Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	13. Commitments and Contingencies Minimum Purchase Commitments We have a non-cancellable cloud hosting arrangement with Amazon Web Services (“AWS”) that contains provisions for minimum purchase commitments. Specifically, purchase commitments under the agreement total $131.0 million over five years. The agreement, which started July 2021 and is now in its third year as of December 31, 2023, contains minimum spending requirements of $28.0 million in each of the third, fourth, and fifth years. Spending under this agreement for the year ended December 31, 2023, 2022, and 2021 totaled $36.6 million, $33.1 million, and $11.8 million, respectively. The timing of payments under the agreement may vary. Exclusive of the AWS contract, we have other non-cancellable agreements for subscription software products that contain provisions stipulating minimum purchase commitments. However, the annual purchase commitments under these contracts are, individually and in the aggregate, immaterial to our consolidated financial statements. Pegasystems Litigation On May 29, 2020, we filed a civil complaint against Pegasystems, Inc. (“Pegasystems”) and Youyong Zou, a Virginia resident, in the Circuit Court for Fairfax County, Virginia. Appian Corp v. Pegasystems Inc. & Youyong Zou, No. 2020-07216 (Fairfax Cty. Ct.). On May 10, 2022, we announced the jury awarded us $2.036 billion in damages for misappropriation of our trade secrets and $1 in damages for violating the Virginia Computer Crimes Act. Pegasystems filed several post-trial motions seeking relief in the form of reducing the damages award or setting aside the jury’s verdict and either granting a new trial or entering judgment in Pegasystems’ favor. All of these motions were denied, and final judgment was entered by the Court on September 15, 2022. The final judgment reaffirmed the $2.036 billion in damages and also ordered Pegasystems to pay Appian $23.6 million in attorney's fees associated with the case as well as statutory post-judgment interest on the judgment at an annual rate of 6%, or approximately $122.0 million per year. Defendant Youyong Zou has satisfied the judgment of $5,000 (plus interest) against him in lieu of appealing that judgment. On September 15, 2022, Pegasystems filed a notice of appeal to the Court of Appeals of Virginia. Both sides have submitted their respective appeal briefs to the Court of Appeals, and the Court held a hearing on the appeal on November 15, 2023. The timeline of the case is solely within the control of the Court of Appeals until it rules. Pegasystems is not required to pay us the judgment, attorney’s fees, or post-judgment interest until all appeals are exhausted. We cannot predict the outcome of any appeals or the exact time it will take to resolve them. Consistent with other judgments, there is no guarantee we will be able to collect all or any portion of the judgment. Consequently, we will not record the award in our consolidated financial statements until all contingencies are resolved and we collect on the judgment. Judgment Preservation Insurance On September 1, 2023, we entered into a Judgment Preservation Insurance (“JPI”) policy in connection with our $2.036 billion judgment against Pegasystems. The total cost of the policy was $57.3 million and is comprised of the premium, a one-time broker fee, and Virginia lines tax. The policy provides up to $500.0 million of coverage. The total cost of the policy was capitalized and will be amortized on a straight-line basis over the estimated length of the appeals process. As of December 31, 2023, we estimated the length of the appeals process (solely for amortization purposes) to be approximately three years. This estimate will be updated each reporting period. Amortization expense associated with the JPI premium is recorded to general and administrative expenses in our consolidated statements of operations. JPI amortization expense was $6.0 million for the year ended December 31, 2023. As of December 31, 2023, $18.1 million of the unamortized balance is classified as ‘Prepaid expenses and other current assets’ while the remaining $33.2 million is classified as ‘Other assets’ on our consolidated balance sheets. Other Legal Matters From time to time, we are subject to legal, regulatory, and other proceedings and claims that arise in the ordinary course of business. Other than as disclosed elsewhere in this Annual Report, we are not presently a party to any legal proceedings that, if determined adversely to us, would individually or taken together have a material adverse effect on our business, operating results, financial condition, or cash flows. Regardless of the outcome, litigation can have an adverse impact on us because of defense and settlement costs, diversion of management resources, and other factors.