Consolidated Statements of Comprehensive Income - Unaudited - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income attributable to Bryn Mawr Bank Corporation	$ 16,682	$ 10,739	$ 46,656	$ 29,216
Other comprehensive (loss) income:
Net unrealized (losses) gains arising during the period, net of tax (benefit) expense of $(616), $105, $(2,337), and $535, respectively	(2,319)	196	(8,792)	995
Reclassification adjustment for net (gain) on sale realized in net income, net of tax (expense) of $0, $(25), $(1), and $(25), respectively	0	(47)	(6)	(48)
Reclassification adjustment for net (gain) realized on transfer of investment securities available for sale to trading, net of tax (expense) benefit of $0, $0, $(88), and $0, respectively	0	0	(329)	0
Unrealized investment (losses) gains, net of tax (benefit) expense of $(616), $80, $(2,426), and $510, respectively	(2,319)	149	(9,127)	947
Net change in unfunded pension liability:
Change in unfunded pension liability related to unrealized loss, prior service cost and transition obligation, net of tax expense of $28, $9, $37, and $34, respectively	108	15	139	62
Total other comprehensive (loss) income	(2,211)	164	(8,988)	1,009
Total comprehensive income	$ 14,471	$ 10,903	$ 37,668	$ 30,225