Description of Business and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2014
Basis of Presentation	Basis of Presentation The accompanying unaudited consolidated financial statements and footnotes thereto of the Company and its wholly owned subsidiaries have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and applicable rules and regulations of the Securities and Exchange Commission (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. Therefore, these consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in the Company’s prospectus filed with the SEC pursuant to Rule 424(b) under the Securities Act of 1933 with the SEC on March 27, 2014. There have been no changes to the Company’s significant accounting policies described in the prospectus that have had a material impact on our consolidated financial statements and related notes. All intercompany accounts and transactions have been eliminated in consolidation. The accompanying unaudited consolidated balance sheets present the current assets and current liabilities directly related to the processing of human resources transactions as WSE-related assets and WSE-related liabilities, respectively. WSE-related assets comprise cash and investments restricted for current workers compensation claim payments, payroll funds collected, accounts receivable, unbilled service revenues, and refundable or prepaid amounts related to the Company-sponsored workers compensation and health plan programs. WSE-related liabilities comprise customer prepayments, wages and payroll taxes accrued and payable, and liabilities related to the Company-sponsored workers compensation and health plan programs resulting from workers compensation case reserves, premium amounts due to providers for enrolled employees, and workers compensation and health reserves that are expected to be disbursed within the next 12 months. The unaudited interim financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, necessary for fair presentation. The results of the three months ended March 31, 2014 are not necessarily indicative of the results to be expected for the year ending December 31, 2014.
Use of Estimates	Seasonality Historically, the Company has experienced its highest monthly addition of WSEs, as well as its highest monthly levels of client attrition, in the month of January, primarily because clients that change their payroll service providers tend to do so at the beginning of a calendar year. In addition, the Company experiences higher levels of client attrition in connection with renewals of the health insurance it provides for its WSEs, in the event that such renewals result in increased premiums that it passes on to its clients. The Company has also historically experienced higher insurance claim volumes in the second and third quarters of a fiscal year than in the first and fourth quarters of a fiscal year, as WSEs typically access their health care providers more often in the second and third quarters of a fiscal year, which has negatively impacted the Company’s insurance costs in these quarters. These historical trends may change, and other seasonal trends may develop that make it more difficult for the Company to manage its business. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect certain reported amounts and disclosures. These estimates include, but are not limited to, allowances for accounts receivable, workers compensation related assets and liabilities, health plan assets and liabilities, recoverability of goodwill and other intangible assets, income taxes, stock-based compensation and other contingent liabilities. Such estimates are based on historical experience and on various other assumptions that Company management believes to be reasonable under the circumstances. Actual results could differ from those estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In July 2013, the Financial Accounting Standards Board (FASB) issued ASU 2013-11—Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists, which requires that an unrecognized tax benefit, or portion of an unrecognized tax benefit, be presented as a reduction of a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. If an applicable deferred tax asset is not available or a company does not expect to use the applicable deferred tax asset, the unrecognized tax benefit should be presented as a liability in the financial statements and should not be combined with an unrelated deferred tax asset. ASU 2013-11 is effective for annual reporting periods, and interim periods within those years, beginning after December 15, 2013. The amendments should be applied prospectively to all unrecognized tax benefits that exist at the effective date, however retrospective application is permitted. The Company adopted this guidance in 2014. The adoption of ASU 2013-11 did not have a material impact on the Company’s consolidated financial statements.