Earnings per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Net income attributable to Bryn Mawr Bank Corporation	$ 21,342	$ 15,035	$ 38,425	$ 3,872
Denominator for basic earnings per share – weighted average shares outstanding (in shares)	19,878,981	19,926,737	19,893,347	19,989,948
Effect of dilutive common shares (in shares)	171,838	81,482	153,809	87,211
Denominator for diluted earnings per share – adjusted weighted average shares outstanding (in shares)	20,050,819	20,008,219	20,047,156	20,077,159
Basic earnings per share (in dollars per share)	$ 1.07	$ 0.75	$ 1.93	$ 0.19
Diluted earnings per share (in dollars per share)	$ 1.06	$ 0.75	$ 1.92	$ 0.19
Antidilutive shares excluded from computation of average dilutive earnings per share (in shares)	0	76,038	0	71,260