use asset, for the lease term. The Company adopted this guidance as of January 1, 2019, using the transition method that allowed it to initially apply the guidance as of January 1, 2019. The Company elected the package of practical expedients available under the new standard, which allowed the Company to forgo a reassessment of (1) whether any expired or existing contracts are or contain leases, (2) the lease classification for any expired or existing leases, and (3) the initial direct costs for any existing leases. The adoption of this guidance had a material impact on the Company’s Condensed Consolidated Statement of Financial Position beginning January 1, 2019. Prior periods were not restated. See Note F for further discussion of leases. Internal-use Software—Cloud Computing. In August 2018, the FASB issued authoritative guidance which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. Entities are required to present the expense related to capitalized implementation costs in the same line item in the statement of operations as the fees associated with the hosting elements of the arrangement and classify the payments for the capitalized implementation costs in the statement of cash flows in the same manner as payments made for fees associated with the hosting element. Entities are also required to present the capitalized implementation costs in the statement of financial position in the same line item that a prepayment of the fees of the associated hosting arrangement would be presented. The new guidance is effective for annual and interim periods beginning after December 15, 2019, although early adoption is permitted. The Company has adopted the new guidance prospectively as of January 1, 2019, and the impact of adoption was not material to its financial statements. Recently Issued Accounting Pronouncements Not Yet Adopted Current Expected Credit Losses Model. In June 2016, the FASB issued authoritative guidance amending how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. The guidance requires the application of a current expected credit loss model, which is a new impairment model based on expected losses. The new guidance is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted for annual reporting periods beginning after December 15, 2018. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements and related disclosures. Simplifying the Test for Goodwill Impairment. In January 2017, the FASB issued authoritative guidance to simplify the goodwill impairment testing process. The new standard eliminates Step 2 of the goodwill impairment test. If a company determines in Step 1 of the goodwill impairment test that the carrying value of goodwill is greater than the fair value, an impairment in that amount should be recorded to the income statement, rather than proceeding to Step 2. The new guidance is effective for the Company for fiscal years beginning after December 15, 2019, although early adoption is permitted. The Company believes the adoption of this guidance will not have a material impact on its financial statements.
Commitments and Contingencies	Legal costs associated with the resolution of claims, lawsuits and other contingencies are expensed as incurred.
Treasury Stock	The repurchased shares are held in treasury and are presented as if constructively retired. Treasury stock is accounted for using the cost method. Repurchase activity for the three months ended March 31, 2019 and 2018, (consisting of stock option exercises and the purchase of shares for the treasury) is presented in the unaudited Condensed Consolidated Statements of Stockholders’ Equity.Repurchases of shares and issuances of cash dividends are applied first to the extent of retained earnings and any remaining amounts are applied to capital surplus.

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2019

Nature of Operations. Robert Half International Inc. (the “Company”) provides specialized staffing and risk consulting services through such divisions as Accountemps^®, Robert Half^® Finance & Accounting, OfficeTeam^®, Robert Half^® Technology, Robert Half^® Management Resources, Robert Half^® Legal, The Creative Group^®, and Protiviti^®. The Company, through its Accountemps, Robert Half Finance & Accounting, and Robert Half Management Resources divisions, is a specialized provider of temporary, full-time, and senior-level project professionals in the fields of accounting and finance. OfficeTeam specializes in highly skilled temporary administrative support professionals. Robert Half Technology provides project and full-time technology professionals. Robert Half Legal provides temporary, project, and full-time staffing of lawyers, paralegals and legal support personnel. The Creative Group provides creative, digital, marketing, advertising and public relations professionals. Protiviti is a global consulting firm that helps companies solve problems in finance, technology, operations, data, analytics, governance, risk and internal audit, and is a wholly-owned subsidiary of the Company. Revenues are predominantly derived from specialized staffing services. The Company operates in North America, South America, Europe, Asia and Australia. The Company is a Delaware corporation.

Basis of Presentation

Basis of Presentation. The unaudited Condensed Consolidated Financial Statements (“Financial Statements”) of the Company are prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and the rules of the Securities and Exchange Commission (“SEC”). The comparative year-end Condensed Consolidated Statement of Financial Position data presented was derived from audited financial statements. In the opinion of management, all adjustments (consisting of only normal recurring adjustments) necessary for a fair statement of the financial position and results of operations for the periods presented have been included. These Financial Statements should be read in conjunction with the audited Consolidated Financial Statements of the Company for the year ended December 31, 2018, included in its Annual Report on Form 10-K. The results of operations for any interim period are not necessarily indicative of, nor comparable to, the results of operations for a full year.

Principles of Consolidation

Principles of Consolidation. The Financial Statements include the accounts of the Company and its subsidiaries, all of which are wholly-owned. All intercompany balances have been eliminated.

Use of Estimates

Use of Estimates. The preparation of financial statements in conformity with 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 revenues and expenses during the reporting period. As of March 31, 2019, such estimates also include allowances for uncollectible accounts receivable, sales adjustments and allowances, workers’ compensation losses, income and other taxes, and assumptions used in the Company’s goodwill impairment assessment and in the valuation of stock grants subject to market conditions. Actual results and outcomes may differ from management's estimates and assumptions.

Advertising Costs

Advertising Costs. The Company expenses all advertising costs as incurred.

Leases

Leases. The Company determines if a contractual arrangement is a lease at inception. Operating leases are included in operating lease right-of-use (“ROU”) assets, current operating lease liabilities, and noncurrent operating lease liabilities on the Company’s Condensed Consolidated Statement of Financial Position. The Company does not currently have finance leases.

Internal-use Software

Internal-use Software. The Company capitalizes direct costs incurred in the development of internal-use software. Implementation costs incurred in hosting arrangements are capitalized and reported as a component of other current assets. All other internal-use software development costs are capitalized and reported as a component of computer software within property and equipment.

New Accounting Pronouncements

Recently Adopted Accounting Pronouncements

Lease Accounting. In February 2016, the Financial Accounting Standards Board (“FASB”) issued authoritative guidance which changes financial reporting as it relates to leasing transactions. Under the new guidance, lessees are required to recognize a lease liability, measured on a discounted basis; and a right-of-use asset, for the lease term. The Company adopted this guidance as of January 1, 2019, using the transition method that allowed it to initially apply the guidance as of January 1, 2019. The Company elected the package of practical expedients available under the new standard, which allowed the Company to forgo a reassessment of (1) whether any expired or existing contracts are or contain leases, (2) the lease classification for any expired or existing leases, and (3) the initial direct costs for any existing leases. The adoption of this guidance had a material impact on the Company’s Condensed Consolidated Statement of Financial Position beginning January 1, 2019. Prior periods were not restated. See Note F for further discussion of leases.

Internal-use Software—Cloud Computing. In August 2018, the FASB issued authoritative guidance which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. Entities are required to present the expense related to capitalized implementation costs in the same line item in the statement of operations as the fees associated with the hosting elements of the arrangement and classify the payments for the capitalized implementation costs in the statement of cash flows in the same manner as payments made for fees associated with the hosting element. Entities are also required to present the capitalized implementation costs in the statement of financial position in the same line item that a prepayment of the fees of the associated hosting arrangement would be presented. The new guidance is effective for annual and interim periods beginning after December 15, 2019, although early adoption is permitted. The Company has adopted the new guidance prospectively as of January 1, 2019, and the impact of adoption was not material to its financial statements.

Recently Issued Accounting Pronouncements Not Yet Adopted

Current Expected Credit Losses Model. In June 2016, the FASB issued authoritative guidance amending how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. The guidance requires the application of a current expected credit loss model, which is a new impairment model based on expected losses. The new guidance is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted for annual reporting periods beginning after December 15, 2018. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements and related disclosures.

Simplifying the Test for Goodwill Impairment. In January 2017, the FASB issued authoritative guidance to simplify the goodwill impairment testing process. The new standard eliminates Step 2 of the goodwill impairment test. If a company determines in Step 1 of the goodwill impairment test that the carrying value of goodwill is greater than the fair value, an impairment in that amount should be recorded to the income statement, rather than proceeding to Step 2. The new guidance is effective for the Company for fiscal years beginning after December 15, 2019, although early adoption is permitted. The Company believes the adoption of this guidance will not have a material impact on its financial statements.

Commitments and Contingencies

Legal costs associated with the resolution of claims, lawsuits and other contingencies are expensed as incurred.

Treasury Stock

The repurchased shares are held in treasury and are presented as if constructively retired. Treasury stock is accounted for using the cost method. Repurchase activity for the three months ended March 31, 2019 and 2018, (consisting of stock option exercises and the purchase of shares for the treasury) is presented in the unaudited Condensed Consolidated Statements of Stockholders’ Equity.Repurchases of shares and issuances of cash dividends are applied first to the extent of retained earnings and any remaining amounts are applied to capital surplus.