CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 38,485,000	$ 34,531,000	$ 51,278,000	$ (21,034,000)	$ 73,016,000	$ 30,244,000
Adjustments to reconcile net income to net cash provided by operating activities:
Net gain on sales of securities available-for-sale and other assets						(730,000)
Net gain on equity securities	0		0		0	(131,000)
Net gain on sale of loans held for sale					(1,304,000)	(23,063,000)
Loss on termination of derivatives						16,505,000
Net depreciation, amortization and accretion					4,370,000	817,000
Amortization of other intangible assets	430,000		835,000		1,016,000	1,192,000
Loss on extinguishment of debt			157,000		740,000	1,751,000
Stock-based compensation					2,165,000	2,350,000
(Credit) provision for credit losses	44,000		(4,248,000)		(1,548,000)	11,531,000
Originations of loans held for sale					(14,790,000)	(26,198,000)
Proceeds from sale of loans originated for sale					28,069,000	42,679,000
Increase in cash surrender value of BOLI					(3,826,000)	(2,932,000)
Gain from death benefits from BOLI					(2,156,000)
(Increase) decrease in other assets					(32,856,000)	93,355,000
Increase (decrease) in other liabilities					94,513,000	(89,649,000)
Net cash provided by operating activities					147,409,000	57,721,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sales of securities available-for-sale						138,077,000
Proceeds from sales of marketable equity securities						6,101,000
Purchases of securities available-for-sale					(6,210,000)	(508,315,000)
Purchases of securities held-to-maturity					(41,631,000)
Proceeds from calls and principal repayments of securities available-for-sale					112,270,000	290,439,000
Proceeds from calls and principal repayments of securities held-to-maturity					14,102,000
Purchase of BOLI					(30,000,000)	(40,000,000)
Proceeds received from cash surrender value of BOLI					2,843,000
Proceeds from the sale of portfolio loans transferred to held for sale					13,201,000	667,629,000
Net increase in loans					(439,736,000)	(24,351,000)
Purchases of fixed assets, net					(1,753,000)	(643,000)
(Purchases) redemptions of restricted stock, net					(4,378,000)	61,620,000
Net cash received in business combination					0	715,988,000
Net cash (used in) provided by investing activities					(381,292,000)	1,306,545,000
CASH FLOWS FROM FINANCING ACTIVITIES:
Increase in deposits					107,245,000	1,125,900,000
Proceeds (repayments) from FHLBNY advances, short-term, net					75,000,000	(1,228,865,000)
Repayments of FHLBNY advances, long-term						(190,150,000)
Proceeds from FHLBNY advances, long-term						25,000,000
Proceeds (repayments) of other short-term borrowings, net					300,000	(118,159,000)
Proceeds from subordinated debentures issuance, net					157,559,000
Redemption of subordinated debentures					(155,000,000)
Proceeds from exercise of stock options						396,000
Release of stock for benefit plan awards					568,000	539,000
Payments related to tax withholding for equity awards					(1,415,000)	(147,000)
BMP ESOP shares received to satisfy distribution of retirement benefits						(993,000)
Purchase of treasury stock					(40,292,000)	(13,825,000)
Cash dividends paid to preferred stockholders					(3,643,000)	(3,643,000)
Cash dividends paid to common stockholders					(18,674,000)	(19,739,000)
Net cash provided by (used in) financing activities					121,648,000	(423,686,000)
(Decrease) increase in cash and cash equivalents					(112,235,000)	940,580,000
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD		$ 393,722,000		$ 243,603,000	393,722,000	243,603,000	$ 243,603,000
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 281,487,000		$ 1,184,183,000		281,487,000	1,184,183,000	$ 393,722,000
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for income taxes					22,057,000	4,655,000
Cash paid for interest					10,895,000	17,302,000
Securities available-for-sale transferred to held-to-maturity					372,153,000
Loans transferred to held for sale					24,178,000	674,350,000
Loans transferred to held for investment					4,078,000
Premises transferred to held for sale						2,799,000
Operating lease assets in exchange for operating lease liabilities					$ 1,004,000	4,048,000
Cumulative change due to Current Expected Credit Loss ("CECL") Standard adoption						1,686,000
Net non-cash liabilities assumed in Merger (See Note 2)						$ 324,479,000