Commitments and Contingencies	9 Months Ended
Sep. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 8. Commitments and Contingencies Letters of Credit and Guarantees We provide letters of credit to landlords (lessors) of our leased premises in lieu of cash security deposits, which totaled $0.9 million and $2.3 million at September 30, 2018 and December 31, 2017, respectively. In addition, we provide license bonds to various state agencies to meet certain licensing requirements. The amount of license bonds outstanding was $2.9 million and $2.5 million at September 30, 2018 and December 31, 2017, respectively. Legal Proceedings In 2010, CBIZ, Inc. and its subsidiary, CBIZ MHM, LLC (fka CBIZ Accounting, Tax & Advisory Services, LLC) (the “CBIZ Parties”), were named as defendants in lawsuits filed in the U.S. District Court for the District of Arizona and the Superior Court for Maricopa County, Arizona. The federal court case is captioned Robert Facciola, et al v. Greenberg Traurig LLP, et al, and the state court cases are captioned Victims Recovery, LLC v. Greenberg Traurig LLP, et al, Roger Ashkenazi, et al v. Greenberg Traurig LLP, et al, Mary Marsh, et al v. Greenberg Traurig LLP, et al; and ML Liquidating Trust v. Mayer Hoffman McCann, P.C. (“Mayer Hoffman”), et al. Prior to these suits CBIZ MHM, LLC was named as a defendant in Jeffrey C. Stone v. Greenberg Traurig LLP, et al. These lawsuits arose out of the bankruptcy of Mortgages Ltd., a mortgage lender to developers in the Phoenix, Arizona area. Various other professional firms and individuals not related to the Company were also named defendants in these lawsuits. The lawsuits asserted claims for, among others things, violations of the Arizona Securities Act, common law fraud, and negligent misrepresentation, and sought to hold the CBIZ Parties vicariously liable for Mayer Hoffman’s conduct as Mortgage Ltd.’s auditor, as either a statutory control person under the Arizona Securities Act or a joint venturer under Arizona common law. With the exception of claims being pursued by two plaintiffs from the Ashkenazi lawsuit (“Baldino Group”), all other related matters have been dismissed or settled without payment by the CBIZ Parties. The Baldino Group’s claims, which allege damages of approximately $16 million, are currently stayed as to the CBIZ Parties and Mayer Hoffman, and no trial date has been set. On September 16, 2016, CBIZ, Inc. and its subsidiary CBIZ Benefits & Insurance Services, Inc. (“CBIZ Benefits”) were named as defendants in a lawsuit filed in the U.S. District Court for the Western District of Pennsylvania. The federal court case is brought by UPMC, d/b/a University of Pittsburgh Medical Center, and a health system it acquired, UPMC Altoona (formerly, Altoona Regional Health System). The lawsuit asserts professional negligence, breach of contract, and negligent misrepresentation claims against CBIZ, CBIZ Benefits and a former employee of CBIZ Benefits in connection with actuarial services provided by CBIZ Benefits to Altoona Regional Health System. The complaint seeks damages in an amount of no less than $142 million. We cannot predict the outcome of the above matters or estimate the possible loss or range of possible loss, if any. Although the proceedings are subject to uncertainties inherent in the litigation process and the ultimate disposition of these proceedings is not presently determinable, we intend to vigorously defend these cases. In addition to those items disclosed above, we are, from time to time, subject to claims and suits arising in the ordinary course of business.

Note 8. Commitments and Contingencies

Letters of Credit and Guarantees

We provide letters of credit to landlords (lessors) of our leased premises in lieu of cash security deposits, which totaled $0.9 million and $2.3 million at September 30, 2018 and December 31, 2017, respectively. In addition, we provide license bonds to various state agencies to meet certain licensing requirements. The amount of license bonds outstanding was $2.9 million and $2.5 million at September 30, 2018 and December 31, 2017, respectively.

Legal Proceedings

In 2010, CBIZ, Inc. and its subsidiary, CBIZ MHM, LLC (fka CBIZ Accounting, Tax & Advisory Services, LLC) (the “CBIZ Parties”), were named as defendants in lawsuits filed in the U.S. District Court for the District of Arizona and the Superior Court for Maricopa County, Arizona. The federal court case is captioned Robert Facciola, et al v. Greenberg Traurig LLP, et al, and the state court cases are captioned Victims Recovery, LLC v. Greenberg Traurig LLP, et al, Roger Ashkenazi, et al v. Greenberg Traurig LLP, et al, Mary Marsh, et al v. Greenberg Traurig LLP, et al; and ML Liquidating Trust v. Mayer Hoffman McCann, P.C. (“Mayer Hoffman”), et al. Prior to these suits CBIZ MHM, LLC was named as a defendant in Jeffrey C. Stone v. Greenberg Traurig LLP, et al.

These lawsuits arose out of the bankruptcy of Mortgages Ltd., a mortgage lender to developers in the Phoenix, Arizona area. Various other professional firms and individuals not related to the Company were also named defendants in these lawsuits. The lawsuits asserted claims for, among others things, violations of the Arizona Securities Act, common law fraud, and negligent misrepresentation, and sought to hold the CBIZ Parties vicariously liable for Mayer Hoffman’s conduct as Mortgage Ltd.’s auditor, as either a statutory control person under the Arizona Securities Act or a joint venturer under Arizona common law.

With the exception of claims being pursued by two plaintiffs from the Ashkenazi lawsuit (“Baldino Group”), all other related matters have been dismissed or settled without payment by the CBIZ Parties. The Baldino Group’s claims, which allege damages of approximately $16 million, are currently stayed as to the CBIZ Parties and Mayer Hoffman, and no trial date has been set.

On September 16, 2016, CBIZ, Inc. and its subsidiary CBIZ Benefits & Insurance Services, Inc. (“CBIZ Benefits”) were named as defendants in a lawsuit filed in the U.S. District Court for the Western District of Pennsylvania. The federal court case is brought by UPMC, d/b/a University of Pittsburgh Medical Center, and a health system it acquired, UPMC Altoona (formerly, Altoona Regional Health System). The lawsuit asserts professional negligence, breach of contract, and negligent misrepresentation claims against CBIZ, CBIZ Benefits and a former employee of CBIZ Benefits in connection with actuarial services provided by CBIZ Benefits to Altoona Regional Health System. The complaint seeks damages in an amount of no less than $142 million.

We cannot predict the outcome of the above matters or estimate the possible loss or range of possible loss, if any. Although the proceedings are subject to uncertainties inherent in the litigation process and the ultimate disposition of these proceedings is not presently determinable, we intend to vigorously defend these cases.

In addition to those items disclosed above, we are, from time to time, subject to claims and suits arising in the ordinary course of business.