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Allowance for Credit Losses (“ACL”) on Loans - Amount of Loans Receivable Held-for-Investment and Related Allowances Per Loan Portfolio Segment (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				$ 37,607,000				$ 28,707,000	$ 37,607,000	$ 28,707,000	$ 27,497,000
Charge-offs									(3,081,000)	(4,307,000)	(987,000)
Recoveries									278,000	465,000	2,175,000
Provisions (credit)	$ 39,000	$ (148,000)	$ (3,701,000)	(2,374,000)	$ 2,473,000	$ 165,000	$ 1,921,000	8,183,000	(6,184,000)	12,742,000	22,000
Ending Balance	38,973,000				37,607,000				38,973,000	37,607,000	28,707,000
Originated Loans Net
Ending balance: individually evaluated for impairment	30,200				73,000				30,200	73,000
Ending balance: collectively evaluated for impairment	34,211,000				37,534,000				34,211,000	37,534,000
Ending balance: PCD loans evaluated for impairment	4,732,000								4,732,000
Loans held-for-investment, net	3,806,617,000				3,823,238,000				3,806,617,000	3,823,238,000
Ending balance: individually evaluated for impairment	9,986,000				13,242,000				9,986,000	13,242,000
Ending balance: collectively evaluated for impairment	3,740,295,000				3,683,461,000				3,740,295,000	3,683,461,000
Ending balance: PCD loans evaluated for impairment	15,819,000								15,819,000
PPP loans not evaluated for impairment	40,517,000				126,535,000				40,517,000	126,535,000
Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				10,353,000				0	10,353,000	0	0
Ending Balance	10,400,000				10,353,000				10,400,000	10,353,000	0
Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				47,960,000				28,707,000	47,960,000	28,707,000	27,497,000
Ending Balance					47,960,000					47,960,000	28,707,000
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				36,726,000				27,918,000	36,726,000	27,918,000
Charge-offs									(670,000)	(4,307,000)
Recoveries									159,000	465,000
Provisions (credit)									(5,515,000)	12,650,000
Ending Balance	34,241,000				36,726,000				34,241,000	36,726,000	27,918,000
Originated Loans Net
Ending balance: individually evaluated for impairment	30,000				73,000				30,000	73,000
Ending balance: collectively evaluated for impairment	34,211,000				36,653,000				34,211,000	36,653,000
Ending balance: PCD loans evaluated for impairment	0								0
Loans held-for-investment, net	3,790,798,000				3,804,720,000				3,790,798,000	3,804,720,000
Ending balance: individually evaluated for impairment	9,986,000				13,242,000				9,986,000	13,242,000
Ending balance: collectively evaluated for impairment	3,740,295,000				3,664,943,000				3,740,295,000	3,664,943,000
Ending balance: PCD loans evaluated for impairment	0								0
PPP loans not evaluated for impairment	40,517,000				126,535,000				40,517,000	126,535,000
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Real Estate
Originated Loans Net
Loans held-for-investment, net	3,647,778,000				3,610,210,000				3,647,778,000	3,610,210,000
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Commercial and Industrial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				1,842,000				1,640,000	1,842,000	1,640,000
Charge-offs									(646,000)	(94,000)
Recoveries									39,000	13,000
Provisions (credit)									991,000	283,000
Ending Balance	3,173,000				1,842,000				3,173,000	1,842,000	1,640,000
Originated Loans Net
Ending balance: individually evaluated for impairment	1,000				4,000				1,000	4,000
Ending balance: collectively evaluated for impairment	3,172,000				1,838,000				3,172,000	1,838,000
Ending balance: PCD loans evaluated for impairment	0								0
Loans held-for-investment, net	141,005,000				191,481,000				141,005,000	191,481,000
Ending balance: individually evaluated for impairment	34,000				16,000				34,000	16,000
Ending balance: collectively evaluated for impairment	100,454,000				64,930,000				100,454,000	64,930,000
Ending balance: PCD loans evaluated for impairment	0								0
PPP loans not evaluated for impairment	40,517,000				126,535,000				40,517,000	126,535,000
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Other loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				198,000				151,000	198,000	151,000
Charge-offs									(3,000)	0
Recoveries									5,000	6,000
Provisions (credit)									(3,000)	41,000
Ending Balance	9,000				198,000				9,000	198,000	151,000
Originated Loans Net
Ending balance: individually evaluated for impairment	0				0				0	0
Ending balance: collectively evaluated for impairment	9,000				198,000				9,000	198,000
Ending balance: PCD loans evaluated for impairment	0								0
Loans held-for-investment, net	2,015,000				3,029,000				2,015,000	3,029,000
Ending balance: individually evaluated for impairment	0				0				0	0
Ending balance: collectively evaluated for impairment	2,015,000				3,029,000				2,015,000	3,029,000
Ending balance: PCD loans evaluated for impairment	0								0
PPP loans not evaluated for impairment	0				0				0	0
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				3,541,000					3,541,000
Ending Balance					3,541,000					3,541,000
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjustment | Commercial and Industrial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				947,000					947,000
Ending Balance					947,000					947,000
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjustment | Other loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				(188,000)					(188,000)
Ending Balance					(188,000)					(188,000)
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				40,267,000					40,267,000
Ending Balance					40,267,000					40,267,000
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjusted Balance | Commercial and Industrial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				2,789,000					2,789,000
Ending Balance					2,789,000					2,789,000
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjusted Balance | Other loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				10,000					10,000
Ending Balance					10,000					10,000
Purchased Credit-Impaired
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				881,000				789,000	881,000	789,000
Charge-offs									(2,411,000)	0
Recoveries									119,000	0
Provisions (credit)									(669,000)	92,000
Ending Balance	4,732,000				881,000				4,732,000	881,000	789,000
Originated Loans Net
Ending balance: individually evaluated for impairment	0				0				0	0
Ending balance: collectively evaluated for impairment	0				881,000				0	881,000
Ending balance: PCD loans evaluated for impairment	4,732,000								4,732,000
Loans held-for-investment, net	15,819,000				18,518,000				15,819,000	18,518,000
Ending balance: individually evaluated for impairment	0				0				0	0
Ending balance: collectively evaluated for impairment	0				18,518,000				0	18,518,000
Ending balance: PCD loans evaluated for impairment	15,819,000								15,819,000
PPP loans not evaluated for impairment	0				0				0	0
Purchased Credit-Impaired | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				6,812,000					6,812,000
Ending Balance					6,812,000					6,812,000
Purchased Credit-Impaired | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				7,693,000					7,693,000
Ending Balance					7,693,000					7,693,000
Commercial and multifamily | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				33,005,000					33,005,000
Charge-offs									0
Recoveries									60,000
Provisions (credit)									(4,331,000)
Ending Balance	26,785,000				33,005,000				26,785,000	33,005,000
Originated Loans Net
Ending balance: individually evaluated for impairment	25,000								25,000
Ending balance: collectively evaluated for impairment	26,760,000								26,760,000
Ending balance: PCD loans evaluated for impairment	0								0
Loans held-for-investment, net	3,326,662,000								3,326,662,000
Ending balance: individually evaluated for impairment	8,352,000								8,352,000
Ending balance: collectively evaluated for impairment	3,318,310,000								3,318,310,000
Ending balance: PCD loans evaluated for impairment	0								0
PPP loans not evaluated for impairment	0								0
Commercial and multifamily | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjustment | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				(1,949,000)					(1,949,000)
Ending Balance					(1,949,000)					(1,949,000)
Commercial and multifamily | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjusted Balance | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				31,056,000					31,056,000
Ending Balance					31,056,000					31,056,000
Commercial | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				6,010,000				4,891,000	6,010,000	4,891,000
Charge-offs										(4,213,000)
Recoveries										414,000
Provisions (credit)										4,918,000
Ending Balance					6,010,000					6,010,000	4,891,000
Originated Loans Net
Ending balance: individually evaluated for impairment					66,000					66,000
Ending balance: collectively evaluated for impairment					5,944,000					5,944,000
Loans held-for-investment, net	808,597,000				717,566,000				808,597,000	717,566,000
Ending balance: individually evaluated for impairment					10,650,000					10,650,000
Ending balance: collectively evaluated for impairment					706,916,000					706,916,000
PPP loans not evaluated for impairment					0					0
Multifamily | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				26,995,000				20,203,000	26,995,000	20,203,000
Charge-offs										0
Recoveries										0
Provisions (credit)										6,792,000
Ending Balance					26,995,000					26,995,000	20,203,000
Originated Loans Net
Ending balance: individually evaluated for impairment					0					0
Ending balance: collectively evaluated for impairment					26,995,000					26,995,000
Loans held-for-investment, net	2,518,065,000				2,512,934,000				2,518,065,000	2,512,934,000
Ending balance: individually evaluated for impairment					626,000					626,000
Ending balance: collectively evaluated for impairment					2,512,308,000					2,512,308,000
PPP loans not evaluated for impairment					0					0
One-to-four family residential mortgage | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				207,000				180,000	207,000	180,000
Charge-offs									(21,000)	0
Recoveries									29,000	5,000
Provisions (credit)									(1,903,000)	22,000
Ending Balance	3,545,000				207,000				3,545,000	207,000	180,000
Originated Loans Net
Ending balance: individually evaluated for impairment	2,000				0				2,000	0
Ending balance: collectively evaluated for impairment	3,543,000				207,000				3,543,000	207,000
Ending balance: PCD loans evaluated for impairment	0								0
Loans held-for-investment, net	183,665,000				212,222,000				183,665,000	212,222,000
Ending balance: individually evaluated for impairment	1,562,000				1,903,000				1,562,000	1,903,000
Ending balance: collectively evaluated for impairment	182,103,000				210,319,000				182,103,000	210,319,000
Ending balance: PCD loans evaluated for impairment	0								0
PPP loans not evaluated for impairment	0				0				0	0
One-to-four family residential mortgage | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjustment | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				5,233,000					5,233,000
Ending Balance					5,233,000					5,233,000
One-to-four family residential mortgage | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjusted Balance | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				5,440,000					5,440,000
Ending Balance					5,440,000					5,440,000
Home Equity and Lines of Credit | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				260,000				317,000	260,000	317,000
Charge-offs									0	0
Recoveries									26,000	27,000
Provisions (credit)									(145,000)	(84,000)
Ending Balance	560,000				260,000				560,000	260,000	317,000
Originated Loans Net
Ending balance: individually evaluated for impairment	2,000				3,000				2,000	3,000
Ending balance: collectively evaluated for impairment	558,000				257,000				558,000	257,000
Ending balance: PCD loans evaluated for impairment	0								0
Loans held-for-investment, net	109,956,000				93,137,000				109,956,000	93,137,000
Ending balance: individually evaluated for impairment	38,000				47,000				38,000	47,000
Ending balance: collectively evaluated for impairment	109,918,000				93,090,000				109,918,000	93,090,000
Ending balance: PCD loans evaluated for impairment	0								0
PPP loans not evaluated for impairment	0				0				0	0
Home Equity and Lines of Credit | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjustment | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				419,000					419,000
Ending Balance					419,000					419,000
Home Equity and Lines of Credit | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjusted Balance | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				679,000					679,000
Ending Balance					679,000					679,000
Construction and Land | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				1,214,000				$ 536,000	1,214,000	536,000
Charge-offs									0	0
Recoveries									0	0
Provisions (credit)									(124,000)	678,000
Ending Balance	169,000				1,214,000				169,000	1,214,000	$ 536,000
Originated Loans Net
Ending balance: individually evaluated for impairment	0				0				0	0
Ending balance: collectively evaluated for impairment	169,000				1,214,000				169,000	1,214,000
Ending balance: PCD loans evaluated for impairment	0								0
Loans held-for-investment, net	27,495,000				74,351,000				27,495,000	74,351,000
Ending balance: individually evaluated for impairment	0				0				0	0
Ending balance: collectively evaluated for impairment	27,495,000				74,351,000				27,495,000	74,351,000
Ending balance: PCD loans evaluated for impairment	0								0
PPP loans not evaluated for impairment	$ 0				0				0	0
Construction and Land | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjustment | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				(921,000)					(921,000)
Ending Balance					(921,000)					(921,000)
Construction and Land | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Cumulative Effect, Period of Adoption, Adjusted Balance | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				$ 293,000					$ 293,000
Ending Balance					$ 293,000					$ 293,000

X

- Definition

Financing Receivable, Allowance for Credit Losses, PCD Loans Evaluated for Impairment

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No definition available.

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Financing Receivable, Not Evaluated For Impairment

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Financing Receivables, PCD Loans Evaluated For Impairment

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Originated loans, net.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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-Publisher FASB
-Name Accounting Standards Codification
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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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Amount of increase in allowance for credit loss on financing receivable from recovery.

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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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