Significant Accounting Policies (Notes)	6 Months Ended
Significant Accounting Policies (Notes)	Jun. 30, 2025
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Revenue Recognition The Company generally recognizes revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers (“Topic 606”). The Company earns commission revenue by providing insurance placement services to insureds or insurance companies (“clients”) under direct bill and agency bill arrangements with insurance company partners or reinsurance company partners for private risk management, commercial risk management, employee benefits and Medicare insurance types. Commission revenues are usually a percentage of the premium paid by clients and generally depend upon the type of insurance, the insurance company partner or reinsurance company partner, and the nature of the services provided. In some cases, the Company shares commissions with other agents or brokers who have acted jointly with the Company in a transaction. The Company controls the fulfillment of the performance obligation and its relationship with its insurance company partners, reinsurance company partners, and the outside agents. Commissions shared with downstream agents or brokers are recorded in outside commissions in the condensed consolidated statements of comprehensive income (loss). Commission revenue is recorded net of allowances for estimated policy cancellations, which are determined based on an evaluation of historical and current cancellation data. Commissions for brokerage services may be invoiced near the effective date of the underlying policy or over the term of the arrangement in installments during the policy period. However, regardless of the payment terms, commissions are recognized at a point in time upon the effective date of bound insurance coverage, as no performance obligation exists after coverage is bound. The Company earns service fee revenue for providing insurance placement services to clients for a negotiated fee, and consulting revenue is earned by providing specialty insurance consulting and other advisory services. Service fee and consulting revenues from certain agreements are recognized over time depending on when the services within the contract are satisfied and when the Company has transferred control of the related services to the customer. Profit-sharing commissions represent bonus-type revenue that is earned by the Company as a sales incentive provided by certain insurance company partners and reinsurance company partners. The Company receives profit-sharing commissions based primarily on underwriting results, but may also contain considerations for volume, growth, loss performance or retention. Profit-sharing commissions associated with relatively predictable measures are estimated and recognized over time. The profit-sharing commissions are recorded as the underlying policies that contribute to the achievement of the metric are placed with any adjustments recognized when payments are received or as additional information that affects the estimate becomes available. Profit-sharing commissions associated with loss performance are uncertain, and therefore, are subject to significant reversal as loss data remains subject to material change. Management estimates profit-sharing commissions using historical outcomes and known trends impacting premium volume or loss ratios, subject to a constraint. The constraint is relieved when management estimates the revenue is not subject to significant reversal, which often coincides with the earlier of written notice from the insurance company partner that the target has been achieved, or cash collection. Year-end and quarter-end amounts incorporate estimates subject to a constraint or where applicable, are based on confirmation from insurance company partners after calculation of premium volume or loss ratios that are impacted by catastrophic losses. The Company earns policy fee revenue for acting in its capacity as a managing general agent (“MGA”) on behalf of the insurance company partner and fulfilling certain services, including delivery of policy documents, processing payments and other administrative functions during the term of the insurance policy. Policy fee revenue is deferred and recognized over the life of the policy. These deferred amounts are recognized as contract liabilities, which are included as a component of accrued expenses and other current liabilities on the consolidated balance sheets. The Company earns installment fee revenue for payment processing services performed on behalf of the insurance company partner related to policy premiums paid on an installment basis. The Company recognizes installment fee revenue in the period the services are performed. The Company pays an incremental amount of compensation in the form of producer commissions on new business. These incremental costs are capitalized as deferred commission expense and amortized over five years, which represents management’s estimate of the average benefit period for new business. The Company has concluded that this period is consistent with the transfer to the client of the services to which the asset relates. Due to the relatively short time period between the information gathering phase and binding insurance coverage, the Company has determined that costs to fulfill contracts are not significant. Therefore, costs to fulfill a contract are expensed as incurred. The Company recognizes revenue for the Captive business (as defined further below) in accordance with ASC Topic 944, Insurance, in the form of assumed premium earned. Assumed premium earned is recognized ratably over the associated policy periods. The Company also earns investment income, which primarily consists of interest earnings on available cash invested in treasury money market funds. The Company recognizes investment income in the period the revenue is earned. Captive Insurance Operations The Company’s Underwriting, Capacity & Technology Solutions operating group includes TBG Assurance Company, LLC, a wholly-owned protected cell captive insurance company (“PCC”) domiciled in Tennessee, which was established to allow Baldwin to further participate in the underwriting results of a small portion of its MGA programs. The PCC allows for the creation of multiple independent cells (series) within a single legal entity, TBG Assurance Company, LLC (the “Core”). Effective January 1, 2025, the initial series, MSI Multifamily Series Protected Cell (the “MSI Cell” and, collectively with the Core, the “Captive”), was licensed and participates as a quota share reinsurer on two of MSI’s multifamily programs, renters and master tenant legal liability, for the purpose of further participating in the programs’ underwriting results. The reinsurance quota share contracts feature an adjustment to assumed premium based on the loss ratio performance of the business ceded. Assumed premiums are recognized as income over the coverage period of the related policies. Unearned premiums represent the portion of premiums written that relate to the unexpired terms of the policies in force and are determined on a pro rata basis. Assumed premium earned is recorded to commissions and fees in the condensed consolidated statements of comprehensive income (loss). Assumed premiums receivable are included as a component of assumed premiums, commissions and fees receivable, net on the condensed consolidated balance sheets. Unearned premiums are included as a component of accrued expenses and other current liabilities on the condensed consolidated balance sheets. The Company establishes its assumed insurance loss reserves for the estimated total unpaid costs of losses, including the loss adjustment expense (“LAE”). Loss and LAE reserves reflect management’s best estimate of the total cost of (i) claims that have been incurred, but not yet paid in full, and (ii) claims that have been incurred but not yet reported to the Company. Reserves established by management represent an estimate of the outcome of future events and, as such, cannot be considered an exact calculation of the Company’s liability. Rather, loss and LAE reserves represent management’s best estimate of the Company’s liability based on the application of actuarial techniques and other projection methodologies and taking into consideration other facts and circumstances known at the balance sheet date. The Company engages the services of an outside actuarial consulting firm (the “Actuary”) to assist on an annual basis to render an opinion on the sufficiency of the Company’s estimates for unpaid losses and related LAE reserves. The Actuary utilizes both industry experience and the Company’s own experience to develop estimates of those amounts as of year-end. These estimated liabilities are subject to the impact of future changes in claim severity, frequency and other factors. Despite the variability inherent in such estimates, management believes that the liabilities for unpaid losses and related LAE reserves are adequate. Unpaid losses and LAE reserves are included as a component of accrued expenses and other current liabilities on the condensed consolidated balance sheets. Cash and Cash Equivalents and Fiduciary Cash The Company considers all highly liquid short-term instruments with original maturities of three months or less to be cash equivalents. These instruments held by the Company included money market funds at June 30, 2025 and December 31, 2024, which are included as a component of cash and cash equivalents and fiduciary cash on the condensed consolidated balance sheets. Money market funds are carried at cost, which approximates fair value, and are considered Level 1 measurements within the fair value hierarchy. As of June 30, 2025 and December 31, 2024, the Company's money market funds totaled $286.6 million and $237.5 million, respectively.