Summary of Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited interim consolidated financial statements include the financial results of Software and its wholly owned subsidiaries and have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the SEC regarding interim financial statements that permit reduced disclosure for interim periods. Intercompany balances and transactions have been eliminated in consolidation. In the opinion of management, the accompanying unaudited consolidated financial statements include all adjustments necessary for the fair presentation of the Company’s results for the interim periods presented. These unaudited consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and related notes presented in the Form 10-K. The results of operations for the three and six months ended June 30, 2024 are not necessarily indicative of the results expected for the full year.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates include income taxes, loss contingencies, the useful life of property and equipment and intangible assets, the life of our client relationships, the fair value of our stock-based awards and the fair value of our financial instruments, intangible assets and goodwill. These estimates are based on historical experience, where applicable, and other assumptions that management believes are reasonable under the circumstances. Actual results could materially differ from these estimates.
Seasonality	Seasonality Our revenues are seasonal in nature. Generally, we expect our first and fourth quarter recurring revenues to be higher than other quarters during the year because payroll tax filing forms and Affordable Care Act forms are typically processed in the first quarter, and unscheduled payroll runs (such as bonuses) for our clients are typically concentrated in the fourth quarter. In addition, these seasonal fluctuations in recurring revenues impact operating income.
Funds Held for Clients and Client Funds Obligation	Funds Held for Clients and Client Funds Obligation As part of our payroll and tax filing services, we (i) collect client funds to satisfy their respective payroll and employment tax obligations, (ii) remit such funds to accounts designated by our clients and to the appropriate taxing authorities, as applicable, and (iii) manage client tax filings and any related correspondence with taxing authorities. Amounts collected from clients for their employment taxes are invested by us, and we earn interest on these funds during the interval between receipt and disbursement. These investments are shown in our consolidated balance sheets as funds held for clients, and the associated liability for the tax filings is shown as client funds obligation. The liability is recorded in the accompanying consolidated balance sheets at the time we obtain the funds from clients. The client funds obligation represents liabilities that will be repaid within one year of the consolidated balance sheet date. We typically invest funds held for clients in money market funds, demand deposit accounts, certificates of deposit, commercial paper and U.S. treasury securities. Short-term investments in instruments with an original maturity of less than three months are classified as cash and cash equivalents within funds held for clients in the consolidated balance sheets. Investments in instruments with an original maturity greater than three months are classified as available-for-sale securities and are also included within funds held for clients in the consolidated balance sheets. These available-for-sale securities are recorded at fair value, with the difference between the amortized cost and fair value of these available-for-sale securities recorded as unrealized net gains (losses) on available-for-sale securities, and are included within comprehensive earnings (loss) in the consolidated statements of comprehensive income. Funds held for clients are classified as a current asset in the consolidated balance sheets because the funds are held solely to satisfy the client funds obligation. Additionally, the funds held for clients is classified as restricted cash and restricted cash equivalents and presented within the reconciliation of cash, cash equivalents, restricted cash and restricted cash equivalents on the consolidated statements of cash flows. The Company reports the cash flows related to the purchases of investments from funds held for clients and related to the proceeds from the maturities of investments from funds held for clients on a gross basis in the cash flows from investing activities section of the consolidated statements of cash flows. Additionally, the Company reports cash flows related to cash received from and paid on behalf of clients on a net basis within the net change in client funds obligation in the cash flows from financing activities section of the consolidated statements of cash flows.
Stock Repurchase Plan	Stock Repurchase Plan In May 2016, our Board of Directors authorized a stock repurchase plan allowing for the repurchase of shares of our common stock in open market transactions at prevailing market prices, in privately negotiated transactions or by other means in accordance with federal securities laws, including Rule 10b5-1 programs. Since the initial authorization of the stock repurchase plan, our Board of Directors has amended and extended and authorized new stock repurchase plans from time to time. In August 2022, our Board of Directors authorized the repurchase of up to $1.1 billion of our common stock over a two-year period expiring on August 15, 2024. As of June 30, 2024, there was $705.9 million available for repurchases under our stock repurchase plan. On July 29, 2024, our Board of Directors increased and extended the stock repurchase plan. See Note 14 for additional information. Our stock repurchase plan may be suspended or discontinued at any time. The actual timing, number and value of shares repurchased depends on a number of factors, including the market price of our common stock, general market and economic conditions, shares withheld for taxes associated with the vesting of equity incentive awards and other corporate considerations. During the six months ended June 30, 2024, we repurchased an aggregate of 589,424 shares of our common stock at an average cost of $158.06 per share, including 68,482 shares withheld to satisfy tax withholding obligations for certain employees upon the vesting of equity incentive awards.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”). ASU 2023-07 requires incremental disclosures in annual and interim periods related reportable segments, and segment expenses but does not change the definition of a segment, the method for determining segments, or the criteria for aggregating operating segments into reportable segments. This ASU is effective for fiscal years beginning after December 15, 2023 and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. We are assessing the impact of this ASU on our consolidated financial statements and disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. ASU 2023-09 requires disaggregated information about a reporting entity’s effective tax rate reconciliation, as well as information on income taxes paid. This ASU is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. We are assessing the impact of this ASU on our consolidated financial statements and disclosures.

Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2024

The accompanying unaudited interim consolidated financial statements include the financial results of Software and its wholly owned subsidiaries and have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the SEC regarding interim financial statements that permit reduced disclosure for interim periods. Intercompany balances and transactions have been eliminated in consolidation. In the opinion of management, the accompanying unaudited consolidated financial statements include all adjustments necessary for the fair presentation of the Company’s results for the interim periods presented. These unaudited consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and related notes presented in the Form 10-K. The results of operations for the three and six months ended June 30, 2024 are not necessarily indicative of the results expected for the full year.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates include income taxes, loss contingencies, the useful life of property and equipment and intangible assets, the life of our client relationships, the fair value of our stock-based awards and the fair value of our financial instruments, intangible assets and goodwill. These estimates are based on historical experience, where applicable, and other assumptions that management believes are reasonable under the circumstances. Actual results could materially differ from these estimates.

Seasonality

Our revenues are seasonal in nature. Generally, we expect our first and fourth quarter recurring revenues to be higher than other quarters during the year because payroll tax filing forms and Affordable Care Act forms are typically processed in the first quarter, and unscheduled payroll runs (such as bonuses) for our clients are typically concentrated in the fourth quarter. In addition, these seasonal fluctuations in recurring revenues impact operating income.

Funds Held for Clients and Client Funds Obligation

As part of our payroll and tax filing services, we (i) collect client funds to satisfy their respective payroll and employment tax obligations, (ii) remit such funds to accounts designated by our clients and to the appropriate taxing authorities, as applicable, and (iii) manage client tax filings and any related correspondence with taxing authorities. Amounts collected from clients for their employment taxes are invested by us, and we earn interest on these funds during the interval between receipt and disbursement.

These investments are shown in our consolidated balance sheets as funds held for clients, and the associated liability for the tax filings is shown as client funds obligation. The liability is recorded in the accompanying consolidated balance sheets at the time we obtain the funds from clients. The client funds obligation represents liabilities that will be repaid within one year of the consolidated balance sheet date. We typically invest funds held for clients in money market funds, demand deposit accounts, certificates of deposit, commercial paper and U.S. treasury securities. Short-term investments in instruments with an original maturity of less than three months are classified as cash and cash equivalents within funds held for clients in the consolidated balance sheets. Investments in instruments with an original maturity greater than three months are classified as available-for-sale securities and are also included within funds held for clients in the consolidated balance sheets.

These available-for-sale securities are recorded at fair value, with the difference between the amortized cost and fair value of these available-for-sale securities recorded as unrealized net gains (losses) on available-for-sale securities, and are included within comprehensive earnings (loss) in the consolidated statements of comprehensive income. Funds held for clients are classified as a current asset in the consolidated balance sheets because the funds are held solely to satisfy the client funds obligation. Additionally, the funds held for clients is classified as restricted cash and restricted cash equivalents and presented within the reconciliation of cash, cash equivalents, restricted cash and restricted cash equivalents on the consolidated statements of cash flows.

The Company reports the cash flows related to the purchases of investments from funds held for clients and related to the proceeds from the maturities of investments from funds held for clients on a gross basis in the cash flows from investing activities section of the consolidated statements of cash flows. Additionally, the Company reports cash flows related to cash received from and paid on behalf of clients on a net basis within the net change in client funds obligation in the cash flows from financing activities section of the consolidated statements of cash flows.

Stock Repurchase Plan

In May 2016, our Board of Directors authorized a stock repurchase plan allowing for the repurchase of shares of our common stock in open market transactions at prevailing market prices, in privately negotiated transactions or by other means in accordance with federal securities laws, including Rule 10b5-1 programs. Since the initial authorization of the stock repurchase plan, our Board of Directors has amended and extended and authorized new stock repurchase plans from time to time. In August 2022, our Board of Directors authorized the repurchase of up to $1.1 billion of our common stock over a two-year period expiring on August 15, 2024. As of June 30, 2024, there was $705.9 million available for repurchases under our stock repurchase plan. On July 29, 2024, our Board of Directors increased and extended the stock repurchase plan. See Note 14 for additional information. Our stock repurchase plan may be suspended or discontinued at any time. The actual timing, number and value of shares repurchased depends on a number of factors, including the market price of our common stock, general market and economic conditions, shares withheld for taxes associated with the vesting of equity incentive awards and other corporate considerations.

During the six months ended June 30, 2024, we repurchased an aggregate of 589,424 shares of our common stock at an average cost of $158.06 per share, including 68,482 shares withheld to satisfy tax withholding obligations for certain employees upon the vesting of equity incentive awards.

Recently Issued Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”). ASU 2023-07 requires incremental disclosures in annual and interim periods related reportable segments, and segment expenses but does not change the definition of a segment, the method for determining segments, or the criteria for aggregating operating segments into reportable segments. This ASU is effective for fiscal years beginning after December 15, 2023 and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. We are assessing the impact of this ASU on our consolidated financial statements and disclosures.

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. ASU 2023-09 requires disaggregated information about a reporting entity’s effective tax rate reconciliation, as well as information on income taxes paid. This ASU is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. We are assessing the impact of this ASU on our consolidated financial statements and disclosures.