Earnings Per Common Share - Additional Information (Detail) - shares		3 Months Ended		9 Months Ended
	Nov. 22, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Old Line Bancshares, Inc. [Member]
Schedule Of Antidilutive Securities Included In Computation Of Earnings Per Share [Line Items]
Number of shares issued for acquisition	13,351,837
Old Line Bancshares, Inc. [Member] | Treasury Stock [Member]
Schedule Of Antidilutive Securities Included In Computation Of Earnings Per Share [Line Items]
Shares issued for acquisition, shares	34,998
Stock Option [Member]
Schedule Of Antidilutive Securities Included In Computation Of Earnings Per Share [Line Items]
Securities excluded from computation of net income per diluted shares		729,985	352,250	536,761	352,250
Restricted Stock [Member]
Schedule Of Antidilutive Securities Included In Computation Of Earnings Per Share [Line Items]
Shares contingently issuable under shareholder return plan				27,371	30,137