Earnings per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share [Abstract]
Net income attributable to Bryn Mawr Bank Corporation	$ 14,688	$ 9,433	$ 29,974	$ 18,477
Denominator for basic earnings per share – weighted average shares outstanding	20,238,852	16,984,563	20,221,010	16,969,431
Effect of dilutive common shares	174,726	248,204	206,782	238,381
Denominator for diluted earnings per share – adjusted weighted average shares outstanding	20,413,578	17,232,767	20,427,792	17,207,812
Basic earnings per share (in dollars per share)	$ 0.73	$ 0.56	$ 1.48	$ 1.09
Diluted earnings per share (in dollars per share)	$ 0.72	$ 0.55	$ 1.47	$ 1.07
Antidilutive shares excluded from computation of average dilutive earnings per share	1,422	0	2,495	0