Dime Community Bancshares (DCOM) 10-Q 9 Nov 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Oct. 31, 2021
Entity Listings [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2021
Entity File Number	001-34096
Entity Registrant Name	DIME COMMUNITY BANCSHARES, INC
Entity Incorporation, State or Country Code	NY
Entity Tax Identification Number	11-2934195
Entity Address, Address Line One	898 Veterans Memorial Highway
Entity Address, City or Town	Suite 560, Hauppauge
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	11788
City Area Code	631
Local Phone Number	537-1000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		40,454,438
Entity Central Index Key	0000846617
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false
Common Stock
Entity Listings [Line Items]
Title of 12(b) Security	Common Stock, $0.01 Par Value
Trading Symbol	DCOM
Security Exchange Name	NASDAQ
Preferred stock, Series A
Entity Listings [Line Items]
Title of 12(b) Security	Preferred Stock, Series A, $0.01 Par Value
Trading Symbol	DCOMP
Security Exchange Name	NASDAQ

CONSOLIDATED STATEMENTS OF FINA

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Cash and due from banks	$ 629,011	$ 243,603
Mortgage-backed securities available-for-sale, at fair value	1,212,383	426,979
Investment securities available-for-sale, at fair value	496,680	111,882
Investment securities held-to-maturity	40,303
Marketable equity securities, at fair value		5,970
Loans held for sale	14,720	5,903
Loans held for investment, net:
Loans	9,284,871	5,622,044
Allowance for credit losses	(81,255)	(41,461)
Total loans held for investment, net	9,203,616	5,580,583
Premises and fixed assets, net	49,615	19,053
Premises held for sale	2,799
Restricted stock	37,719	60,707
Bank Owned Life Insurance ("BOLI")	293,898	156,096
Goodwill	155,339	55,638
Other intangible assets	9,077
Operating lease assets	56,836	33,898
Derivative assets	41,700	18,932
Accrued interest receivable	43,284	34,815
Other assets	77,401	27,551
Total assets	12,364,381	6,781,610
Due to depositors:
Interest-bearing deposits	6,852,205	3,744,371
Non-interest-bearing deposits	3,821,832	780,751
Total deposits	10,674,037	4,525,122
Federal Home Loan Bank of New York ("FHLBNY") advances	25,000	1,204,010
Other short-term borrowings	2,629	120,000
Subordinated debt, net	197,142	114,052
Operating lease liabilities	62,870	39,874
Derivative liabilities	38,889	37,374
Other liabilities	162,697	40,082
Total liabilities	11,163,264	6,080,514
Commitments and contingencies
Stockholders' equity:
Preferred stock, Series A ($0.01 par, $25.00 liquidation value, 10,000,000 shares authorized and 5,299,200 shares issued and outstanding at September 30, 2021 and December 31, 2020)	116,569	116,569
Common stock ($0.01 par 80,000,000 shares authorized, 41,599,973 shares and 34,813,302 shares issued at September 30, 2021 and December 31, 2020, respectively, and 40,714,828 shares and 21,232,984 shares outstanding at September 30, 2021 and December 31, 2020, respectively)	416	348
Additional paid-in capital	493,775	278,295
Retained earnings	630,744	600,641
Accumulated other comprehensive loss, net of deferred taxes	(1,042)	(5,924)
Unearned equity awards	(9,417)
Common stock held by the Benefit Maintenance Plan ("BMP")		(1,496)
Treasury stock, at cost (885,145 shares and 13,580,318 shares at September 30, 2021 and December 31, 2020, respectively)	(29,928)	(287,337)
Total stockholders' equity	1,201,117	701,096
Total liabilities and stockholders' equity	12,364,381	6,781,610
Real estate
Loans held for investment, net:
Loans	8,251,743	4,978,195
Commercial and Industrial ("C&I") Loans
Loans held for investment, net:
Loans	1,012,415	641,533
Other Loans
Loans held for investment, net:
Loans	$ 20,713	$ 2,316

CONSOLIDATED STATEMENTS OF FI_2

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Stockholders' equity:
Investment securities held-to-maturity, fair value	$ 40,303,000	$ 0
Preferred stock, Series A, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, Series A, liquidation value (in dollars per share)	$ 25	$ 25
Preferred stock, Series A, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, Series A, shares issued (in shares)	5,299,200	5,299,200
Preferred stock, Series A, shares outstanding (in shares)	5,299,200	5,299,200
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	80,000,000	80,000,000
Common stock, shares issued (in shares)	41,599,973	34,813,302
Common stock, shares outstanding (in shares)	40,714,828	21,232,984
Treasury stock (in shares)	885,145	13,580,318

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Interest income:
Loans	$ 94,045,000	$ 53,245,000	$ 269,715,000	$ 161,564,000
Securities	6,030,000	3,422,000	15,536,000	10,794,000
Other short-term investments	583,000	729,000	2,563,000	2,577,000
Total interest income	100,658,000	57,396,000	287,814,000	174,935,000
Interest expense:
Deposits and escrow	3,565,000	6,672,000	13,666,000	28,298,000
Borrowed funds	2,265,000	5,780,000	8,225,000	17,613,000
Total interest expense	5,830,000	12,452,000	21,891,000	45,911,000
Net interest income	94,828,000	44,944,000	265,923,000	129,024,000
(Credit) provision for credit losses	(5,187,000)	5,931,000	6,344,000	20,003,000
Net interest income after (credit) provision for credit losses	100,015,000	39,013,000	259,579,000	109,021,000
Non-interest income:
Service charges and other fees	4,581,000	1,632,000	11,377,000	3,918,000
Title fees	482,000		1,603,000
Loan level derivative income	445,000	1,544,000	2,796,000	5,201,000
BOLI income	2,249,000	1,033,000	5,181,000	3,831,000
Gain on sale of SBA loans	348,000	808,000	22,182,000	972,000
Gain on sale of residential loans	304,000	617,000	1,533,000	974,000
Net gain on equity securities	0	175,000	131,000	139,000
Net gain on sale of securities and other assets		215,000	730,000	3,357,000
Loss on termination of derivatives			(16,505,000)
Other	1,319,000	125,000	2,861,000	379,000
Total non-interest income	9,728,000	6,149,000	31,889,000	18,771,000
Non-interest expense:
Salaries and employee benefits	28,276,000	14,316,000	80,693,000	45,030,000
Severance			1,875,000	4,000,000
Occupancy and equipment	7,814,000	4,046,000	22,913,000	12,061,000
Data processing costs	3,573,000	2,146,000	12,132,000	6,177,000
Marketing	1,054,000	345,000	2,702,000	1,140,000
Professional services	2,751,000	935,000	7,154,000	2,713,000
Federal deposit insurance premiums	1,173,000	761,000	3,046,000	1,767,000
Loss from extinguishment of debt			1,751,000
Curtailment loss			1,543,000
Merger expenses and transaction costs	2,472,000	769,000	42,250,000	2,427,000
Branch restructuring costs	4,518,000		6,177,000
Amortization of other intangible assets	715,000	0	1,907,000	0
Other	4,437,000	1,535,000	10,327,000	4,924,000
Total non-interest expense	56,783,000	24,853,000	194,470,000	80,239,000
Income before income taxes	52,960,000	20,309,000	96,998,000	47,553,000
Income tax expense	14,565,000	4,441,000	28,359,000	10,327,000
Net income	38,395,000	15,868,000	68,639,000	37,226,000
Preferred stock dividends	1,822,000	1,822,000	5,465,000	2,962,000
Net income available to common stockholders	$ 36,573,000	$ 14,046,000	$ 63,174,000	$ 34,264,000
Earnings per common share:
Basic	$ 0.89	$ 0.66	$ 1.62	$ 1.57
Diluted	$ 0.89	$ 0.65	$ 1.62	$ 1.56

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 38,395	$ 15,868	$ 68,639	$ 37,226
Other comprehensive income (loss):
Change in net unrealized gain or loss during the period	(8,654)	1,716	(15,222)	15,769
Reclassification adjustment for net gains included in net gain on securities and other assets		(215)	(1,207)	(3,357)
Change in pension and other postretirement obligations:
Reclassification adjustment for expense included in other expense	(735)	4	(1,595)	194
Reclassification adjustment for curtailment loss			1,543
Change in the net actuarial gain or loss	941	267	2,470	619
Change in unrealized gain or loss on derivatives:
Change in net unrealized gain or loss during the period	225	100	3,767	(25,098)
Reclassification adjustment for loss included in loss on termination of derivatives			16,505
Reclassification adjustment for expense included in interest expense	38	2,319	902	3,679
Other comprehensive (loss) income before income taxes	(8,185)	4,191	7,163	(8,194)
Deferred tax (benefit) expense	(2,567)	1,327	2,281	(2,595)
Total other comprehensive (loss) income, net of tax	(5,618)	2,864	4,882	(5,599)
Total comprehensive income	$ 32,777	$ 18,732	$ 73,521	$ 31,627

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Preferred StockCumulative Effect, Period of Adoption, Adjusted Balance	Preferred Stock	Common StockCumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Additional Paid-in CapitalCumulative Effect, Period of Adoption, Adjusted Balance	Additional Paid-in Capital	Retained EarningsCumulative Effect, Period of Adoption, Adjustment	Retained EarningsCumulative 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 BMPCumulative Effect, Period of Adoption, Adjusted Balance	Common Stock Held by BMP	Treasury Stock, at CostCumulative 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

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 68,639,000	$ 37,226,000
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)	(3,357,000)
Net gain on equity securities	(131,000)	(139,000)
Net gain on sale of loans held for sale	(23,715,000)	(1,946,000)
Loss on termination of derivatives	16,505,000
Net depreciation, amortization and accretion	4,907,000	3,786,000
Amortization of Intangible Assets	1,907,000	0
Stock-based compensation	3,885,000	1,953,000
Provision for credit losses	6,344,000	20,003,000
Originations of loans held for sale	(38,709,000)	(26,007,000)
Proceeds from sale of loans originated for sale	57,558,000	38,789,000
Increase in cash surrender value of BOLI	(4,831,000)	(2,697,000)
Gain from death benefits from BOLI	(350,000)	(1,134,000)
Deferred income tax benefit	(12,704,000)	(6,841,000)
Decrease (increase) in other assets	126,377,000	(17,810,000)
(Decrease) increase in other liabilities	(45,669,000)	6,148,000
Net cash provided by operating activities	159,283,000	47,974,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sales of securities available-for-sale	138,077,000	68,784,000
Proceeds from sales of marketable equity securities	6,101,000	410,000
Purchases of securities available-for-sale	(1,025,697,000)	(149,353,000)
Purchases of securities held-to-maturity	(40,303,000)
Acquisition of marketable equity securities	0	(136,000)
Proceeds from calls and principal repayments of securities available-for-sale	350,598,000	121,169,000
Purchase of BOLI	(40,000,000)	(40,000,000)
Proceeds received from cash surrender value of BOLI	1,464,000	3,020,000
Loans purchased	(9,855,000)	(18,892,000)
Proceeds from the sale of portfolio loans transferred to held for sale	681,956,000	35,025,000
Net decrease (increase) in loans	244,995,000	(266,490,000)
Purchases of fixed assets, net	(781,000)	(1,442,000)
Redemptions (purchases) of restricted stock, net	46,350,000	(1,286,000)
Net cash received in business combination	715,988,000	0
Net cash provided by (used in) investing activities	1,068,893,000	(249,191,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Increase in deposits	733,744,000	133,042,000
Repayments of FHLBNY advances, long-term	(190,150,000)	(188,800,000)
Repayments of FHLBNY advances, short-term, net	(2,663,865,000)
Proceeds from FHLBNY advances, short-term	1,435,000,000	127,500,000
Proceeds from FHLBNY advances, long-term	25,000,000	97,450,000
Repayments of other short-term borrowings, net	(117,371,000)	(40,000,000)
Proceeds from preferred stock issuance, net	0	116,569,000
Proceeds from exercise of stock options	396,000	38,000
Release of stock for benefit plan awards	779,000	28,000
Payments related to tax withholding for equity awards	(147,000)	(329,000)
BMP ESOP shares received to satisfy distribution of retirement benefits	(993,000)
Treasury shares repurchased	(29,973,000)	(35,356,000)
Redemption of REIT preferred stock	(121,000)
Cash dividends paid to preferred stockholders	(5,465,000)	(2,962,000)
Cash dividends paid to common stockholders	(29,602,000)	(14,168,000)
Net cash (used in) provided by financing activities	(842,768,000)	193,012,000
Increase (decrease) in cash and cash equivalents	385,408,000	(8,205,000)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	243,603,000	155,488,000
CASH AND CASH EQUIVALENTS, END OF PERIOD	629,011,000	147,283,000
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for income taxes	17,930,000	13,755,000
Cash paid for interest	21,995,000	46,972,000
Loans transferred to held for sale	685,747,000	47,938,000
Loans transferred to held for investment	10,000,000
Premises held for investment transferred to held for sale	2,799,000
Premises held for sale transferred premises and fixed assets, net	0	(514,000)
Operating lease assets in exchange for operating lease liabilities	4,048,000	$ 1,524,000
Cumulative change due to CECL adoption	1,686,000
Net non-cash liabilities assumed in Merger (See Note 2)	$ 324,479,000

BASIS OF PRESENTATION

BASIS OF PRESENTATION	9 Months Ended
	Sep. 30, 2021
BASIS OF PRESENTATION
BASIS OF PRESENTATION	1. On February 1, 2021, Dime Community Bancshares, Inc., a Delaware corporation (“Legacy Dime”) merged with and into Bridge Bancorp, Inc., a New York corporation (“Bridge”) (the “Merger”), with Bridge as the surviving corporation under the name “Dime Community Bancshares, Inc.” (the “Holding Company”). At the effective time of the Merger (the “Effective Time”), each outstanding share of Legacy Dime common stock, par value $0.01 per share, was converted into the right to receive 0.6480 shares of the Holding Company’s common stock, par value $0.01 per share. At the Effective Time, each outstanding share of Legacy Dime’s Series A preferred stock, par value $0.01 (the “Dime Preferred Stock”), was converted into the right to receive one share of a newly created series of the Holding Company’s preferred stock having the same powers, preferences and rights as the Dime Preferred Stock. Immediately following the Merger, Dime Community Bank, a New York-chartered commercial bank and a wholly-owned subsidiary of Legacy Dime, merged with and into BNB Bank, a New York-chartered trust company and a wholly-owned subsidiary of Bridge, with BNB Bank as the surviving bank, under the name “Dime Community Bank” (the “Bank”). The unaudited consolidated financial statements presented in this Quarterly Report on Form 10-Q include the collective results of the Holding Company and its wholly-owned subsidiary, the Bank, which are collectively herein referred to as “we”, “us”, “our” and the “Company.” The Merger was accounted for as a reverse merger using the acquisition method of accounting, which means that for accounting and financial reporting purposes, Legacy Dime was deemed to have acquired Bridge in the Merger, even though Bridge was the legal acquirer. Accordingly, Legacy Dime’s historical financial statements are the historical financial statements of the combined company for all periods before February 1, 2021 (the “Merger Date”). The Company’s results of operations for 2021 include the results of operations of Bridge on and after the Merger Date. Results for periods before the Merger Date reflect only those of Legacy Dime and do not include the results of operations of Bridge. The number of shares issued and outstanding, earnings per share, additional paid-in capital, dividends paid and all references to share quantities of the Company have been retrospectively adjusted to reflect the equivalent number of shares issued to holders of Legacy Dime common stock in the Merger. The assets and liabilities of Bridge as of the Merger Date have been recorded at their estimated fair value and added to those of Legacy Dime. See Note 2. Merger for further information. As of September 30, 2021, we operated 65 branch locations throughout Long Island and the New York City boroughs of Brooklyn, Queens, Manhattan, and the Bronx. The Company is a bank holding company engaged in commercial banking and financial services through its wholly-owned subsidiary, Dime Community Bank, which was known as BNB Bank prior to the Merger. The Bank was established in 1910 and is headquartered in Hauppauge, New York. The Holding Company was incorporated under the laws of the State of New York in 1988 to serve as the holding company for the Bank. The Company functions primarily as the holder of all of the Bank’s common stock. Our bank operations include Dime Community Inc., a real estate investment trust subsidiary which was formerly known as Bridgehampton Community, Inc., as an operating subsidiary. Our bank operations also include Bridge Abstract LLC (“Bridge Abstract”), a wholly-owned subsidiary of the Bank, which is a broker of title insurance services. In connection with the Merger, on February 1, 2021, the Holding Company acquired Dime Community Bank and its wholly-owned subsidiaries. In September 2021, the Company dissolved two REITs, DSBW Preferred Funding Corporation and DSBW Residential Preferred Funding Corporation, which were wholly-owned subsidiaries of the Bank. The preferred shares issued by the REITs were redeemed in connection with the dissolutions. The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. The unaudited consolidated financial statements included herein reflect all normal recurring adjustments that are, in the opinion of management, necessary for a fair presentation of the results for the interim periods presented. In preparing the interim financial statements, management has made estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reported periods. Such estimates are subject to change in the future as additional information becomes available or previously existing circumstances are modified. Actual future results could differ significantly from those estimates. The annualized results of operations for the nine months ended September 30, 2021 are not necessarily indicative of the results of operations that may be expected for the entire fiscal year. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain reclassifications have been made to prior year amounts, and the related discussion and analysis, to conform to the current year presentation. These reclassifications did not have an impact on net income or total stockholders' equity. The unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Legacy Dime’s Annual Report on Form 10-K for the year ended December 31, 2019, which remain significantly unchanged and have been followed similarly as in prior periods except for the allowance for credit losses policy, resulting from the adoption of Accounting Standard Update (“ASU”) No. 2016-13, “Financial Instruments – Credit Losses (Topic 326)” and certain policies added as a result of the Merger. Risks and Uncertainties In March 2020, the World Health Organization declared the outbreak of COVID-19 as a global pandemic, which has spread to most countries, including the United States. The pandemic has adversely affected economic activity globally, nationally and locally. In March 2020, the United States declared a National Public Health Emergency in response to the COVID-19 pandemic. In an effort to mitigate the spread of COVID-19, local state governments, including New York (in which the Bank has retail banking offices), have taken preventative or protective actions such as travel restrictions, advising or requiring individuals to limit or forego their time outside of their homes, and other forced closures for certain types of non-essential businesses. The impact of these actions is expected to continue to have an adverse impact on the economies and financial markets in the United States. The Coronavirus Aid, Relief and Economic Security (“CARES”) Act was signed into law at the end of March 2020. The CARES Act is intended to provide relief and lessen a severe economic downturn. The stimulus package includes direct financial aid to American families and economic stimulus to significantly impacted industry sectors. The package also includes extensive emergency funding for hospitals and healthcare providers. In December 2020, the 2021 Consolidated Appropriations Act was signed into law to provide additional relief. It is possible that there will be continued material, adverse impacts to significant estimates, asset valuations, and business operations, including intangible assets, investments, loans, deferred tax assets, and derivative counter party risk.

MERGER

MERGER	9 Months Ended
	Sep. 30, 2021
MERGER
MERGER	2 . As described in Note 1. Basis of Presentation, on February 1, 2021, we completed our Merger with Legacy Dime. Pursuant to the merger agreement, Legacy Dime merged with and into Bridge with Bridge as the surviving corporation under the name “Dime Community Bancshares, Inc.” At the effective time of the Merger, each outstanding share of Legacy Dime common stock, par value $0.01 per share, was converted into 0.6480 shares of the Company’s common stock, par value $0.01 per share. At the Effective Time, each outstanding share of Legacy Dime’s Series A preferred stock, par value $0.01 was converted into one share of a newly created series of the Company’s preferred stock having the same powers, preferences and rights as the Dime Preferred Stock. In connection with the Merger, the Company assumed $115.0 million in aggregate principal amount of the 4.50% Fixed-to-Floating Rate Subordinated Debentures due 2027 of Legacy Dime. The Merger constituted a business combination and was accounted for as a reverse merger using the acquisition method of accounting. As a result, Legacy Dime was the accounting acquirer and Bridge was the legal acquirer and the accounting acquiree. Accordingly, the historical financial statements of Legacy Dime became the historical financial statements of the combined company. In addition, the assets and liabilities of Bridge have been recorded at their estimated fair values and added to those of Legacy Dime as of the Merger Date. The determination of fair value required management to make estimates about discount rates, expected future cash flows, market conditions and other future events that are subjective and subject to change. The Company issued 21.2 million shares of its common stock to Legacy Dime stockholders in connection with the Merger, which represented 51.5% of the voting interests in the Company upon completion of the Merger. In accordance with FASB ASC 805-40-30-2, the purchase price in a reverse acquisition is determined based on the number of equity interests the legal acquiree would have had to issue to give the owners of the legal acquirer the same percentage equity interest in the combined entity that results from the reverse acquisition. The table below summarizes the ownership of the combined company following the Merger, for each shareholder group, as well as the market capitalization of the combined company using shares of Bridge and Legacy Dime common stock outstanding at January 31, 2021 and Bridge’s closing price on January 31, 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Dime Community Bancshares, Inc. Ownership and Market Value ​ ​ Number of ​ ​ ​ ​ Market Value at ​ ​ Bridge ​ Percentage ​ $24.43 Bridge (Dollars and shares in thousands) ​ Outstanding Shares ​ Ownership ​ Share Price Bridge shareholders ​ 19,993 ​ 48.5% $ 488,420 Legacy Dime shareholders ​ ​ 21,233 ​ ​ 51.5% ​ ​ 518,720 Total ​ ​ 41,226 ​ ​ 100.0% ​ $ 1,007,140 ​ The table below summarizes the hypothetical number of shares as of January 31, 2021 that Legacy Dime would have to issue to give Bridge owners the same percentage ownership in the combined company. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Hypothetical Legacy Dime Ownership ​ ​ Number of ​ ​ ​ ​ ​ Legacy Dime ​ Percentage (Shares in thousands) ​ Outstanding Shares ​ Ownership Bridge shareholders ​ 30,853 ​ 48.5% Legacy Dime shareholders ​ ​ 32,767 ​ ​ 51.5% Total ​ ​ 63,620 ​ ​ 100.0% ​ The purchase price is calculated based on the number of hypothetical shares of Legacy Dime common stock issued to Bridge shareholders multiplied by the share price as demonstrated in the table below. ​ ​ ​ ​ ​ (Dollars and shares in thousands) ​ ​ ​ Number of hypothetical Legacy Dime shares issued to Bridge shareholders ​ ​ 30,853 Legacy Dime market price per share as of February 1, 2021 ​ $ 15.90 Purchase price determination of hypothetical Legacy Dime shares issued to Bridge shareholders ​ $ 490,560 Value of Bridge stock options hypothetically converted to options to acquire shares of Legacy Dime common stock ​ ​ 643 Cash in lieu of fractional shares ​ ​ 7 Purchase price consideration ​ $ 491,210 ​ The following table provides the purchase price allocation as of the Merger Date and the Bridge assets acquired and liabilities assumed at their estimated fair value as of the Merger Date as recorded by Dime Community Bancshares. We recorded the estimate of fair value based on initial valuations available at the Merger Date and these estimates are considered preliminary and subject to adjustment for up to one year after the Merger Date. While we believe that the information available on the Merger Date provided a reasonable basis for estimating fair value, we are currently within the measurement period and our estimates of fair value are provisional. During the third quarter of 2021, no material fair value adjustments to acquired assets and assumed liabilities were identified. We expect that we may obtain additional information and evidence during the measurement period that would result in changes to the estimated fair value amounts. The measurement period ends on the earlier of one year after the Merger Date or the date we are able to determine that we have obtained all necessary information about the facts and circumstances that existed as of Merger Date. We expect to finalize all valuations and record final adjustments during the fourth quarter of 2021. Subsequent adjustments to fair value, if necessary, will be reflected in our future filings. ​ ​ ​ ​ ​ (In thousands) ​ ​ ​ Purchase price consideration ​ $ 491,210 ​ ​ ​ ​ Fair value of assets acquired: ​ ​ ​ Cash and due from banks ​ ​ 715,988 Securities available-for-sale ​ ​ 651,997 Loans held for sale ​ ​ 10,000 Loans held for investment ​ ​ 4,531,640 Premises and fixed assets ​ ​ 37,881 Restricted stock ​ ​ 23,362 BOLI ​ ​ 94,085 Other intangible assets ​ ​ 10,984 Operating lease assets ​ ​ 45,603 Other assets ​ ​ 117,474 Total assets acquired ​ ​ 6,239,014 Fair value of liabilities assumed: ​ ​ ​ Deposits ​ ​ 5,405,575 Other short-term borrowings ​ ​ 216,298 Subordinated debt ​ ​ 83,200 Operating lease liabilities ​ ​ 45,285 Other liabilities ​ ​ 97,147 Total liabilities assumed ​ ​ 5,847,505 Fair value of net identifiable assets ​ ​ 391,509 Goodwill resulting from Merger ​ $ 99,701 ​ ​ ​ ​ ​ As a result of the Merger, we recorded $99.7 million of goodwill. The goodwill recorded is not deductible for income tax purposes. ​ As described in detail in Note 3. Summary of Accounting Policies, the Company is required to record purchased financial assets with credit deterioration (PCD assets), defined as a more-than-insignificant deterioration in credit quality since origination or issuance, at the purchase price plus the allowance for credit losses expected at the time of acquisition. Under this method, there is no credit loss expense affecting net income on acquisition of PCD assets. Changes in estimates of expected losses after acquisition are recognized as credit loss expense (or reversal of credit loss expense) in subsequent periods as they arise. Any non-credit discount or premium resulting from acquiring a pool of purchased financial assets with credit deterioration shall be allocated to each individual asset. At the acquisition date, the initial allowance for credit losses determined on a collective basis shall be allocated to individual assets to appropriately allocate any non-credit discount or premium. The non-credit discount or premium, after the adjustment for the allowance for credit losses, shall be accreted to interest income using the interest method based on the effective interest rate determined after the adjustment for credit losses at the adoption date. ​ ​ ​ ​ ​ (In thousands) ​ ​ ​ PCD loans: ​ Unpaid principal balance ​ $ 295,306 Non-credit discount at acquisition ​ (9,050) Unpaid principal balance, net ​ 286,256 ​ ​ ​ ​ Allowance for credit losses at acquisition ​ ​ (52,284) Fair value at acquisition ​ ​ 233,972 ​ ​ ​ ​ Non-PCD loans: ​ Unpaid principal balance ​ 4,289,236 Premium at acquisition ​ 8,432 Fair value at acquisition ​ 4,297,668 ​ ​ ​ Total fair value at acquisition ​ $ 4,531,640 ​ Supplemental disclosures of cash flow information related to investing and financing activities regarding the Merger are as follows for the nine months ended September 30, 2021: ​ ​ ​ ​ ​ (In thousands) ​ ​ ​ Business combination: ​ Fair value of tangible assets acquired ​ $ 6,228,030 Goodwill, core deposit intangible and other intangible assets acquired ​ 110,685 Liabilities assumed ​ 5,847,505 Purchase price consideration ​ ​ 491,210 ​ Other intangible assets consisted of core deposit intangibles and a non-compete agreement with estimated fair values at the Merger Date of $10.2 million and $780 thousand, respectively. Core deposit intangibles are being amortized over a life of 10 years on an accelerated basis. The non-compete agreement is being amortized over a life of 13 months. ​ ​ Pro Forma Combined Results of Operations The following pro forma financial information presents the consolidated results of operations of Legacy Dime and Bridge as if the Merger occurred as of January 1, 2020 with pro forma adjustments. The pro forma adjustments give effect to any change in interest income due to the accretion of discounts (premiums) associated with the fair value adjustments of acquired loans, any change in interest expense due to estimated premium amortization/discount accretion associated with the fair value adjustments to acquired time deposits and other debt, and the amortization of the core deposit intangible that would have resulted had the deposits been acquired as of January 1, 2020. Merger related expenses incurred by the Company during the three and nine months ended September 30, 2021 are not reflected in the pro forma amounts. The pro forma information does not necessarily reflect the results of operations that would have occurred had Legacy Dime merged with Bridge at the beginning of 2020. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (Dollars in thousands except per share amounts) 2021 2020 ​ 2021 2020 Net interest income $ 93,316 $ 86,818 ​ $ 274,499 $ 252,455 Non-interest income ​ ​ 9,728 ​ ​ 12,939 ​ ​ 33,240 ​ ​ 33,030 Net income ​ ​ 39,978 ​ ​ 29,971 ​ ​ 92,782 ​ ​ 72,015 Net income available to common shareholders ​ ​ 37,700 ​ ​ 27,791 ​ ​ 86,390 ​ ​ 68,169 Earnings per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ ​ 0.93 ​ ​ 0.68 ​ ​ 2.11 ​ ​ 1.66 Diluted ​ ​ 0.93 ​ ​ 0.68 ​ ​ 2.11 ​ ​ 1.66 ​

SUMMARY OF ACCOUNTING POLICIES

SUMMARY OF ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2021
SUMMARY OF ACCOUNTING POLICIES
SUMMARY OF ACCOUNTING POLICIES	3 . Summary of Significant Accounting Policies In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all adjustments necessary for a fair presentation of the Company’s financial condition as of September 30, 2021 and December 31, 2020, the results of operations and statements of comprehensive income for the three and nine months ended September 30, 2021 and 2020, the changes in stockholders’ equity for the three and nine months ended September 30, 2021 and 2020, and cash flows for the nine months ended September 30, 2021 and 2020. Please see "Part I - Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations - Critical Accounting Policies" for a discussion of areas in the accompanying unaudited condensed consolidated financial statements utilizing significant estimates. Recent Accounting Pronouncements Allowance for Credit Losses – The adoption of the CECL Standard resulted in an initial decrease of $3.9 million to the allowance for credit losses and an increase of $1.4 million to the reserve for unfunded commitments in other liabilities. The after-tax cumulative-effect adjustment of $1.7 million was recorded in retained earnings as of January 1, 2021. There were no held-to-maturity securities as of January 1, 2021 and, therefore, no impact from the adoption of the CECL Standard. ​ The allowance for credit losses is a valuation allowance that is deducted from the amortized cost basis of loans to present the net amount expected to be collected on the loans. Loan losses are charged against the allowance when management believes it has confirmed the loan balance is uncollectible. Subsequent recoveries, if any, are credited to the allowance. ​ The CECL Standard requires that debt securities held-to-maturity be accounted for under the current expected credit losses model, including historical loss experience and impact of current conditions and reasonable and supportable forecasts, with an associated allowance for credit losses. In addition, while credit losses on debt securities available-for-sale should be measured in accordance with the other-than-temporary impairment (“OTTI”) framework under current GAAP, the amendments in the CECL Standard require that these credit losses be presented as an allowance for credit losses. For AFS debt securities, a decline in fair value due to credit loss results in recording an allowance for credit losses to the extent the fair value is less than the amortized cost basis. Management estimates the allowance for credit losses for the Company’s loan portfolio required using relevant available information, from internal and external sources, relating to past events, current conditions, and reasonable and supportable forecasts. Historically observed credit loss experience of peer banks within our geography provide the basis for the estimation of expected credit losses. Adjustments to historical loss information are made for differences in current loan-specific risk characteristics such as differences in underwriting standards, portfolio mix, delinquency level, or terms as well as changes in environmental conditions, such as changes in unemployment rates, gross domestic product, and real estate pricing. Management evaluates the adequacy of the allowance on a quarterly basis. ​ Accrued interest receivable is excluded from the estimate of credit losses. The allowance for credit losses is measured on a collective (pool) basis when similar risk characteristics exist. The Company has identified the following portfolio segments and measures the allowance for credit losses using the following methods: ​ One-to-four family residential, including condominium and cooperative apartment loans - ​ Multifamily residential and residential mixed-use loans - ​ Commercial real estate and commercial mixed-use loans - ​ Acquisition, development, and construction loans ​ Commercial, Industrial and Agricultural Loans - ​ Other Loans ​ As allowed by ASC 326, the Entity elected to maintain pools of loans accounted for under ASC 310-30. In accordance with the standard, management did not reassess whether modifications to individual acquired financial assets accounted for in pools were troubled debt restructurings (“TDRs”) as of the date of adoption. TDRs Loans that do not share risk characteristics are evaluated on an individual basis based on various factors. Loans evaluated individually are not included in the collective evaluation. Factors that may be considered are borrower delinquency trends and non-accrual status, probability of foreclosure or note sale, changes in the borrower’s circumstances or cash collections, borrower’s industry, or other facts and circumstances of the loan or collateral. ​ Individually Evaluated Loans with an ACL and Other Real Estate Owned determined based on recent appraised values. The fair value of other real estate owned is also determined based on recent appraised values less the estimated cost to sell. These appraisals may utilize a single valuation approach or a combination of approaches including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between the comparable sales and income data available. Adjustments may relate to location, square footage, condition, amenities, market rate of leases as well as timing of comparable sales. All appraisals undergo a second review process to ensure that the methodology employed and the values derived are reasonable. The fair value of non-real estate collateral, which includes inventory, may be determined based on an appraisal, net book value per the borrower’s financial statements, aging reports, or by reference to market activity, adjusted or discounted based on management’s historical knowledge, changes in market conditions from the time of the valuation and management’s expertise and knowledge of the borrower and its business. For non-collateral-dependent loans, ACL is measured based on the difference between the present value of expected cash flows and the amortized cost basis of the loan as of the measurement date. Appraisals for collateral-dependent loans are performed by certified general appraisers (for commercial properties) or certified residential appraisers (for residential properties) whose qualifications and licenses have been reviewed and verified by the Company. Once received, the Appraisal and Credit Departments review the assumptions and approaches utilized in the appraisal as well as the overall resulting fair value in comparison with independent data sources such as recent market data or industry-wide statistics. Management also considers the appraisal values for commercial properties associated with current loan origination activity. Collectively, this information is reviewed to help assess current trends in commercial property values. For each collateral dependent loan, management considers information that relates to the type of property to determine if such properties may have appreciated or depreciated in value since the date of the most recent appraisal. Adjustments to fair value are made only when the analysis indicates a probable decline in collateral values. Adjustments made in the appraisal process are not deemed material to the overall consolidated financial statements given the level of collateral dependent loans measured at fair value on a non-recurring basis. Allowance for Credit Losses on Off-Balance Sheet Credit Exposures – The Company estimates expected credit losses over the contractual period in which the Company is exposed to credit risk via a contractual obligation to extend credit, unless that obligation is unconditionally cancellable by the Company. The allowance for credit losses on off-balance sheet credit exposures, which is included in other liabilities on the consolidated statements of financial condition, is adjusted as a provision for credit loss expense. The estimate includes consideration of the likelihood that funding will occur and an estimate of expected credit losses on commitments expected to be funded over its estimated life, which is the same as the expected loss factor as determined based on the corresponding portfolio segment. Loans acquired in a business combination – ​ A purchased financial asset that does not qualify as a PCD asset is accounted for similar to an originated financial asset. Generally, this means that an entity recognizes the allowance for credit losses for non-PCD assets through net income at the time of acquisition. In addition, both the credit discount and non-credit discount or premium resulting from acquiring a pool of purchased financial assets that do not qualify as PCD assets shall be allocated to each individual asset. This combined discount or premium shall be accreted to interest income using the effective yield method. ​ For further discussion of our loan accounting and acquisitions, see Note 2 – Merger and Note 8 – Loans. ​ Held-to-maturity debt securities and the allowance for credit losses To the extent that debt securities in the held-to-maturity portfolio share common risk characteristics, estimated expected credit losses are calculated in a manner like that used for loans held for investment. That is, for pools of such debt securities with common risk characteristics, the historical lifetime probability of default and severity of loss in the event of default is derived or obtained from external sources and adjusted for the expected effects of reasonable and supportable forecasts over the expected lives of the securities. Expected credit loss on each debt security in the held-to-maturity portfolio that do not share common risk characteristics with any of the pools of debt securities is individually measured based on net realizable value, or the difference between the discounted value of the expected future cash flows, based on the original effective interest rate, and the recorded amortized cost basis of the security. With respect to certain classes of debt securities, primarily U.S. Treasuries and securities issued by Government Sponsored Entities (“GSEs”), the Company considers the history of credit losses, current conditions and reasonable and supportable forecasts, which may indicate that the expectation that nonpayment of the amortized cost basis is or continues to be zero, even if the U.S. government were to technically default. Therefore, the Company did not record an allowance for expected credit losses on its securities issued by GSEs at September 30, 2021. Accrued interest receivable is excluded from the estimate of credit losses. Available-for-sale debt securities and the allowance for credit losses For available-for-sale debt securities in an unrealized loss position, management first assesses whether it intends to sell, or is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through income. For available-for-sale debt securities that do not meet the aforementioned criteria, management evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes in the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. If the assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis for the security, a credit loss exists and an allowance for credit losses is recorded, limited to the amount the fair value is less than amortized cost basis. Declines in fair value that have not been recorded through an allowance for credit losses, such as declines due to changes in market interest rates, are excluded from earnings and reported, net of tax, in other comprehensive income (“OCI”). Changes in the allowance for credit losses are recorded as provision for (or reversal of) credit loss expense. Losses are charged against the allowance when management believes the collectability of an available-for-sale security is confirmed or when the criteria regarding intent or requirement to sell is met. Accrued interest receivable is excluded from the estimate of credit losses. ​ ​ ​

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	9 Months Ended
	Sep. 30, 2021
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS).
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	4 . Activity in accumulated other comprehensive income (loss), net of tax, was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ Securities ​ Defined ​ ​ ​ ​ Other ​ ​ Available- ​ Benefit ​ ​ ​ ​ Comprehensive (In thousands) for-Sale Plans Derivatives Income (Loss) Balance as of January 1, 2021 ​ $ 12,694 ​ $ (6,086) ​ $ (12,532) ​ $ (5,924) Other comprehensive (loss) income before reclassifications ​ (10,378) ​ 2,706 ​ 13,850 ​ 6,178 Amounts reclassified from accumulated other comprehensive loss ​ (826) ​ (1,082) ​ 612 ​ (1,296) Net other comprehensive (loss) income during the period ​ (11,204) ​ 1,624 ​ 14,462 ​ 4,882 Balance as of September 30, 2021 ​ $ 1,490 ​ $ (4,462) ​ $ 1,930 ​ $ (1,042) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of January 1, 2020 ​ $ 4,621 ​ $ (6,024) ​ $ (4,537) ​ $ (5,940) Other comprehensive income (loss) before reclassifications ​ 10,783 ​ 423 ​ (17,150) ​ (5,944) Amounts reclassified from accumulated other comprehensive loss ​ (2,302) ​ 133 ​ 2,514 ​ 345 Net other comprehensive income (loss) during the period ​ 8,481 ​ 556 ​ (14,636) ​ (5,599) Balance as of September 30, 2020 ​ $ 13,102 ​ $ (5,468) ​ $ (19,173) ​ $ (11,539) ​ The before and after-tax amounts allocated to each component of other comprehensive income (loss) are presented in the table below for the periods indicated. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands) 2021 2020 ​ 2021 2020 Change in unrealized holding gain or loss on securities available-for-sale: ​ ​ ​ ​ Change in net unrealized gain or loss during the period ​ $ (8,654) ​ $ 1,716 ​ $ (15,222) ​ $ 15,769 Reclassification adjustment for net gains included in net gain on securities and other assets ​ — ​ (215) ​ (1,207) ​ (3,357) Net change ​ (8,654) ​ 1,501 ​ (16,429) ​ 12,412 Tax (benefit) expense ​ (2,714) ​ 475 ​ (5,226) ​ 3,931 Net change in unrealized holding gain or loss on securities available-for-sale, net of reclassification adjustments and tax ​ (5,940) ​ 1,026 ​ (11,203) ​ 8,481 Change in pension and other postretirement obligations: ​ ​ ​ ​ Reclassification adjustment for expense included in other expense ​ (735) ​ 4 ​ (1,595) ​ 194 Reclassification adjustment for curtailment loss ​ ​ — ​ ​ — ​ ​ 1,543 ​ ​ — Change in the net actuarial gain or loss ​ 941 ​ 267 ​ 2,470 ​ 619 Net change ​ 206 ​ ​ 271 ​ 2,418 ​ 813 Tax expense ​ 65 ​ 86 ​ 795 ​ 257 Net change in pension and other postretirement obligations ​ 141 ​ 185 ​ 1,623 ​ 556 Change in unrealized gain or loss on derivatives: ​ ​ ​ ​ Change in net unrealized gain or loss during the period ​ 225 ​ 100 ​ 3,767 ​ (25,098) Reclassification adjustment for loss included in loss on termination of derivatives ​ ​ — ​ ​ — ​ ​ 16,505 ​ ​ — Reclassification adjustment for expense included in interest expense ​ 38 ​ 2,319 ​ 902 ​ 3,679 Net change ​ 263 ​ 2,419 ​ 21,174 ​ (21,419) Tax expense (benefit) ​ 82 ​ 766 ​ 6,712 ​ (6,783) Net change in unrealized gain or loss on derivatives, net of reclassification adjustments and tax ​ 181 ​ 1,653 ​ 14,462 ​ (14,636) Other comprehensive (loss) income, net of tax ​ $ (5,618) ​ $ 2,864 ​ $ 4,882 ​ $ (5,599) ​

EARNINGS PER COMMON SHARE ("EPS

EARNINGS PER COMMON SHARE ("EPS")	9 Months Ended
	Sep. 30, 2021
EARNINGS PER COMMON SHARE ("EPS")
EARNINGS PER COMMON SHARE ("EPS")	5 . Basic EPS is computed by dividing net income available to common stockholders by the weighted-average common shares outstanding during the reporting period. Diluted EPS is computed using the same method as basic EPS, but reflects the potential dilution that would occur if "in the money" stock options were exercised and converted into common stock, and prior to 2021, if all likely aggregate performance-based share awards ("PSA”) were issued. In determining the weighted average shares outstanding for basic and diluted EPS, treasury shares are excluded. Vested restricted stock award ("RSA") shares are included in the calculation of the weighted average shares outstanding for basic and diluted EPS. Unvested RSA and PSA shares not yet awarded are recognized as a special class of participating securities under ASC 260, and are included in the calculation of the weighted average shares outstanding for basic and diluted EPS. The following is a reconciliation of the numerators and denominators of basic and diluted EPS for the periods presented: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands except share and per share amounts) 2021 2020 2021 2020 ​ ​ ​ ​ ​ ​ Net income available to common stockholders ​ $ 36,573 ​ $ 14,046 ​ $ 63,174 ​ $ 34,264 Less: Dividends paid and earnings allocated to participating securities ​ (437) ​ (83) ​ (811) ​ (195) Income attributable to common stock ​ $ 36,136 ​ $ 13,963 ​ $ 62,363 ​ $ 34,069 Weighted average common shares outstanding, including participating securities ​ 40,915,012 ​ 21,378,332 ​ 38,979,259 ​ 21,848,184 Less: weighted average participating securities ​ (489,274) ​ (187,781) ​ (405,102) ​ (191,438) Weighted average common shares outstanding ​ 40,425,738 ​ 21,190,551 ​ 38,574,157 ​ 21,656,746 Basic EPS ​ $ 0.89 ​ $ 0.66 ​ $ 1.62 ​ $ 1.57 ​ ​ ​ ​ ​ Income attributable to common stock ​ $ 36,136 ​ $ 13,963 ​ $ 62,363 ​ $ 34,069 Weighted average common shares outstanding ​ 40,425,738 ​ 21,190,551 ​ 38,574,157 ​ 21,656,746 Weighted average common equivalent shares outstanding ​ 423 ​ 133,636 ​ 700 ​ 134,334 Weighted average common and equivalent shares outstanding ​ 40,426,161 ​ 21,324,187 ​ 38,574,857 ​ 21,791,080 Diluted EPS ​ $ 0.89 ​ $ 0.65 ​ $ 1.62 ​ $ 1.56 ​ Common and equivalent shares resulting from the dilutive effect of "in-the-money" outstanding stock options are calculated based upon the excess of the average market value of the common stock over the exercise price of outstanding in-the-money stock options during the period. There were 174,584 and 177,953 weighted-average stock options outstanding for the three and nine-month periods ended September 30, 2021, respectively, which were not considered in the calculation of diluted EPS since their exercise prices exceeded the average market price during the period. There were no "out-of-the-money" stock options during the three-month or the nine-month period ended September 30, 2020.

PREFERRED STOCK

PREFERRED STOCK	9 Months Ended
	Sep. 30, 2021
PREFERRED STOCK.
PREFERRED STOCK	6 . On February 5, 2020, Legacy Dime completed an underwritten public offering of 2,999,200 shares, or $75.0 million in aggregate liquidation preference, of its 5.50% Fixed-Rate Non-Cumulative Perpetual Preferred Stock, Series A, par value $0.01 per share, with a liquidation preference of $25.00 per share (the “Legacy Dime Preferred Stock”). The net proceeds received from the issuance of preferred stock at the time of closing were $72.2 million. On June 10, 2020, Legacy Dime completed an underwritten public offering, a reopening of the February 5, 2020 original issuance, of 2,300,000 shares, or $57.5 million in aggregate liquidation preference, of the Legacy Dime Preferred Stock. The net proceeds received from the issuance of preferred stock at the time of closing were $44.3 million. At the Effective Time of the Merger, each outstanding share of the Legacy Dime Preferred Stock was converted into the right to receive one share of a newly created series of the Company’s preferred stock having the same powers, preferences and rights as the Legacy Dime Preferred Stock. The Company expects to pay dividends when, as, and if declared by its board of directors, at a fixed rate of 5.50% per annum, payable quarterly, in arrears, on February 15, May 15, August 15 and November 15 of each year. The Preferred Stock is perpetual and has no stated maturity. The Company may redeem the Preferred Stock at its option at a redemption price equal to $25.00 per share, plus any declared and unpaid dividends (without regard to any undeclared dividends), subject to regulatory approval, on or after June 15, 2025 or within 90 days following a regulatory capital treatment event, as described in the prospectus supplement and accompanying prospectus relating to the offering.

INVESTMENT AND MORTGAGE-BACKED

INVESTMENT AND MORTGAGE-BACKED SECURITIES	9 Months Ended
	Sep. 30, 2021
INVESTMENT AND MORTGAGE-BACKED SECURITIES
INVESTMENT AND MORTGAGE-BACKED SECURITIES	7 . The following tables summarize the major categories of securities owned by the Company as of the dates indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair (In thousands) Cost Gains Losses Value Securities available-for-sale: ​ ​ ​ ​ Agency notes ​ $ 82,475 ​ $ — ​ $ (1,457) ​ $ 81,018 Treasury securities ​ ​ 248,173 ​ ​ 5 ​ ​ (482) ​ ​ 247,696 Corporate securities ​ 122,476 ​ 4,758 ​ (401) ​ 126,833 Pass-through MBS issued by GSEs ​ 622,225 ​ 6,005 ​ (6,273) ​ 621,957 Agency Collateralized Mortgage Obligations ("CMOs") ​ 590,385 ​ 5,159 ​ (5,118) ​ 590,426 State and municipal obligations ​ ​ 41,158 ​ ​ 153 ​ ​ (178) ​ ​ 41,133 Total securities available-for-sale ​ $ 1,706,892 ​ $ 16,080 ​ $ (13,909) ​ $ 1,709,063 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrecognized ​ Unrecognized ​ Fair (In thousands) Cost Gains Losses Value Securities held-to-maturity: ​ ​ ​ ​ Pass-through MBS issued by GSEs ​ $ 25,325 ​ $ — ​ $ — ​ $ 25,325 Agency Collateralized Mortgage Obligations ("CMOs") ​ 14,978 ​ — ​ — ​ 14,978 Total securities held-to-maturity ​ $ 40,303 ​ $ — ​ $ — ​ $ 40,303 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair (In thousands) Cost Gains Losses Value Securities available-for-sale: ​ ​ ​ ​ Agency notes ​ $ 47,500 ​ $ 12 ​ $ (91) ​ $ 47,421 Corporate securities ​ 62,021 ​ 2,440 ​ — ​ 64,461 Pass-through MBS issued by GSEs ​ 135,842 ​ 7,672 ​ (31) ​ 143,483 Agency CMOs ​ 274,898 ​ 8,674 ​ (76) ​ 283,496 Total securities available-for-sale ​ $ 520,261 ​ $ 18,798 ​ $ (198) ​ $ 538,861 ​ As a result of the Merger, the Company acquired $652.0 million of securities available-for-sale on the Merger Date. As of December 31, 2020, there were no securities held-to-maturity. The carrying amount of securities pledged as collateral was $684.0 million and $99.4 million at September 30, 2021 and December 31, 2020, respectively. At September 30, 2021 and December 31, 2020, there were no holdings of securities of any one issuer, other than the U.S. Government and its agencies, in an amount greater than 10% of stockholders' equity. ​ The amortized cost and fair value of debt securities are shown by contractual maturity. Expected maturities may differ from contractual maturities if borrowers have the right to call or prepay obligations with or without call or prepayment penalties. Securities not due at a single maturity date are shown separately. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ Amortized ​ Fair (In thousands) ​ Cost ​ Value Available-for-sale ​ ​ ​ ​ ​ ​ Within one year ​ $ 1,346 ​ $ 1,351 One to five years ​ ​ 270,069 ​ ​ 269,665 Five to ten years ​ ​ 209,938 ​ ​ 212,881 Beyond ten years ​ ​ 12,929 ​ ​ 12,783 Pass-through MBS issued by GSEs and agency CMO ​ ​ 1,212,610 ​ ​ 1,212,383 Total ​ $ 1,706,892 ​ $ 1,709,063 ​ ​ ​ ​ ​ ​ ​ Held-to-maturity ​ ​ ​ ​ ​ ​ Pass-through MBS issued by GSEs and agency CMO ​ $ 40,303 ​ $ 40,303 Total ​ $ 40,303 ​ $ 40,303 ​ The following table presents the information related to sales of securities available-for-sale as of the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands) 2021 2020 ​ 2021 2020 Agency Notes: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Proceeds ​ $ — ​ $ — ​ $ — ​ $ 273 Gross gains ​ ​ — ​ ​ — ​ ​ — ​ ​ — Tax expense on gain ​ ​ — ​ ​ — ​ ​ — ​ ​ — Gross losses ​ ​ — ​ ​ — ​ ​ — ​ ​ — Tax benefit on loss ​ ​ — ​ ​ — ​ ​ — ​ ​ — Corporate Securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Proceeds ​ ​ — ​ ​ — ​ ​ 50,273 ​ ​ 25,403 Gross gains ​ ​ — ​ ​ — ​ ​ 729 ​ ​ 1,344 Tax expense on gain ​ ​ — ​ ​ — ​ ​ 232 ​ ​ 423 Gross losses ​ ​ — ​ ​ — ​ ​ 41 ​ ​ — Tax benefit on loss ​ ​ — ​ ​ — ​ ​ 13 ​ ​ — Pass through MBS issued by GSEs: ​ ​ ​ ​ ​ ​ Proceeds ​ ​ — ​ ​ 5,987 ​ ​ 26,823 ​ ​ 39,182 Gross gains ​ — ​ 215 ​ 187 ​ 2,005 Tax expense on gain ​ — ​ 67 ​ 59 ​ 630 Gross losses ​ — ​ — ​ 35 ​ — Tax benefit on loss ​ — ​ — ​ 11 ​ — Agency CMOs: ​ ​ ​ ​ ​ Proceeds ​ — ​ — ​ 41,324 ​ 4,199 Gross gains ​ — ​ — ​ 268 ​ 8 Tax expense on gain ​ — ​ — ​ 85 ​ 3 Gross losses ​ ​ — ​ ​ — ​ ​ 44 ​ ​ — Tax benefit on loss ​ ​ — ​ ​ — ​ ​ 14 ​ ​ — State and municipal obligations: ​ ​ ​ ​ Proceeds ​ — ​ — ​ 19,657 ​ — Gross gains ​ — ​ — ​ 143 ​ — Tax expense on gain ​ — ​ — ​ 45 ​ — Gross losses ​ ​ — ​ ​ — ​ ​ — ​ ​ — Tax benefit on loss ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands) 2021 2020 ​ 2021 2020 Proceeds: ​ ​ ​ ​ ​ Marketable equity securities ​ $ — ​ $ 137 ​ $ — ​ $ 410 ​ There were no gains on marketable equity securities for the three months ended September 30, 2021. Net gain of $175 thousand was recognized on marketable equity securities for the three months ended September 30, 2020. Net gains of $131 thousand and $139 thousand were recognized on marketable equity securities for the nine months ended September 30, 2021 and 2020, respectively. Marketable equity securities were fully liquidated in connection with the termination of the BMP. There were no sales of securities held-to-maturity during the three months ended September 30, 2021 and 2020. There were no sales of securities held-to-maturity during the nine months ended September 30, 2021 and 2020. There were no transfers to or from securities held-to-maturity during the three months ended September 30, 2021 and 2020. There were no transfers to or from securities held-to-maturity during the nine months ended September 30, 2021 and 2020. The following table summarizes the gross unrealized losses and fair value of investment and mortgage-backed securities aggregated by investment category and the length of time the securities were in a continuous unrealized loss position as of the dates indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ Less than 12 ​ 12 Consecutive ​ ​ ​ ​ ​ ​ ​ ​ Consecutive Months ​ Months or Longer ​ Total ​ ​ Fair ​ Unrealized ​ Fair ​ Unrealized ​ Fair ​ Unrealized (In thousands) Value Losses Value Losses Value Losses Securities available-for-sale: ​ ​ ​ ​ ​ ​ Agency notes ​ $ 81,018 ​ $ 1,457 ​ $ — ​ $ — ​ $ 81,018 ​ $ 1,457 Treasury securities ​ ​ 231,984 ​ ​ 482 ​ ​ — ​ ​ — ​ ​ 231,984 ​ ​ 482 Corporate securities ​ ​ 17,863 ​ ​ 401 ​ ​ — ​ ​ — ​ ​ 17,863 ​ ​ 401 Pass-through MBS issued by GSEs ​ ​ 446,864 ​ ​ 6,273 ​ ​ — ​ ​ — ​ ​ 446,864 ​ ​ 6,273 Agency CMOs ​ ​ 347,726 ​ ​ 5,118 ​ ​ — ​ ​ — ​ ​ 347,726 ​ ​ 5,118 State and municipal obligations ​ 16,412 ​ 178 ​ — ​ — ​ 16,412 ​ 178 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ Less than 12 ​ 12 Consecutive ​ ​ ​ ​ ​ ​ ​ ​ Consecutive Months ​ Months or Longer ​ Total ​ ​ Fair ​ Unrealized ​ Fair ​ Unrealized ​ Fair ​ Unrealized (In thousands) Value Losses Value Losses Value Losses Securities available-for-sale: ​ ​ ​ ​ ​ ​ Agency notes ​ $ 22,409 ​ $ 91 ​ $ — ​ $ — ​ $ 22,409 ​ $ 91 Pass-through MBS issued by GSEs ​ 5,007 ​ 31 ​ — ​ — ​ 5,007 ​ 31 Agency CMOs ​ 6,563 ​ 30 ​ 4,954 ​ 46 ​ 11,517 ​ 76 ​ The issuers of securities available-for-sale are primarily U.S. government-sponsored entities or agencies. The decline in fair value is attributable to changes in interest rates and illiquidity, and not credit quality. In accordance with the Company’s investment policy, corporate notes are rated "investment grade" at the time of purchase and the financials of the issuers are reviewed quarterly. It is likely that the Company will not be required to sell the securities before their anticipated recovery, and as such, the Company does not consider these securities to be other-than-temporarily-impaired at September 30, 2021.

LOANS HELD FOR INVESTMENT, NET

LOANS HELD FOR INVESTMENT, NET	9 Months Ended
	Sep. 30, 2021
LOANS HELD FOR INVESTMENT, NET
LOANS HELD FOR INVESTMENT, NET	8. The following table presents the loan categories for the period ended as indicated: ​ ​ ​ ​ ​ ​ ​ (In thousands) September 30, 2021 December 31, 2020 One-to-four family residential and cooperative/condominium apartment ​ $ 683,665 ​ $ 184,989 Multifamily residential and residential mixed-use ​ 3,468,262 ​ 2,758,743 Commercial real estate ("CRE") ​ 3,814,437 ​ 1,878,167 Acquisition, development, and construction ("ADC") ​ 285,379 ​ 156,296 Total real estate loans ​ 8,251,743 ​ 4,978,195 Commercial and industrial ("C&I") ​ 1,012,415 ​ 641,533 Other loans ​ 20,713 ​ 2,316 Total ​ 9,284,871 ​ 5,622,044 Allowance for credit losses ​ (81,255) ​ (41,461) Loans held for investment, net ​ $ 9,203,616 ​ $ 5,580,583 ​ As a result of the Merger, the Company recorded $4.53 billion of loans held for investment on the Merger Date. ​ As of September 30, 2021, included in C&I loans was $134.1 million of SBA PPP loans. There was $313.4 million of SBA PPP loans at December 31, 2020. These loans carry a 100% guarantee from the SBA and have no allowance for credit losses allocated to them based on the nature of the guarantee. In June 2021, the Company sold $596.2 million of SBA PPP loans and recorded a gain of $20.7 million in Gain on sale of SBA loans in the consolidated statements of income. The following tables present data regarding the allowance for credit losses activity for the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or for the Three Months Ended September 30, 2021 ​ ​ Real Estate Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-Four ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Family ​ Multifamily ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Residential and ​ Residential ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cooperative/ ​ and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Condominium ​ Residential ​ ​ ​ ​ ​ ​ Total Real ​ ​ ​ ​ Other ​ ​ ​ (In thousands) Apartment Mixed-Use CRE ADC Estate C&I Loans Total Allowance for credit losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance ​ $ 5,522 ​ $ 10,285 ​ $ 41,201 ​ $ 5,158 ​ $ 62,166 ​ $ 30,095 ​ $ 499 $ 92,760 Provision (credit) for credit losses ​ 583 ​ ​ (1,998) ​ ​ (8,649) ​ ​ (139) ​ (10,203) ​ 1,943 ​ ​ 946 ​ (7,314) Charge-offs ​ (1) ​ (58) ​ (2,952) ​ — ​ (3,011) ​ (497) ​ (768) ​ (4,276) Recoveries ​ ​ — ​ ​ 78 ​ ​ 3 ​ ​ — ​ ​ 81 ​ ​ 4 ​ ​ — ​ ​ 85 Ending balance ​ $ 6,104 ​ $ 8,307 ​ $ 29,603 ​ $ 5,019 ​ $ 49,033 ​ $ 31,545 ​ $ 677 ​ $ 81,255 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or for the Three Months Ended September 30, 2020 ​ ​ Real Estate Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-Four ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Family ​ Multifamily ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Residential and ​ Residential ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cooperative/ ​ and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Condominium ​ Residential ​ ​ ​ ​ ​ ​ Total Real ​ ​ ​ ​ Other ​ ​ ​ (In thousands) Apartment Mixed-Use CRE ADC Estate C&I Loans Total Allowance for credit losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance ​ $ 671 ​ $ 16,666 ​ $ 9,859 ​ $ 1,777 ​ $ 28,973 ​ $ 13,502 ​ $ 17 $ 42,492 Provision (credit) for credit losses ​ 134 ​ 3,468 ​ 2,162 ​ 274 ​ 6,038 ​ (107) ​ — ​ 5,931 Charge-offs ​ (6) ​ (13) ​ — ​ — ​ (19) ​ — ​ (1) ​ (20) Recoveries ​ — ​ 89 ​ — ​ — ​ 89 ​ — ​ — ​ 89 Ending balance ​ $ 799 ​ $ 20,210 ​ $ 12,021 ​ $ 2,051 ​ $ 35,081 ​ $ 13,395 ​ $ 16 ​ $ 48,492 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or for the Nine Months Ended September 30, 2021 ​ ​ Real Estate Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-Four ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Family ​ Multifamily ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Residential and ​ Residential ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cooperative/ ​ and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Condominium ​ Residential ​ ​ ​ ​ ​ ​ Total Real ​ ​ ​ ​ Other ​ ​ ​ ​ Apartment Mixed-Use CRE ADC Estate C&I Loans Total Allowance for credit losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance, prior to the adoption of CECL ​ $ 644 ​ $ 17,016 ​ $ 9,059 ​ $ 1,993 ​ $ 28,712 ​ $ 12,737 ​ $ 12 $ 41,461 Impact of adopting CECL ​ ​ 1,048 ​ ​ (8,254) ​ ​ 4,849 ​ ​ 381 ​ ​ (1,976) ​ ​ (1,935) ​ ​ (8) ​ ​ (3,919) Adjusted beginning balance as of January 1, 2021 ​ ​ 1,692 ​ ​ 8,762 ​ ​ 13,908 ​ ​ 2,374 ​ ​ 26,736 ​ ​ 10,802 ​ ​ 4 ​ ​ 37,542 PCD Day 1 ​ ​ 2,220 ​ ​ 3,292 ​ ​ 23,124 ​ ​ 117 ​ ​ 28,753 ​ ​ 23,374 ​ ​ 157 ​ ​ 52,284 Provision (credit) for credit losses ​ 2,212 ​ (3,361) ​ (4,068) ​ 2,528 ​ (2,689) ​ 2,215 ​ 1,286 ​ 812 Charge-offs ​ (20) ​ (467) ​ (3,365) ​ — ​ (3,852) ​ (4,959) ​ (773) ​ (9,584) Recoveries ​ ​ — ​ ​ 81 ​ ​ 4 ​ ​ — ​ ​ 85 ​ ​ 113 ​ ​ 3 ​ ​ 201 Ending balance ​ $ 6,104 ​ $ 8,307 ​ $ 29,603 ​ $ 5,019 ​ $ 49,033 ​ $ 31,545 ​ $ 677 ​ $ 81,255 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or for the Nine Months Ended September 30, 2020 ​ ​ Real Estate Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-Four ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Family ​ Multifamily ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Residential and ​ Residential ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cooperative/ ​ and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Condominium ​ Residential ​ ​ ​ ​ ​ ​ Total Real ​ ​ ​ ​ Other ​ ​ ​ ​ ​ Apartment Mixed-Use CRE ADC Estate C&I Loans Total Allowance for credit losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance ​ $ 269 ​ $ 10,142 ​ $ 3,900 ​ $ 1,244 ​ $ 15,555 ​ $ 12,870 ​ $ 16 $ 28,441 Provision for credit losses ​ 540 ​ 10,010 ​ 8,127 ​ 807 ​ 19,484 ​ 518 ​ 1 ​ 20,003 Charge-offs ​ (10) ​ (45) ​ (6) ​ — ​ (61) ​ — ​ (1) ​ (62) Recoveries ​ — ​ 103 ​ — ​ — ​ 103 ​ 7 ​ — ​ 110 Ending balance ​ $ 799 ​ $ 20,210 ​ $ 12,021 ​ $ 2,051 ​ $ 35,081 ​ $ 13,395 ​ $ 16 ​ $ 48,492 ​ The following table presents the amortized cost basis of loans on non-accrual status as of the period indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ Non-accrual with ​ ​ Non-accrual with ​ ​ ​ (In thousands) No Allowance Allowance ​ Reserve One-to-four family residential and cooperative/condominium apartment $ - ​ $ 4,938 ​ $ 781 Multifamily residential and residential mixed-use ​ 859 ​ ​ - ​ ​ - CRE 1,240 ​ 2,882 ​ ​ 812 C&I ​ - ​ ​ 23,727 ​ ​ 11,191 Other ​ - ​ ​ 374 ​ ​ 371 Total $ 2,099 ​ $ 31,921 ​ $ 13,155 ​ The Company did not recognize interest income on non-accrual loans during the three and nine-months ended September 30, 2021. ​ The following table presents the balance in the allowance for loan losses and the recorded investment in loans by portfolio segment and based on impairment method, prior to the adoption of ASC 326, as of the dates indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ Real Estate Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-Four ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Family ​ Multifamily ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Residential and ​ Residential ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cooperative/ ​ and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Condominium ​ Residential ​ ​ ​ ​ ​ ​ Total Real ​ ​ ​ ​ Other ​ ​ ​ (In thousands) Apartment Mixed-Use CRE ADC Estate C&I Loans Total Allowance for loan losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Individually evaluated for impairment ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ 6,474 ​ $ — $ 6,474 Collectively evaluated for impairment ​ 644 ​ 17,016 ​ 9,059 ​ 1,993 ​ 28,712 ​ 6,263 ​ 12 ​ 34,987 Total ending allowance balance ​ $ 644 ​ $ 17,016 ​ $ 9,059 ​ $ 1,993 ​ $ 28,712 ​ $ 12,737 ​ $ 12 $ 41,461 ​ ​ ​ ​ ​ ​ ​ ​ ​ Loans: ​ ​ ​ ​ ​ ​ ​ ​ Individually evaluated for impairment ​ $ — ​ $ 1,863 ​ $ 2,704 ​ $ — ​ $ 4,567 ​ $ 12,502 ​ $ — $ 17,069 Collectively evaluated for impairment ​ 184,989 ​ 2,756,880 ​ 1,875,463 ​ 156,296 ​ 4,973,628 ​ 629,031 ​ 2,316 ​ 5,604,975 Total ending loans balance ​ $ 184,989 ​ $ 2,758,743 ​ $ 1,878,167 ​ $ 156,296 ​ $ 4,978,195 ​ $ 641,533 ​ $ 2,316 $ 5,622,044 ​ Impaired Loans (prior to the adoption of ASC 326) A loan is considered impaired when, based on then current information and events, it is probable that all contractual amounts due will not be collected in accordance with the terms of the loan. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays or shortfalls generally are not classified as impaired. Management determines the significance of payment delays and shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. The Bank considers TDRs and all non-accrual loans, except non-accrual one-to-four family loans in less than the Federal National Mortgage Association (“FNMA”) Limits, to be impaired. Non-accrual one-to-four family loans equal to or less than the FNMA Limits, as well as all consumer loans, are considered homogeneous loan pools and are not required to be evaluated individually for impairment unless considered a TDR. Impairment is typically measured using the difference between the outstanding loan principal balance and either: 1) the likely realizable value of a note sale; 2) the fair value of the underlying collateral, net of likely disposal costs, if repayment is expected to come from liquidation of the collateral; or 3) the present value of estimated future cash flows (using the loan’s pre-modification rate for certain performing TDRs). If a TDR is substantially performing in accordance with its restructured terms, management will look to either the potential net liquidation proceeds of the underlying collateral or the present value of the expected cash flows from the debt service in measuring impairment (whichever is deemed most appropriate under the circumstances). If a TDR has re-defaulted, generally the likely realizable net proceeds from either a note sale or the liquidation of the collateral is considered when measuring impairment. Measured impairment is either charged off immediately or, in limited instances, recognized as an allocated reserve within the allowance for loan losses. The following tables summarize impaired loans with no related allowance recorded and with related allowance recorded as of the periods indicated (by collateral type within the real estate loan segment): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ Unpaid ​ ​ ​ ​ ​ ​ ​ Principal ​ Recorded ​ Related (In thousands) Balance Investment (1) Allowance With no related allowance recorded: ​ ​ ​ ​ ​ ​ Multifamily residential and residential mixed-use ​ $ 1,863 ​ $ 1,863 ​ $ — CRE ​ 2,704 ​ 2,704 ​ — Total with no related allowance recorded ​ 4,567 ​ 4,567 ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ With an allowance recorded: ​ ​ ​ C&I ​ 12,502 ​ 12,502 ​ 6,474 Total with an allowance recorded ​ 12,502 ​ 12,502 ​ 6,474 Total ​ $ 17,069 ​ $ 17,069 ​ $ 6,474 (1) The recorded investment excludes net deferred costs due to immateriality. The following table presents information for impaired loans for the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, 2020 ​ September 30, 2020 ​ ​ Average ​ Interest ​ Average ​ Interest ​ ​ Recorded ​ Income ​ Recorded ​ Income ​ Investment (1) Recognized (2) ​ Investment (1) Recognized (2) With no related allowance recorded: ​ ​ ​ ​ ​ ​ ​ ​ One-to-four family residential, including condominium and cooperative apartment ​ $ — ​ $ — ​ $ 10 ​ $ 4 Multifamily residential and residential mixed-use ​ 1,295 ​ — ​ 416 ​ 7 Commercial real estate and commercial mixed-use ​ 1,525 ​ — ​ 2,688 ​ 54 Total with no related allowance recorded ​ 2,820 ​ — ​ 3,114 ​ 65 ​ ​ ​ ​ ​ With an allowance recorded: ​ ​ ​ ​ C&I ​ 10,232 ​ — ​ 7,500 ​ 153 Total ​ $ 13,052 ​ $ — ​ $ 10,614 ​ $ 218 (1) The recorded investment excludes net deferred costs due to immateriality. (2) Cash basis interest and interest income recognized on accrual basis approximate each other. ​ The following tables summarize the past due status of the Company’s investment in loans as of the dates indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ Loans 90 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Days or ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 30 to 59 ​ 60 to 89 ​ More Past Due ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Days ​ Days ​ and Still ​ ​ ​ Total ​ ​ ​ ​ Total (In thousands) Past Due Past Due Accruing Interest Non-accrual Past Due Current Loans Real estate: ​ ​ ​ ​ ​ ​ ​ One-to-four family residential, including condominium and cooperative apartment ​ $ 3,135 ​ $ 1,245 ​ $ 5,021 ​ $ 4,938 ​ $ 14,339 ​ $ 669,326 ​ $ 683,665 Multifamily residential and residential mixed-use ​ 10,251 ​ 2,738 ​ — ​ 859 ​ 13,848 ​ 3,454,414 ​ 3,468,262 CRE ​ 8,360 ​ 1,069 ​ 1,004 ​ 4,122 ​ 14,555 ​ 3,799,882 ​ 3,814,437 ADC ​ 17,700 ​ — ​ — ​ — ​ 17,700 ​ 267,679 ​ 285,379 Total real estate ​ 39,446 ​ 5,052 ​ 6,025 ​ 9,919 ​ 60,442 ​ 8,191,301 ​ 8,251,743 C&I ​ 10,962 ​ 2,455 ​ 257 ​ 23,727 ​ 37,401 ​ 975,014 ​ 1,012,415 Other ​ ​ 730 ​ ​ 2 ​ ​ — ​ ​ 374 ​ ​ 1,106 ​ ​ 19,607 ​ ​ 20,713 Total ​ $ 51,138 ​ $ 7,509 ​ $ 6,282 ​ $ 34,020 ​ $ 98,949 ​ $ 9,185,922 ​ $ 9,284,871 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ Loans 90 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Days or ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 30 to 59 ​ 60 to 89 ​ More Past Due ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Days ​ Days ​ and Still ​ ​ ​ Total ​ ​ ​ ​ Total (In thousands) Past Due Past Due Accruing Interest Non-accrual Past Due Current Loans Real estate: ​ ​ ​ ​ ​ ​ ​ One-to-four family residential, including condominium and cooperative apartment ​ $ — ​ $ — ​ $ 44 ​ $ 858 ​ $ 902 ​ $ 184,087 ​ $ 184,989 Multifamily residential and residential mixed-use ​ — ​ — ​ 437 ​ 1,863 ​ 2,300 ​ 2,756,443 ​ 2,758,743 CRE ​ 15,351 ​ — ​ — ​ 2,704 ​ 18,055 ​ 1,860,112 ​ 1,878,167 ADC ​ — ​ — ​ — ​ — ​ — ​ 156,296 ​ 156,296 Total real estate ​ 15,351 ​ — ​ 481 ​ 5,425 ​ 21,257 ​ 4,956,938 ​ 4,978,195 C&I ​ — ​ 917 ​ 2,848 ​ 12,502 ​ 16,267 ​ 625,266 ​ 641,533 Other ​ ​ 8 ​ ​ 1 ​ ​ — ​ ​ 1 ​ ​ 10 ​ ​ 2,306 ​ ​ 2,316 Total ​ $ 15,359 ​ $ 918 ​ $ 3,329 ​ $ 17,928 ​ $ 37,534 ​ $ 5,584,510 ​ $ 5,622,044 ​ ​ Accruing Loans 90 Days or More Past Due: ​ The Company continued accruing interest on loans with an outstanding balance of $6.3 million at September 30, 2021, and loans with an outstanding balance of $3.3 million at December 31, 2020, all of which were 90 days or more past due on their respective contractual maturity dates. These loans continued to make monthly payments consistent with their initial contractual amortization schedule exclusive of the balloon payments due at maturity. These loans were well secured and/or were expected to be refinanced, and, therefore, remained on accrual status and were deemed performing assets at the dates indicated above. ​ Collateral Dependent Loans: ​ At September 30, 2021, the Company had collateral dependent loans which were individually evaluated to determine expected credit losses. ​ Collateral dependent CRE loans totaled $53.2 million and had a related allowance for credit losses totaling $7.6 million at September 30, 2021. The loans were secured by real estate. ​ Collateral dependent multi-family residential and residential mixed-use loans totaled $8.5 million and had a related allowance for credit losses totaling $0.6 million at September 30, 2021. The loans were secured by real estate. ​ Collateral dependent C&I loans totaled $4.4 million and had a related allowance for credit losses totaling $0.7 million at September 30, 2021. The loans were secured by business assets. ​ TDRs As of September 30, 2021, the Company had TDRs totaling $528 thousand. The Company has allocated $481 thousand of allowance for those loans at September 30, 2021, with no commitments to lend additional amounts. ​ During the nine months ended September 30, 2021, TDR modifications included reduction of outstanding principal, extensions of maturity dates, or favorable interest rates and loan terms than the prevailing market interest rates and loan terms. ​ During the three months ended September 30, 2021, the Company modified one CRE loan as a TDR, which subsequently paid off during the quarter. ​ The following table presents the loans by category modified as TDRs that occurred during the nine months ended September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Modifications During the Nine Months Ended September 30, 2021 ​ ​ ​ ​ ​ Pre- ​ ​ Post- ​ ​ ​ ​ ​ Modification ​ ​ Modification ​ ​ ​ ​ ​ Outstanding ​ ​ Outstanding ​ ​ Number of ​ ​ Recorded ​ ​ Recorded (Dollars in thousands) ​ Loans ​ ​ Investment ​ ​ Investment One-to-four family residential and cooperative/condominium apartment ​ 1 ​ $ 50 ​ $ 50 Commercial real estate ("CRE") ​ 1 ​ ​ 10,000 ​ ​ 10,000 Commercial and industrial ("C&I") ​ 1 ​ ​ 456 ​ ​ 488 Total ​ 3 ​ $ 10,506 ​ $ 10,538 ​ ​ There were no TDR charge-offs during the three and nine months ended September 30, 2021. TDRs did not have a material impact to the allowance for credit losses. ​ ​ Loan payment deferrals due to COVID-19 Consistent with regulatory guidance to work with borrowers during the unprecedented situation caused by the COVID-19 pandemic and as outlined in the CARES Act, the Company established a formal payment deferral program in April 2020 for borrowers that have been adversely affected by the pandemic. ​ As of September 30, 2021, the Company had 17 loans, representing outstanding loan balances of $26.6 million, that were deferring full principal and interest (“P&I” deferrals). ​ The table below presents the P&I deferrals as of September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ Number ​ ​ ​ ​ ​ ​ of Loans Balance (1) % of Portfolio ​ (Dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ One-to-four family residential and cooperative/condominium apartment 10 ​ $ 9,255 ​ 1.4 % CRE 1 ​ 3,487 ​ 0.1 ​ C&I ​ 6 ​ ​ 13,861 ​ 1.4 ​ Total 17 ​ $ 26,603 ​ 0.3 ​ (1) Amount excludes net deferred costs due to immateriality. Pursuant to guidance under Section 4013 of the CARES Act, a qualified loan modification, such as a payment deferral, is exempt from classification as a TDR as defined by GAAP. This applies if the loan was current as of December 31, 2019 and the modifications are related to arrangements that defer or delay the payment of principal or interest, or change the interest rate of the loan. This guidance was expected to expire on December 31, 2020. The 2021 Consolidated Appropriations Act, which was signed into law December of 2020, extended the exemption for TDR classification until the earlier of January 1, 2022 or the date that is 60 days after the date on which the national emergency concerning the COVID-19 outbreak is lifted. Risk-ratings on COVID-19 loan deferrals are evaluated on an ongoing basis. Credit Quality Indicators The Company categorizes loans into risk categories based on relevant information about the ability of borrowers to service their debt such as: current financial information, historical payment experience, credit structure, loan documentation, public information, and current economic trends, among other factors. The Company analyzes loans individually by classifying them as to credit risk. This analysis includes all loans, such as multifamily residential, mixed-use residential ( i.e., i.e. ​ Special Mention. Loans classified as special mention have a potential weakness that deserves management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the loan or of the Bank’s credit position at some future date. Substandard. ​ Doubtful. For the three and nine months ended September 30, 2021, there were $11.9 million and $66.5 million of sales of criticized loans, respectively. For the three and nine months ended September 30, 2020, there were $3.0 million and $10.0 million of sales of criticized loans, respectively. ​ The following is a summary of the credit risk profile of loans by internally assigned grade as of the periods indicated, the years represent the year of origination for non-revolving loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 (In thousands) ​ 2021 ​ 2020 ​ 2019 ​ 2018 ​ 2017 ​ 2016 and Prior ​ Revolving ​ Revolving-Term ​ Total One-to-four family residential, and condominium/cooperative apartment: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ $ 104,830 ​ $ 93,315 ​ $ 86,214 ​ $ 79,981 ​ $ 84,075 ​ $ 143,807 ​ $ 52,483 ​ $ 11,162 ​ $ 655,867 Special mention ​ ​ — ​ ​ — ​ ​ 337 ​ ​ 756 ​ ​ 345 ​ ​ 2,168 ​ ​ 846 ​ ​ 1,089 ​ ​ 5,541 Substandard ​ ​ — ​ ​ 1,461 ​ ​ 2,048 ​ ​ 862 ​ ​ 2,206 ​ ​ 14,691 ​ ​ — ​ ​ 966 ​ ​ 22,234 Doubtful ​ ​ — ​ ​ — ​ ​ — ​ ​ 23 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 23 Total one-to-four family residential, and condominium/cooperative apartment ​ ​ 104,830 ​ ​ 94,776 ​ ​ 88,599 ​ ​ 81,622 ​ ​ 86,626 ​ ​ 160,666 ​ ​ 53,329 ​ ​ 13,217 ​ ​ 683,665 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Multifamily residential and residential mixed-use: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ ​ 426,164 ​ ​ 347,900 ​ ​ 493,077 ​ ​ 193,738 ​ ​ 373,965 ​ ​ 1,329,688 ​ ​ 5,111 ​ ​ 825 ​ ​ 3,170,468 Special mention ​ ​ — ​ ​ 12,550 ​ ​ 14,551 ​ ​ — ​ ​ 11,842 ​ ​ 22,378 ​ ​ — ​ ​ — ​ ​ 61,321 Substandard ​ ​ — ​ ​ — ​ ​ 35,886 ​ ​ 27,265 ​ ​ 51,680 ​ ​ 118,179 ​ ​ 3,463 ​ ​ — ​ ​ 236,473 Doubtful ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Total multifamily residential and residential mixed-use ​ ​ 426,164 ​ ​ 360,450 ​ ​ 543,514 ​ ​ 221,003 ​ ​ 437,487 ​ ​ 1,470,245 ​ ​ 8,574 ​ ​ 825 ​ ​ 3,468,262 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CRE: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ ​ 636,234 ​ ​ 872,347 ​ ​ 578,758 ​ ​ 331,636 ​ ​ 337,930 ​ ​ 863,215 ​ ​ 39,323 ​ ​ 5,164 ​ ​ 3,664,607 Special mention ​ ​ 5,354 ​ ​ 2,384 ​ ​ — ​ ​ 4,191 ​ ​ 11,109 ​ ​ 15,416 ​ ​ — ​ ​ — ​ ​ 38,454 Substandard ​ ​ 2,335 ​ ​ 1,752 ​ ​ 7,110 ​ ​ 39,892 ​ ​ 19,733 ​ ​ 40,448 ​ ​ — ​ ​ — ​ ​ 111,270 Doubtful ​ ​ — ​ ​ — ​ ​ 106 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 106 Total CRE ​ ​ 643,923 ​ ​ 876,483 ​ ​ 585,974 ​ ​ 375,719 ​ ​ 368,772 ​ ​ 919,079 ​ ​ 39,323 ​ ​ 5,164 ​ ​ 3,814,437 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ADC: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ ​ 101,947 ​ ​ 69,546 ​ ​ 62,414 ​ ​ 24,587 ​ ​ 8,120 ​ ​ 807 ​ ​ 2,686 ​ ​ 600 ​ ​ 270,707 Special mention ​ ​ — ​ ​ — ​ ​ — ​ ​ 1,078 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 1,078 Substandard ​ ​ — ​ ​ — ​ ​ — ​ ​ 13,500 ​ ​ — ​ ​ 94 ​ ​ — ​ ​ — ​ ​ 13,594 Doubtful ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Total ADC ​ ​ 101,947 ​ ​ 69,546 ​ ​ 62,414 ​ ​ 39,165 ​ ​ 8,120 ​ ​ 901 ​ ​ 2,686 ​ ​ 600 ​ ​ 285,379 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ C&I: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ ​ 52,667 ​ ​ 199,677 ​ ​ 58,835 ​ ​ 54,190 ​ ​ 38,065 ​ ​ 25,948 ​ ​ 479,111 ​ ​ 10,359 ​ ​ 918,852 Special mention ​ ​ — ​ ​ 1,690 ​ ​ 265 ​ ​ 2,260 ​ ​ 611 ​ ​ 61 ​ ​ 1,685 ​ ​ 1,368 ​ ​ 7,940 Substandard ​ ​ — ​ ​ 5,949 ​ ​ 4,842 ​ ​ 6,175 ​ ​ 2,982 ​ ​ 1,057 ​ ​ 34,996 ​ ​ 6,764 ​ ​ 62,765 Doubtful ​ ​ — ​ ​ — ​ ​ 10,087 ​ ​ 752 ​ ​ 11,989 ​ ​ 30 ​ ​ — ​ ​ — ​ ​ 22,858 Total C&I ​ ​ 52,667 ​ ​ 207,316 ​ ​ 74,029 ​ ​ 63,377 ​ ​ 53,647 ​ ​ 27,096 ​ ​ 515,792 ​ ​ 18,491 ​ ​ 1,012,415 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ ​ 1,321,842 ​ ​ 1,582,785 ​ ​ 1,279,298 ​ ​ 684,132 ​ ​ 842,155 ​ ​ 2,363,465 ​ ​ 578,714 ​ ​ 28,110 ​ ​ 8,680,501 Special mention ​ ​ 5,354 ​ ​ 16,624 ​ ​ 15,153 ​ ​ 8,285 ​ ​ 23,907 ​ ​ 40,023 ​ ​ 2,531 ​ ​ 2,457 ​ ​ 114,334 Substandard ​ ​ 2,335 ​ ​ 9,162 ​ ​ 49,886 ​ ​ 87,694 ​ ​ 76,601 ​ ​ 174,469 ​ ​ 38,459 ​ ​ 7,730 ​ ​ 446,336 Doubtful ​ ​ — ​ ​ — ​ ​ 10,193 ​ ​ 775 ​ ​ 11,989 ​ ​ 30 ​ ​ — ​ ​ — ​ ​ 22,987 Total Loans ​ $ 1,329,531 ​ $ 1,608,571 ​ $ 1,354,530 ​ $ 780,886 ​ $ 954,652 ​ $ 2,577,987 ​ $ 619,704 ​ $ 38,297 ​ $ 9,264,158 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ Special ​ ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) Pass Mention Substandard Doubtful Total Real Estate: ​ ​ ​ ​ ​ One-to-four family residential and condominium/cooperative apartment ​ $ 183,293 ​ $ — ​ $ 1,696 ​ $ — ​ $ 184,989 Multifamily residential and residential mixed-use ​ 2,523,258 ​ 56,400 ​ 179,085 ​ — ​ 2,758,743 CRE ​ 1,831,712 ​ 13,861 ​ 32,594 ​ — ​ 1,878,167 ADC ​ 142,796 ​ 13,500 ​ — ​ — ​ 156,296 Total real estate ​ 4,681,059 ​ 83,761 ​ 213,375 ​ — ​ 4,978,195 C&I ​ 613,691 ​ 2,131 ​ 13,315 ​ 12,396 ​ 641,533 Total Real Estate and C&I ​ $ 5,294,750 ​ $ 85,892 ​ $ 226,690 ​ $ 12,396 ​ $ 5,619,728 ​ For other loans, the Company evaluates credit quality based on payment activity. Other loans that are 90 days or more past due are placed on non-accrual status, while all remaining other loans are classified and evaluated as performing. The following is a summary of the credit risk profile of other loans by internally assigned grade: ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) September 30, 2021 December 31, 2020 Performing ​ $ 20,339 ​ $ 2,315 Non-accrual ​ 374 ​ 1 Total ​ $ 20,713 ​ $ 2,316 ​

LEASES

LEASES	9 Months Ended
	Sep. 30, 2021
LEASES
LEASES	9 . As a result of the Merger, the Company acquired $45.6 million of operating lease assets and $45.3 million of operating lease liabilities on the Merger Date. During the nine months ended September 30, 2021, the Company elected to terminate three leases in connection with the combination of three branches into other locations, which resulted in a decrease to the Company’s operating lease liabilities of $3.7 million, and an early termination fee of $4.0 million. The early termination fee is reported in branch restructuring costs in the consolidated statements of income. The Company recognizes operating lease assets and corresponding lease liabilities related to its office facilities and retail branches. The operating lease assets represent the Company’s right to use an underlying asset for the lease term, and the lease liability represents the Company’s obligation to make lease payments over the lease term. The operating lease asset and lease liability are determined at the commencement date of the lease based on the present value of the lease payments. As most of our leases do not provide an implicit rate, the Company used its incremental borrowing rate, the rate of interest to borrow on a collateralized basis for a similar term, at the lease commencement date. The Company made a policy election to exclude the recognition requirements of ASU 2016-02 to short-term leases, those leases with original terms of 12 months or less. Short-term lease payments are recognized in the income statement on a straight-line basis over the lease term. Certain leases may include one or more options to renew. The exercise of lease renewal options is typically at the Company’s discretion and are included in the operating lease liability if it is reasonably certain that the renewal option will be exercised. Certain real estate leases may contain lease and non-lease components, such as common area maintenance charges, real estate taxes, and insurance, which are generally accounted for separately and are not included in the measurement of the lease liability since they are generally able to be segregated. The Company does not sublease any of its leased properties. The Company does not lease properties from any related parties. Maturities of the Company’s operating lease liabilities at September 30, 2021 are as follows: ​ ​ ​ ​ ​ ​ Rent to be (In thousands) Capitalized 2021 $ 3,374 2022 ​ 11,006 2023 ​ 9,301 2024 ​ 9,186 2025 ​ 8,941 Thereafter ​ 25,439 Total undiscounted lease payments ​ 67,247 Less amounts representing interest ​ (4,377) Operating lease liabilities ​ $ 62,870 ​ Other information related to operating leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands) 2021 2020 2021 2020 Operating lease cost ​ $ 4,012 ​ $ 1,636 ​ $ 11,178 ​ $ 4,867 Cash paid for amounts included in the measurement of operating lease liabilities ​ ​ 3,724 ​ ​ 1,745 ​ ​ 10,496 ​ ​ 5,295 ​ The weighted average remaining lease term at September 30, 2021 and December 31, 2020 was 6.9 years and 6.5 years, respectively. The weighted average discount rate at September 30, 2021 and December 31, 2020 was 1.82% and 3.23%, respectively.

DERIVATIVES AND HEDGING ACTIVIT

DERIVATIVES AND HEDGING ACTIVITIES	9 Months Ended
	Sep. 30, 2021
DERIVATIVES AND HEDGING ACTIVITIES
DERIVATIVES AND HEDGING ACTIVITIES	10. The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources, and duration of its assets and liabilities and the use of derivative financial instruments. Specifically, the Company enters into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. The Company’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Company’s known or expected cash receipts and its known or expected cash payments principally related to the Company’s loan portfolio. The Company’s objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company primarily uses interest rate swaps as part of its interest rate risk management strategy. The Company engages in both cash flow hedges and freestanding derivatives. Cash Flow Hedges Cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. The Company uses these types of derivatives to hedge the variable cash flows associated with existing or forecasted issuances of short-term borrowings. For derivatives designated and that qualify as cash flow hedges of interest rate risk, the gain or loss on the derivative is recorded in Accumulated Other Comprehensive Income (Loss) and subsequently reclassified into interest expense in the same periods during which the hedged transaction affects earnings. Amounts reported in accumulated other comprehensive income related to derivatives will be reclassified to interest expense as interest payments are made on the Company’s debt. During the next twelve months, the Company estimates that an additional $356 thousand will be reclassified as an increase to interest expense. The Company is hedging its exposure to the variability in future cash flows for forecasted transactions over a maximum period of twenty-four months (excluding forecasted transactions related to the payment of variable interest on existing financial instruments). During the three months ended September 30, 2021, the Company did not The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the Consolidated Statements of Financial Condition as of the dates indicated. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ December 31, 2020 ​ ​ ​ ​ Notional ​ Fair Value ​ Fair Value ​ ​ ​ Notional ​ Fair Value ​ Fair Value (Dollars in thousands) Count Amount Assets Liabilities Count Amount Assets Liabilities Included in derivative assets/(liabilities): ​ ​ ​ ​ ​ ​ Interest rate swaps related to FHLBNY advances 4 ​ $ 150,000 ​ $ 2,811 ​ $ — — ​ $ — ​ $ — ​ $ — Interest rate swaps related to FHLBNY advances — ​ $ — ​ $ — ​ $ — 32 ​ $ 655,000 ​ $ — ​ $ (18,442) ​ The table below presents the effect of the cash flow hedge accounting on Accumulated Other Comprehensive Income (Loss) for the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ (In thousands) 2021 2020 ​ 2021 2020 ​ Gain (loss) recognized in other comprehensive income ​ $ 225 ​ $ 100 ​ $ 3,767 ​ $ (25,098) ​ Gain recognized on termination of derivatives ​ ​ — ​ ​ — ​ ​ 16,505 ​ ​ — ​ Loss reclassified from other comprehensive income into interest expense ​ (38) ​ (2,319) ​ (902) ​ (3,679) ​ ​ All cash flow hedges are recorded gross on the balance sheet. The cash flow hedges involve derivative agreements with third-party counterparties that contain provisions requiring the Bank to post cash collateral if the derivative exposure exceeds a threshold amount. As of September 30, 2021, the bank did not Freestanding Derivatives The Company maintains an interest-rate risk protection program for its loan portfolio in order to offer loan level derivatives with certain borrowers and to generate loan level derivative income. The Company enters into interest rate swap or interest rate floor agreements with borrowers. These interest rate derivatives are designed such that the borrower synthetically attains a fixed-rate loan, while the Company receives floating rate loan payments. The Company offsets the loan level interest rate swap exposure by entering into an offsetting interest rate swap or interest rate floor with an unaffiliated and reputable bank counterparty. These interest rate derivatives do not qualify as designated hedges, under ASU 815; therefore, each interest rate derivative is accounted for as a freestanding derivative. The notional amounts of the interest rate derivatives do not represent amounts exchanged by the parties. The amount exchanged is determined by reference to the notional amount and the other terms of the individual interest rate derivative agreements. The following tables reflect freestanding derivatives included in the Consolidated Statements of Financial Condition as of the dates indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ ​ Notional ​ Fair Value ​ Fair Value (In thousands) Count Amount Assets Liabilities Included in derivative assets/(liabilities): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loan level interest rate swaps with borrower 128 ​ $ 818,370 ​ $ 36,095 ​ $ — Loan level interest rate swaps with borrower 61 ​ 439,198 ​ — ​ (7,414) Loan level interest rate floors with borrower ​ 47 ​ ​ 405,685 ​ ​ — ​ ​ (4,072) Loan level interest rate swaps with third-party counterparties 128 ​ 818,370 ​ — ​ (36,095) Loan level interest rate swaps with third-party counterparties ​ 61 ​ ​ 439,198 ​ ​ 7,414 ​ ​ — Loan level interest rate floors with third-party counterparties 47 ​ 405,685 ​ 4,072 ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ Notional ​ Fair Value ​ Fair Value (In thousands) Count Amount Assets Liabilities Included in derivative assets/(liabilities): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loan level interest rate swaps with borrower 65 ​ $ 570,277 ​ $ 24,764 ​ $ — Loan level interest rate floors with borrower 41 ​ 364,643 ​ — ​ (5,832) Loan level interest rate swaps with third-party counterparties 65 ​ 570,277 ​ — ​ (24,764) Loan level interest rate floors with third-party counterparties 41 ​ 364,643 ​ 5,832 ​ — ​ Loan level derivative income is recognized on the mark-to-market of the interest rate swap as a fair value adjustment at the time the transaction is closed. Total loan level derivative income is included in non-interest income as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands) 2021 2020 ​ 2021 2020 Loan level derivative income ​ $ 445 ​ $ 1,544 ​ $ 2,796 ​ $ 5,201 ​ The interest rate swap product with the borrower is cross collateralized with the underlying loan and therefore there is no posted collateral. Certain interest rate swap agreements with third-party counterparties contain provisions that require the Company to post collateral if the derivative exposure exceeds a threshold amount. As of September 30, 2021, posted collateral was $23.5 million. Credit Risk Related Contingent Features The Company’s agreements with each of its derivative counterparties state that if the Company defaults on any of its indebtedness, it could also be declared in default on its derivative obligations and could be required to terminate its derivative positions with the counterparty. The Company’s agreements with certain of its derivative counterparties state that if the Bank fails to maintain its status as a well-capitalized institution, the Bank could be required to terminate its derivative positions with the counterparty. As of September 30, 2021, the termination value of derivatives in a net liability position, which includes accrued interest but excludes any adjustment for nonperformance risk, related to these agreements was $24.6 million for those related to loan level derivatives. If the Company had breached any of the above provisions at September 30, 2021, it could have been required to settle its obligations under the agreements at the termination value with the respective counterparty. There were no provisions breached for the nine months ended September 30, 2021.

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS	9 Months Ended
	Sep. 30, 2021
FAIR VALUE OF FINANCIAL INSTRUMENTS
FAIR VALUE OF FINANCIAL INSTRUMENTS	11. Fair value is the exchange price that would be received for an asset or paid to transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. There are three levels of inputs that may be used to measure fair values: Level 1 Inputs Level 2 Inputs e.g. Level 3 Inputs – Assets and Liabilities Measured at Fair Value on a Recurring Basis Securities The Company’s marketable equity securities and available-for-sale securities are reported at fair value, which were determined utilizing prices obtained from independent parties. The valuations obtained are based upon market data, and often utilize evaluated pricing models that vary by asset and incorporate available trade, bid and other market information. For securities that do not trade on a daily basis, pricing applications apply available information such as benchmarking and matrix pricing. The market inputs normally sought in the evaluation of securities include benchmark yields, reported trades, broker/dealer quotes (obtained only from market makers or broker/dealers recognized as market participants), issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data. For certain securities, additional inputs may be used or some market inputs may not be applicable. Prioritization of inputs may vary on any given day based on market conditions. All MBS, CMOs, treasury securities, agency notes, and state and municipal obligations available-for-sale are guaranteed either implicitly or explicitly by GSEs as of September 30, 2021 and December 31, 2020. In accordance with the Company’s investment policy, corporate securities are rated "investment grade" at the time of purchase and the financials of the issuers are reviewed quarterly. Obtaining market values as of September 30, 2021 and December 31, 2020 for these securities utilizing significant observable inputs was not difficult due to their liquid nature. Derivatives Derivatives represent interest rate swaps and estimated fair values are based on valuation models using observable market data as of the measurement date. The following tables present financial assets and liabilities measured at fair value on a recurring basis as of the dates indicated, segmented by level within the fair value hierarchy. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ ​ ​ ​ at September 30, 2021 Using ​ ​ ​ ​ ​ Level 1 ​ Level 2 ​ Level 3 (In thousands) Total Inputs Inputs Inputs Financial Assets: ​ ​ ​ ​ Securities available-for-sale: ​ ​ ​ ​ Agency notes ​ $ 81,018 ​ $ — ​ $ 81,018 ​ $ — Treasury securities ​ ​ 247,696 ​ ​ — ​ ​ 247,696 ​ ​ — Corporate securities ​ 126,833 ​ — ​ 126,833 ​ — Pass-through MBS issued by GSEs ​ 621,957 ​ — ​ 621,957 ​ — Agency CMOs ​ 590,426 ​ — ​ 590,426 ​ — State and municipal obligations ​ ​ 41,133 ​ ​ — ​ ​ 41,133 ​ ​ — Derivative – cash flow hedges ​ 2,811 ​ — ​ 2,811 ​ — Derivative – freestanding derivatives, net ​ 38,889 ​ — ​ 38,889 ​ — Financial Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivative – freestanding derivatives, net ​ 38,889 ​ — ​ 38,889 ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ ​ ​ ​ at December 31, 2020 Using ​ ​ ​ ​ ​ Level 1 ​ Level 2 ​ Level 3 (In thousands) Total Inputs Inputs Inputs Financial Assets: ​ ​ ​ ​ Marketable equity securities (Registered mutual funds) ​ ​ ​ ​ Domestic equity mutual funds ​ $ 1,769 ​ $ 1,769 ​ $ — ​ $ — International equity mutual funds ​ 468 ​ 468 ​ — ​ — Fixed income mutual funds ​ 3,733 ​ 3,733 ​ — ​ — Securities available-for-sale: ​ ​ ​ ​ Agency notes ​ 47,421 ​ — ​ 47,421 ​ — Corporate securities ​ 64,461 ​ — ​ 64,461 ​ — Pass-through MBS issued by GSEs ​ 143,483 ​ — ​ 143,483 ​ — Agency CMOs ​ 283,496 ​ — ​ 283,496 ​ — Derivative – freestanding derivatives ​ ​ 30,596 ​ ​ — ​ ​ 30,596 ​ ​ — Financial Liabilities: ​ ​ ​ ​ Derivative – cash flow hedges ​ 18,442 ​ — ​ 18,442 ​ — Derivative – freestanding derivatives ​ 30,596 ​ — ​ 30,596 ​ — ​ Assets and Liabilities Measured at Fair Value on a Non-recurring Basis Certain financial assets and financial liabilities are measured at fair value on a nonrecurring basis. That is, they are subject to fair value adjustments in certain circumstances. Financial assets measured at fair value on a non-recurring basis include certain individually evaluated loans (or impaired loans prior to the adoption of ASC 326) reported at the fair value of the underlying collateral if repayment is expected solely from the collateral. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ ​ ​ Fair Value Measurements Using: ​ ​ ​ Quoted Prices ​ ​ ​ ​ ​ ​ ​ In Active ​ Significant ​ ​ ​ ​ ​ Markets for ​ Other ​ Significant ​ ​ ​ ​ Identical ​ Observable ​ Unobservable ​ ​ Carrying ​ Assets ​ Inputs ​ Inputs (In thousands) Value (Level 1) (Level 2) (Level 3) Individually evaluated loans ​ $ 55,146 ​ $ — $ — $ 55,146 ​ Individually evaluated loans with an allowance for credit losses at September 30, 2021 had a carrying amount of $55.1 million, which is made up of the outstanding balance of $63.9 million, net of a valuation allowance of $8.8 million. Collateral dependent individually analyzed loans as of September 30, 2021 resulted in a credit loss recovery of $9.0 million and $8.7 million, which is included in the amounts reported in the consolidated statements of income for the three and nine months ended September 30, 2021, respectively. There were no collateral dependent impaired loans (prior to the adoption of the CECL Standard) with an allowance for credit losses at December 31, 2020. Financial Instruments Not Measured at Fair Value The methods of determining the fair value of assets and liabilities presented in this note are consistent with our methodologies disclosed in Note 24 to the Company’s consolidated financial statements included in the Annual Report on Form 10-K. The following tables present the carrying amounts and estimated fair values of financial instruments other than those measured at fair value on either a recurring or nonrecurring basis for the dates indicated, segmented by level within the fair value hierarchy. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ ​ ​ ​ at September 30, 2021 Using ​ ​ Carrying ​ Level 1 ​ Level 2 ​ Level 3 ​ ​ ​ (In thousands) Amount Inputs Inputs Inputs Total Financial Assets: ​ ​ ​ ​ ​ Cash and due from banks ​ $ 629,011 ​ $ 629,011 ​ $ — ​ $ — ​ $ 629,011 Securities held-to-maturity ​ ​ 40,303 ​ — ​ 40,303 ​ — ​ 40,303 Loans held for investment, net ​ 9,148,470 ​ — ​ — ​ 9,212,454 ​ 9,212,454 Accrued interest receivable ​ 43,284 ​ — ​ 4,228 ​ 39,056 ​ 43,284 Financial Liabilities: ​ ​ ​ ​ ​ Savings, money market and checking accounts ​ 9,657,821 ​ 9,657,821 ​ — ​ — ​ 9,657,821 Certificates of Deposits ("CDs") ​ 1,016,216 ​ — ​ 1,021,029 ​ — ​ 1,021,029 FHLBNY advances ​ 25,000 ​ — ​ 25,015 ​ — ​ 25,015 Subordinated debt, net ​ 197,142 ​ — ​ 203,355 ​ — ​ 203,355 Other short-term borrowings ​ 2,629 ​ 2,629 ​ — ​ — ​ 2,629 Accrued interest payable ​ 1,630 ​ — ​ 1,630 ​ — ​ 1,630 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ ​ ​ ​ at December 31, 2020 Using ​ ​ Carrying ​ Level 1 ​ Level 2 ​ Level 3 ​ ​ ​ (In thousands) Amount Inputs Inputs Inputs Total Financial Assets: ​ ​ ​ ​ ​ Cash and due from banks ​ $ 243,603 ​ $ 243,603 ​ $ — ​ $ — ​ $ 243,603 Loans held for investment, net ​ 5,580,583 ​ — ​ — ​ 5,598,787 ​ 5,598,787 Accrued interest receivable ​ 34,815 ​ 2 ​ 1,584 ​ 33,229 ​ 34,815 Financial Liabilities: ​ ​ ​ ​ ​ Savings, money market and checking accounts ​ 3,202,484 ​ 3,202,484 ​ — ​ — ​ 3,202,484 CDs ​ 1,322,638 ​ — ​ 1,328,554 ​ — ​ 1,328,554 FHLBNY advances ​ 1,204,010 ​ — ​ 1,207,890 ​ — ​ 1,207,890 Subordinated debt, net ​ 114,052 ​ — ​ 114,340 ​ — ​ 114,340 Other short-term borrowings ​ ​ 120,000 ​ ​ 120,000 ​ ​ — ​ ​ — ​ ​ 120,000 Accrued interest payable ​ 1,734 ​ — ​ 1,734 ​ — ​ 1,734 ​

OTHER INTANGIBLE ASSETS

OTHER INTANGIBLE ASSETS	9 Months Ended
	Sep. 30, 2021
OTHER INTANGIBLE ASSETS
OTHER INTANGIBLE ASSETS	12. As a result of the Merger, the Company recorded $10.2 million of core deposit intangible assets and a $780 thousand non-compete agreement intangible asset on the Merger Date. ​ The following table presents the carrying amount and accumulated amortization of intangible assets that are amortizable and arose from the Merger. There were no intangible assets at December 31, 2020. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ Core Deposit ​ ​ Non-complete ​ ​ ​ (In thousands) ​ ​ Intangibles ​ Agreement ​ Total Gross carrying value ​ $ 10,204 ​ $ 780 ​ $ 10,984 Accumulated amortization ​ (1,427) ​ ​ (480) ​ ​ (1,907) Net carrying amount ​ $ 8,777 ​ $ 300 ​ $ 9,077 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization expense recognized on intangible assets was $715 thousand and $1.9 million for the three and nine months ended September 30, 2021, respectively. There was no amortization expense recognized on intangible assets for the three or nine months ended September 30, 2020. ​ Estimated amortization expense for the remainder of 2021 through 2025 and thereafter is as follows: ​ ​ ​ ​ ​ (In thousands) ​ ​ Total 2021 ​ $ 715 2022 ​ ​ 1,878 2023 ​ ​ 1,425 2024 ​ ​ 1,163 2025 ​ ​ 958 Thereafter ​ ​ 2,938 Total ​ $ 9,077 ​

FEDERAL HOME LOAN BANK OF NEW Y

FEDERAL HOME LOAN BANK OF NEW YORK ADVANCES	9 Months Ended
	Sep. 30, 2021
FEDERAL HOME LOAN BANK OF NEW YORK ADVANCES
FEDERAL HOME LOAN BANK OF NEW YORK ADVANCES	​ 13. The following tables present the contractual maturities and weighted average interest rates of FHLBNY advances for each of the next five years. There were no FHLBNY advances with an overnight contractual maturity at September 30, 2021 and December 31, 2020. There are no FHLBNY advances with contractual maturities after 2021 and 2022 at September 30, 2021 and December 31, 2020, respectively. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 (Dollars in thousands) ​ ​ ​ ​ Weighted Contractual Maturity Amount Average Rate 2021 ​ $ 25,000 0.35 % Total FHLBNY advances ​ $ 25,000 0.35 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 (Dollars in thousands) ​ ​ ​ ​ Weighted Contractual Maturity Amount Average 2021 ​ $ 1,144,010 0.52 % 2022 ​ ​ 60,000 ​ 0.60 ​ Total FHLBNY advances ​ $ 1,204,010 0.53 % ​ Each FHLBNY advance is payable at its maturity date, with a prepayment penalty for fixed rate advances. The advances were collateralized by $4.25 billion and $2.15 billion of residential and commercial mortgage loans under a blanket lien arrangement at September 30, 2021 and December 31, 2020, respectively. Based on this collateral and the Company's holdings of FHLBNY stock, the Company is eligible to borrow up to a total of $3.71 billion at September 30, 2021. As part of the Merger, $216.3 million of FHLBNY advances were acquired on the Merger Date. During the three months ended September 30, 2021, the Company did not extinguish any FHLBNY advances. During the nine months ended September 30, 2021, the Company extinguished $209.0 million of FHLBNY advances that had a weighted average rate of 1.31%. The prepayment penalty expense was recognized as a $1.8 million loss on extinguishment of debt during the first nine months of 2021. There were no prepayments of FHLBNY advances during the three or nine months ended September 30, 2020. ​

SUBORDINATED DEBENTURES

SUBORDINATED DEBENTURES	9 Months Ended
	Sep. 30, 2021
SUBORDINATED DEBENTURES.
SUBORDINATED DEBENTURES	14. In connection with the Merger, the Company assumed $115.0 million in aggregate principal amount of the 4.50% Fixed-to-Floating Rate Subordinated Debentures due 2027 of Legacy Dime on the Merger Date. During the year ended December 31, 2017, the Legacy Dime issued $115.0 million of fixed-to-floating rate subordinated notes due June 2027, which become callable commencing on June 15, 2022. The notes will mature on June 15, 2027 (the “Maturity Date”). From and including June 13, 2017 until but excluding June 15, 2022, interest will be paid semi-annually in arrears on each June 15 and December 15 at a fixed annual interest rate equal to 4.50%. From and including June 15, 2022 to, but excluding, the Maturity Date or earlier redemption date, the interest rate shall reset quarterly to an annual interest rate equal to the then-current three-month LIBOR plus 266 basis points, payable quarterly in arrears. Debt issuance cost directly associated with subordinated debt offering was capitalized and netted with subordinated notes payable on the Consolidated Statements of Financial Condition. In September 2015, the Company issued $80.0 million in aggregate principal amount of fixed-to-floating rate subordinated debentures. $40.0 million of the subordinated debentures are callable at par after five years, have a stated maturity of September 30, 2025 and bear interest at a fixed annual rate of 5.25% per year, from and including September 21, 2015 until but excluding September 30, 2020. From and including September 30, 2020 to the maturity date or early redemption date, the interest rate will reset quarterly to an annual interest rate equal to the then-current three-month LIBOR plus 360 basis points. The remaining $40.0 million of the subordinated debentures are callable at par after ten years, have a stated maturity of September 30, 2030 and bear interest at a fixed annual rate of 5.75% per year, from and including September 21, 2015 until but excluding September 30, 2025. From and including September 30, 2025 to the maturity date or early redemption date, the interest rate will reset quarterly to an annual interest rate equal to the then-current three-month LIBOR plus 345 basis points. The subordinated debentures totaled $197.1 million at September 30, 2021 and $114.1 million at December 31, 2020. Interest expense related to the subordinated debt was $2.2 million and $1.3 million during the three months ended September 30, 2021 and 2020, respectively. Interest expense related to the subordinated debt was $6.3 million and $4.0 million during the nine months ended September 30, 2021 and 2020, respectively. The subordinated debentures are included in tier 2 capital (with certain limitations applicable) under current regulatory guidelines and interpretations. ​

RETIREMENT AND POSTRETIREMENT P

RETIREMENT AND POSTRETIREMENT PLANS	9 Months Ended
	Sep. 30, 2021
RETIREMENT AND POSTRETIREMENT PLANS
RETIREMENT AND POSTRETIREMENT PLANS	15. As of September 30, 2021, the Company maintains one Legacy Dime employee benefit plan, the Retirement Plan of Dime Community Bank (the "Employee Retirement Plan"). The Company also maintains the two Bridge employee benefit plans that existed before the Merger: (i) the BNB Bank 401(k) Plan (the “401(k) Plan”) and (ii) the BNB Bank Pension Plan. The Dime Community Bank KSOP Plan (“Dime KSOP Plan”) was terminated by resolution of the Legacy Dime Board of Directors. The effective date of the Dime KSOP Plan termination was January 31, 2021, the day immediately prior to the closing of the Merger. As such, all participants were required to transfer their assets out of the Dime KSOP Plan. The 401(k) Plan is available to all former Dime employees that continue to be employed following the Merger Date, that meet eligibility requirements, and provides tax deferred salary deductions and alternative investment options. Under the provisions of the 401(k) plan, employee contributions are partially matched by the Bank as follows: 100% of each employee’s contributions up to 1% of each employee’s compensation plus 50% of each employee’s contributions over 1% but not in excess of 6% of each employee’s compensation for a maximum contribution of 3.5% of a participating employee’s compensation. Participants can invest their account balances into several investment alternatives. While the Company does not allow for the investment of plan contributions in the Company’s common stock, former Legacy Dime employees that continue to be employed following the Merger Date may rollover and hold shares in-kind held in the Dime KSOP Plan to the 401(k) plan and hold the shares in the 401(k) plan. The 401(k) plan also includes a discretionary profit-sharing component. ​ The following table represents the components of net periodic benefit (credit) cost included in other non-interest expense, except for service cost which is reported in salaries and employee benefits expense, in the consolidated statements of income. Net expenses associated with these plans were comprised of the following components: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ ​ ​ 2021 ​ 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ BMP, Postretirement ​ ​ BNB Bank ​ Employee ​ Employee ​ and Outside Director (In thousands) ​ Pension Plan ​ Retirement Plan ​ Retirement Plan ​ Retirement Plans Service cost ​ $ 223 ​ $ — ​ $ — ​ $ — Interest cost ​ ​ 302 ​ ​ 183 ​ ​ 10 ​ ​ 241 Expected return on assets ​ ​ (1,244) ​ ​ (428) ​ ​ — ​ ​ (428) Unrecognized past service liability ​ ​ — ​ ​ — ​ ​ (2) ​ ​ — Amortization of unrealized loss ​ ​ 207 ​ ​ 229 ​ ​ — ​ ​ 274 Net periodic benefit (credit) cost ​ $ (512) ​ $ (16) ​ $ 8 ​ $ 87 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ ​ 2021 ​ 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ BMP, Postretirement ​ ​ BNB Bank ​ Employee ​ Employee ​ and Outside Director (In thousands) ​ Pension Plan ​ Retirement Plan ​ Retirement Plan ​ Retirement Plans Service cost ​ $ 594 ​ $ — ​ $ — ​ $ — Interest cost ​ ​ 854 ​ ​ 549 ​ ​ 30 ​ ​ 723 Expected return on assets ​ (3,473) ​ (1,284) ​ — ​ (1,284) Unrecognized past service liability ​ ​ — ​ ​ — ​ ​ (6) ​ ​ — Amortization of unrealized loss ​ 619 ​ 687 ​ — ​ 822 Net periodic (credit) cost ​ $ (1,406) ​ $ (48) ​ $ 24 ​ $ 261 ​ There were no contributions to the BNB Bank Pension Plan or the Employee Retirement Plan for the nine months ended September 30, 2021. ​ In connection with the Merger, the Outside Director Retirement Plan and the BMP were terminated resulting in lump sum payments to the participants in the amounts of $2.8 million for the Outside Director Retirement Plan and $6.2 million for the BMP. The total expense recognized as a curtailment loss during the three months ended March 31, 2021 was $1.5 million. ​ During the year ended December 31, 2020, Legacy Dime approved the termination of the Postretirement Plan in anticipation of the Merger. ​ During the three months ended March 31, 2021, the Company made gross lump-sum distributions totaling $11.6 million from the BMP. These distributions were satisfied by 88,081 shares of common stock with a market value of $2.4 million, held by the previous ESOP component of the BMP, of which 41,101 shares were returned to Treasury Stock to cover income tax liabilities, and cash of $9.2 million. As a result of the distribution, a non-cash tax benefit of $301 thousand was recognized as a discrete item in income tax expense in accordance to ASU 2016-09 for the difference between the market value and the cost basis of the common stock held by the BMP.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	9 Months Ended
	Sep. 30, 2021
STOCK-BASED COMPENSATION
STOCK-BASED COMPENSATION	16. Before the Merger, Bridge and Legacy Dime granted share-based awards under their respective share-based compensation plans, (collectively, the “Legacy Stock Plans”), which are both subject to the accounting requirements of ASC 718. In May 2021, the Company’s shareholders approved the Dime Community Bancshares, Inc. 2021 Equity Incentive Plan (the “2021 Equity Incentive Plan”) to provide the Company with sufficient equity compensation to meet the objectives of appropriately incentivizing its officers, other employees, and directors to execute our strategic plan to build shareholder value, while providing appropriate shareholder protections. The Company no longer makes grants under the Legacy Stock Plans. Awards outstanding under the Legacy Stock Plans will continue to remain outstanding and subject to the terms and conditions of the Legacy Stock Plans. At September 30, 2021, there were 1,123,639 shares reserved for issuance under the 2021 Equity Incentive Plan. In anticipation of the Merger, Legacy Dime accelerated and vested all unvested and outstanding share-based awards such that there were no outstanding awards as of December 31, 2020. In connection with the Merger, all outstanding stock options granted under Legacy Dime’s equity plans, were legally assumed by the combined company and adjusted so that its holder is entitled to receive a number of shares of Dime’s common stock equal to the product of (a) the number of shares of Legacy Dime common stock subject to such award multiplied by (b) the Exchange Ratio and (c) rounded, as applicable, to the nearest whole share, and otherwise subject to the same terms and conditions (including, without limitation, with respect to vesting conditions (taking into account any vesting that occurred at the Merger Date)). In connection with the Merger, all outstanding stock options and time-vesting restricted stock units of Bridge, which we refer to as the Bridge equity awards, which were outstanding immediately before the Merger Date continue to be awards in respect of Dime common stock following the Merger, subject to the same terms and conditions that were applicable to such awards before the Merger Date. ​ Stock Option Awards The following table presents a summary of activity related to stock options granted under the Legacy Stock Plans, and changes during the period then ended: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ Aggregate ​ ​ ​ ​ Weighted- ​ Remaining ​ Intrinsic ​ ​ Number of ​ Average Exercise ​ Contractual ​ Value ​ Options Price Years (In thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options outstanding at January 1, 2021 ​ 28,842 ​ $ 15.05 ​ ​ ​ ​ ​ Options outstanding at January 1, 2021 as adjusted for conversion ​ 18,685 ​ ​ 23.23 ​ ​ ​ ​ ​ Options acquired ​ 180,020 ​ ​ 35.39 ​ ​ ​ ​ ​ Options exercised ​ (17,102) ​ 23.40 ​ ​ ​ ​ ​ Options forfeited ​ (29,421) ​ 35.38 ​ ​ ​ ​ ​ Options outstanding at September 30, 2021 152,182 ​ $ 35.24 7.4 ​ $ 18 Options vested and exercisable at September 30, 2021 152,182 ​ $ 35.24 7.4 ​ $ 18 ​ ​ Information related to stock options during each period is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands) 2021 2020 ​ 2021 2020 Cash received for option exercise cost ​ $ — ​ $ — ​ $ 396 ​ $ 38 Income tax benefit recognized on stock option exercises ​ — ​ — ​ — ​ — Intrinsic value of options exercised ​ — ​ — ​ 77 ​ 8 ​ Restricted Stock Awards The Company has made RSA grants to outside Directors and certain officers under the Legacy Stock Plans and the 2021 Equity Incentive Plan. Typically, awards to outside Directors fully vest on the first anniversary of the grant date, while awards to officers vest over a pre-determined requisite period. All awards were made at the fair value of the Company’s common stock on the grant date. Compensation expense on all RSAs is based upon the fair value of the shares on the respective dates of the grant. The following table presents a summary of activity related to the RSAs granted, and changes during the period then ended: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ Number of ​ Grant-Date ​ Shares Fair Value ​ ​ ​ ​ ​ ​ Unvested allocated shares outstanding at January 1, 2021 ​ — ​ $ — Shares acquired in the Merger ​ 101,778 ​ ​ 25.98 Shares granted 390,027 ​ 26.48 Shares vested ​ (9,838) ​ ​ 25.41 Shares forfeited (33,089) ​ 25.73 Unvested allocated shares at September 30, 2021 448,878 ​ $ 26.45 ​ Information related to RSAs during each period is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (Dollars in thousands) 2021 2020 ​ 2021 2020 Compensation expense recognized ​ $ 1,454 ​ $ 444 ​ $ 3,804 ​ $ 1,311 Income tax expense recognized on vesting of RSA ​ — ​ (38) ​ (86) ​ (95) ​ As of September 30, 2021, there was $8.3 million of total unrecognized compensation cost related to unvested RSAs to be recognized over a weighted-average period of 2.8 years. Performance Based Share Awards The Company maintained a long-term incentive award program (“LTIP”) for certain officers, which meets the criteria for equity-based accounting. For each award, threshold (50% of target), target (100% of target) and stretch (150% of target) opportunities are eligible to be earned over a three-year performance period based on the Company’s relative performance on certain goals that were established at the onset of the performance period and cannot be altered subsequently. Shares of common stock are issued on the grant date and held as unvested stock awards until the end of the performance period. Shares are issued at the stretch opportunity in order to ensure that an adequate number of shares are allocated for shares expected to vest at the end of the performance period. At December 31, 2020, Legacy Dime modified certain PSAs to accelerate the vesting of all outstanding awards in connection with the Merger. There were no outstanding PSAs at December 31, 2020. This plan continued into 2021, and as of September 30, 2021, 38,948 shares have been granted. The following table presents a summary of activity related to the PSAs granted, and changes during the period then ended: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ Number of ​ Grant-Date ​ Shares Fair Value Maximum aggregate share payout at January 1, 2021 ​ — ​ $ — Shares granted 38,948 ​ 31.40 Maximum aggregate share payout at September 30, 2021 38,948 ​ $ 31.40 Minimum aggregate share payout — ​ ​ — Expected aggregate share payout 25,963 ​ $ 31.40 ​ Information related to PSAs during each period is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ (In thousands) 2021 2020 ​ 2021 2020 ​ Compensation expense recognized ​ $ 81 ​ $ 210 ​ $ 81 ​ $ 362 ​ Income tax expense recognized on vesting of LTIP ​ — ​ — ​ — ​ — ​ ​ As of September 30, 2021, there was $1.0 million of total unrecognized compensation cost related to unvested PSAs. Sales Incentive Awards Legacy Dime maintained a sales incentive award program for certain officers, which meets the criteria for equity-based accounting. For each quarter an individual can earn their shares based on their sales performance in that quarter. The shares then vest one year from the quarter in which they are earned. Shares of common stock are issued on the grant date and held as unvested stock awards until the end of the performance period. They are issued at the maximum opportunity in order to ensure that an adequate number of shares are allocated for shares expected to vest at the end of the performance period. At December 31, 2020, the Legacy Dime modified certain performance based share awards to accelerate the vesting of all outstanding awards in connection with the Merger. There were no outstanding sales incentive share awards at December 31, 2020. Total compensation expense of $150 thousand was recognized during the three-month period ended September 30, 2020, and $280 thousand for the nine-month period ended September 30, 2020.

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2021
INCOME TAXES
INCOME TAXES	17. During the three months ended September 30, 2021 and 2020, the Company’s consolidated effective tax rates were 27.5% and 21.9%, respectively. During the nine months ended September 30, 2021 and 2020, the Company's consolidated effective tax rates were 29.2% and 21.7%, respectively. There were no significant unusual income tax items during the nine-month periods ended September 30, 2021 or 2020.

MERGER RELATED EXPENSES

MERGER RELATED EXPENSES	9 Months Ended
	Sep. 30, 2021
MERGER RELATED EXPENSES
MERGER RELATED EXPENSES	18. Merger-related expenses were recorded in the consolidated statements of income as a component of non-interest expense and include costs relating to the Merger, as described in Note 2. Merger. These charges represent one-time costs associated with merger activities and do not represent ongoing costs of the fully integrated combined organization. Accounting guidance requires that merger-related transactional and restructuring costs incurred by the Company be charged to expense as incurred. Costs associated with employee severance and other merger-related compensation expense incurred in connection with the Merger totaled $1.1 million and $15.0 million for the three and nine months ended September 30, 2021, respectively, and were recorded in merger expenses and transaction costs expense in the consolidated statements of income. Transaction costs (inclusive of costs to terminate leases) in connection with the Merger totaled $1.4 million and $27.3 million, respectively, for the three and nine months ended September 30, 2021, and were recorded in merger expenses and transaction costs in the consolidated statements of income. There were no costs associated with employee severance and other merger-related compensation expense incurred in connection with the Merger with Bridge for the three and nine months ended September 30, 2020, respectively. Transaction costs in connection with the Merger totaled $769 thousand and $2.4 million for the three and nine months ended September 30, 2020, respectively, and were recorded in merger expenses and transaction costs in the consolidated statements of income. ​

BRANCH RESTRUCTURING COSTS

BRANCH RESTRUCTURING COSTS	9 Months Ended
	Sep. 30, 2021
BRANCH RESTRUCTURING COSTS
BRANCH RESTRUCTURING COSTS	19. On June 29, 2021, the Company issued a press release announcing that the Bank planned to combine five branch locations into other existing branches. The combinations took place in October 2021. Costs associated with early lease terminations and accelerated depreciation of fixed assets totaled $4.5 million and $6.2 million for the three and nine months ended September 30, 2021, and were recorded in branch restructuring costs in the consolidated statements of income. There were no branch restructuring costs for the three or nine months periods ended September 30, 2020. ​

BASIS OF PRESENTATION (Policies

BASIS OF PRESENTATION (Policies)	9 Months Ended
	Sep. 30, 2021
BASIS OF PRESENTATION
Risks and Uncertainties	Risks and Uncertainties In March 2020, the World Health Organization declared the outbreak of COVID-19 as a global pandemic, which has spread to most countries, including the United States. The pandemic has adversely affected economic activity globally, nationally and locally. In March 2020, the United States declared a National Public Health Emergency in response to the COVID-19 pandemic. In an effort to mitigate the spread of COVID-19, local state governments, including New York (in which the Bank has retail banking offices), have taken preventative or protective actions such as travel restrictions, advising or requiring individuals to limit or forego their time outside of their homes, and other forced closures for certain types of non-essential businesses. The impact of these actions is expected to continue to have an adverse impact on the economies and financial markets in the United States. The Coronavirus Aid, Relief and Economic Security (“CARES”) Act was signed into law at the end of March 2020. The CARES Act is intended to provide relief and lessen a severe economic downturn. The stimulus package includes direct financial aid to American families and economic stimulus to significantly impacted industry sectors. The package also includes extensive emergency funding for hospitals and healthcare providers. In December 2020, the 2021 Consolidated Appropriations Act was signed into law to provide additional relief. It is possible that there will be continued material, adverse impacts to significant estimates, asset valuations, and business operations, including intangible assets, investments, loans, deferred tax assets, and derivative counter party risk.

SUMMARY OF ACCOUNTING POLICIES

SUMMARY OF ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2021
SUMMARY OF ACCOUNTING POLICIES
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all adjustments necessary for a fair presentation of the Company’s financial condition as of September 30, 2021 and December 31, 2020, the results of operations and statements of comprehensive income for the three and nine months ended September 30, 2021 and 2020, the changes in stockholders’ equity for the three and nine months ended September 30, 2021 and 2020, and cash flows for the nine months ended September 30, 2021 and 2020. Please see "Part I - Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations - Critical Accounting Policies" for a discussion of areas in the accompanying unaudited condensed consolidated financial statements utilizing significant estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Allowance for Credit Losses – The adoption of the CECL Standard resulted in an initial decrease of $3.9 million to the allowance for credit losses and an increase of $1.4 million to the reserve for unfunded commitments in other liabilities. The after-tax cumulative-effect adjustment of $1.7 million was recorded in retained earnings as of January 1, 2021. There were no held-to-maturity securities as of January 1, 2021 and, therefore, no impact from the adoption of the CECL Standard. ​ The allowance for credit losses is a valuation allowance that is deducted from the amortized cost basis of loans to present the net amount expected to be collected on the loans. Loan losses are charged against the allowance when management believes it has confirmed the loan balance is uncollectible. Subsequent recoveries, if any, are credited to the allowance. ​ The CECL Standard requires that debt securities held-to-maturity be accounted for under the current expected credit losses model, including historical loss experience and impact of current conditions and reasonable and supportable forecasts, with an associated allowance for credit losses. In addition, while credit losses on debt securities available-for-sale should be measured in accordance with the other-than-temporary impairment (“OTTI”) framework under current GAAP, the amendments in the CECL Standard require that these credit losses be presented as an allowance for credit losses. For AFS debt securities, a decline in fair value due to credit loss results in recording an allowance for credit losses to the extent the fair value is less than the amortized cost basis. Management estimates the allowance for credit losses for the Company’s loan portfolio required using relevant available information, from internal and external sources, relating to past events, current conditions, and reasonable and supportable forecasts. Historically observed credit loss experience of peer banks within our geography provide the basis for the estimation of expected credit losses. Adjustments to historical loss information are made for differences in current loan-specific risk characteristics such as differences in underwriting standards, portfolio mix, delinquency level, or terms as well as changes in environmental conditions, such as changes in unemployment rates, gross domestic product, and real estate pricing. Management evaluates the adequacy of the allowance on a quarterly basis. ​ Accrued interest receivable is excluded from the estimate of credit losses. The allowance for credit losses is measured on a collective (pool) basis when similar risk characteristics exist. The Company has identified the following portfolio segments and measures the allowance for credit losses using the following methods: ​ One-to-four family residential, including condominium and cooperative apartment loans - ​ Multifamily residential and residential mixed-use loans - ​ Commercial real estate and commercial mixed-use loans - ​ Acquisition, development, and construction loans ​ Commercial, Industrial and Agricultural Loans - ​ Other Loans ​ As allowed by ASC 326, the Entity elected to maintain pools of loans accounted for under ASC 310-30. In accordance with the standard, management did not reassess whether modifications to individual acquired financial assets accounted for in pools were troubled debt restructurings (“TDRs”) as of the date of adoption. TDRs Loans that do not share risk characteristics are evaluated on an individual basis based on various factors. Loans evaluated individually are not included in the collective evaluation. Factors that may be considered are borrower delinquency trends and non-accrual status, probability of foreclosure or note sale, changes in the borrower’s circumstances or cash collections, borrower’s industry, or other facts and circumstances of the loan or collateral. ​ Individually Evaluated Loans with an ACL and Other Real Estate Owned determined based on recent appraised values. The fair value of other real estate owned is also determined based on recent appraised values less the estimated cost to sell. These appraisals may utilize a single valuation approach or a combination of approaches including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between the comparable sales and income data available. Adjustments may relate to location, square footage, condition, amenities, market rate of leases as well as timing of comparable sales. All appraisals undergo a second review process to ensure that the methodology employed and the values derived are reasonable. The fair value of non-real estate collateral, which includes inventory, may be determined based on an appraisal, net book value per the borrower’s financial statements, aging reports, or by reference to market activity, adjusted or discounted based on management’s historical knowledge, changes in market conditions from the time of the valuation and management’s expertise and knowledge of the borrower and its business. For non-collateral-dependent loans, ACL is measured based on the difference between the present value of expected cash flows and the amortized cost basis of the loan as of the measurement date. Appraisals for collateral-dependent loans are performed by certified general appraisers (for commercial properties) or certified residential appraisers (for residential properties) whose qualifications and licenses have been reviewed and verified by the Company. Once received, the Appraisal and Credit Departments review the assumptions and approaches utilized in the appraisal as well as the overall resulting fair value in comparison with independent data sources such as recent market data or industry-wide statistics. Management also considers the appraisal values for commercial properties associated with current loan origination activity. Collectively, this information is reviewed to help assess current trends in commercial property values. For each collateral dependent loan, management considers information that relates to the type of property to determine if such properties may have appreciated or depreciated in value since the date of the most recent appraisal. Adjustments to fair value are made only when the analysis indicates a probable decline in collateral values. Adjustments made in the appraisal process are not deemed material to the overall consolidated financial statements given the level of collateral dependent loans measured at fair value on a non-recurring basis. Allowance for Credit Losses on Off-Balance Sheet Credit Exposures – The Company estimates expected credit losses over the contractual period in which the Company is exposed to credit risk via a contractual obligation to extend credit, unless that obligation is unconditionally cancellable by the Company. The allowance for credit losses on off-balance sheet credit exposures, which is included in other liabilities on the consolidated statements of financial condition, is adjusted as a provision for credit loss expense. The estimate includes consideration of the likelihood that funding will occur and an estimate of expected credit losses on commitments expected to be funded over its estimated life, which is the same as the expected loss factor as determined based on the corresponding portfolio segment. Loans acquired in a business combination – ​ A purchased financial asset that does not qualify as a PCD asset is accounted for similar to an originated financial asset. Generally, this means that an entity recognizes the allowance for credit losses for non-PCD assets through net income at the time of acquisition. In addition, both the credit discount and non-credit discount or premium resulting from acquiring a pool of purchased financial assets that do not qualify as PCD assets shall be allocated to each individual asset. This combined discount or premium shall be accreted to interest income using the effective yield method. ​ For further discussion of our loan accounting and acquisitions, see Note 2 – Merger and Note 8 – Loans. ​ Held-to-maturity debt securities and the allowance for credit losses To the extent that debt securities in the held-to-maturity portfolio share common risk characteristics, estimated expected credit losses are calculated in a manner like that used for loans held for investment. That is, for pools of such debt securities with common risk characteristics, the historical lifetime probability of default and severity of loss in the event of default is derived or obtained from external sources and adjusted for the expected effects of reasonable and supportable forecasts over the expected lives of the securities. Expected credit loss on each debt security in the held-to-maturity portfolio that do not share common risk characteristics with any of the pools of debt securities is individually measured based on net realizable value, or the difference between the discounted value of the expected future cash flows, based on the original effective interest rate, and the recorded amortized cost basis of the security. With respect to certain classes of debt securities, primarily U.S. Treasuries and securities issued by Government Sponsored Entities (“GSEs”), the Company considers the history of credit losses, current conditions and reasonable and supportable forecasts, which may indicate that the expectation that nonpayment of the amortized cost basis is or continues to be zero, even if the U.S. government were to technically default. Therefore, the Company did not record an allowance for expected credit losses on its securities issued by GSEs at September 30, 2021. Accrued interest receivable is excluded from the estimate of credit losses. Available-for-sale debt securities and the allowance for credit losses For available-for-sale debt securities in an unrealized loss position, management first assesses whether it intends to sell, or is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through income. For available-for-sale debt securities that do not meet the aforementioned criteria, management evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes in the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. If the assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis for the security, a credit loss exists and an allowance for credit losses is recorded, limited to the amount the fair value is less than amortized cost basis. Declines in fair value that have not been recorded through an allowance for credit losses, such as declines due to changes in market interest rates, are excluded from earnings and reported, net of tax, in other comprehensive income (“OCI”). Changes in the allowance for credit losses are recorded as provision for (or reversal of) credit loss expense. Losses are charged against the allowance when management believes the collectability of an available-for-sale security is confirmed or when the criteria regarding intent or requirement to sell is met. Accrued interest receivable is excluded from the estimate of credit losses. ​ ​

MERGER (Tables)

MERGER (Tables)	9 Months Ended
	Sep. 30, 2021
MERGER
Schedule of Bridge and legacy Dime common stock	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Dime Community Bancshares, Inc. Ownership and Market Value ​ ​ Number of ​ ​ ​ ​ Market Value at ​ ​ Bridge ​ Percentage ​ $24.43 Bridge (Dollars and shares in thousands) ​ Outstanding Shares ​ Ownership ​ Share Price Bridge shareholders ​ 19,993 ​ 48.5% $ 488,420 Legacy Dime shareholders ​ ​ 21,233 ​ ​ 51.5% ​ ​ 518,720 Total ​ ​ 41,226 ​ ​ 100.0% ​ $ 1,007,140
Schedule of hypothetical number of shares	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Hypothetical Legacy Dime Ownership ​ ​ Number of ​ ​ ​ ​ ​ Legacy Dime ​ Percentage (Shares in thousands) ​ Outstanding Shares ​ Ownership Bridge shareholders ​ 30,853 ​ 48.5% Legacy Dime shareholders ​ ​ 32,767 ​ ​ 51.5% Total ​ ​ 63,620 ​ ​ 100.0%
Schedule of purchase price	​ ​ ​ ​ ​ (Dollars and shares in thousands) ​ ​ ​ Number of hypothetical Legacy Dime shares issued to Bridge shareholders ​ ​ 30,853 Legacy Dime market price per share as of February 1, 2021 ​ $ 15.90 Purchase price determination of hypothetical Legacy Dime shares issued to Bridge shareholders ​ $ 490,560 Value of Bridge stock options hypothetically converted to options to acquire shares of Legacy Dime common stock ​ ​ 643 Cash in lieu of fractional shares ​ ​ 7 Purchase price consideration ​ $ 491,210
Schedule of purchase price allocation	​ ​ ​ ​ ​ (In thousands) ​ ​ ​ Purchase price consideration ​ $ 491,210 ​ ​ ​ ​ Fair value of assets acquired: ​ ​ ​ Cash and due from banks ​ ​ 715,988 Securities available-for-sale ​ ​ 651,997 Loans held for sale ​ ​ 10,000 Loans held for investment ​ ​ 4,531,640 Premises and fixed assets ​ ​ 37,881 Restricted stock ​ ​ 23,362 BOLI ​ ​ 94,085 Other intangible assets ​ ​ 10,984 Operating lease assets ​ ​ 45,603 Other assets ​ ​ 117,474 Total assets acquired ​ ​ 6,239,014 Fair value of liabilities assumed: ​ ​ ​ Deposits ​ ​ 5,405,575 Other short-term borrowings ​ ​ 216,298 Subordinated debt ​ ​ 83,200 Operating lease liabilities ​ ​ 45,285 Other liabilities ​ ​ 97,147 Total liabilities assumed ​ ​ 5,847,505 Fair value of net identifiable assets ​ ​ 391,509 Goodwill resulting from Merger ​ $ 99,701 ​ ​ ​ ​
Schedule of loans acquired	​ ​ ​ ​ ​ (In thousands) ​ ​ ​ PCD loans: ​ Unpaid principal balance ​ $ 295,306 Non-credit discount at acquisition ​ (9,050) Unpaid principal balance, net ​ 286,256 ​ ​ ​ ​ Allowance for credit losses at acquisition ​ ​ (52,284) Fair value at acquisition ​ ​ 233,972 ​ ​ ​ ​ Non-PCD loans: ​ Unpaid principal balance ​ 4,289,236 Premium at acquisition ​ 8,432 Fair value at acquisition ​ 4,297,668 ​ ​ ​ Total fair value at acquisition ​ $ 4,531,640
Schedule of supplemental disclosures of cash flow information	​ ​ ​ ​ ​ (In thousands) ​ ​ ​ Business combination: ​ Fair value of tangible assets acquired ​ $ 6,228,030 Goodwill, core deposit intangible and other intangible assets acquired ​ 110,685 Liabilities assumed ​ 5,847,505 Purchase price consideration ​ ​ 491,210
Schedule of pro forma amount	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (Dollars in thousands except per share amounts) 2021 2020 ​ 2021 2020 Net interest income $ 93,316 $ 86,818 ​ $ 274,499 $ 252,455 Non-interest income ​ ​ 9,728 ​ ​ 12,939 ​ ​ 33,240 ​ ​ 33,030 Net income ​ ​ 39,978 ​ ​ 29,971 ​ ​ 92,782 ​ ​ 72,015 Net income available to common shareholders ​ ​ 37,700 ​ ​ 27,791 ​ ​ 86,390 ​ ​ 68,169 Earnings per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ ​ 0.93 ​ ​ 0.68 ​ ​ 2.11 ​ ​ 1.66 Diluted ​ ​ 0.93 ​ ​ 0.68 ​ ​ 2.11 ​ ​ 1.66

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables)	9 Months Ended
	Sep. 30, 2021
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS).
Activity in Accumulated Other Comprehensive Income (Loss), Net of Tax	Activity in accumulated other comprehensive income (loss), net of tax, was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ Securities ​ Defined ​ ​ ​ ​ Other ​ ​ Available- ​ Benefit ​ ​ ​ ​ Comprehensive (In thousands) for-Sale Plans Derivatives Income (Loss) Balance as of January 1, 2021 ​ $ 12,694 ​ $ (6,086) ​ $ (12,532) ​ $ (5,924) Other comprehensive (loss) income before reclassifications ​ (10,378) ​ 2,706 ​ 13,850 ​ 6,178 Amounts reclassified from accumulated other comprehensive loss ​ (826) ​ (1,082) ​ 612 ​ (1,296) Net other comprehensive (loss) income during the period ​ (11,204) ​ 1,624 ​ 14,462 ​ 4,882 Balance as of September 30, 2021 ​ $ 1,490 ​ $ (4,462) ​ $ 1,930 ​ $ (1,042) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of January 1, 2020 ​ $ 4,621 ​ $ (6,024) ​ $ (4,537) ​ $ (5,940) Other comprehensive income (loss) before reclassifications ​ 10,783 ​ 423 ​ (17,150) ​ (5,944) Amounts reclassified from accumulated other comprehensive loss ​ (2,302) ​ 133 ​ 2,514 ​ 345 Net other comprehensive income (loss) during the period ​ 8,481 ​ 556 ​ (14,636) ​ (5,599) Balance as of September 30, 2020 ​ $ 13,102 ​ $ (5,468) ​ $ (19,173) ​ $ (11,539)
Other Comprehensive Income (Loss)	The before and after-tax amounts allocated to each component of other comprehensive income (loss) are presented in the table below for the periods indicated. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands) 2021 2020 ​ 2021 2020 Change in unrealized holding gain or loss on securities available-for-sale: ​ ​ ​ ​ Change in net unrealized gain or loss during the period ​ $ (8,654) ​ $ 1,716 ​ $ (15,222) ​ $ 15,769 Reclassification adjustment for net gains included in net gain on securities and other assets ​ — ​ (215) ​ (1,207) ​ (3,357) Net change ​ (8,654) ​ 1,501 ​ (16,429) ​ 12,412 Tax (benefit) expense ​ (2,714) ​ 475 ​ (5,226) ​ 3,931 Net change in unrealized holding gain or loss on securities available-for-sale, net of reclassification adjustments and tax ​ (5,940) ​ 1,026 ​ (11,203) ​ 8,481 Change in pension and other postretirement obligations: ​ ​ ​ ​ Reclassification adjustment for expense included in other expense ​ (735) ​ 4 ​ (1,595) ​ 194 Reclassification adjustment for curtailment loss ​ ​ — ​ ​ — ​ ​ 1,543 ​ ​ — Change in the net actuarial gain or loss ​ 941 ​ 267 ​ 2,470 ​ 619 Net change ​ 206 ​ ​ 271 ​ 2,418 ​ 813 Tax expense ​ 65 ​ 86 ​ 795 ​ 257 Net change in pension and other postretirement obligations ​ 141 ​ 185 ​ 1,623 ​ 556 Change in unrealized gain or loss on derivatives: ​ ​ ​ ​ Change in net unrealized gain or loss during the period ​ 225 ​ 100 ​ 3,767 ​ (25,098) Reclassification adjustment for loss included in loss on termination of derivatives ​ ​ — ​ ​ — ​ ​ 16,505 ​ ​ — Reclassification adjustment for expense included in interest expense ​ 38 ​ 2,319 ​ 902 ​ 3,679 Net change ​ 263 ​ 2,419 ​ 21,174 ​ (21,419) Tax expense (benefit) ​ 82 ​ 766 ​ 6,712 ​ (6,783) Net change in unrealized gain or loss on derivatives, net of reclassification adjustments and tax ​ 181 ​ 1,653 ​ 14,462 ​ (14,636) Other comprehensive (loss) income, net of tax ​ $ (5,618) ​ $ 2,864 ​ $ 4,882 ​ $ (5,599)

EARNINGS PER COMMON SHARE ("E_2

EARNINGS PER COMMON SHARE ("EPS") (Tables)	9 Months Ended
	Sep. 30, 2021
EARNINGS PER COMMON SHARE ("EPS")
Reconciliation of Numerators and Denominators of Basic and Diluted EPS	The following is a reconciliation of the numerators and denominators of basic and diluted EPS for the periods presented: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands except share and per share amounts) 2021 2020 2021 2020 ​ ​ ​ ​ ​ ​ Net income available to common stockholders ​ $ 36,573 ​ $ 14,046 ​ $ 63,174 ​ $ 34,264 Less: Dividends paid and earnings allocated to participating securities ​ (437) ​ (83) ​ (811) ​ (195) Income attributable to common stock ​ $ 36,136 ​ $ 13,963 ​ $ 62,363 ​ $ 34,069 Weighted average common shares outstanding, including participating securities ​ 40,915,012 ​ 21,378,332 ​ 38,979,259 ​ 21,848,184 Less: weighted average participating securities ​ (489,274) ​ (187,781) ​ (405,102) ​ (191,438) Weighted average common shares outstanding ​ 40,425,738 ​ 21,190,551 ​ 38,574,157 ​ 21,656,746 Basic EPS ​ $ 0.89 ​ $ 0.66 ​ $ 1.62 ​ $ 1.57 ​ ​ ​ ​ ​ Income attributable to common stock ​ $ 36,136 ​ $ 13,963 ​ $ 62,363 ​ $ 34,069 Weighted average common shares outstanding ​ 40,425,738 ​ 21,190,551 ​ 38,574,157 ​ 21,656,746 Weighted average common equivalent shares outstanding ​ 423 ​ 133,636 ​ 700 ​ 134,334 Weighted average common and equivalent shares outstanding ​ 40,426,161 ​ 21,324,187 ​ 38,574,857 ​ 21,791,080 Diluted EPS ​ $ 0.89 ​ $ 0.65 ​ $ 1.62 ​ $ 1.56

INVESTMENT AND MORTGAGE-BACKE_2

INVESTMENT AND MORTGAGE-BACKED SECURITIES (Tables)	9 Months Ended
	Sep. 30, 2021
INVESTMENT AND MORTGAGE-BACKED SECURITIES
Major Categories of Securities Owned by Entity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair (In thousands) Cost Gains Losses Value Securities available-for-sale: ​ ​ ​ ​ Agency notes ​ $ 82,475 ​ $ — ​ $ (1,457) ​ $ 81,018 Treasury securities ​ ​ 248,173 ​ ​ 5 ​ ​ (482) ​ ​ 247,696 Corporate securities ​ 122,476 ​ 4,758 ​ (401) ​ 126,833 Pass-through MBS issued by GSEs ​ 622,225 ​ 6,005 ​ (6,273) ​ 621,957 Agency Collateralized Mortgage Obligations ("CMOs") ​ 590,385 ​ 5,159 ​ (5,118) ​ 590,426 State and municipal obligations ​ ​ 41,158 ​ ​ 153 ​ ​ (178) ​ ​ 41,133 Total securities available-for-sale ​ $ 1,706,892 ​ $ 16,080 ​ $ (13,909) ​ $ 1,709,063 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrecognized ​ Unrecognized ​ Fair (In thousands) Cost Gains Losses Value Securities held-to-maturity: ​ ​ ​ ​ Pass-through MBS issued by GSEs ​ $ 25,325 ​ $ — ​ $ — ​ $ 25,325 Agency Collateralized Mortgage Obligations ("CMOs") ​ 14,978 ​ — ​ — ​ 14,978 Total securities held-to-maturity ​ $ 40,303 ​ $ — ​ $ — ​ $ 40,303 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair (In thousands) Cost Gains Losses Value Securities available-for-sale: ​ ​ ​ ​ Agency notes ​ $ 47,500 ​ $ 12 ​ $ (91) ​ $ 47,421 Corporate securities ​ 62,021 ​ 2,440 ​ — ​ 64,461 Pass-through MBS issued by GSEs ​ 135,842 ​ 7,672 ​ (31) ​ 143,483 Agency CMOs ​ 274,898 ​ 8,674 ​ (76) ​ 283,496 Total securities available-for-sale ​ $ 520,261 ​ $ 18,798 ​ $ (198) ​ $ 538,861
Schedule of amortized cost and fair value of debt securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ Amortized ​ Fair (In thousands) ​ Cost ​ Value Available-for-sale ​ ​ ​ ​ ​ ​ Within one year ​ $ 1,346 ​ $ 1,351 One to five years ​ ​ 270,069 ​ ​ 269,665 Five to ten years ​ ​ 209,938 ​ ​ 212,881 Beyond ten years ​ ​ 12,929 ​ ​ 12,783 Pass-through MBS issued by GSEs and agency CMO ​ ​ 1,212,610 ​ ​ 1,212,383 Total ​ $ 1,706,892 ​ $ 1,709,063 ​ ​ ​ ​ ​ ​ ​ Held-to-maturity ​ ​ ​ ​ ​ ​ Pass-through MBS issued by GSEs and agency CMO ​ $ 40,303 ​ $ 40,303 Total ​ $ 40,303 ​ $ 40,303
Summary of Sale of Available-for-sale Securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands) 2021 2020 ​ 2021 2020 Agency Notes: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Proceeds ​ $ — ​ $ — ​ $ — ​ $ 273 Gross gains ​ ​ — ​ ​ — ​ ​ — ​ ​ — Tax expense on gain ​ ​ — ​ ​ — ​ ​ — ​ ​ — Gross losses ​ ​ — ​ ​ — ​ ​ — ​ ​ — Tax benefit on loss ​ ​ — ​ ​ — ​ ​ — ​ ​ — Corporate Securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Proceeds ​ ​ — ​ ​ — ​ ​ 50,273 ​ ​ 25,403 Gross gains ​ ​ — ​ ​ — ​ ​ 729 ​ ​ 1,344 Tax expense on gain ​ ​ — ​ ​ — ​ ​ 232 ​ ​ 423 Gross losses ​ ​ — ​ ​ — ​ ​ 41 ​ ​ — Tax benefit on loss ​ ​ — ​ ​ — ​ ​ 13 ​ ​ — Pass through MBS issued by GSEs: ​ ​ ​ ​ ​ ​ Proceeds ​ ​ — ​ ​ 5,987 ​ ​ 26,823 ​ ​ 39,182 Gross gains ​ — ​ 215 ​ 187 ​ 2,005 Tax expense on gain ​ — ​ 67 ​ 59 ​ 630 Gross losses ​ — ​ — ​ 35 ​ — Tax benefit on loss ​ — ​ — ​ 11 ​ — Agency CMOs: ​ ​ ​ ​ ​ Proceeds ​ — ​ — ​ 41,324 ​ 4,199 Gross gains ​ — ​ — ​ 268 ​ 8 Tax expense on gain ​ — ​ — ​ 85 ​ 3 Gross losses ​ ​ — ​ ​ — ​ ​ 44 ​ ​ — Tax benefit on loss ​ ​ — ​ ​ — ​ ​ 14 ​ ​ — State and municipal obligations: ​ ​ ​ ​ Proceeds ​ — ​ — ​ 19,657 ​ — Gross gains ​ — ​ — ​ 143 ​ — Tax expense on gain ​ — ​ — ​ 45 ​ — Gross losses ​ ​ — ​ ​ — ​ ​ — ​ ​ — Tax benefit on loss ​ ​ — ​ ​ — ​ ​ — ​ ​ —
Sales of Marketable Equity Securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands) 2021 2020 ​ 2021 2020 Proceeds: ​ ​ ​ ​ ​ Marketable equity securities ​ $ — ​ $ 137 ​ $ — ​ $ 410
Gross Unrealized Losses and Fair Value of Investment Securities by Investment Category and Length of Time in a Continuous Unrealized Loss Position	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ Less than 12 ​ 12 Consecutive ​ ​ ​ ​ ​ ​ ​ ​ Consecutive Months ​ Months or Longer ​ Total ​ ​ Fair ​ Unrealized ​ Fair ​ Unrealized ​ Fair ​ Unrealized (In thousands) Value Losses Value Losses Value Losses Securities available-for-sale: ​ ​ ​ ​ ​ ​ Agency notes ​ $ 81,018 ​ $ 1,457 ​ $ — ​ $ — ​ $ 81,018 ​ $ 1,457 Treasury securities ​ ​ 231,984 ​ ​ 482 ​ ​ — ​ ​ — ​ ​ 231,984 ​ ​ 482 Corporate securities ​ ​ 17,863 ​ ​ 401 ​ ​ — ​ ​ — ​ ​ 17,863 ​ ​ 401 Pass-through MBS issued by GSEs ​ ​ 446,864 ​ ​ 6,273 ​ ​ — ​ ​ — ​ ​ 446,864 ​ ​ 6,273 Agency CMOs ​ ​ 347,726 ​ ​ 5,118 ​ ​ — ​ ​ — ​ ​ 347,726 ​ ​ 5,118 State and municipal obligations ​ 16,412 ​ 178 ​ — ​ — ​ 16,412 ​ 178 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ Less than 12 ​ 12 Consecutive ​ ​ ​ ​ ​ ​ ​ ​ Consecutive Months ​ Months or Longer ​ Total ​ ​ Fair ​ Unrealized ​ Fair ​ Unrealized ​ Fair ​ Unrealized (In thousands) Value Losses Value Losses Value Losses Securities available-for-sale: ​ ​ ​ ​ ​ ​ Agency notes ​ $ 22,409 ​ $ 91 ​ $ — ​ $ — ​ $ 22,409 ​ $ 91 Pass-through MBS issued by GSEs ​ 5,007 ​ 31 ​ — ​ — ​ 5,007 ​ 31 Agency CMOs ​ 6,563 ​ 30 ​ 4,954 ​ 46 ​ 11,517 ​ 76

LOANS HELD FOR INVESTMENT, NET

LOANS HELD FOR INVESTMENT, NET (Tables)	9 Months Ended
	Sep. 30, 2021
LOANS HELD FOR INVESTMENT, NET
Loan Categories	The following table presents the loan categories for the period ended as indicated: ​ ​ ​ ​ ​ ​ ​ (In thousands) September 30, 2021 December 31, 2020 One-to-four family residential and cooperative/condominium apartment ​ $ 683,665 ​ $ 184,989 Multifamily residential and residential mixed-use ​ 3,468,262 ​ 2,758,743 Commercial real estate ("CRE") ​ 3,814,437 ​ 1,878,167 Acquisition, development, and construction ("ADC") ​ 285,379 ​ 156,296 Total real estate loans ​ 8,251,743 ​ 4,978,195 Commercial and industrial ("C&I") ​ 1,012,415 ​ 641,533 Other loans ​ 20,713 ​ 2,316 Total ​ 9,284,871 ​ 5,622,044 Allowance for credit losses ​ (81,255) ​ (41,461) Loans held for investment, net ​ $ 9,203,616 ​ $ 5,580,583
Activity in Allowance for Loan Losses	The following tables present data regarding the allowance for credit losses activity for the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or for the Three Months Ended September 30, 2021 ​ ​ Real Estate Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-Four ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Family ​ Multifamily ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Residential and ​ Residential ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cooperative/ ​ and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Condominium ​ Residential ​ ​ ​ ​ ​ ​ Total Real ​ ​ ​ ​ Other ​ ​ ​ (In thousands) Apartment Mixed-Use CRE ADC Estate C&I Loans Total Allowance for credit losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance ​ $ 5,522 ​ $ 10,285 ​ $ 41,201 ​ $ 5,158 ​ $ 62,166 ​ $ 30,095 ​ $ 499 $ 92,760 Provision (credit) for credit losses ​ 583 ​ ​ (1,998) ​ ​ (8,649) ​ ​ (139) ​ (10,203) ​ 1,943 ​ ​ 946 ​ (7,314) Charge-offs ​ (1) ​ (58) ​ (2,952) ​ — ​ (3,011) ​ (497) ​ (768) ​ (4,276) Recoveries ​ ​ — ​ ​ 78 ​ ​ 3 ​ ​ — ​ ​ 81 ​ ​ 4 ​ ​ — ​ ​ 85 Ending balance ​ $ 6,104 ​ $ 8,307 ​ $ 29,603 ​ $ 5,019 ​ $ 49,033 ​ $ 31,545 ​ $ 677 ​ $ 81,255 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or for the Three Months Ended September 30, 2020 ​ ​ Real Estate Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-Four ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Family ​ Multifamily ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Residential and ​ Residential ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cooperative/ ​ and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Condominium ​ Residential ​ ​ ​ ​ ​ ​ Total Real ​ ​ ​ ​ Other ​ ​ ​ (In thousands) Apartment Mixed-Use CRE ADC Estate C&I Loans Total Allowance for credit losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance ​ $ 671 ​ $ 16,666 ​ $ 9,859 ​ $ 1,777 ​ $ 28,973 ​ $ 13,502 ​ $ 17 $ 42,492 Provision (credit) for credit losses ​ 134 ​ 3,468 ​ 2,162 ​ 274 ​ 6,038 ​ (107) ​ — ​ 5,931 Charge-offs ​ (6) ​ (13) ​ — ​ — ​ (19) ​ — ​ (1) ​ (20) Recoveries ​ — ​ 89 ​ — ​ — ​ 89 ​ — ​ — ​ 89 Ending balance ​ $ 799 ​ $ 20,210 ​ $ 12,021 ​ $ 2,051 ​ $ 35,081 ​ $ 13,395 ​ $ 16 ​ $ 48,492 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or for the Nine Months Ended September 30, 2021 ​ ​ Real Estate Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-Four ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Family ​ Multifamily ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Residential and ​ Residential ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cooperative/ ​ and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Condominium ​ Residential ​ ​ ​ ​ ​ ​ Total Real ​ ​ ​ ​ Other ​ ​ ​ ​ Apartment Mixed-Use CRE ADC Estate C&I Loans Total Allowance for credit losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance, prior to the adoption of CECL ​ $ 644 ​ $ 17,016 ​ $ 9,059 ​ $ 1,993 ​ $ 28,712 ​ $ 12,737 ​ $ 12 $ 41,461 Impact of adopting CECL ​ ​ 1,048 ​ ​ (8,254) ​ ​ 4,849 ​ ​ 381 ​ ​ (1,976) ​ ​ (1,935) ​ ​ (8) ​ ​ (3,919) Adjusted beginning balance as of January 1, 2021 ​ ​ 1,692 ​ ​ 8,762 ​ ​ 13,908 ​ ​ 2,374 ​ ​ 26,736 ​ ​ 10,802 ​ ​ 4 ​ ​ 37,542 PCD Day 1 ​ ​ 2,220 ​ ​ 3,292 ​ ​ 23,124 ​ ​ 117 ​ ​ 28,753 ​ ​ 23,374 ​ ​ 157 ​ ​ 52,284 Provision (credit) for credit losses ​ 2,212 ​ (3,361) ​ (4,068) ​ 2,528 ​ (2,689) ​ 2,215 ​ 1,286 ​ 812 Charge-offs ​ (20) ​ (467) ​ (3,365) ​ — ​ (3,852) ​ (4,959) ​ (773) ​ (9,584) Recoveries ​ ​ — ​ ​ 81 ​ ​ 4 ​ ​ — ​ ​ 85 ​ ​ 113 ​ ​ 3 ​ ​ 201 Ending balance ​ $ 6,104 ​ $ 8,307 ​ $ 29,603 ​ $ 5,019 ​ $ 49,033 ​ $ 31,545 ​ $ 677 ​ $ 81,255 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or for the Nine Months Ended September 30, 2020 ​ ​ Real Estate Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-Four ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Family ​ Multifamily ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Residential and ​ Residential ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cooperative/ ​ and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Condominium ​ Residential ​ ​ ​ ​ ​ ​ Total Real ​ ​ ​ ​ Other ​ ​ ​ ​ ​ Apartment Mixed-Use CRE ADC Estate C&I Loans Total Allowance for credit losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance ​ $ 269 ​ $ 10,142 ​ $ 3,900 ​ $ 1,244 ​ $ 15,555 ​ $ 12,870 ​ $ 16 $ 28,441 Provision for credit losses ​ 540 ​ 10,010 ​ 8,127 ​ 807 ​ 19,484 ​ 518 ​ 1 ​ 20,003 Charge-offs ​ (10) ​ (45) ​ (6) ​ — ​ (61) ​ — ​ (1) ​ (62) Recoveries ​ — ​ 103 ​ — ​ — ​ 103 ​ 7 ​ — ​ 110 Ending balance ​ $ 799 ​ $ 20,210 ​ $ 12,021 ​ $ 2,051 ​ $ 35,081 ​ $ 13,395 ​ $ 16 ​ $ 48,492 The following table presents the amortized cost basis of loans on non-accrual status as of the period indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ Non-accrual with ​ ​ Non-accrual with ​ ​ ​ (In thousands) No Allowance Allowance ​ Reserve One-to-four family residential and cooperative/condominium apartment $ - ​ $ 4,938 ​ $ 781 Multifamily residential and residential mixed-use ​ 859 ​ ​ - ​ ​ - CRE 1,240 ​ 2,882 ​ ​ 812 C&I ​ - ​ ​ 23,727 ​ ​ 11,191 Other ​ - ​ ​ 374 ​ ​ 371 Total $ 2,099 ​ $ 31,921 ​ $ 13,155 The following table presents the balance in the allowance for loan losses and the recorded investment in loans by portfolio segment and based on impairment method, prior to the adoption of ASC 326, as of the dates indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ Real Estate Loans ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-Four ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Family ​ Multifamily ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Residential and ​ Residential ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cooperative/ ​ and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Condominium ​ Residential ​ ​ ​ ​ ​ ​ Total Real ​ ​ ​ ​ Other ​ ​ ​ (In thousands) Apartment Mixed-Use CRE ADC Estate C&I Loans Total Allowance for loan losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Individually evaluated for impairment ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ 6,474 ​ $ — $ 6,474 Collectively evaluated for impairment ​ 644 ​ 17,016 ​ 9,059 ​ 1,993 ​ 28,712 ​ 6,263 ​ 12 ​ 34,987 Total ending allowance balance ​ $ 644 ​ $ 17,016 ​ $ 9,059 ​ $ 1,993 ​ $ 28,712 ​ $ 12,737 ​ $ 12 $ 41,461 ​ ​ ​ ​ ​ ​ ​ ​ ​ Loans: ​ ​ ​ ​ ​ ​ ​ ​ Individually evaluated for impairment ​ $ — ​ $ 1,863 ​ $ 2,704 ​ $ — ​ $ 4,567 ​ $ 12,502 ​ $ — $ 17,069 Collectively evaluated for impairment ​ 184,989 ​ 2,756,880 ​ 1,875,463 ​ 156,296 ​ 4,973,628 ​ 629,031 ​ 2,316 ​ 5,604,975 Total ending loans balance ​ $ 184,989 ​ $ 2,758,743 ​ $ 1,878,167 ​ $ 156,296 ​ $ 4,978,195 ​ $ 641,533 ​ $ 2,316 $ 5,622,044
Impaired Real Estate Loans	The following tables summarize impaired loans with no related allowance recorded and with related allowance recorded as of the periods indicated (by collateral type within the real estate loan segment): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ Unpaid ​ ​ ​ ​ ​ ​ ​ Principal ​ Recorded ​ Related (In thousands) Balance Investment (1) Allowance With no related allowance recorded: ​ ​ ​ ​ ​ ​ Multifamily residential and residential mixed-use ​ $ 1,863 ​ $ 1,863 ​ $ — CRE ​ 2,704 ​ 2,704 ​ — Total with no related allowance recorded ​ 4,567 ​ 4,567 ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ With an allowance recorded: ​ ​ ​ C&I ​ 12,502 ​ 12,502 ​ 6,474 Total with an allowance recorded ​ 12,502 ​ 12,502 ​ 6,474 Total ​ $ 17,069 ​ $ 17,069 ​ $ 6,474 (1) The recorded investment excludes net deferred costs due to immateriality. The following table presents information for impaired loans for the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, 2020 ​ September 30, 2020 ​ ​ Average ​ Interest ​ Average ​ Interest ​ ​ Recorded ​ Income ​ Recorded ​ Income ​ Investment (1) Recognized (2) ​ Investment (1) Recognized (2) With no related allowance recorded: ​ ​ ​ ​ ​ ​ ​ ​ One-to-four family residential, including condominium and cooperative apartment ​ $ — ​ $ — ​ $ 10 ​ $ 4 Multifamily residential and residential mixed-use ​ 1,295 ​ — ​ 416 ​ 7 Commercial real estate and commercial mixed-use ​ 1,525 ​ — ​ 2,688 ​ 54 Total with no related allowance recorded ​ 2,820 ​ — ​ 3,114 ​ 65 ​ ​ ​ ​ ​ With an allowance recorded: ​ ​ ​ ​ C&I ​ 10,232 ​ — ​ 7,500 ​ 153 Total ​ $ 13,052 ​ $ — ​ $ 10,614 ​ $ 218 (1) The recorded investment excludes net deferred costs due to immateriality. (2) Cash basis interest and interest income recognized on accrual basis approximate each other.
Past Due Financing Receivables	The following tables summarize the past due status of the Company’s investment in loans as of the dates indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ Loans 90 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Days or ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 30 to 59 ​ 60 to 89 ​ More Past Due ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Days ​ Days ​ and Still ​ ​ ​ Total ​ ​ ​ ​ Total (In thousands) Past Due Past Due Accruing Interest Non-accrual Past Due Current Loans Real estate: ​ ​ ​ ​ ​ ​ ​ One-to-four family residential, including condominium and cooperative apartment ​ $ 3,135 ​ $ 1,245 ​ $ 5,021 ​ $ 4,938 ​ $ 14,339 ​ $ 669,326 ​ $ 683,665 Multifamily residential and residential mixed-use ​ 10,251 ​ 2,738 ​ — ​ 859 ​ 13,848 ​ 3,454,414 ​ 3,468,262 CRE ​ 8,360 ​ 1,069 ​ 1,004 ​ 4,122 ​ 14,555 ​ 3,799,882 ​ 3,814,437 ADC ​ 17,700 ​ — ​ — ​ — ​ 17,700 ​ 267,679 ​ 285,379 Total real estate ​ 39,446 ​ 5,052 ​ 6,025 ​ 9,919 ​ 60,442 ​ 8,191,301 ​ 8,251,743 C&I ​ 10,962 ​ 2,455 ​ 257 ​ 23,727 ​ 37,401 ​ 975,014 ​ 1,012,415 Other ​ ​ 730 ​ ​ 2 ​ ​ — ​ ​ 374 ​ ​ 1,106 ​ ​ 19,607 ​ ​ 20,713 Total ​ $ 51,138 ​ $ 7,509 ​ $ 6,282 ​ $ 34,020 ​ $ 98,949 ​ $ 9,185,922 ​ $ 9,284,871 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ Loans 90 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Days or ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 30 to 59 ​ 60 to 89 ​ More Past Due ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Days ​ Days ​ and Still ​ ​ ​ Total ​ ​ ​ ​ Total (In thousands) Past Due Past Due Accruing Interest Non-accrual Past Due Current Loans Real estate: ​ ​ ​ ​ ​ ​ ​ One-to-four family residential, including condominium and cooperative apartment ​ $ — ​ $ — ​ $ 44 ​ $ 858 ​ $ 902 ​ $ 184,087 ​ $ 184,989 Multifamily residential and residential mixed-use ​ — ​ — ​ 437 ​ 1,863 ​ 2,300 ​ 2,756,443 ​ 2,758,743 CRE ​ 15,351 ​ — ​ — ​ 2,704 ​ 18,055 ​ 1,860,112 ​ 1,878,167 ADC ​ — ​ — ​ — ​ — ​ — ​ 156,296 ​ 156,296 Total real estate ​ 15,351 ​ — ​ 481 ​ 5,425 ​ 21,257 ​ 4,956,938 ​ 4,978,195 C&I ​ — ​ 917 ​ 2,848 ​ 12,502 ​ 16,267 ​ 625,266 ​ 641,533 Other ​ ​ 8 ​ ​ 1 ​ ​ — ​ ​ 1 ​ ​ 10 ​ ​ 2,306 ​ ​ 2,316 Total ​ $ 15,359 ​ $ 918 ​ $ 3,329 ​ $ 17,928 ​ $ 37,534 ​ $ 5,584,510 ​ $ 5,622,044 ​ ​
Schedule of loans by class modified as trouble debt restructurings	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Modifications During the Nine Months Ended September 30, 2021 ​ ​ ​ ​ ​ Pre- ​ ​ Post- ​ ​ ​ ​ ​ Modification ​ ​ Modification ​ ​ ​ ​ ​ Outstanding ​ ​ Outstanding ​ ​ Number of ​ ​ Recorded ​ ​ Recorded (Dollars in thousands) ​ Loans ​ ​ Investment ​ ​ Investment One-to-four family residential and cooperative/condominium apartment ​ 1 ​ $ 50 ​ $ 50 Commercial real estate ("CRE") ​ 1 ​ ​ 10,000 ​ ​ 10,000 Commercial and industrial ("C&I") ​ 1 ​ ​ 456 ​ ​ 488 Total ​ 3 ​ $ 10,506 ​ $ 10,538
Loans Approved for Deferral	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ Number ​ ​ ​ ​ ​ ​ of Loans Balance (1) % of Portfolio ​ (Dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ One-to-four family residential and cooperative/condominium apartment 10 ​ $ 9,255 ​ 1.4 % CRE 1 ​ 3,487 ​ 0.1 ​ C&I ​ 6 ​ ​ 13,861 ​ 1.4 ​ Total 17 ​ $ 26,603 ​ 0.3 ​ (1) Amount excludes net deferred costs due to immateriality.
Credit Risk Profile of the Real Estate Loans	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 (In thousands) ​ 2021 ​ 2020 ​ 2019 ​ 2018 ​ 2017 ​ 2016 and Prior ​ Revolving ​ Revolving-Term ​ Total One-to-four family residential, and condominium/cooperative apartment: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ $ 104,830 ​ $ 93,315 ​ $ 86,214 ​ $ 79,981 ​ $ 84,075 ​ $ 143,807 ​ $ 52,483 ​ $ 11,162 ​ $ 655,867 Special mention ​ ​ — ​ ​ — ​ ​ 337 ​ ​ 756 ​ ​ 345 ​ ​ 2,168 ​ ​ 846 ​ ​ 1,089 ​ ​ 5,541 Substandard ​ ​ — ​ ​ 1,461 ​ ​ 2,048 ​ ​ 862 ​ ​ 2,206 ​ ​ 14,691 ​ ​ — ​ ​ 966 ​ ​ 22,234 Doubtful ​ ​ — ​ ​ — ​ ​ — ​ ​ 23 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 23 Total one-to-four family residential, and condominium/cooperative apartment ​ ​ 104,830 ​ ​ 94,776 ​ ​ 88,599 ​ ​ 81,622 ​ ​ 86,626 ​ ​ 160,666 ​ ​ 53,329 ​ ​ 13,217 ​ ​ 683,665 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Multifamily residential and residential mixed-use: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ ​ 426,164 ​ ​ 347,900 ​ ​ 493,077 ​ ​ 193,738 ​ ​ 373,965 ​ ​ 1,329,688 ​ ​ 5,111 ​ ​ 825 ​ ​ 3,170,468 Special mention ​ ​ — ​ ​ 12,550 ​ ​ 14,551 ​ ​ — ​ ​ 11,842 ​ ​ 22,378 ​ ​ — ​ ​ — ​ ​ 61,321 Substandard ​ ​ — ​ ​ — ​ ​ 35,886 ​ ​ 27,265 ​ ​ 51,680 ​ ​ 118,179 ​ ​ 3,463 ​ ​ — ​ ​ 236,473 Doubtful ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Total multifamily residential and residential mixed-use ​ ​ 426,164 ​ ​ 360,450 ​ ​ 543,514 ​ ​ 221,003 ​ ​ 437,487 ​ ​ 1,470,245 ​ ​ 8,574 ​ ​ 825 ​ ​ 3,468,262 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CRE: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ ​ 636,234 ​ ​ 872,347 ​ ​ 578,758 ​ ​ 331,636 ​ ​ 337,930 ​ ​ 863,215 ​ ​ 39,323 ​ ​ 5,164 ​ ​ 3,664,607 Special mention ​ ​ 5,354 ​ ​ 2,384 ​ ​ — ​ ​ 4,191 ​ ​ 11,109 ​ ​ 15,416 ​ ​ — ​ ​ — ​ ​ 38,454 Substandard ​ ​ 2,335 ​ ​ 1,752 ​ ​ 7,110 ​ ​ 39,892 ​ ​ 19,733 ​ ​ 40,448 ​ ​ — ​ ​ — ​ ​ 111,270 Doubtful ​ ​ — ​ ​ — ​ ​ 106 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 106 Total CRE ​ ​ 643,923 ​ ​ 876,483 ​ ​ 585,974 ​ ​ 375,719 ​ ​ 368,772 ​ ​ 919,079 ​ ​ 39,323 ​ ​ 5,164 ​ ​ 3,814,437 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ADC: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ ​ 101,947 ​ ​ 69,546 ​ ​ 62,414 ​ ​ 24,587 ​ ​ 8,120 ​ ​ 807 ​ ​ 2,686 ​ ​ 600 ​ ​ 270,707 Special mention ​ ​ — ​ ​ — ​ ​ — ​ ​ 1,078 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 1,078 Substandard ​ ​ — ​ ​ — ​ ​ — ​ ​ 13,500 ​ ​ — ​ ​ 94 ​ ​ — ​ ​ — ​ ​ 13,594 Doubtful ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Total ADC ​ ​ 101,947 ​ ​ 69,546 ​ ​ 62,414 ​ ​ 39,165 ​ ​ 8,120 ​ ​ 901 ​ ​ 2,686 ​ ​ 600 ​ ​ 285,379 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ C&I: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ ​ 52,667 ​ ​ 199,677 ​ ​ 58,835 ​ ​ 54,190 ​ ​ 38,065 ​ ​ 25,948 ​ ​ 479,111 ​ ​ 10,359 ​ ​ 918,852 Special mention ​ ​ — ​ ​ 1,690 ​ ​ 265 ​ ​ 2,260 ​ ​ 611 ​ ​ 61 ​ ​ 1,685 ​ ​ 1,368 ​ ​ 7,940 Substandard ​ ​ — ​ ​ 5,949 ​ ​ 4,842 ​ ​ 6,175 ​ ​ 2,982 ​ ​ 1,057 ​ ​ 34,996 ​ ​ 6,764 ​ ​ 62,765 Doubtful ​ ​ — ​ ​ — ​ ​ 10,087 ​ ​ 752 ​ ​ 11,989 ​ ​ 30 ​ ​ — ​ ​ — ​ ​ 22,858 Total C&I ​ ​ 52,667 ​ ​ 207,316 ​ ​ 74,029 ​ ​ 63,377 ​ ​ 53,647 ​ ​ 27,096 ​ ​ 515,792 ​ ​ 18,491 ​ ​ 1,012,415 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ ​ 1,321,842 ​ ​ 1,582,785 ​ ​ 1,279,298 ​ ​ 684,132 ​ ​ 842,155 ​ ​ 2,363,465 ​ ​ 578,714 ​ ​ 28,110 ​ ​ 8,680,501 Special mention ​ ​ 5,354 ​ ​ 16,624 ​ ​ 15,153 ​ ​ 8,285 ​ ​ 23,907 ​ ​ 40,023 ​ ​ 2,531 ​ ​ 2,457 ​ ​ 114,334 Substandard ​ ​ 2,335 ​ ​ 9,162 ​ ​ 49,886 ​ ​ 87,694 ​ ​ 76,601 ​ ​ 174,469 ​ ​ 38,459 ​ ​ 7,730 ​ ​ 446,336 Doubtful ​ ​ — ​ ​ — ​ ​ 10,193 ​ ​ 775 ​ ​ 11,989 ​ ​ 30 ​ ​ — ​ ​ — ​ ​ 22,987 Total Loans ​ $ 1,329,531 ​ $ 1,608,571 ​ $ 1,354,530 ​ $ 780,886 ​ $ 954,652 ​ $ 2,577,987 ​ $ 619,704 ​ $ 38,297 ​ $ 9,264,158 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ Special ​ ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) Pass Mention Substandard Doubtful Total Real Estate: ​ ​ ​ ​ ​ One-to-four family residential and condominium/cooperative apartment ​ $ 183,293 ​ $ — ​ $ 1,696 ​ $ — ​ $ 184,989 Multifamily residential and residential mixed-use ​ 2,523,258 ​ 56,400 ​ 179,085 ​ — ​ 2,758,743 CRE ​ 1,831,712 ​ 13,861 ​ 32,594 ​ — ​ 1,878,167 ADC ​ 142,796 ​ 13,500 ​ — ​ — ​ 156,296 Total real estate ​ 4,681,059 ​ 83,761 ​ 213,375 ​ — ​ 4,978,195 C&I ​ 613,691 ​ 2,131 ​ 13,315 ​ 12,396 ​ 641,533 Total Real Estate and C&I ​ $ 5,294,750 ​ $ 85,892 ​ $ 226,690 ​ $ 12,396 ​ $ 5,619,728 ​ ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) September 30, 2021 December 31, 2020 Performing ​ $ 20,339 ​ $ 2,315 Non-accrual ​ 374 ​ 1 Total ​ $ 20,713 ​ $ 2,316

LEASES (Tables)

LEASES (Tables)	9 Months Ended
	Sep. 30, 2021
LEASES
Maturities of Operating Lease Liabilities	Maturities of the Company’s operating lease liabilities at September 30, 2021 are as follows: ​ ​ ​ ​ ​ ​ Rent to be (In thousands) Capitalized 2021 $ 3,374 2022 ​ 11,006 2023 ​ 9,301 2024 ​ 9,186 2025 ​ 8,941 Thereafter ​ 25,439 Total undiscounted lease payments ​ 67,247 Less amounts representing interest ​ (4,377) Operating lease liabilities ​ $ 62,870
Other Information Related to Operating Leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands) 2021 2020 2021 2020 Operating lease cost ​ $ 4,012 ​ $ 1,636 ​ $ 11,178 ​ $ 4,867 Cash paid for amounts included in the measurement of operating lease liabilities ​ ​ 3,724 ​ ​ 1,745 ​ ​ 10,496 ​ ​ 5,295

DERIVATIVES AND HEDGING ACTIV_2

DERIVATIVES AND HEDGING ACTIVITIES (Tables)	9 Months Ended
	Sep. 30, 2021
Derivatives, Fair Value [Line Items]
Effect of Cash Flow Hedge Accounting on Accumulated Other Comprehensive Income (Loss)	The table below presents the effect of the cash flow hedge accounting on Accumulated Other Comprehensive Income (Loss) for the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ (In thousands) 2021 2020 ​ 2021 2020 ​ Gain (loss) recognized in other comprehensive income ​ $ 225 ​ $ 100 ​ $ 3,767 ​ $ (25,098) ​ Gain recognized on termination of derivatives ​ ​ — ​ ​ — ​ ​ 16,505 ​ ​ — ​ Loss reclassified from other comprehensive income into interest expense ​ (38) ​ (2,319) ​ (902) ​ (3,679) ​
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments and Classification on Consolidated Statements of Financial Condition	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ December 31, 2020 ​ ​ ​ ​ Notional ​ Fair Value ​ Fair Value ​ ​ ​ Notional ​ Fair Value ​ Fair Value (Dollars in thousands) Count Amount Assets Liabilities Count Amount Assets Liabilities Included in derivative assets/(liabilities): ​ ​ ​ ​ ​ ​ Interest rate swaps related to FHLBNY advances 4 ​ $ 150,000 ​ $ 2,811 ​ $ — — ​ $ — ​ $ — ​ $ — Interest rate swaps related to FHLBNY advances — ​ $ — ​ $ — ​ $ — 32 ​ $ 655,000 ​ $ — ​ $ (18,442)
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments and Classification on Consolidated Statements of Financial Condition	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ ​ Notional ​ Fair Value ​ Fair Value (In thousands) Count Amount Assets Liabilities Included in derivative assets/(liabilities): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loan level interest rate swaps with borrower 128 ​ $ 818,370 ​ $ 36,095 ​ $ — Loan level interest rate swaps with borrower 61 ​ 439,198 ​ — ​ (7,414) Loan level interest rate floors with borrower ​ 47 ​ ​ 405,685 ​ ​ — ​ ​ (4,072) Loan level interest rate swaps with third-party counterparties 128 ​ 818,370 ​ — ​ (36,095) Loan level interest rate swaps with third-party counterparties ​ 61 ​ ​ 439,198 ​ ​ 7,414 ​ ​ — Loan level interest rate floors with third-party counterparties 47 ​ 405,685 ​ 4,072 ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ Notional ​ Fair Value ​ Fair Value (In thousands) Count Amount Assets Liabilities Included in derivative assets/(liabilities): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loan level interest rate swaps with borrower 65 ​ $ 570,277 ​ $ 24,764 ​ $ — Loan level interest rate floors with borrower 41 ​ 364,643 ​ — ​ (5,832) Loan level interest rate swaps with third-party counterparties 65 ​ 570,277 ​ — ​ (24,764) Loan level interest rate floors with third-party counterparties 41 ​ 364,643 ​ 5,832 ​ —
Loan Level Derivative Income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands) 2021 2020 ​ 2021 2020 Loan level derivative income ​ $ 445 ​ $ 1,544 ​ $ 2,796 ​ $ 5,201

FAIR VALUE OF FINANCIAL INSTR_2

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	9 Months Ended
	Sep. 30, 2021
FAIR VALUE OF FINANCIAL INSTRUMENTS
Fair Value, Assets and Liabilities Measured on Recurring Basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ ​ ​ ​ at September 30, 2021 Using ​ ​ ​ ​ ​ Level 1 ​ Level 2 ​ Level 3 (In thousands) Total Inputs Inputs Inputs Financial Assets: ​ ​ ​ ​ Securities available-for-sale: ​ ​ ​ ​ Agency notes ​ $ 81,018 ​ $ — ​ $ 81,018 ​ $ — Treasury securities ​ ​ 247,696 ​ ​ — ​ ​ 247,696 ​ ​ — Corporate securities ​ 126,833 ​ — ​ 126,833 ​ — Pass-through MBS issued by GSEs ​ 621,957 ​ — ​ 621,957 ​ — Agency CMOs ​ 590,426 ​ — ​ 590,426 ​ — State and municipal obligations ​ ​ 41,133 ​ ​ — ​ ​ 41,133 ​ ​ — Derivative – cash flow hedges ​ 2,811 ​ — ​ 2,811 ​ — Derivative – freestanding derivatives, net ​ 38,889 ​ — ​ 38,889 ​ — Financial Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivative – freestanding derivatives, net ​ 38,889 ​ — ​ 38,889 ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ ​ ​ ​ at December 31, 2020 Using ​ ​ ​ ​ ​ Level 1 ​ Level 2 ​ Level 3 (In thousands) Total Inputs Inputs Inputs Financial Assets: ​ ​ ​ ​ Marketable equity securities (Registered mutual funds) ​ ​ ​ ​ Domestic equity mutual funds ​ $ 1,769 ​ $ 1,769 ​ $ — ​ $ — International equity mutual funds ​ 468 ​ 468 ​ — ​ — Fixed income mutual funds ​ 3,733 ​ 3,733 ​ — ​ — Securities available-for-sale: ​ ​ ​ ​ Agency notes ​ 47,421 ​ — ​ 47,421 ​ — Corporate securities ​ 64,461 ​ — ​ 64,461 ​ — Pass-through MBS issued by GSEs ​ 143,483 ​ — ​ 143,483 ​ — Agency CMOs ​ 283,496 ​ — ​ 283,496 ​ — Derivative – freestanding derivatives ​ ​ 30,596 ​ ​ — ​ ​ 30,596 ​ ​ — Financial Liabilities: ​ ​ ​ ​ Derivative – cash flow hedges ​ 18,442 ​ — ​ 18,442 ​ — Derivative – freestanding derivatives ​ 30,596 ​ — ​ 30,596 ​ —
Schedule of assets measured at fair value on a non-recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ ​ ​ Fair Value Measurements Using: ​ ​ ​ Quoted Prices ​ ​ ​ ​ ​ ​ ​ In Active ​ Significant ​ ​ ​ ​ ​ Markets for ​ Other ​ Significant ​ ​ ​ ​ Identical ​ Observable ​ Unobservable ​ ​ Carrying ​ Assets ​ Inputs ​ Inputs (In thousands) Value (Level 1) (Level 2) (Level 3) Individually evaluated loans ​ $ 55,146 ​ $ — $ — $ 55,146
Fair Value Measurements, Nonrecurring	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ ​ ​ ​ at September 30, 2021 Using ​ ​ Carrying ​ Level 1 ​ Level 2 ​ Level 3 ​ ​ ​ (In thousands) Amount Inputs Inputs Inputs Total Financial Assets: ​ ​ ​ ​ ​ Cash and due from banks ​ $ 629,011 ​ $ 629,011 ​ $ — ​ $ — ​ $ 629,011 Securities held-to-maturity ​ ​ 40,303 ​ — ​ 40,303 ​ — ​ 40,303 Loans held for investment, net ​ 9,148,470 ​ — ​ — ​ 9,212,454 ​ 9,212,454 Accrued interest receivable ​ 43,284 ​ — ​ 4,228 ​ 39,056 ​ 43,284 Financial Liabilities: ​ ​ ​ ​ ​ Savings, money market and checking accounts ​ 9,657,821 ​ 9,657,821 ​ — ​ — ​ 9,657,821 Certificates of Deposits ("CDs") ​ 1,016,216 ​ — ​ 1,021,029 ​ — ​ 1,021,029 FHLBNY advances ​ 25,000 ​ — ​ 25,015 ​ — ​ 25,015 Subordinated debt, net ​ 197,142 ​ — ​ 203,355 ​ — ​ 203,355 Other short-term borrowings ​ 2,629 ​ 2,629 ​ — ​ — ​ 2,629 Accrued interest payable ​ 1,630 ​ — ​ 1,630 ​ — ​ 1,630 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ ​ ​ ​ at December 31, 2020 Using ​ ​ Carrying ​ Level 1 ​ Level 2 ​ Level 3 ​ ​ ​ (In thousands) Amount Inputs Inputs Inputs Total Financial Assets: ​ ​ ​ ​ ​ Cash and due from banks ​ $ 243,603 ​ $ 243,603 ​ $ — ​ $ — ​ $ 243,603 Loans held for investment, net ​ 5,580,583 ​ — ​ — ​ 5,598,787 ​ 5,598,787 Accrued interest receivable ​ 34,815 ​ 2 ​ 1,584 ​ 33,229 ​ 34,815 Financial Liabilities: ​ ​ ​ ​ ​ Savings, money market and checking accounts ​ 3,202,484 ​ 3,202,484 ​ — ​ — ​ 3,202,484 CDs ​ 1,322,638 ​ — ​ 1,328,554 ​ — ​ 1,328,554 FHLBNY advances ​ 1,204,010 ​ — ​ 1,207,890 ​ — ​ 1,207,890 Subordinated debt, net ​ 114,052 ​ — ​ 114,340 ​ — ​ 114,340 Other short-term borrowings ​ ​ 120,000 ​ ​ 120,000 ​ ​ — ​ ​ — ​ ​ 120,000 Accrued interest payable ​ 1,734 ​ — ​ 1,734 ​ — ​ 1,734

OTHER INTANGIBLE ASSETS (Tables

OTHER INTANGIBLE ASSETS (Tables)	9 Months Ended
	Sep. 30, 2021
OTHER INTANGIBLE ASSETS
Schedule of acquired intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ Core Deposit ​ ​ Non-complete ​ ​ ​ (In thousands) ​ ​ Intangibles ​ Agreement ​ Total Gross carrying value ​ $ 10,204 ​ $ 780 ​ $ 10,984 Accumulated amortization ​ (1,427) ​ ​ (480) ​ ​ (1,907) Net carrying amount ​ $ 8,777 ​ $ 300 ​ $ 9,077 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of estimated amortization expense	​ ​ ​ ​ ​ (In thousands) ​ ​ Total 2021 ​ $ 715 2022 ​ ​ 1,878 2023 ​ ​ 1,425 2024 ​ ​ 1,163 2025 ​ ​ 958 Thereafter ​ ​ 2,938 Total ​ $ 9,077

FEDERAL HOME LOAN BANK OF NEW_2

FEDERAL HOME LOAN BANK OF NEW YORK ADVANCES (Tables)	9 Months Ended
	Sep. 30, 2021
FEDERAL HOME LOAN BANK OF NEW YORK ADVANCES
Schedule of contractual maturities and weighted average interest rates of FHLBNY advances	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 (Dollars in thousands) ​ ​ ​ ​ Weighted Contractual Maturity Amount Average Rate 2021 ​ $ 25,000 0.35 % Total FHLBNY advances ​ $ 25,000 0.35 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 (Dollars in thousands) ​ ​ ​ ​ Weighted Contractual Maturity Amount Average 2021 ​ $ 1,144,010 0.52 % 2022 ​ ​ 60,000 ​ 0.60 ​ Total FHLBNY advances ​ $ 1,204,010 0.53 %

RETIREMENT AND POSTRETIREMENT_2

RETIREMENT AND POSTRETIREMENT PLANS (Tables)	9 Months Ended
	Sep. 30, 2021
RETIREMENT AND POSTRETIREMENT PLANS
Net Periodic Costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ ​ ​ 2021 ​ 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ BMP, Postretirement ​ ​ BNB Bank ​ Employee ​ Employee ​ and Outside Director (In thousands) ​ Pension Plan ​ Retirement Plan ​ Retirement Plan ​ Retirement Plans Service cost ​ $ 223 ​ $ — ​ $ — ​ $ — Interest cost ​ ​ 302 ​ ​ 183 ​ ​ 10 ​ ​ 241 Expected return on assets ​ ​ (1,244) ​ ​ (428) ​ ​ — ​ ​ (428) Unrecognized past service liability ​ ​ — ​ ​ — ​ ​ (2) ​ ​ — Amortization of unrealized loss ​ ​ 207 ​ ​ 229 ​ ​ — ​ ​ 274 Net periodic benefit (credit) cost ​ $ (512) ​ $ (16) ​ $ 8 ​ $ 87 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ ​ 2021 ​ 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ BMP, Postretirement ​ ​ BNB Bank ​ Employee ​ Employee ​ and Outside Director (In thousands) ​ Pension Plan ​ Retirement Plan ​ Retirement Plan ​ Retirement Plans Service cost ​ $ 594 ​ $ — ​ $ — ​ $ — Interest cost ​ ​ 854 ​ ​ 549 ​ ​ 30 ​ ​ 723 Expected return on assets ​ (3,473) ​ (1,284) ​ — ​ (1,284) Unrecognized past service liability ​ ​ — ​ ​ — ​ ​ (6) ​ ​ — Amortization of unrealized loss ​ 619 ​ 687 ​ — ​ 822 Net periodic (credit) cost ​ $ (1,406) ​ $ (48) ​ $ 24 ​ $ 261 ​

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	9 Months Ended
	Sep. 30, 2021
STOCK-BASED COMPENSATION
Activity Related to Stock Options	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ Aggregate ​ ​ ​ ​ Weighted- ​ Remaining ​ Intrinsic ​ ​ Number of ​ Average Exercise ​ Contractual ​ Value ​ Options Price Years (In thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options outstanding at January 1, 2021 ​ 28,842 ​ $ 15.05 ​ ​ ​ ​ ​ Options outstanding at January 1, 2021 as adjusted for conversion ​ 18,685 ​ ​ 23.23 ​ ​ ​ ​ ​ Options acquired ​ 180,020 ​ ​ 35.39 ​ ​ ​ ​ ​ Options exercised ​ (17,102) ​ 23.40 ​ ​ ​ ​ ​ Options forfeited ​ (29,421) ​ 35.38 ​ ​ ​ ​ ​ Options outstanding at September 30, 2021 152,182 ​ $ 35.24 7.4 ​ $ 18 Options vested and exercisable at September 30, 2021 152,182 ​ $ 35.24 7.4 ​ $ 18 ​
Information Related to Stock Option Plan	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (In thousands) 2021 2020 ​ 2021 2020 Cash received for option exercise cost ​ $ — ​ $ — ​ $ 396 ​ $ 38 Income tax benefit recognized on stock option exercises ​ — ​ — ​ — ​ — Intrinsic value of options exercised ​ — ​ — ​ 77 ​ 8
Activity Related to Restricted Stock Awards	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ Number of ​ Grant-Date ​ Shares Fair Value ​ ​ ​ ​ ​ ​ Unvested allocated shares outstanding at January 1, 2021 ​ — ​ $ — Shares acquired in the Merger ​ 101,778 ​ ​ 25.98 Shares granted 390,027 ​ 26.48 Shares vested ​ (9,838) ​ ​ 25.41 Shares forfeited (33,089) ​ 25.73 Unvested allocated shares at September 30, 2021 448,878 ​ $ 26.45
Information Related to Restricted Stock Award Plan	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, (Dollars in thousands) 2021 2020 ​ 2021 2020 Compensation expense recognized ​ $ 1,454 ​ $ 444 ​ $ 3,804 ​ $ 1,311 Income tax expense recognized on vesting of RSA ​ — ​ (38) ​ (86) ​ (95)
Activity Related to Performance Based Equity Awards	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ Number of ​ Grant-Date ​ Shares Fair Value Maximum aggregate share payout at January 1, 2021 ​ — ​ $ — Shares granted 38,948 ​ 31.40 Maximum aggregate share payout at September 30, 2021 38,948 ​ $ 31.40 Minimum aggregate share payout — ​ ​ — Expected aggregate share payout 25,963 ​ $ 31.40
Information Related to Performance Based Share Award Plan	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ (In thousands) 2021 2020 ​ 2021 2020 ​ Compensation expense recognized ​ $ 81 ​ $ 210 ​ $ 81 ​ $ 362 ​ Income tax expense recognized on vesting of LTIP ​ — ​ — ​ — ​ — ​

BASIS OF PRESENTATION (Details)

BASIS OF PRESENTATION (Details)	Feb. 01, 2021$ / sharesshares	Sep. 30, 2021item$ / shares	Sep. 30, 2021item$ / shares	Dec. 31, 2020$ / shares
BASIS OF PRESENTATION
Number of branch locations | item			65
Number of real estate investments dissolved | item		2
Merger agreement:
Common stock, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Common stock converted into right to receive shares (in shares) | shares	0.6480
Preferred stock, Series A, par value (in dollars per share) | $ / shares		$ 0.01	$ 0.01	$ 0.01

MERGER (Details)

MERGER (Details) $ / shares in Units, $ in Millions	Feb. 01, 2021USD ($)$ / sharesshares	Jan. 31, 2021shares	Sep. 30, 2021$ / shares	Dec. 31, 2020$ / shares	Sep. 30, 2015USD ($)
MERGER
Common stock, par value (in dollars per share)	$ 0.01		$ 0.01	$ 0.01
Share conversion ratio	0.6480
Preferred stock, Series A, par value (in dollars per share)			$ 0.01	$ 0.01
Aggregate principal amount | $					$ 80
Preferred Stock
MERGER
Share conversion ratio	1
Legacy Dime
MERGER
Common stock, par value (in dollars per share)	$ 0.01
Aggregate principal amount | $	$ 115
Fixed interest rate of debentures	4.50%
Legacy Dime | Preferred Stock
MERGER
Preferred stock, Series A, par value (in dollars per share)	$ 0.01
Merger Agreement
MERGER
Number of Bridge Outstanding Shares | shares		41,226,000
Percentage Ownership		100.00%
Merger Agreement | Bridge shareholders
MERGER
Number of Bridge Outstanding Shares | shares	21,200,000	19,993,000
Percentage Ownership	51.50%	48.50%
Merger Agreement | Legacy Dime shareholders
MERGER
Number of Bridge Outstanding Shares | shares	30,853,000	21,233,000
Percentage Ownership		51.50%

MERGER - Dime Community Bancsha

MERGER - Dime Community Bancshares, Inc. Ownership and Market Value (Details) - Merger Agreement - USD ($) $ / shares in Units, $ in Thousands	Feb. 01, 2021	Jan. 31, 2021
MERGER
Number of Bridge Outstanding Shares		41,226,000
Percentage Ownership		100.00%
Market Value at $24.43 Bridge Share Price		$ 1,007,140
Bridge shareholders
MERGER
Number of Bridge Outstanding Shares	21,200,000	19,993,000
Percentage Ownership	51.50%	48.50%
Market Value at $24.43 Bridge Share Price		$ 488,420
Bridge Share Price		$ 24.43
Legacy Dime shareholders
MERGER
Number of Bridge Outstanding Shares	30,853,000	21,233,000
Percentage Ownership		51.50%
Market Value at $24.43 Bridge Share Price	$ 7	$ 518,720

MERGER - Hypothetical Legacy Di

MERGER - Hypothetical Legacy Dime Ownership (Details) - Merger Agreement shares in Thousands	Jan. 31, 2021shares
MERGER
Number of Legacy Dime Outstanding Shares	63,620
Percentage Ownership	100.00%
Bridge shareholders
MERGER
Number of Legacy Dime Outstanding Shares	30,853
Percentage Ownership	48.50%
Legacy Dime shareholders
MERGER
Number of Legacy Dime Outstanding Shares	32,767
Percentage Ownership	51.50%

MERGER - Purchase Price (Detail

MERGER - Purchase Price (Details) - USD ($) $ / shares in Units, $ in Thousands	Feb. 01, 2021	Jan. 31, 2021	Sep. 30, 2021
MERGER
Purchase price consideration			$ 491,210
Merger Agreement
MERGER
Number of hypothetical Legacy Dime shares issued to Bridge shareholders		41,226,000
Number of Bridge Outstanding Shares		41,226,000
Cash in lieu of fractional shares		$ 1,007,140
Merger Agreement | Bridge shareholders
MERGER
Number of hypothetical Legacy Dime shares issued to Bridge shareholders	21,200,000	19,993,000
Number of Bridge Outstanding Shares	21,200,000	19,993,000
Cash in lieu of fractional shares		$ 488,420
Merger Agreement | Legacy Dime shareholders
MERGER
Number of hypothetical Legacy Dime shares issued to Bridge shareholders	30,853,000	21,233,000
Legacy Dime market price per share as of February 1, 2021	$ 15.90
Purchase price determination of hypothetical Legacy Dime shares issued to Bridge shareholders	$ 490,560
Number of Bridge Outstanding Shares	30,853,000	21,233,000
Cash in lieu of fractional shares	$ 7	$ 518,720
Purchase price consideration	$ 491,210
Merger Agreement | Legacy Dime shareholders | Common Stock
MERGER
Number of hypothetical Legacy Dime shares issued to Bridge shareholders	643,000
Number of Bridge Outstanding Shares	643,000

MERGER - Purchase Price Allocat

MERGER - Purchase Price Allocation (Details) - USD ($) $ in Thousands	Feb. 01, 2021	Sep. 30, 2021	Dec. 31, 2020
Fair value of assets acquired:
Operating lease assets	$ 45,600
Fair value of liabilities assumed:
Operating lease liabilities	45,300
Total liabilities assumed		$ 5,847,505
Goodwill resulting from Merger		$ 155,339	$ 55,638
Bridge assets acquired
Purchase price consideration:
Purchase price consideration	491,210
Fair value of assets acquired:
Cash and due from banks	715,988
Securities available-for-sale	651,997
Loans held for sale	10,000
Loans held for investment	4,531,640
Premises and fixed assets	37,881
Restricted stock	23,362
BOLI	94,085
Other intangible assets	10,984
Operating lease assets	45,603
Other assets	117,474
Total assets acquired	6,239,014
Fair value of liabilities assumed:
Deposits	5,405,575
Other short-term borrowings	216,298
Subordinated debt	83,200
Operating lease liabilities	45,285
Other liabilities	97,147
Total liabilities assumed	5,847,505
Fair value of net identifiable assets	391,509
Goodwill resulting from Merger	$ 99,701

MERGER - Loans Acquired (Detail

MERGER - Loans Acquired (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Feb. 01, 2021
MERGER
Total fair value at acquisition	$ 4,530,000	$ 4,531,640
PCD loans
MERGER
Unpaid principal balance		295,306
Non-credit discount at acquisition		(9,050)
Unpaid principal balance, net		286,256
Allowance for credit losses at acquisition		(52,284)
Total fair value at acquisition		233,972
Non-PCD loans
MERGER
Unpaid principal balance		4,289,236
Premium at acquisition		8,432
Unpaid principal balance, net		$ 4,297,668

MERGER - Supplemental of cash f

MERGER - Supplemental of cash flow information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
MERGER
Fair value of tangible assets acquired	$ 6,228,030
Goodwill, core deposit intangible and other intangible assets acquired	110,685
Liabilities assumed	5,847,505
Purchase price consideration	$ 491,210

MERGER - Other intangible asset

MERGER - Other intangible assets (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Core deposits
MERGER
Other intangible assets	$ 10,200
Weighted average life	10 years
Noncompete Agreements
MERGER
Other intangible assets	$ 780
Weighted average life	13 months

MERGER - Pro Forma (Details)

MERGER - Pro Forma (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
MERGER
Net interest income	$ 93,316	$ 86,818	$ 274,499	$ 252,455
Non-interest income	9,728	12,939	33,240	33,030
Net income	39,978	29,971	92,782	72,015
Net income available to common shareholders	$ 37,700	$ 27,791	$ 86,390	$ 68,169
Earnings per share:
Basic	$ 0.93	$ 0.68	$ 2.11	$ 1.66
Diluted	$ 0.93	$ 0.68	$ 2.11	$ 1.66

SUMMARY OF ACCOUNTING POLICIE_2

SUMMARY OF ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Jan. 01, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ 81,255	$ 92,760		$ 41,461	$ 48,492	$ 42,492	$ 28,441
Retained earnings	630,744			600,641
Cumulative Effect, Period of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses				(3,919)
Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	(3,900)
Reserve for unfunded commitments	1,400
Retained earnings			$ 1,700
One-to-four family residential and cooperative/condominium apartment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ 6,104	5,522		644	799	671	269
One-to-four family residential and cooperative/condominium apartment | Cumulative Effect, Period of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses				1,048
One-to-four family residential and cooperative/condominium apartment | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Value ratio	75.00%
One-to-four family residential and cooperative/condominium apartment | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt service ratio	1.25%
Multifamily residential and residential mixed-use
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ 8,307	10,285		17,016	20,210	16,666	10,142
Multifamily residential and residential mixed-use | Cumulative Effect, Period of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses				(8,254)
Multifamily residential and residential mixed-use | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Value ratio	75.00%
Multifamily residential and residential mixed-use | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt service ratio	1.20%
Commercial real estate ("CRE")
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ 29,603	41,201		9,059	12,021	9,859	3,900
Commercial real estate ("CRE") | Cumulative Effect, Period of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses				4,849
Commercial real estate ("CRE") | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Value ratio	75.00%
Commercial real estate ("CRE") | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt service ratio	1.25%
Acquisition, Development, And Construction Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Value ratio	50.00%
Commercial and Industrial ("C&I") Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ 31,545	30,095		12,737	13,395	13,502	12,870
Value ratio	100.00%
Commercial and Industrial ("C&I") Loans | Cumulative Effect, Period of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses				(1,935)
Other Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ 677	$ 499		12	$ 16	$ 17	$ 16
Other Loans | Cumulative Effect, Period of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses				$ (8)

ACCUMULATED OTHER COMPREHENSI_3

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance	$ 1,204,276	$ 1,172,824	$ 701,096	$ 681,543	$ 645,648	$ 596,758	$ 701,096	$ 596,758
Other comprehensive (loss) income before reclassifications							6,178	(5,944)
Amounts reclassified from accumulated other comprehensive loss							(1,296)	345
Total other comprehensive (loss) income, net of tax	(5,618)	4,045	6,455	2,864	(1,771)	(6,692)	4,882	(5,599)
Balance	1,201,117	1,204,276	1,172,824	694,158	681,543	645,648	1,201,117	694,158
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance	4,576	531	(5,924)	(14,403)	(12,632)	(5,940)	(5,924)	(5,940)
Total other comprehensive (loss) income, net of tax	(5,618)	4,045	6,455	2,864	(1,771)	(6,692)
Balance	(1,042)	$ 4,576	531	(11,539)	$ (14,403)	(12,632)	(1,042)	(11,539)
Securities Available-for-Sale
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance			12,694			4,621	12,694	4,621
Other comprehensive (loss) income before reclassifications							(10,378)	10,783
Amounts reclassified from accumulated other comprehensive loss							(826)	(2,302)
Total other comprehensive (loss) income, net of tax							(11,204)	8,481
Balance	1,490			13,102			1,490	13,102
Defined Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance			(6,086)			(6,024)	(6,086)	(6,024)
Other comprehensive (loss) income before reclassifications							2,706	423
Amounts reclassified from accumulated other comprehensive loss							(1,082)	133
Total other comprehensive (loss) income, net of tax							1,624	556
Balance	(4,462)			(5,468)			(4,462)	(5,468)
Derivatives
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance			$ (12,532)			$ (4,537)	(12,532)	(4,537)
Other comprehensive (loss) income before reclassifications							13,850	(17,150)
Amounts reclassified from accumulated other comprehensive loss							612	2,514
Total other comprehensive (loss) income, net of tax							14,462	(14,636)
Balance	$ 1,930			$ (19,173)			$ 1,930	$ (19,173)

ACCUMULATED OTHER COMPREHENSI_4

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Before and After Tax Amounts by Component (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Change in unrealized holding gain or loss on securities available-for-sale:
Change in net unrealized gain or loss during the period	$ (8,654)			$ 1,716			$ (15,222)	$ 15,769
Reclassification adjustment for net gains included in net gain on securities and other assets				(215)			(1,207)	(3,357)
Net change	(8,654)			1,501			(16,429)	12,412
Tax (benefit) expense	(2,714)			475			(5,226)	3,931
Net change in unrealized holding gain or loss on securities available-for-sale, net of reclassification adjustments and tax	(5,940)			1,026			(11,203)	8,481
Change in pension and other postretirement obligations:
Reclassification adjustment for expense included in other expense	(735)			4			(1,595)	194
Reclassification adjustment for curtailment loss							1,543
Change in the net actuarial gain or loss	941			267			2,470	619
Net change	206			271			2,418	813
Tax expense	65			86			795	257
Net change in pension and other postretirement obligations	141			185			1,623	556
Change in unrealized gain or loss on derivatives:
Change in net unrealized gain or loss during the period	225			100			3,767	(25,098)
Reclassification adjustment for loss included in loss on termination of derivatives							16,505
Reclassification adjustment for expense included in interest expense	38			2,319			902	3,679
Net change	263			2,419			21,174	(21,419)
Tax expense (benefit)	82			766			6,712	(6,783)
Net change in unrealized gain or loss on derivatives, net of reclassification adjustments and tax	181			1,653			14,462	(14,636)
Total other comprehensive (loss) income, net of tax	$ (5,618)	$ 4,045	$ 6,455	$ 2,864	$ (1,771)	$ (6,692)	$ 4,882	$ (5,599)

EARNINGS PER COMMON SHARE ("E_3

EARNINGS PER COMMON SHARE ("EPS") (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Abstract]
Net income available to common stockholders	$ 36,573	$ 14,046	$ 63,174	$ 34,264
Less: Dividends paid and earnings allocated to participating securities	(437)	(83)	(811)	(195)
Income attributable to common stock	$ 36,136	$ 13,963	$ 62,363	$ 34,069
Weighted average common shares outstanding, including participating securities (in shares)	40,915,012	21,378,332	38,979,259	21,848,184
Less: weighted average participating securities (in shares)	(489,274)	(187,781)	(405,102)	(191,438)
Weighted average common shares outstanding (in shares)	40,425,738	21,190,551	38,574,157	21,656,746
Basic EPS (in dollars per share)	$ 0.89	$ 0.66	$ 1.62	$ 1.57
Weighted average common shares outstanding (in shares)	40,425,738	21,190,551	38,574,157	21,656,746
Weighted average common equivalent shares outstanding (in shares)	423	133,636	700	134,334
Weighted average common and equivalent shares outstanding (in shares)	40,426,161	21,324,187	38,574,857	21,791,080
Diluted EPS (in dollars per share)	$ 0.89	$ 0.65	$ 1.62	$ 1.56
Stock Option Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Abstract]
Weighted average shares excluded from earnings per share calculation (in shares)	174,584	0	177,953	0

PREFERRED STOCK (Details)

PREFERRED STOCK (Details) - USD ($) $ / shares in Units, $ in Millions	Jun. 10, 2020	Feb. 05, 2020	Sep. 30, 2021	Dec. 31, 2020
Public Offering [Abstract]
Preferred stock, Series A, par value (in dollars per share)			$ 0.01	$ 0.01
Preferred stock, liquidation preference (in dollars per share)			25	$ 25
Preferred stock, Series A
Public Offering [Abstract]
Number of share issued in public offering (in shares)	2,300,000	2,999,200
Preferred stock, liquidation preference	$ 57.5	$ 75
Preferred stock, interest rate	5.50%	5.50%
Preferred stock, Series A, par value (in dollars per share)		$ 0.01
Preferred stock, liquidation preference (in dollars per share)		$ 25
Proceeds from issuance of preferred stock	$ 44.3	$ 72.2
Preferred stock, redemption price (in dollars per share)			$ 25

INVESTMENT AND MORTGAGE-BACKE_3

INVESTMENT AND MORTGAGE-BACKED SECURITIES - Securities Available-for-sale Major Categories (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Securities available-for-sale:
Amortized Cost	$ 1,706,892	$ 520,261
Gross Unrealized Gains	16,080	18,798
Gross Unrealized Losses	(13,909)	(198)
Fair Value	1,709,063	538,861
Agency Notes
Securities available-for-sale:
Amortized Cost	82,475	47,500
Gross Unrealized Gains		12
Gross Unrealized Losses	(1,457)	(91)
Fair Value	81,018	47,421
Treasury Securities
Securities available-for-sale:
Amortized Cost	248,173
Gross Unrealized Gains	5
Gross Unrealized Losses	(482)
Fair Value	247,696
Corporate Securities
Securities available-for-sale:
Amortized Cost	122,476	62,021
Gross Unrealized Gains	4,758	2,440
Gross Unrealized Losses	(401)
Fair Value	126,833	64,461
Pass-through MBS issued by GSEs
Securities available-for-sale:
Amortized Cost	622,225	135,842
Gross Unrealized Gains	6,005	7,672
Gross Unrealized Losses	(6,273)	(31)
Fair Value	621,957	143,483
Agency Collateralized Mortgage Obligations ("CMOs")
Securities available-for-sale:
Amortized Cost	590,385	274,898
Gross Unrealized Gains	5,159	8,674
Gross Unrealized Losses	(5,118)	(76)
Fair Value	590,426	$ 283,496
State and municipal obligations.
Securities available-for-sale:
Amortized Cost	41,158
Gross Unrealized Gains	153
Gross Unrealized Losses	(178)
Fair Value	$ 41,133

INVESTMENT AND MORTGAGE-BACKE_4

INVESTMENT AND MORTGAGE-BACKED SECURITIES - Securities Held-to-maturity Major Categories (Details) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 40,303,000
Fair Value	40,303,000	$ 0
Pass-through MBS issued by GSEs
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	25,325,000
Fair Value	25,325,000
Agency Collateralized Mortgage Obligations ("CMOs")
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	14,978,000
Fair Value	$ 14,978,000

INVESTMENT AND MORTGAGE-BACKE_5

INVESTMENT AND MORTGAGE-BACKED SECURITIES - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Feb. 01, 2021
INVESTMENT AND MORTGAGE-BACKED SECURITIES
Acquired securities available-for-sale on the Merger Date						$ 652,000,000
Investment securities held-to-maturity, fair value	$ 40,303,000		$ 40,303,000		$ 0
Securities pledged as collateral, carrying amount	$ 684,000,000		$ 684,000,000		$ 99,400,000
Number of holdings of securities of any one issuer in an amount greater than 10% of stockholders equity	0		0		0
Threshold for disclosure percentage	10.00%				10.00%
Net gain on equity securities	$ 0	$ 175,000	$ 131,000	$ 139,000

INVESTMENT AND MORTGAGE-BACKE_6

INVESTMENT AND MORTGAGE-BACKED SECURITIES - Amortized Cost and Fair Value By Contractual Maturity (Details) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Available for sale, Amortized Cost
Within one year	$ 1,346,000
One to five years	270,069,000
Five to ten years	209,938,000
Beyond ten years	12,929,000
Pass-through MBS issued by GSEs and Agency CMO	1,212,610,000
Amortized Cost	1,706,892,000	$ 520,261,000
Available for sale, Fair Value
Within one year	1,351,000
One to five years	269,665,000
Five to ten years	212,881,000
Beyond ten years	12,783,000
Pass-through MBS issued by GSEs and Agency CMO	1,212,383,000
Total	1,709,063,000	538,861,000
Held-to-maturity, Amortized Cost
Pass-through MBS issued by GSEs and agency CMO	40,303,000
Total	40,303,000
Held-to-maturity, Fair Value
Pass-through MBS issued by GSEs and agency CMO	40,303,000
Fair Value	$ 40,303,000	$ 0

INVESTMENT AND MORTGAGE-BACKE_7

INVESTMENT AND MORTGAGE-BACKED SECURITIES - Sales Information and Marketable Equity Securities (Details) - USD ($)	3 Months Ended		9 Months Ended		15 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021
Sales of Available-for-sale Securities:
Proceeds			$ 138,077,000	$ 68,784,000
Proceeds:
Marketable equity securities		$ 137,000	6,101,000	410,000
Net gain on equity securities	$ 0	175,000	131,000	139,000
Sales of securities held-to-maturity			0	0	$ 0
Transfers to or from securities held-to-maturity	$ 0	0	0	0
Agency Notes
Sales of Available-for-sale Securities:
Proceeds				273,000
Corporate Securities
Sales of Available-for-sale Securities:
Proceeds			50,273,000	25,403,000
Gross gains			729,000	1,344,000
Tax expense on gain			232,000	423,000
Gross losses			41,000
Tax benefit on loss			13,000
Pass-through MBS issued by GSEs
Sales of Available-for-sale Securities:
Proceeds		5,987,000	26,823,000	39,182,000
Gross gains		215,000	187,000	2,005,000
Tax expense on gain		$ 67,000	59,000	630,000
Gross losses			35,000
Tax benefit on loss			11,000
Agency Collateralized Mortgage Obligations ("CMOs")
Sales of Available-for-sale Securities:
Proceeds			41,324,000	4,199,000
Gross gains			268,000	8,000
Tax expense on gain			85,000	$ 3,000
Gross losses			44,000
Tax benefit on loss			14,000
State and municipal obligations.
Sales of Available-for-sale Securities:
Proceeds			19,657,000
Gross gains			143,000
Tax expense on gain			$ 45,000

INVESTMENT AND MORTGAGE-BACKE_8

INVESTMENT AND MORTGAGE-BACKED SECURITIES - Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Pass-through MBS issued by GSEs
Securities available-for-sale, Fair Value [Abstract]
Less than 12 Consecutive Months	$ 446,864	$ 5,007
12 Consecutive Months or Longer	0	0
Total	446,864	5,007
Securities available-for-sale, Unrealized Losses [Abstract]
Less than 12 Consecutive Months	6,273	31
12 Consecutive Months or Longer	0	0
Total	6,273	31
Treasury Securities
Securities available-for-sale, Fair Value [Abstract]
Less than 12 Consecutive Months	231,984
12 Consecutive Months or Longer	0
Total	231,984
Securities available-for-sale, Unrealized Losses [Abstract]
Less than 12 Consecutive Months	482
12 Consecutive Months or Longer	0
Total	482
State and municipal obligations
Securities available-for-sale, Fair Value [Abstract]
Less than 12 Consecutive Months	16,412
12 Consecutive Months or Longer	0
Total	16,412
Securities available-for-sale, Unrealized Losses [Abstract]
Less than 12 Consecutive Months	178
12 Consecutive Months or Longer	0
Total	178
Agency Notes
Securities available-for-sale, Fair Value [Abstract]
Less than 12 Consecutive Months	81,018	22,409
12 Consecutive Months or Longer	0	0
Total	81,018	22,409
Securities available-for-sale, Unrealized Losses [Abstract]
Less than 12 Consecutive Months	1,457	91
12 Consecutive Months or Longer	0	0
Total	1,457	91
Corporate Notes
Securities available-for-sale, Fair Value [Abstract]
Less than 12 Consecutive Months	17,863
12 Consecutive Months or Longer	0
Total	17,863
Securities available-for-sale, Unrealized Losses [Abstract]
Less than 12 Consecutive Months	401
12 Consecutive Months or Longer	0
Total	401
Agency Collateralized Mortgage Obligations ("CMOs")
Securities available-for-sale, Fair Value [Abstract]
Less than 12 Consecutive Months	347,726	6,563
12 Consecutive Months or Longer	0	4,954
Total	347,726	11,517
Securities available-for-sale, Unrealized Losses [Abstract]
Less than 12 Consecutive Months	5,118	30
12 Consecutive Months or Longer	0	46
Total	$ 5,118	$ 76

LOANS HELD FOR INVESTMENT, NE_2

LOANS HELD FOR INVESTMENT, NET - Loan Categories (Details) - USD ($) $ in Thousands	1 Months Ended
	Jun. 30, 2021	Sep. 30, 2021	Feb. 01, 2021	Dec. 31, 2020
Loans held for investment, net:
Total Loans		$ 9,284,871		$ 5,622,044
Allowance for loan losses		(81,255)		(41,461)
Total loans held for investment, net		9,203,616		5,580,583
Loans acquired on merger		4,530,000	$ 4,531,640
Paycheck Protection Program ("PPP") loans
Loans held for investment, net:
Total Loans		134,100
Allowance for loan losses		$ 0
Loan and leases carry guarantee rate		100.00%
Total real estate loans
Loans held for investment, net:
Total Loans		$ 8,251,743		4,978,195
One-to-four family residential and cooperative/condominium apartment
Loans held for investment, net:
Total Loans		683,665		184,989
Multifamily residential and residential mixed-use
Loans held for investment, net:
Total Loans		3,468,262		2,758,743
Commercial real estate ("CRE")
Loans held for investment, net:
Total Loans		3,814,437		1,878,167
Acquisition, development, and construction ("ADC")
Loans held for investment, net:
Total Loans		285,379		156,296
Commercial and Industrial ("C&I") Loans
Loans held for investment, net:
Total Loans		1,012,415		641,533
Commercial and Industrial ("C&I") Loans | Paycheck Protection Program ("PPP") loans
Loans held for investment, net:
Total Loans		1,012,415		313,400
Gain recorded on sale of SBA loans	$ 20,700
Sold amount	$ 596,200
Commercial and Industrial ("C&I") Loans | Total real estate loans
Loans held for investment, net:
Total Loans				5,619,728
Other Loans
Loans held for investment, net:
Total Loans		$ 20,713		$ 2,316

LOANS HELD FOR INVESTMENT, NE_3

LOANS HELD FOR INVESTMENT, NET - Allowance for Credit Losses Activity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Allowance for loan losses [Roll Forward]
Beginning balance	$ 92,760	$ 42,492	$ 41,461	$ 28,441
PCD Day 1			52,284
Provision (credit) for credit loss expense	(7,314)	5,931	812	20,003
Charge-offs	(4,276)	(20)	(9,584)	(62)
Recoveries	85	89	201	110
Ending balance	81,255	48,492	81,255	48,492
Non-accrual with No Allowance	2,099		2,099
Non-accrual with Allowance	31,921		31,921
Reserve			13,155
Interest income on non-accrual loans	0		0
Allowance for loan losses:
Individually evaluated for impairment					$ 6,474
Collectively evaluated for impairment					34,987
Total ending allowance balance	81,255	48,492	81,255	48,492	41,461
Loans:
Individually evaluated for impairment					17,069
Collectively evaluated for impairment					5,604,975
Total ending loans balance					5,622,044
Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses [Roll Forward]
Beginning balance			(3,919)
Allowance for loan losses:
Total ending allowance balance					(3,919)
Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses [Roll Forward]
Beginning balance			37,542
Allowance for loan losses:
Total ending allowance balance					37,542
Total real estate loans
Allowance for loan losses [Roll Forward]
Beginning balance	62,166	28,973	28,712	15,555
PCD Day 1			28,753
Provision (credit) for credit loss expense	(10,203)	6,038	(2,689)	19,484
Charge-offs	(3,011)	(19)	(3,852)	(61)
Recoveries	81	89	85	103
Ending balance	49,033	35,081	49,033	35,081
Allowance for loan losses:
Collectively evaluated for impairment					28,712
Total ending allowance balance	49,033	35,081	49,033	35,081	28,712
Loans:
Individually evaluated for impairment					4,567
Collectively evaluated for impairment					4,973,628
Total ending loans balance					4,978,195
Total real estate loans | Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses [Roll Forward]
Beginning balance			(1,976)
Allowance for loan losses:
Total ending allowance balance					(1,976)
Total real estate loans | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses [Roll Forward]
Beginning balance			26,736
Allowance for loan losses:
Total ending allowance balance					26,736
One-to-four family residential and cooperative/condominium apartment
Allowance for loan losses [Roll Forward]
Beginning balance	5,522	671	644	269
PCD Day 1			2,220
Provision (credit) for credit loss expense	583	134	2,212	540
Charge-offs	(1)	(6)	(20)	(10)
Recoveries		0
Ending balance	6,104	799	6,104	799
Non-accrual with Allowance	4,938		4,938
Reserve			781
Allowance for loan losses:
Collectively evaluated for impairment					644
Total ending allowance balance	6,104	799	6,104	799	644
Loans:
Collectively evaluated for impairment					184,989
Total ending loans balance					184,989
One-to-four family residential and cooperative/condominium apartment | Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses [Roll Forward]
Beginning balance			1,048
Allowance for loan losses:
Total ending allowance balance					1,048
One-to-four family residential and cooperative/condominium apartment | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses [Roll Forward]
Beginning balance			1,692
Allowance for loan losses:
Total ending allowance balance					1,692
Multifamily residential and residential mixed-use
Allowance for loan losses [Roll Forward]
Beginning balance	10,285	16,666	17,016	10,142
PCD Day 1			3,292
Provision (credit) for credit loss expense	(1,998)	3,468	(3,361)	10,010
Charge-offs	(58)	(13)	(467)	(45)
Recoveries	78	89	81	103
Ending balance	8,307	20,210	8,307	20,210
Non-accrual with No Allowance	859		859
Allowance for loan losses:
Collectively evaluated for impairment					17,016
Total ending allowance balance	8,307	20,210	8,307	20,210	17,016
Loans:
Individually evaluated for impairment					1,863
Collectively evaluated for impairment					2,756,880
Total ending loans balance					2,758,743
Multifamily residential and residential mixed-use | Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses [Roll Forward]
Beginning balance			(8,254)
Allowance for loan losses:
Total ending allowance balance					(8,254)
Multifamily residential and residential mixed-use | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses [Roll Forward]
Beginning balance			8,762
Allowance for loan losses:
Total ending allowance balance					8,762
Commercial real estate ("CRE")
Allowance for loan losses [Roll Forward]
Beginning balance	41,201	9,859	9,059	3,900
PCD Day 1			23,124
Provision (credit) for credit loss expense	(8,649)	2,162	(4,068)	8,127
Charge-offs	(2,952)	0	(3,365)	(6)
Recoveries	3	0	4
Ending balance	29,603	12,021	29,603	12,021
Non-accrual with No Allowance	1,240		1,240
Non-accrual with Allowance	2,882		2,882
Reserve			812
Allowance for loan losses:
Collectively evaluated for impairment					9,059
Total ending allowance balance	29,603	12,021	29,603	12,021	9,059
Loans:
Individually evaluated for impairment					2,704
Collectively evaluated for impairment					1,875,463
Total ending loans balance					1,878,167
Commercial real estate ("CRE") | Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses [Roll Forward]
Beginning balance			4,849
Allowance for loan losses:
Total ending allowance balance					4,849
Commercial real estate ("CRE") | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses [Roll Forward]
Beginning balance			13,908
Allowance for loan losses:
Total ending allowance balance					13,908
Acquisition, development, and construction ("ADC")
Allowance for loan losses [Roll Forward]
Beginning balance	5,158	1,777	1,993	1,244
PCD Day 1			117
Provision (credit) for credit loss expense	(139)	274	2,528	807
Charge-offs		0
Recoveries		0
Ending balance	5,019	2,051	5,019	2,051
Allowance for loan losses:
Collectively evaluated for impairment					1,993
Total ending allowance balance	5,019	2,051	5,019	2,051	1,993
Loans:
Collectively evaluated for impairment					156,296
Total ending loans balance					156,296
Acquisition, development, and construction ("ADC") | Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses [Roll Forward]
Beginning balance			381
Allowance for loan losses:
Total ending allowance balance					381
Acquisition, development, and construction ("ADC") | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses [Roll Forward]
Beginning balance			2,374
Allowance for loan losses:
Total ending allowance balance					2,374
Commercial and Industrial ("C&I") Loans
Allowance for loan losses [Roll Forward]
Beginning balance	30,095	13,502	12,737	12,870
PCD Day 1			23,374
Provision (credit) for credit loss expense	1,943	(107)	2,215	518
Charge-offs	(497)	0	(4,959)
Recoveries	4	0	113	7
Ending balance	31,545	13,395	31,545	13,395
Non-accrual with Allowance	23,727		23,727
Reserve			11,191
Allowance for loan losses:
Individually evaluated for impairment					6,474
Collectively evaluated for impairment					6,263
Total ending allowance balance	31,545	13,395	31,545	13,395	12,737
Loans:
Individually evaluated for impairment					12,502
Collectively evaluated for impairment					629,031
Total ending loans balance					641,533
Commercial and Industrial ("C&I") Loans | Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses [Roll Forward]
Beginning balance			(1,935)
Allowance for loan losses:
Total ending allowance balance					(1,935)
Commercial and Industrial ("C&I") Loans | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses [Roll Forward]
Beginning balance			10,802
Allowance for loan losses:
Total ending allowance balance					10,802
Other Loans
Allowance for loan losses [Roll Forward]
Beginning balance	499	17	12	16
PCD Day 1			157
Provision (credit) for credit loss expense	946		1,286	1
Charge-offs	(768)	(1)	(773)	(1)
Recoveries		0	3
Ending balance	677	16	677	16
Non-accrual with Allowance	374		374
Reserve			371
Allowance for loan losses:
Collectively evaluated for impairment					12
Total ending allowance balance	$ 677	$ 16	677	$ 16	12
Loans:
Collectively evaluated for impairment					2,316
Total ending loans balance					2,316
Other Loans | Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses [Roll Forward]
Beginning balance			(8)
Allowance for loan losses:
Total ending allowance balance					(8)
Other Loans | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses [Roll Forward]
Beginning balance			$ 4
Allowance for loan losses:
Total ending allowance balance					$ 4

LOANS HELD FOR INVESTMENT, NE_4

LOANS HELD FOR INVESTMENT, NET - Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2020
Unpaid Principal Balance
With no related allowance recorded			$ 4,567
With related allowance recorded			12,502
Total			17,069
Recorded Investment
With no related allowance recorded			4,567
With related allowance recorded			12,502
Total			17,069
Related Allowance
Impaired Financing Receivable, Related Allowance			6,474
Average Recorded Investment
With no related allowance recorded	$ 2,820	$ 3,114
Total	13,052	10,614
Interest Income Recognized
With no related allowance recorded		65
Total		218
One-to-four family residential and cooperative/condominium apartment
Unpaid Principal Balance
With no related allowance recorded			1,863
Recorded Investment
With no related allowance recorded			1,863
Related Allowance
Impaired Financing Receivable, Related Allowance			0
Average Recorded Investment
With no related allowance recorded		10
Interest Income Recognized
With no related allowance recorded		4
Multifamily residential and residential mixed-use
Average Recorded Investment
With no related allowance recorded	1,295	416
Interest Income Recognized
With no related allowance recorded		7
Commercial real estate ("CRE")
Unpaid Principal Balance
With no related allowance recorded			2,704
Recorded Investment
With no related allowance recorded			2,704
Related Allowance
Impaired Financing Receivable, Related Allowance			0
Average Recorded Investment
With no related allowance recorded	1,525	2,688
Interest Income Recognized
With no related allowance recorded		54
Commercial and Industrial ("C&I") Loans
Unpaid Principal Balance
With related allowance recorded			12,502
Recorded Investment
With related allowance recorded			12,502
Related Allowance
Impaired Financing Receivable, Related Allowance			$ 6,474
Average Recorded Investment
With related allowance recorded	$ 10,232	7,500
Interest Income Recognized
With related allowance recorded		$ 153

LOANS HELD FOR INVESTMENT, NE_5

LOANS HELD FOR INVESTMENT, NET - Past Due Status (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	$ 9,284,871	$ 5,622,044
Non-accrual	34,020	17,928
Aggregate outstanding balance	6,300	3,300
Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	98,949	37,534
30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	51,138	15,359
60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	7,509	918
Loans 90 Days or More Past Due and Still Accruing Interest
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	6,282	3,329
Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	9,185,922	5,584,510
Total real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	8,251,743	4,978,195
Non-accrual	9,919	5,425
Total real estate loans | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	60,442	21,257
Total real estate loans | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	39,446	15,351
Total real estate loans | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	5,052	0
Total real estate loans | Loans 90 Days or More Past Due and Still Accruing Interest
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	6,025	481
Total real estate loans | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	8,191,301	4,956,938
One-to-four family residential and cooperative/condominium apartment
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	683,665	184,989
Non-accrual	4,938	858
One-to-four family residential and cooperative/condominium apartment | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	14,339	902
One-to-four family residential and cooperative/condominium apartment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	3,135	0
One-to-four family residential and cooperative/condominium apartment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	1,245	0
One-to-four family residential and cooperative/condominium apartment | Loans 90 Days or More Past Due and Still Accruing Interest
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	5,021	44
One-to-four family residential and cooperative/condominium apartment | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	669,326	184,087
Multifamily residential and residential mixed-use
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	3,468,262	2,758,743
Non-accrual	859	1,863
Multifamily residential and residential mixed-use | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	13,848	2,300
Multifamily residential and residential mixed-use | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	10,251	0
Multifamily residential and residential mixed-use | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	2,738	0
Multifamily residential and residential mixed-use | Loans 90 Days or More Past Due and Still Accruing Interest
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans		437
Multifamily residential and residential mixed-use | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	3,454,414	2,756,443
Commercial real estate ("CRE")
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	3,814,437	1,878,167
Non-accrual	4,122	2,704
Commercial real estate ("CRE") | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	14,555	18,055
Commercial real estate ("CRE") | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	8,360	15,351
Commercial real estate ("CRE") | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	1,069	0
Commercial real estate ("CRE") | Loans 90 Days or More Past Due and Still Accruing Interest
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	1,004	0
Commercial real estate ("CRE") | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	3,799,882	1,860,112
Acquisition, development, and construction ("ADC")
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	285,379	156,296
Non-accrual	0	0
Acquisition, development, and construction ("ADC") | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	17,700	0
Acquisition, development, and construction ("ADC") | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	17,700	0
Acquisition, development, and construction ("ADC") | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	0	0
Acquisition, development, and construction ("ADC") | Loans 90 Days or More Past Due and Still Accruing Interest
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	0	0
Acquisition, development, and construction ("ADC") | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	267,679	156,296
Commercial and Industrial ("C&I") Loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	1,012,415	641,533
Non-accrual	23,727	12,502
Commercial and Industrial ("C&I") Loans | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	37,401	16,267
Commercial and Industrial ("C&I") Loans | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	10,962	0
Commercial and Industrial ("C&I") Loans | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	2,455	917
Commercial and Industrial ("C&I") Loans | Loans 90 Days or More Past Due and Still Accruing Interest
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	257	2,848
Commercial and Industrial ("C&I") Loans | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	975,014	625,266
Commercial and Industrial ("C&I") Loans | Total real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans		5,619,728
Other Loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	20,713	2,316
Non-accrual	374	1
Other Loans | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	1,106	10
Other Loans | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	730	8
Other Loans | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	2	1
Other Loans | Loans 90 Days or More Past Due and Still Accruing Interest
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	0	0
Other Loans | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans	$ 19,607	$ 2,306

LOANS HELD FOR INVESTMENT, NE_6

LOANS HELD FOR INVESTMENT, NET - Collateral Dependent Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for impairment		$ 17,069
Individually evaluated for impairment		6,474
Commercial real estate ("CRE")
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for impairment		2,704
Multifamily residential and residential mixed-use
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for impairment		1,863
Commercial and Industrial ("C&I") Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for impairment		12,502
Individually evaluated for impairment		$ 6,474
Collateral Dependent Loans | Commercial real estate ("CRE")
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for impairment	$ 53,200
Individually evaluated for impairment	7,600
Collateral Dependent Loans | Multifamily residential and residential mixed-use
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for impairment	8,500
Individually evaluated for impairment	600
Collateral Dependent Loans | Commercial and Industrial ("C&I") Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for impairment	4,400
Individually evaluated for impairment	$ 700

LOANS HELD FOR INVESTMENT, NE_7

LOANS HELD FOR INVESTMENT, NET - Modified as TDRs (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)contract	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)loan	Sep. 30, 2020USD ($)
Financing Receivable, Allowance for Credit Loss [Line Items]
Provision for credit losses	$ (5,187,000)	$ 5,931,000	$ 6,344,000	$ 20,003,000
Number of Loans	1		3
Pre-Modification Outstanding Recorded Investment			$ 10,506,000
Post-Modification Outstanding Recorded Investment			10,538,000
TDRs
Financing Receivable, Allowance for Credit Loss [Line Items]
Modifications recorded investment	$ 528,000		$ 528,000
Provision for credit losses	481,000
Commitments to lend additional amounts	$ 0
One-to-four family residential and cooperative/condominium apartment
Financing Receivable, Allowance for Credit Loss [Line Items]
Number of Loans | loan			1
Pre-Modification Outstanding Recorded Investment			$ 50,000
Post-Modification Outstanding Recorded Investment			$ 50,000
Commercial real estate ("CRE")
Financing Receivable, Allowance for Credit Loss [Line Items]
Number of Loans | loan			1
Pre-Modification Outstanding Recorded Investment			$ 10,000,000
Post-Modification Outstanding Recorded Investment			$ 10,000,000
Commercial and Industrial ("C&I") Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Number of Loans | loan			1
Pre-Modification Outstanding Recorded Investment			$ 456,000
Post-Modification Outstanding Recorded Investment			$ 488,000

LOANS HELD FOR INVESTMENT, NE_8

LOANS HELD FOR INVESTMENT, NET - Deferral Loans (Details) $ in Thousands		Sep. 30, 2021USD ($)loan	Dec. 31, 2020USD ($)
CARES Act Loan [Abstract]
Balance		$ 9,284,871	$ 5,622,044
COVID-19 [Member]
CARES Act Loan [Abstract]
Number of loans | loan		17
Balance	[1]	$ 26,603
% of portfolio		0.30%
One-to-four family residential and cooperative/condominium apartment
CARES Act Loan [Abstract]
Balance		$ 683,665	184,989
One-to-four family residential and cooperative/condominium apartment | COVID-19 [Member]
CARES Act Loan [Abstract]
Number of loans | loan		10
Balance	[1]	$ 9,255
% of portfolio		1.40%
Commercial real estate ("CRE")
CARES Act Loan [Abstract]
Balance		$ 3,814,437	1,878,167
Commercial real estate ("CRE") | COVID-19 [Member]
CARES Act Loan [Abstract]
Number of loans | loan		1
Balance	[1]	$ 3,487
% of portfolio		0.10%
Commercial and Industrial ("C&I") Loans
CARES Act Loan [Abstract]
Balance		$ 1,012,415	$ 641,533
Commercial and Industrial ("C&I") Loans | COVID-19 [Member]
CARES Act Loan [Abstract]
Number of loans | loan		6
Balance	[1]	$ 13,861
% of portfolio		1.40%
[1]	Amount excludes net deferred costs due to immateriality.

LOANS HELD FOR INVESTMENT, NE_9

LOANS HELD FOR INVESTMENT, NET - Credit Quality Indicators (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Credit Risk Profile of Real Estate Loans [Abstract]
Percentage of aggregate rental income			50.00%
Loans	$ 9,284,871		$ 9,284,871		$ 5,622,044
2021	1,329,531		1,329,531
2020	1,608,571		1,608,571
2019	1,354,530		1,354,530
2018	780,886		780,886
2017	954,652		954,652
2016 and Prior	2,577,987		2,577,987
Revolving	619,704		619,704
Revolving-Term	38,297		38,297
Total Loans	9,264,158		9,264,158
Pass
Credit Risk Profile of Real Estate Loans [Abstract]
2021	1,321,842		1,321,842
2020	1,582,785		1,582,785
2019	1,279,298		1,279,298
2018	684,132		684,132
2017	842,155		842,155
2016 and Prior	2,363,465		2,363,465
Revolving	578,714		578,714
Revolving-Term	28,110		28,110
Total Loans	8,680,501		8,680,501
Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
2021	5,354		5,354
2020	16,624		16,624
2019	15,153		15,153
2018	8,285		8,285
2017	23,907		23,907
2016 and Prior	40,023		40,023
Revolving	2,531		2,531
Revolving-Term	2,457		2,457
Total Loans	114,334		114,334
Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
2021	2,335		2,335
2020	9,162		9,162
2019	49,886		49,886
2018	87,694		87,694
2017	76,601		76,601
2016 and Prior	174,469		174,469
Revolving	38,459		38,459
Revolving-Term	7,730		7,730
Total Loans	446,336		446,336
Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
2019	10,193		10,193
2018	775		775
2017	11,989		11,989
2016 and Prior	30		30
Total Loans	22,987		22,987
Criticized
Credit Risk Profile of Real Estate Loans [Abstract]
Sold amount	11,900	$ 3,000	66,500	$ 10,000
Total real estate loans
Credit Risk Profile of Real Estate Loans [Abstract]
Loans	8,251,743		8,251,743		4,978,195
Total real estate loans | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					4,681,059
Total real estate loans | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					83,761
Total real estate loans | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					213,375
Total real estate loans | Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					0
One-to-four family residential and cooperative/condominium apartment
Credit Risk Profile of Real Estate Loans [Abstract]
Loans	683,665		683,665		184,989
2021	104,830		104,830
2020	94,776		94,776
2019	88,599		88,599
2018	81,622		81,622
2017	86,626		86,626
2016 and Prior	160,666		160,666
Revolving	53,329		53,329
Revolving-Term	13,217		13,217
Total Loans	683,665		683,665
One-to-four family residential and cooperative/condominium apartment | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					183,293
2021	104,830		104,830
2020	93,315		93,315
2019	86,214		86,214
2018	79,981		79,981
2017	84,075		84,075
2016 and Prior	143,807		143,807
Revolving	52,483		52,483
Revolving-Term	11,162		11,162
Total Loans	655,867		655,867
One-to-four family residential and cooperative/condominium apartment | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					0
2019	337		337
2018	756		756
2017	345		345
2016 and Prior	2,168		2,168
Revolving	846		846
Revolving-Term	1,089		1,089
Total Loans	5,541		5,541
One-to-four family residential and cooperative/condominium apartment | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					1,696
2020	1,461		1,461
2019	2,048		2,048
2018	862		862
2017	2,206		2,206
2016 and Prior	14,691		14,691
Revolving-Term	966		966
Total Loans	22,234		22,234
One-to-four family residential and cooperative/condominium apartment | Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					0
2018	23		23
Total Loans	23		23
Multifamily residential and residential mixed-use
Credit Risk Profile of Real Estate Loans [Abstract]
Loans	3,468,262		3,468,262		2,758,743
2021	426,164		426,164
2020	360,450		360,450
2019	543,514		543,514
2018	221,003		221,003
2017	437,487		437,487
2016 and Prior	1,470,245		1,470,245
Revolving	8,574		8,574
Revolving-Term	825		825
Total Loans	3,468,262		3,468,262
Multifamily residential and residential mixed-use | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					2,523,258
2021	426,164		426,164
2020	347,900		347,900
2019	493,077		493,077
2018	193,738		193,738
2017	373,965		373,965
2016 and Prior	1,329,688		1,329,688
Revolving	5,111		5,111
Revolving-Term	825		825
Total Loans	3,170,468		3,170,468
Multifamily residential and residential mixed-use | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					56,400
2020	12,550		12,550
2019	14,551		14,551
2017	11,842		11,842
2016 and Prior	22,378		22,378
Total Loans	61,321		61,321
Multifamily residential and residential mixed-use | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					179,085
2019	35,886		35,886
2018	27,265		27,265
2017	51,680		51,680
2016 and Prior	118,179		118,179
Revolving	3,463		3,463
Total Loans	236,473		236,473
Multifamily residential and residential mixed-use | Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					0
Commercial real estate ("CRE")
Credit Risk Profile of Real Estate Loans [Abstract]
Loans	3,814,437		3,814,437		1,878,167
2021	643,923		643,923
2020	876,483		876,483
2019	585,974		585,974
2018	375,719		375,719
2017	368,772		368,772
2016 and Prior	919,079		919,079
Revolving	39,323		39,323
Revolving-Term	5,164		5,164
Total Loans	3,814,437		3,814,437
Commercial real estate ("CRE") | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					1,831,712
2021	636,234		636,234
2020	872,347		872,347
2019	578,758		578,758
2018	331,636		331,636
2017	337,930		337,930
2016 and Prior	863,215		863,215
Revolving	39,323		39,323
Revolving-Term	5,164		5,164
Total Loans	3,664,607		3,664,607
Commercial real estate ("CRE") | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					13,861
2021	5,354		5,354
2020	2,384		2,384
2018	4,191		4,191
2017	11,109		11,109
2016 and Prior	15,416		15,416
Total Loans	38,454		38,454
Commercial real estate ("CRE") | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					32,594
2021	2,335		2,335
2020	1,752		1,752
2019	7,110		7,110
2018	39,892		39,892
2017	19,733		19,733
2016 and Prior	40,448		40,448
Total Loans	111,270		111,270
Commercial real estate ("CRE") | Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					0
2019	106		106
Total Loans	106		106
Acquisition, development, and construction ("ADC")
Credit Risk Profile of Real Estate Loans [Abstract]
Loans	285,379		285,379		156,296
2021	101,947		101,947
2020	69,546		69,546
2019	62,414		62,414
2018	39,165		39,165
2017	8,120		8,120
2016 and Prior	901		901
Revolving	2,686		2,686
Revolving-Term	600		600
Total Loans	285,379		285,379
Acquisition, development, and construction ("ADC") | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					142,796
2021	101,947		101,947
2020	69,546		69,546
2019	62,414		62,414
2018	24,587		24,587
2017	8,120		8,120
2016 and Prior	807		807
Revolving	2,686		2,686
Revolving-Term	600		600
Total Loans	270,707		270,707
Acquisition, development, and construction ("ADC") | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					13,500
2018	1,078		1,078
Total Loans	1,078		1,078
Acquisition, development, and construction ("ADC") | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					0
2018	13,500		13,500
2016 and Prior	94		94
Total Loans	13,594		13,594
Acquisition, development, and construction ("ADC") | Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					0
Commercial and Industrial ("C&I") Loans
Credit Risk Profile of Real Estate Loans [Abstract]
Loans	1,012,415		1,012,415		641,533
2021	52,667		52,667
2020	207,316		207,316
2019	74,029		74,029
2018	63,377		63,377
2017	53,647		53,647
2016 and Prior	27,096		27,096
Revolving	515,792		515,792
Revolving-Term	18,491		18,491
Total Loans	1,012,415		1,012,415
Commercial and Industrial ("C&I") Loans | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					613,691
2021	52,667		52,667
2020	199,677		199,677
2019	58,835		58,835
2018	54,190		54,190
2017	38,065		38,065
2016 and Prior	25,948		25,948
Revolving	479,111		479,111
Revolving-Term	10,359		10,359
Total Loans	918,852		918,852
Commercial and Industrial ("C&I") Loans | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					2,131
2020	1,690		1,690
2019	265		265
2018	2,260		2,260
2017	611		611
2016 and Prior	61		61
Revolving	1,685		1,685
Revolving-Term	1,368		1,368
Total Loans	7,940		7,940
Commercial and Industrial ("C&I") Loans | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					13,315
2020	5,949		5,949
2019	4,842		4,842
2018	6,175		6,175
2017	2,982		2,982
2016 and Prior	1,057		1,057
Revolving	34,996		34,996
Revolving-Term	6,764		6,764
Total Loans	62,765		62,765
Commercial and Industrial ("C&I") Loans | Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					12,396
2019	10,087		10,087
2018	752		752
2017	11,989		11,989
2016 and Prior	30		30
Total Loans	22,858		22,858
Commercial and Industrial ("C&I") Loans | Total real estate loans
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					5,619,728
Commercial and Industrial ("C&I") Loans | Total real estate loans | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					5,294,750
Commercial and Industrial ("C&I") Loans | Total real estate loans | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					85,892
Commercial and Industrial ("C&I") Loans | Total real estate loans | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					226,690
Commercial and Industrial ("C&I") Loans | Total real estate loans | Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					12,396
Other Loans
Credit Risk Profile of Real Estate Loans [Abstract]
Loans	20,713		20,713		2,316
Other Loans | Credit Risk Profile
Credit Risk Profile of Real Estate Loans [Abstract]
Loans	20,713		20,713
Other Loans | Performing
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					2,315
Other Loans | Performing | Credit Risk Profile
Credit Risk Profile of Real Estate Loans [Abstract]
Loans	20,339		20,339
Other Loans | Non-Accrual
Credit Risk Profile of Real Estate Loans [Abstract]
Loans					$ 1
Other Loans | Non-Accrual | Credit Risk Profile
Credit Risk Profile of Real Estate Loans [Abstract]
Loans	$ 374		$ 374

LEASES - Narrative (Details)

LEASES - Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)leaseitem	Feb. 01, 2021USD ($)
LEASES
Operating lease assets		$ 45.6
Operating lease liabilities		$ 45.3
Number of leases terminated | lease	3
Number of branches combined to other locations | item	3
Decrease in operating lease liability	$ (3.7)
Early termination fee	$ 4

LEASES - Maturities of the Comp

LEASES - Maturities of the Company's operating lease liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Rent to be Captalized
2021	$ 3,374
2022	11,006
2023	9,301
2024	9,186
2025	8,941
Thereafter	25,439
Total undiscounted lease payments	67,247
Less amounts representing interest	(4,377)
Operating lease liabilities	$ 62,870	$ 39,874

LEASES - Other information rela

LEASES - Other information related to operating leases (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Other information related to operating leases:
Operating lease cost	$ 4,012	$ 1,636	$ 11,178	$ 4,867
Cash paid for amounts included in the measurement of operating lease liabilities	$ 3,724	$ 1,745	$ 10,496	$ 5,295
Weighted average remaining lease term	6 years 10 months 24 days		6 years 10 months 24 days		6 years 6 months
Weighted average discount rate	1.82%		1.82%		3.23%

DERIVATIVES AND HEDGING ACTIV_3

DERIVATIVES AND HEDGING ACTIVITIES - Cash Flow Hedges Narrative (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021USD ($)DerivativeInstrument	Sep. 30, 2021USD ($)DerivativeInstrument
Derivative Instruments, Gain (Loss) [Line Items]
Estimated reclassification as an increase to interest expense during next twelve months	$ 356	$ 356
Maximum period for future cash flows of forecasted transactions		24 months
Number of derivatives terminated | DerivativeInstrument	0	34
Termination value of derivatives		$ 785,000
Non-interest income
Derivative Instruments, Gain (Loss) [Line Items]
Loss on termination of derivatives		$ (16,500)

DERIVATIVES AND HEDGING ACTIV_4

DERIVATIVES AND HEDGING ACTIVITIES - Classification on Consolidated Statements of Financial Condition (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)DerivativeInstrument	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)DerivativeInstrument	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)DerivativeInstrument
Not Designated as Hedging Instrument
Cash Flow Hedges
Loan level derivative income	$ 445	$ 1,544	$ 2,796	$ 5,201
Interest rate swaps related to FHLBNY advances | Designated as Hedging Instrument
Cash Flow Hedges
Count, assets | DerivativeInstrument	4		4
Count, liabilities | DerivativeInstrument					32
Notional amount, assets	$ 150,000		$ 150,000
Notional amount, liabilities					$ 655,000
Fair value assets	$ 2,811		$ 2,811
Fair value liabilities					$ 18,442
Loan Level Interest Rate Swaps with Borrower (Assets) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, assets | DerivativeInstrument	128		128		65
Notional amount, assets	$ 818,370		$ 818,370		$ 570,277
Fair value assets	$ 36,095		$ 36,095		$ 24,764
Loan Level Interest Rate Swaps with Borrower (Liabilities) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, liabilities | DerivativeInstrument	61		61
Notional amount, liabilities	$ 439,198		$ 439,198
Fair value liabilities	(7,414)		(7,414)
Posted collateral	$ 0		$ 0
Loan level interest rate floors with borrower | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, liabilities | DerivativeInstrument	47		47		41
Notional amount, liabilities	$ 405,685		$ 405,685		$ 364,643
Fair value liabilities	(4,072)		(4,072)		$ (5,832)
Loan level interest rate swaps with third-party counterparties (Liabilities) | Designated as Hedging Instrument
Cash Flow Hedges
Posted collateral	$ 0		$ 0
Loan level interest rate swaps with third-party counterparties (Liabilities) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, liabilities | DerivativeInstrument	128		128		65
Notional amount, liabilities	$ 818,370		$ 818,370		$ 570,277
Fair value liabilities	(36,095)		(36,095)		$ (24,764)
Posted collateral	$ 23,500		$ 23,500
Loan level interest rate swaps with third party counterparties (Assets) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, assets | DerivativeInstrument	61		61
Notional amount, assets	$ 439,198		$ 439,198
Fair value assets	$ 7,414		$ 7,414
Loan level interest rate floors with third-party counterparties | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, assets | DerivativeInstrument	47		47		41
Notional amount, assets	$ 405,685		$ 405,685		$ 364,643
Fair value assets	$ 4,072		$ 4,072		$ 5,832

DERIVATIVES AND HEDGING ACTIV_5

DERIVATIVES AND HEDGING ACTIVITIES - Effect on Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Effect of cash flow hedge accounting on Accumulated Other Comprehensive Income (Loss):
Gain (loss) recognized in other comprehensive income	$ 225	$ 100	$ 3,767	$ (25,098)
Gain recognized on termination of derivatives			(16,505)
Interest Rate Products | Other Comprehensive Income
Effect of cash flow hedge accounting on Accumulated Other Comprehensive Income (Loss):
Gain (loss) recognized in other comprehensive income	225	100	3,767	(25,098)
Interest Rate Products | Other Comprehensive Income | Interest Expense
Effect of cash flow hedge accounting on Accumulated Other Comprehensive Income (Loss):
Loss reclassified from other comprehensive income into interest expense	$ (38)	$ (2,319)	(902)	$ (3,679)
Interest Rate Products | Other Comprehensive Income | Derivatives.
Effect of cash flow hedge accounting on Accumulated Other Comprehensive Income (Loss):
Gain recognized on termination of derivatives			$ 16,505

DERIVATIVES AND HEDGING ACTIV_6

DERIVATIVES AND HEDGING ACTIVITIES - Credit Risk Related Contingent Features (Details) $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)item
Credit Risk Related Contingent Features [Abstract]
Fair value of derivative liability, including accrued interest | $	$ 24.6
Number of provisions breached | item	0

FAIR VALUE OF FINANCIAL INSTR_3

FAIR VALUE OF FINANCIAL INSTRUMENTS - Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Financial Assets
Derivative assets	$ 41,700		$ 41,700		$ 18,932
Financial Liabilities
Derivative liabilities	38,889		38,889		37,374
Impaired Loans [Abstract]
Individually evaluated CRE loans with an allowance for credit losses, Outstanding balance					12,502
Valuation allowance					6,474
Provision for credit losses	(5,187)	$ 5,931	6,344	$ 20,003
Recurring | Cash flow hedges
Financial Assets
Derivative assets	2,811		2,811
Financial Liabilities
Derivative liabilities					18,442
Recurring | Freestanding derivatives
Financial Assets
Derivative assets	38,889		38,889		30,596
Financial Liabilities
Derivative liabilities	38,889		38,889		30,596
Recurring | Level 2 Inputs [Member] | Cash flow hedges
Financial Assets
Derivative assets	2,811		2,811
Financial Liabilities
Derivative liabilities					18,442
Recurring | Level 2 Inputs [Member] | Freestanding derivatives
Financial Assets
Derivative assets	38,889		38,889		30,596
Financial Liabilities
Derivative liabilities	38,889		38,889		30,596
Nonrecurring [Member]
Impaired Loans [Abstract]
Individually evaluated CRE loans with an allowance for credit losses, Outstanding balance	63,900		63,900
Valuation allowance	8,800		8,800
Provision for credit losses	9,000		8,700
Carrying amount of impaired loans					0
Nonrecurring [Member] | Level 3 Inputs [Member]
Impaired Loans [Abstract]
Individually evaluated loans	55,146		55,146
Carrying Amount | Nonrecurring [Member]
Impaired Loans [Abstract]
Individually evaluated loans	55,146		55,146
Agency Notes | Recurring
Financial Assets
Securities available-for-sale:	81,018		81,018		47,421
Agency Notes | Recurring | Level 2 Inputs [Member]
Financial Assets
Securities available-for-sale:	81,018		81,018		47,421
Treasury Securities | Recurring
Financial Assets
Securities available-for-sale:	247,696		247,696
Treasury Securities | Recurring | Level 2 Inputs [Member]
Financial Assets
Securities available-for-sale:	247,696		247,696
Corporate Securities | Recurring
Financial Assets
Securities available-for-sale:	126,833		126,833		64,461
Corporate Securities | Recurring | Level 2 Inputs [Member]
Financial Assets
Securities available-for-sale:	126,833		126,833		64,461
Pass-through MBS issued by GSEs | Recurring
Financial Assets
Securities available-for-sale:					143,483
Mortgage-backed securities	621,957		621,957
Pass-through MBS issued by GSEs | Recurring | Level 2 Inputs [Member]
Financial Assets
Securities available-for-sale:					143,483
Mortgage-backed securities	621,957		621,957
Agency Collateralized Mortgage Obligations ("CMOs") | Recurring
Financial Assets
Securities available-for-sale:	590,426		590,426		283,496
Agency Collateralized Mortgage Obligations ("CMOs") | Recurring | Level 2 Inputs [Member]
Financial Assets
Securities available-for-sale:	590,426		590,426		283,496
State and municipal obligations. | Recurring
Financial Assets
Securities available-for-sale:	41,133		41,133
State and municipal obligations. | Recurring | Level 2 Inputs [Member]
Financial Assets
Securities available-for-sale:	$ 41,133		$ 41,133
Domestic Equity Mutual Funds | Recurring
Financial Assets
Marketable equity securities (Registered Mutual Funds)					1,769
Domestic Equity Mutual Funds | Recurring | Level 1 Inputs [Member]
Financial Assets
Marketable equity securities (Registered Mutual Funds)					1,769
International Equity Mutual Funds | Recurring
Financial Assets
Marketable equity securities (Registered Mutual Funds)					468
International Equity Mutual Funds | Recurring | Level 1 Inputs [Member]
Financial Assets
Marketable equity securities (Registered Mutual Funds)					468
Fixed Income Mutual Funds | Recurring
Financial Assets
Marketable equity securities (Registered Mutual Funds)					3,733
Fixed Income Mutual Funds | Recurring | Level 1 Inputs [Member]
Financial Assets
Marketable equity securities (Registered Mutual Funds)					$ 3,733

FAIR VALUE OF FINANCIAL INSTR_4

FAIR VALUE OF FINANCIAL INSTRUMENTS - Balance Sheet Groupings (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Carrying Amount
Financial Assets [Abstract]
Cash and due from banks	$ 629,011	$ 243,603
Investment securities held-to-maturity, fair value	40,303
Loans held for investment, net	9,148,470	5,580,583
Accrued interest receivable	43,284	34,815
Financial Liabilities [Abstract]
Savings, money market and checking accounts	9,657,821	3,202,484
Certificates of Deposits ("CDs")	1,016,216	1,322,638
FHLBNY Advances	25,000	1,204,010
Subordinated debt, net	197,142	114,052
Other short-term borrowings	2,629	120,000
Accrued interest payable	1,630	1,734
Fair Value
Financial Assets [Abstract]
Cash and due from banks	629,011	243,603
Investment securities held-to-maturity, fair value	40,303
Loans held for investment, net	9,212,454	5,598,787
Accrued interest receivable	43,284	34,815
Financial Liabilities [Abstract]
Savings, money market and checking accounts	9,657,821	3,202,484
Certificates of Deposits ("CDs")	1,021,029	1,328,554
FHLBNY Advances	25,015	1,207,890
Subordinated debt, net	203,355	114,340
Other short-term borrowings	2,629	120,000
Accrued interest payable	1,630	1,734
Fair Value | Level 1 Inputs [Member]
Financial Assets [Abstract]
Cash and due from banks	629,011	243,603
Accrued interest receivable		2
Financial Liabilities [Abstract]
Savings, money market and checking accounts	9,657,821	3,202,484
Other short-term borrowings	2,629	120,000
Fair Value | Level 2 Inputs [Member]
Financial Assets [Abstract]
Investment securities held-to-maturity, fair value	40,303
Accrued interest receivable	4,228	1,584
Financial Liabilities [Abstract]
Certificates of Deposits ("CDs")	1,021,029	1,328,554
FHLBNY Advances	25,015	1,207,890
Subordinated debt, net	203,355	114,340
Accrued interest payable	1,630	1,734
Fair Value | Level 3 Inputs [Member]
Financial Assets [Abstract]
Loans held for investment, net	9,212,454	5,598,787
Accrued interest receivable	$ 39,056	$ 33,229

OTHER INTANGIBLE ASSETS - Carry

OTHER INTANGIBLE ASSETS - Carrying Amount and Accumulated Amortization of Intangible Assets, Amortizable and Arose from Merger (Details) - USD ($) $ in Thousands	Feb. 01, 2021	Sep. 30, 2021	Dec. 31, 2020
Acquired intangible assets:
Gross carrying value		$ 10,984
Accumulated amortization		(1,907)
Net carrying amount		9,077	$ 0
Core deposits
Acquired intangible assets:
Gross Carrying Amount	$ 10,200
Gross carrying value		10,204
Accumulated amortization		(1,427)
Net carrying amount		8,777
Noncompete Agreements
Acquired intangible assets:
Gross Carrying Amount	$ 780
Gross carrying value		780
Accumulated amortization		(480)
Net carrying amount		$ 300

OTHER INTANGIBLE ASSETS - Narra

OTHER INTANGIBLE ASSETS - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
OTHER INTANGIBLE ASSETS
Amortization expense recognized on intangible assets	$ 715	$ 0	$ 1,907	$ 0

OTHER INTANGIBLE ASSETS - Estim

OTHER INTANGIBLE ASSETS - Estimated Amortization Expense for Next Five Years (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
OTHER INTANGIBLE ASSETS
2021	$ 715
2022	1,878
2023	1,425
2024	1,163
2025	958
Thereafter	2,938
Net carrying amount	$ 9,077	$ 0

FEDERAL HOME LOAN BANK OF NEW_3

FEDERAL HOME LOAN BANK OF NEW YORK ADVANCES (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Contractual Maturity, Amount
Overnight	$ 0	$ 0
2021	25,000
2021		1,144,010
2022		60,000
Total FHLBNY advances	$ 25,000	$ 1,204,010
Weighted Average Rate
2021	0.35%	0.52%
2022		0.60%
Weighted Average Rate for total FHLB advances (as a percent)	0.35%	0.53%

FEDERAL HOME LOAN BANK OF NEW_4

FEDERAL HOME LOAN BANK OF NEW YORK ADVANCES - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Feb. 01, 2021	Dec. 31, 2020
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Advances collateralized amount		$ 4,250,000,000			$ 2,150,000,000
Maximum borrowing amount from FHLBNY term advances		3,710,000,000
FHLBNY advances with contractual maturities after 2021		0			0
FHLBNY advances with an overnight contractual maturity		0			$ 0
Prepayments penalty expenses	$ 0	1,800,000	$ 0
Legacy Dime
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
FHLBNY advances				$ 216,300,000
Extinguishment of FHLBNY		$ 209,000,000
Weighted average rate		1.31%

SUBORDINATED DEBENTURES (Detail

SUBORDINATED DEBENTURES (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2017	Feb. 01, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Fixed-to-floating rate subordinated debentures	$ 80
Subordinated notes payable, net		$ 197.1		$ 197.1				$ 114.1
Interest expense related to the subordinated debt		$ 2.2	$ 1.3	$ 6.3	$ 4
Subordinated Debentures
Debt Instrument [Line Items]
Fixed-to-floating rate subordinated debentures						$ 115	$ 115
Fixed annual interest rate						4.50%	4.50%
Basis points						2.66%
Callable Notes After Five Years | Subordinated Debentures
Debt Instrument [Line Items]
Fixed-to-floating rate subordinated debentures	$ 40
Debt Instrument, Term	5 years
Fixed annual interest rate	0.0525%
Debt instrument variable rate description	three-month LIBOR
Basis points	3.60%
Callable Notes After Ten Years | Subordinated Debentures
Debt Instrument [Line Items]
Fixed-to-floating rate subordinated debentures	$ 40
Debt Instrument, Term	10 years
Fixed annual interest rate	0.0575%
Debt instrument variable rate description	three-month LIBOR
Basis points	3.45%

RETIREMENT AND POSTRETIREMENT_3

RETIREMENT AND POSTRETIREMENT PLANS (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Retirement and Postretirement Plans [Abstract]
Curtailment loss				$ 1,543
Distributions to Retired Participants [Abstract]
Defined contribution plan description				100% of each employee’s contributions up to 1% of each employee’s compensation plus 50% of each employee’s contributions over 1% but not in excess of 6% of each employee’s compensation for a maximum contribution of 3.5% of a participating employee’s compensation.
Minimum employee contribution percentage				1.00%
Percentage of employer matching contribution				50.00%
Threshold limit percentage of employee compensation				6.00%
Maximum percentage of annual contribution per employee				3.50%
Cash				$ 9,200
Market value of Common Stock from Employee Stock Ownership Plan of BMP (000 shares)				$ 2,400
Returned to treasury Stock				41,101
Gross lump-sum distribution		$ 11,600
Non-cash tax benefit				$ 301
Distribution of common stock (in shares)				88,081
BMP Retirement Plan
Retirement and Postretirement Plans [Abstract]
Planned contributions/benefit payments	$ 0			$ 0
Retirement Plans [Member] | BMP Retirement Plan
Net Periodic Benefit Cost [Abstract]
Service cost	223			594
Interest cost	302			854
Expected return on assets	(1,244)			(3,473)
Amortization of unrealized loss	207			619
Net periodic (credit) cost	(512)			(1,406)
Retirement Plans [Member] | Employee Retirement Plan [Member]
Net Periodic Benefit Cost [Abstract]
Interest cost	183		$ 10	549	$ 30
Expected return on assets	(428)			(1,284)
Unrecognized past service liability			(2)		(6)
Amortization of unrealized loss	229			687
Net periodic (credit) cost	(16)		8	(48)	24
Retirement Plans [Member] | BMP, Postretirement And Outside Director Retirement Plans
Net Periodic Benefit Cost [Abstract]
Interest cost			241		723
Expected return on assets			(428)		(1,284)
Amortization of unrealized loss			274		822
Net periodic (credit) cost			$ 87		$ 261
Retirement Plans [Member] | BMP, Employee and Outside Director Retirement Plans [Member]
Retirement and Postretirement Plans [Abstract]
Planned contributions/benefit payments	$ 2,800			2,800
Actual contributions/benefit payments				$ 6,200
Curtailment loss		$ 1,500

STOCK-BASED COMPENSATION, (Deta

STOCK-BASED COMPENSATION, (Details) - shares	Sep. 30, 2021	Dec. 31, 2020
Dime 2020 Equity Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance	1,123,639
Unvested and outstanding share-based awards		0
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested and outstanding share-based awards	38,948,000	0
Sales Incentive Award Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested and outstanding share-based awards		0

STOCK-BASED COMPENSATION, Stock

STOCK-BASED COMPENSATION, Stock Option Awards (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Information Related to Stock Option Plans [Abstract]
Cash received for option exercise cost	$ 396	$ 38
Stock Option Awards
Number of Options [Roll Forward]
Options outstanding, beginning of period (in shares)	28,842
Options outstanding at January 1, 2021 as adjusted for conversion (in shares)	18,685
Options acquired (in shares)	180,020
Options exercised (in shares)	(17,102)
Options forfeited (in shares)	(29,421)
Options outstanding, end of period (in shares)	152,182
Options vested and exercisable, end of period (in shares)	152,182
Weighted-Average Exercise Price [Abstract]
Options outstanding, beginning of period (in dollars per share)	$ 15.05
Options outstanding at January 1, 2021 as adjusted for conversion (in dollars per share)	23.23
Options acquired (in dollars per share)	35.39
Options exercised (in dollars per share)	23.40
Options forfeited (in dollars per share)	35.38
Options outstanding, end of period (in dollars per share)	35.24
Options vested and exercisable. end of period (in dollars per share)	$ 35.24
Weighted-Average Remaining Contractual Years
Options outstanding	7 years 4 months 24 days
Options vested and exercisable	7 years 4 months 24 days
Aggregate Intrinsic Value [Abstract]
Options outstanding	$ 18
Options vested and exercisable	18
Information Related to Stock Option Plans [Abstract]
Cash received for option exercise cost	396	38
Intrinsic value of options exercised	$ 77	$ 8

STOCK-BASED COMPENSATION, Restr

STOCK-BASED COMPENSATION, Restricted Stock Awards (Details) - Restricted Stock Awards [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Restricted Stock Awards [Abstract]
Unrecognized compensation cost	$ 8,300		$ 8,300
Weighted average remaining years for which compensation expense is to be recognized			2 years 9 months 18 days
Number of Shares [Roll Forward]
Shares acquired in the merger (in shares)			101,778
Shares granted (in shares)			390,027
Shares vested (in shares)			(9,838)
Shares forfeited (in shares)			(33,089)
Unvested allocated shares outstanding, end of period (in shares)	448,878		448,878
Weighted-Average Grant-Date Fair Value [Abstract]
Shares acquired in the merger (in dollars per share)			$ 25.98
Shares granted (in dollars per share)			26.48
Shares vested (in dollars per share)			25.41
Shares forfeited (in dollars per share)			25.73
Unvested allocated shares outstanding, end of period (in dollars per share)	$ 26.45		$ 26.45
Information Related to RSAs
Share-based Payment Arrangement, Expense	$ 1,454	$ 444	$ 3,804	$ 1,311
Income tax benefit recognized on vesting of RSA		$ (38)	$ (86)	$ (95)
Weighted average remaining years for which compensation expense is to be recognized			2 years 9 months 18 days

STOCK-BASED COMPENSATION, Perfo

STOCK-BASED COMPENSATION, Performance Based Equity Awards (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Performance Shares
Performance Based Equity Awards [Abstract]
Percentage of threshold target for each award eligible to be earned based on relative performance			50.00%
Percentage of target for each award eligible to be earned based on relative performance			100.00%
Percentage of maximum target for each award eligible to be earned based on relative performance			150.00%
Unrecognized compensation cost	$ 1,000		$ 1,000
Award vesting period			3 years
Number of Shares [Roll Forward]
Shares granted (in shares)			38,948
Expected aggregate share payout (in shares)			25,963
Weighted-Average Grant-Date Fair Value [Abstract]
Shares granted (in dollars per share)			$ 31.40
Expected aggregate share payout (in dollars per share)			$ 31.40
Information Related to Stock Awards [Abstract]
Compensation expense recognized	81	$ 210	$ 81	$ 362
Unrecognized compensation cost	$ 1,000		$ 1,000
Performance Shares | Maximum
Number of Shares [Roll Forward]
Aggregate share payout, end of period (in shares)	38,948		38,948
Weighted-Average Grant-Date Fair Value [Abstract]
Aggregate share payout, end of period (in dollars per share)	$ 31.40		$ 31.40
Sales Incentive Award Program
Performance Based Equity Awards [Abstract]
Award vesting period			1 year
Information Related to Stock Awards [Abstract]
Compensation expense recognized		$ 150		$ 280

INCOME TAXES (Details)

INCOME TAXES (Details) - item	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
INCOME TAXES
Effective tax rate	27.50%	21.90%	29.20%	21.70%
Number of significant and unusual income tax items in the period			0	0

MERGER RELATED EXPENSES (Detail

MERGER RELATED EXPENSES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Business Acquisition [Line Items]
Transaction costs			$ 27,300
Bridge shareholders
Business Acquisition [Line Items]
Costs associated with employee severance and other merger-related compensation expense	$ 1,100	$ 1,400	$ 15,000
Merger expenses		0		$ 0
Transaction costs		$ 769		$ 2,400

BRANCH RESTRUCTURING COSTS (Det

BRANCH RESTRUCTURING COSTS (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)item	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)item	Sep. 30, 2020USD ($)
BRANCH RESTRUCTURING COSTS
Number of branches combined into existing branches | item	5		5
Restructuring costs | $	$ 4.5	$ 0	$ 6.2	$ 0