Summary of Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2020
Accounting Policies [Abstract]
Description of Business	Selected Terms Used in Notes to the Consolidated Financial Statements ASA – Administrative Service Agreement ASC – Accounting Standards Codification ASU – Accounting Standards Update CPA firm – Certified Public Accounting firm FASB – The Financial Accounting Standards Board GAAP – United States Generally Accepted Accounting Principles LIBOR – London Interbank Offered Rate SEC – United States Securities and Exchange Commission Topic 326 – ASU No. 2016-13, Financial Instruments – Credit Losses CECL – Current expected credit losses Description of Business: CBIZ, Inc. is a diversified services company which, acting through its subsidiaries, has been providing professional business services since 1996, primarily to small and medium-sized businesses, as well as individuals, governmental entities, and not-for-profit enterprises throughout the United States and parts of Canada. CBIZ, Inc. manages and reports its operations along three practice groups; Financial Services, Benefits and Insurance Services and National Practices. A further description of products and services offered by each of the practice groups is provided in Note 13, Segment Disclosures, to the accompanying consolidated financial statements.
Basis of Consolidation	Basis of Consolidation: The accompanying unaudited condensed consolidated financial statements include the operations of CBIZ, Inc. and all of its wholly-owned subsidiaries (“CBIZ”, the “Company”, “we”, “us”, or “our”), after elimination of all intercompany balances and transactions. These condensed consolidated financial statements do not reflect the operations or accounts of variable interest entities as the impact is not material to the financial condition, results of operations or cash flows of CBIZ.
Unaudited Interim Financial Statements	Unaudited Interim Financial Statements: The condensed consolidated financial statements have been prepared in accordance with GAAP and applicable rules and regulations of the SEC regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this quarterly report on Form 10-Q should be read in conjunction with the consolidated financial statements and accompanying notes included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2019. In the opinion of CBIZ management, the accompanying condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial condition, results of operations, and cash flows for the interim periods presented, but are not necessarily indicative of the results of operations to be anticipated for the full year ending December 31, 2020.
Use of Estimates	Use of Estimates: The preparation of condensed consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the amounts reported and disclosed in the financial statements and the accompanying notes. Changes in circumstances could cause actual results to differ materially from these estimates.
Changes in Accounting Policies	Changes in Accounting Policies: Except for the adoption of Topic 326, which required a change in our accounting policy, we have consistently applied the accounting policies for the periods presented as described in Note 1, Basis of Presentation and Significant Accounting Policies, to the consolidated financial statements contained in our Annual Report on Form 10-K for the fiscal year ended December 31, 2019. Effective January 1, 2020, we changed our accounting policy for the valuation of accounts receivable allowances and available-for-sale securities as a result of adopting Topic 326 as described in Note 2, New Accounting Pronouncements.
New Accounting Pronouncements	The FASB ASC is the sole source of authoritative GAAP other than the SEC issued rules and regulations that apply only to SEC registrants. The FASB issues an accounting standard to communicate changes to the FASB codification. We assess and review the impact of all accounting standards. Any accounting standards not listed below were reviewed and determined to be either not applicable or are not expected to have a material impact on the consolidated financial statements of the Company. Accounting Standards Adopted in 2020 Credit Losses: Effective January 1, 2020, we adopted Topic 326, which replaces the incurred loss model with an expected loss model that is referred to as the current expected credit loss model. The CECL model requires the Company to immediately recognize an estimate of credit losses that are expected to occur over the life of financial instruments recorded at amortized cost, including trade receivables. Topic 326 also amends the other-than-temporary impairment model for available-for-sale securities by requiring the recognition of credit loss impairments as an allowance rather than a write-down on available-for-sale securities. The length of time a security has been in an unrealized loss position will no longer impact the determination of whether a credit loss exists. For financial instruments recorded at amortized cost, we did not recognize a cumulative-effect adjustment to retained earnings as the adoption of Topic 326 did not have a material impact on our consolidated financial statements. For available-for-sale securities, the updated guidance was applied prospectively. Fair Value Measurement: On January 1, 2020, we adopted ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement. This standard amends existing fair value measurement disclosure requirements by adding, changing, or removing certain disclosures. The adoption of this guidance did not have a material impact on our consolidated financial statements. Income Taxes: On January 1, 2020, we adopted ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The amendments also improve consistent application of and simplify GAAP for other areas of Topic 740 by clarifying and amending existing guidance. The adoption of this guidance did not have a material impact on our consolidated financial statements. Accounting Standards Issued But Not Yet Adopted Reference Rate Reform: In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides optional expedients and exceptions for applying GAAP to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments in this ASU are effective for all entities through December 31, 2022. We are currently evaluating the effect of this new standard on our consolidated financial statements.

Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2020

Description of Business

Selected Terms Used in Notes to the Consolidated Financial Statements

ASA – Administrative Service Agreement

ASC – Accounting Standards Codification

ASU – Accounting Standards Update

CPA firm – Certified Public Accounting firm

FASB – The Financial Accounting Standards Board

GAAP – United States Generally Accepted Accounting Principles

LIBOR – London Interbank Offered Rate

SEC – United States Securities and Exchange Commission

Topic 326 – ASU No. 2016-13, Financial Instruments – Credit Losses

CECL – Current expected credit losses

Description of Business: CBIZ, Inc. is a diversified services company which, acting through its subsidiaries, has been providing professional business services since 1996, primarily to small and medium-sized businesses, as well as individuals, governmental entities, and not-for-profit enterprises throughout the United States and parts of Canada. CBIZ, Inc. manages and reports its operations along three practice groups; Financial Services, Benefits and Insurance Services and National Practices. A further description of products and services offered by each of the practice groups is provided in Note 13, Segment Disclosures, to the accompanying consolidated financial statements.

Basis of Consolidation

Basis of Consolidation: The accompanying unaudited condensed consolidated financial statements include the operations of CBIZ, Inc. and all of its wholly-owned subsidiaries (“CBIZ”, the “Company”, “we”, “us”, or “our”), after elimination of all intercompany balances and transactions. These condensed consolidated financial statements do not reflect the operations or accounts of variable interest entities as the impact is not material to the financial condition, results of operations or cash flows of CBIZ.

Unaudited Interim Financial Statements

Unaudited Interim Financial Statements: The condensed consolidated financial statements have been prepared in accordance with GAAP and applicable rules and regulations of the SEC regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this quarterly report on Form 10-Q should be read in conjunction with the consolidated financial statements and accompanying notes included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2019.

In the opinion of CBIZ management, the accompanying condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial condition, results of operations, and cash flows for the interim periods presented, but are not necessarily indicative of the results of operations to be anticipated for the full year ending December 31, 2020.

Use of Estimates

Use of Estimates: The preparation of condensed consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the amounts reported and disclosed in the financial statements and the accompanying notes. Changes in circumstances could cause actual results to differ materially from these estimates.

Changes in Accounting Policies

Changes in Accounting Policies: Except for the adoption of Topic 326, which required a change in our accounting policy, we have consistently applied the accounting policies for the periods presented as described in Note 1, Basis of Presentation and Significant Accounting Policies, to the consolidated financial statements contained in our Annual Report on Form 10-K for the fiscal year ended December 31, 2019. Effective January 1, 2020, we changed our accounting policy for the valuation of accounts receivable allowances and available-for-sale securities as a result of adopting Topic 326 as described in Note 2, New Accounting Pronouncements.

New Accounting Pronouncements

The FASB ASC is the sole source of authoritative GAAP other than the SEC issued rules and regulations that apply only to SEC registrants. The FASB issues an accounting standard to communicate changes to the FASB codification. We assess and review the impact of all accounting standards. Any accounting standards not listed below were reviewed and determined to be either not applicable or are not expected to have a material impact on the consolidated financial statements of the Company.

Accounting Standards Adopted in 2020

Credit Losses: Effective January 1, 2020, we adopted Topic 326, which replaces the incurred loss model with an expected loss model that is referred to as the current expected credit loss model. The CECL model requires the Company to immediately recognize an estimate of credit losses that are expected to occur over the life of financial instruments recorded at amortized cost, including trade receivables.

Topic 326 also amends the other-than-temporary impairment model for available-for-sale securities by requiring the recognition of credit loss impairments as an allowance rather than a write-down on available-for-sale securities. The length of time a security has been in an unrealized loss position will no longer impact the determination of whether a credit loss exists.

For financial instruments recorded at amortized cost, we did not recognize a cumulative-effect adjustment to retained earnings as the adoption of Topic 326 did not have a material impact on our consolidated financial statements. For available-for-sale securities, the updated guidance was applied prospectively.

Fair Value Measurement: On January 1, 2020, we adopted ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement. This standard amends existing fair value measurement disclosure requirements by adding, changing, or removing certain disclosures. The adoption of this guidance did not have a material impact on our consolidated financial statements.

Income Taxes: On January 1, 2020, we adopted ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The amendments also improve consistent application of and simplify GAAP for other areas of Topic 740 by clarifying and amending existing guidance. The adoption of this guidance did not have a material impact on our consolidated financial statements.

Accounting Standards Issued But Not Yet Adopted

Reference Rate Reform: In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides optional expedients and exceptions for applying GAAP to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments in this ASU are effective for all entities through December 31, 2022. We are currently evaluating the effect of this new standard on our consolidated financial statements.