Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income attributable to Bryn Mawr Bank Corporation	$ 32,573	$ 59,206	$ 63,792
Net change in unrealized gains (losses) on investment securities available for sale:
Net unrealized gains (losses) arising during the period, net of tax expense (benefit) of $1,872, $2,696 and $(806), respectively	7,044	10,139	(3,033)
Reclassification adjustment for net gain on sale realized in net income, net of tax expense of $0, $0 and $(1), respectively	0	0	(6)
Reclassification adjustment for net gain realized on transfer of investment securities available for sale to trading, net of tax expense of $0, $0 and $(88), respectively	0	0	(329)
Unrealized investment losses, net of tax expense (benefit) of $1,872, $2,696 and $(895), respectively	7,044	10,139	(3,368)
Net change in unfunded pension liability:
Change in unfunded pension liability related to unrealized loss, prior service cost and transition obligation, net of tax (benefit) expense of $(75), $(118) and $72, respectively	(283)	(439)	269
Total other comprehensive income (loss)	6,761	9,700	(3,099)
Total comprehensive income	$ 39,334	$ 68,906	$ 60,693