CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Preferred Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Preferred Stock	Common Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Additional Paid-in Capital Cumulative Effect, Period of Adoption, Adjusted Balance	Additional Paid-in Capital	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings	Accumulated Other Comprehensive Income (Loss) Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (Loss)	Unearned Equity Awards	Common Stock Held by BMP Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock Held by BMP	Treasury Stock, at Cost Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury Stock, at Cost	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Total
Balance at Dec. 31, 2019				$ 348		$ 279,511			$ 581,817		$ (5,940)	$ (6,731)		$ (1,496)		$ (250,751)			$ 596,758
Balance (in shares) at Dec. 31, 2019				22,780,208
Increase (Decrease) in Stockholders' Equity
Net (loss) income									8,392										8,392
Other comprehensive income (loss), net of tax											(6,692)								(6,692)
Release of shares, net of forfeitures						5						(7)				2
Release of shares, net of forfeitures (in shares)				59
Stock-based compensation												671							671
Proceeds from Preferred Stock issuance, net		$ 72,224																	72,224
Shares received related to tax withholding																(79)			(79)
Shares received related to tax withholding (in shares)				(3,025)
Cash dividends declared to common stockholders									(4,915)										(4,915)
Repurchase of shares of common stock																(20,711)			(20,711)
Repurchase of shares of common stock (in shares)				(825,992)
Balance at Mar. 31, 2020		72,224		$ 348		279,516			585,294		(12,632)	(6,067)		(1,496)		(271,539)			645,648
Balance (in shares) at Mar. 31, 2020				21,951,250
Balance at Dec. 31, 2019				$ 348		279,511			581,817		(5,940)	(6,731)		(1,496)		(250,751)			596,758
Balance (in shares) at Dec. 31, 2019				22,780,208
Increase (Decrease) in Stockholders' Equity
Net (loss) income																			37,226
Other comprehensive income (loss), net of tax																			(5,599)
Balance at Sep. 30, 2020		116,569		$ 348		278,769			601,913		(11,539)	(6,695)		(1,496)		(283,711)			694,158
Balance (in shares) at Sep. 30, 2020				21,416,284
Balance at Mar. 31, 2020		72,224		$ 348		279,516			585,294		(12,632)	(6,067)		(1,496)		(271,539)			645,648
Balance (in shares) at Mar. 31, 2020				21,951,250
Increase (Decrease) in Stockholders' Equity
Net (loss) income									12,966										12,966
Other comprehensive income (loss), net of tax											(1,771)								(1,771)
Exercise of stock options						38													38
Exercise of stock options (in shares)				1,973
Release of shares, net of forfeitures						(784)						(1,960)				2,772			28
Release of shares, net of forfeitures (in shares)				127,582
Stock-based compensation												478							478
Proceeds from Preferred Stock issuance, net		44,345																	44,345
Shares received related to tax withholding																(169)			(169)
Shares received related to tax withholding (in shares)				(6,912)
Cash dividends declared to preferred stockholders									(1,140)										(1,140)
Cash dividends declared to common stockholders									(4,623)										(4,623)
Repurchase of shares of common stock																(14,257)			(14,257)
Repurchase of shares of common stock (in shares)				(631,842)
Balance at Jun. 30, 2020		116,569		$ 348		278,770			592,497		(14,403)	(7,549)		(1,496)		(283,193)			681,543
Balance (in shares) at Jun. 30, 2020				21,442,051
Increase (Decrease) in Stockholders' Equity
Net (loss) income									15,868										15,868
Other comprehensive income (loss), net of tax											2,864								2,864
Release of shares, net of forfeitures						(1)						50				(49)
Release of shares, net of forfeitures (in shares)				(2,368)
Stock-based compensation												804							804
Shares received related to tax withholding																(81)			(81)
Shares received related to tax withholding (in shares)				(4,203)
Cash dividends declared to preferred stockholders									(1,822)										(1,822)
Cash dividends declared to common stockholders									(4,630)										(4,630)
Repurchase of shares of common stock																(388)			(388)
Repurchase of shares of common stock (in shares)				(19,196)
Balance at Sep. 30, 2020		116,569		$ 348		278,769			601,913		(11,539)	(6,695)		(1,496)		(283,711)			694,158
Balance (in shares) at Sep. 30, 2020				21,416,284
Balance at Dec. 31, 2020	$ 116,569	116,569	$ 348	$ 348	$ 278,295	278,295	$ 1,686	$ 602,327	600,641	$ (5,924)	(5,924)		$ (1,496)	(1,496)	$ (287,337)	(287,337)	$ 1,686	$ 702,782	$ 701,096
Balance (in shares) at Dec. 31, 2020			21,232,984	21,232,984															21,232,984
Increase (Decrease) in Stockholders' Equity
Net (loss) income									(21,034)										$ (21,034)
Other comprehensive income (loss), net of tax											6,455								6,455
Reverse merger with Bridge Bancorp, Inc.				$ 65		206,641						(2,603)				287,107			491,210
Reverse merger with Bridge Bancorp, Inc. (in shares)				19,992,284
Exercise of stock options						292										80			372
Exercise of stock options (in shares)				15,928
Release of shares, net of forfeitures				$ 3		8,562						(8,340)				(33)			192
Release of shares, net of forfeitures (in shares)				335,959
Stock-based compensation												836							836
Shares received to satisfy distribution of retirement benefits						(1,359)								1,496		(1,130)			(993)
Shares received to satisfy distribution of retirement benefits (in shares)				(41,101)
Cash dividends declared to preferred stockholders									(1,821)										(1,821)
Cash dividends declared to common stockholders									(5,175)										(5,175)
Balance at Mar. 31, 2021		116,569		$ 416		492,431			574,297		531	(10,107)				(1,313)			1,172,824
Balance (in shares) at Mar. 31, 2021				41,536,054
Balance at Dec. 31, 2020	$ 116,569	116,569	$ 348	$ 348	$ 278,295	278,295	$ 1,686	$ 602,327	600,641	$ (5,924)	(5,924)		$ (1,496)	$ (1,496)	$ (287,337)	(287,337)	$ 1,686	$ 702,782	$ 701,096
Balance (in shares) at Dec. 31, 2020			21,232,984	21,232,984															21,232,984
Increase (Decrease) in Stockholders' Equity
Net (loss) income																			$ 68,639
Other comprehensive income (loss), net of tax																			4,882
Balance at Sep. 30, 2021		116,569		$ 416		493,775			630,744		(1,042)	(9,417)				(29,928)			$ 1,201,117
Balance (in shares) at Sep. 30, 2021				40,714,828															40,714,828
Balance at Mar. 31, 2021		116,569		$ 416		492,431			574,297		531	(10,107)				(1,313)			$ 1,172,824
Balance (in shares) at Mar. 31, 2021				41,536,054
Increase (Decrease) in Stockholders' Equity
Net (loss) income									51,278										51,278
Other comprehensive income (loss), net of tax											4,045								4,045
Exercise of stock options						(7)										31			24
Exercise of stock options (in shares)				1,174
Release of shares, net of forfeitures						424						64				(141)			347
Release of shares, net of forfeitures (in shares)				3,098
Stock-based compensation												1,514							1,514
Shares received related to tax withholding																(147)			(147)
Shares received related to tax withholding (in shares)				(3,342)
Cash dividends declared to preferred stockholders									(1,822)										(1,822)
Cash dividends declared to common stockholders									(9,962)										(9,962)
Repurchase of shares of common stock																(13,825)			(13,825)
Repurchase of shares of common stock (in shares)				(424,121)
Balance at Jun. 30, 2021		116,569		$ 416		492,848			613,791		4,576	(8,529)				(15,395)			1,204,276
Balance (in shares) at Jun. 30, 2021				41,112,863
Increase (Decrease) in Stockholders' Equity
Net (loss) income									38,395										38,395
Other comprehensive income (loss), net of tax											(5,618)								(5,618)
Release of shares, net of forfeitures						1,048						(2,423)				1,615			240
Release of shares, net of forfeitures (in shares)				82,004
Stock-based compensation												1,535							1,535
Cash dividends declared to preferred stockholders									(1,822)										(1,822)
Cash dividends declared to common stockholders									(19,620)										(19,620)
Redemption of real estate investment trust ("REIT") preferred stock						(121)													(121)
Repurchase of shares of common stock																(16,148)			(16,148)
Repurchase of shares of common stock (in shares)				(480,039)
Balance at Sep. 30, 2021		$ 116,569		$ 416		$ 493,775			$ 630,744		$ (1,042)	$ (9,417)				$ (29,928)			$ 1,201,117
Balance (in shares) at Sep. 30, 2021				40,714,828															40,714,828