Executive Bonus Plan	12 Months Ended
Executive Bonus Plan	Dec. 31, 2023
Compensation Related Costs [Abstract]
Executive Bonus Plan	Executive Bonus Plan Certain of the Company’s key employees, including its named executive officers, participate in the Company’s Bonus Plan. Pursuant to the Bonus Plan, participants are eligible to receive incentive bonuses that are determined based on the Company’s adjusted Management Report Operating Income (“MROI”), as defined in the plan agreement and before deduction for such plan payments. For purposes of the Bonus Plan, the bonus pool thereunder may be funded with up to an aggregate of 20% of the Company’s adjusted MROI, subject to approval by the Sustainability Committee of the Company’s Board of Directors, with payments made to plan participants based on each such participant’s allocated interest in the bonus pool. The plan permits the deduction of certain holdback amounts from the plan’s pool, from which amounts can then be allocated to fund items including equity and/or cash incentive compensation for non‑plan participants and participant charitable contributions. On November 2, 2022, the Sustainability Committee of the Company’s Board of Directors approved an amendment to the Bonus Plan such that with respect to fiscal year 2022, one‑third of the Company’s Chief Investment Officer’s allocated percentage interest will be multiplied by a coefficient derived from the performance of the Company’s BSY Investments group (the Company’s executive team focused on portfolio development, mergers and acquisitions, venture capital investing, digital integrator business activities, and various incubating and accelerating business activities). This coefficient is generally determined by calculating the annual increase (or decrease) in value of the BSY Investments portfolio, taking into account applicable fees and an annual hurdle rate, in all cases, as approved by the Company’s non-employee directors. The Company’s Chief Investment Officer retired effective March 31, 2023 and received one Bonus Plan payout during 2023 in respect to the 2022 fiscal year under the amended allocated percentage interest. A participant may defer any portion, or all, of such participant’s incentive bonus payable pursuant to the Bonus Plan into the DCP (see Note 12). The Bonus Plan provides, in part, that a participant may elect to receive any portion, or all, of such participant’s non‑deferred incentive bonus in the form of shares of fully vested Class B common stock issued under the Bentley Systems, Incorporated 2020 Omnibus Incentive Plan (the “2020 Incentive Award Plan”), subject to the limitation described below. The Company records the election of non‑deferred incentive bonus in the form of shares of fully vested Class B common stock as stock‑based compensation expense in the consolidated statements of operations (see Note 15). Such election must be made prior to the start of the applicable calendar quarter for which the incentive bonus is to be paid, and the number of shares of Class B common stock payable in respect of such elected amount is calculated using a volume-weighted average price of the Company’s Class B common stock for the period commencing on the tenth trading day prior to the end of the applicable calendar quarter and ending on the tenth trading day following the end of the applicable calendar quarter. Notwithstanding participants’ elections to receive shares of fully vested Class B common stock in respect of their non‑deferred incentive bonus payments, if, in any calendar quarter, the aggregate U.S. dollar value of shares of fully vested Class B common stock payable in respect of the non‑deferred incentive bonuses exceeds $7,500, the portion of each participant’s non‑deferred incentive bonus payable in shares of fully vested Class B common stock will be reduced pro rata such that the $7,500 limit is not exceeded, and, for each affected participant, the amount of such reduction will be payable in cash. For the years ended December 31, 2023, 2022, and 2021, the incentive compensation, including cash payments, election to receive shares of fully vested Class B common stock, and deferred compensation to plan participants, recognized under this plan (net of all applicable holdbacks) was $21,463, $33,242, and $33,454, respectively.