Financial Instruments with Off-Balance Sheet Risk, Contingencies and Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Financial Instruments with off Balance Sheet Risk, Contingencies and Concentration of Credit Risk	Financial Instruments with Off-Balance Sheet Risk, Contingencies and Concentration of Credit Risk Off-Balance Sheet Risk The Corporation is a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit. Those instruments involve, to varying degrees, elements of credit risk in excess of the amount recognized in the consolidated statements of financial condition. The contractual amounts of those instruments reflect the extent of involvement the Corporation has in particular classes of financial instruments. The Corporation’s exposure to credit loss in the event of nonperformance by the counterparty to the financial instrument of commitments to extend credit and standby letters of credit is represented by the contractual amount of those instruments. The Corporation uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet financial instruments. Commitments to extend credit, which include unused lines of credit and unfunded commitments to originate loans, are agreements to lend to a customer as long as there is no violation of any condition established in the agreement. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Some of the commitments are expected to expire without being drawn upon, and the total commitment amounts do not necessarily represent future cash requirements. Total commitments to extend credit at December 31, 2020 were $924.5 million. Management evaluates each customer’s creditworthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by the Corporation upon extension of credit, is based on a credit evaluation of the counterparty. Collateral varies but may include accounts receivable, marketable securities, inventory, property, plant and equipment, residential real estate, and income-producing commercial properties. Standby letters of credit are conditional commitments issued by the Bank to a customer for a third party. Such standby letters of credits are issued to support private borrowing arrangements. The credit risk involved in issuing standby letters of credit is similar to that involved in extending loan facilities to customers. The collateral varies, but may include accounts receivable, marketable securities, inventory, property, plant and equipment, and residential real estate for those commitments for which collateral is deemed necessary. The Corporation’s obligation under standby letters of credit as of December 31, 2020 was $21.1 million. Contingencies Legal Matters In the ordinary course of its operations, BMBC and its subsidiaries are parties to various claims, litigation, investigations, and legal and administrative cases and proceedings. Such pending or threatened claims, litigation, investigations, legal and administrative cases and proceedings typically entail matters that are considered incidental to the normal conduct of business. Claims for significant monetary damages may be asserted in many of these types of legal actions. Based on the information currently available, the Corporation believes it has meritorious defenses to the claims asserted against it in its currently outstanding legal proceedings and with respect to such legal proceedings, intends to continue to defend itself vigorously, litigating or settling cases according to management’s judgment as to what is in the best interests of BMBC and its shareholders. On a regular basis, liabilities and contingencies in connection with outstanding legal proceedings are assessed utilizing the latest information available. For those matters where it is probable that the Corporation will incur a loss and the amount of the loss can be reasonably estimated, a liability may be recorded in the consolidated financial statements. These legal reserves may be increased or decreased to reflect any relevant developments on at least a quarterly basis. For other matters, where a loss is not probable or the amount or range of the loss is not estimable, legal reserves are not accrued. While the outcome of legal proceedings is inherently uncertain, based on information currently available, advice of counsel and available insurance coverage, management believes that the established legal reserves are adequate and the liabilities arising from legal proceedings will not have a material adverse effect on the consolidated financial position, consolidated results of operations or consolidated cash flows. However, in the event of unexpected future developments, it is possible that the ultimate resolution of these matters, if unfavorable, may be material to the consolidated financial position, consolidated results of operations or consolidated cash flows of the Corporation. Crusader Servicing Corporation (“Crusader”), which was an 80% owned subsidiary of Royal Bank America that was acquired by the Bank in the RBPI Merger, along with the Bank as successor-in-interest to Royal Bank America, are defendants in the case captioned Snyder v. Crusader Servicing Corporation et al., Case No. 2007-01027, in the Court of Common Pleas of Montgomery County, Pennsylvania. The case involves claims brought by a former Crusader shareholder in 2007 against Crusader, its former directors and remaining shareholders related, among other things, to a purported failure to pay amounts allegedly due to Snyder for his shares of Crusader stock. On May 1, 2019, the Court rendered a decision in favor of Snyder and ordered Crusader to pay Snyder the amount of $2,190,000 plus interest at the rate of 6% from December 1, 2006. The matter was appealed, and on March 18, 2020, the Superior Court of the Commonwealth of Pennsylvania returned an opinion reversing in part and affirming in part the trial court's judgment. The effect of this was to vacate the initial judgment awarded by the trial court, and instead to require an appraisal process in accordance with Crusader's Shareholders' Agreement to determine the value of Mr. Snyder's shares. The parties anticipate the appraisal to commence within the coming months. We do not believe that this ruling and the monetary award, if any, ultimately payable by Crusader will be material to the consolidated financial position, consolidated results of operations or consolidated cash flows of the Corporation. Indemnifications In general, the Corporation does not sell loans with recourse, except to the extent that it arises from standard loan-sale contract provisions. These provisions cover violations of representations and warranties and, under certain circumstances, first payment default by borrowers. These indemnifications may include the repurchase of loans by the Corporation and are considered customary provisions in the secondary market for conforming mortgage loan sales. Repurchases and losses have been rare and no provision is made for losses at the time of sale. There were no such repurchases for the year ended December 31, 2020. As of December 31, 2020, there was one pending and unsettled loan repurchase demand of approximately $200 thousand. Concentrations of Credit Risk The Corporation has a material portion of its loans in real estate-related loans. A predominant percentage of the Corporation’s real estate exposure, both commercial and residential, is in the Corporation’s primary trade area, which includes portions of Delaware, Chester, Montgomery and Philadelphia counties in Southeastern Pennsylvania. Management is aware of this concentration and attempts to mitigate this risk to the extent possible in many ways, including the underwriting and assessment of borrower’s capacity to repay. See Note 5, “Loans and Leases,” in the accompanying Notes to the Consolidated Financial Statements in this Annual Report on Form 10-K for additional information.