Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	14. Commitments and Contingencies Minimum Purchase Commitments In July 2021, we executed 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, including $22.0 million in the first year, $25.0 million in the second year, and $28.0 million in each of the third, fourth, and fifth years. The timing of payments under the agreement may vary, and the total amount of payments may exceed the minimum depending on the volume of services utilized. Spending under this agreement for the year ended December 31, 2022 totaled $33.1 million. Letters of Credit At December 31, 2022 and 2021, we had outstanding letters of credit totaling $12.0 million and $11.2 million, respectively, in connection with securing our leased office space. All letters of credit are secured by our current or historical borrowing arrangements as described in Note 9. 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, and on February 6, 2023, Pegasystems filed its opening brief with the Court of Appeals of Virginia. Appian expects to file its responsive brief in March 2023, to which Pegasystems will file a reply brief. After submission of the reply brief, 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 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. 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. We do not believe any material liability will be imposed as a result of any of the foregoing matters.