CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Optima Bank And Trust Company	Wellesley Bancorp Inc	Common Stock	Additional Paid-In Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income / (Loss)
Beginning balance at Dec. 31, 2018	$ 167,026				$ 4,107	$ 38,271	$ 131,135		$ (6,487)
Accounting Standards Update [Extensible List]	ASU 2020-04				ASU 2020-04	ASU 2020-04	ASU 2020-04		ASU 2020-04
Net income	$ 25,257						$ 25,257
Other comprehensive income (loss)	4,006								$ 4,006
Share based compensation and other share-based activity	2,170				$ 20	$ 2,150
Dividends declared	(9,517)						(9,517)
Common stock issued for merger			$ 59,417		723	58,694
Common stock offering	38,202				551	37,651
Ending balance at Dec. 31, 2019	286,561	$ (347)			5,401	136,766	146,875	$ (347)	(2,481)
Net income	31,959						31,959
Other comprehensive income (loss)	4,915								4,915
Share based compensation and other share-based activity	4,564				23	4,541
Dividends declared	(13,083)						(13,083)
Common stock issued for merger				$ 87,163	1,503	85,660
Ending balance at Dec. 31, 2020	401,732				6,927	226,967	165,404		2,434
Net income	54,024						54,024
Other comprehensive income (loss)	(3,644)								(3,644)
Share based compensation and other share-based activity	2,279				41	2,238
Dividends declared	(16,554)						(16,554)
Ending balance at Dec. 31, 2021	$ 437,837				$ 6,968	$ 229,205	$ 202,874		$ (1,210)