Credit Quality Indicators (Details) - USD ($) $ in Thousands		3 Months Ended
		Jun. 30, 2023	Mar. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		$ 29,503
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		132,533
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		151,934
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		59,692
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		48,981
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		167,891
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		590,534
Loans and Leases Receivable, Net of Deferred Income		590,534	$ 597,896
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff		95
Multifamily
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		3,287
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		54,039
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		53,279
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		29,888
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		18,088
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		20,234
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		178,815
Loans and Leases Receivable, Net of Deferred Income		178,815	179,117
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff		0
Multifamily | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		3,287
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		54,039
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		51,796
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		28,328
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		18,088
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		20,172
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		175,710
Loans and Leases Receivable, Net of Deferred Income			175,981
Multifamily | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		0
Loans and Leases Receivable, Net of Deferred Income			771
Multifamily | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		1,483
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		1,560
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		62
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		3,105
Loans and Leases Receivable, Net of Deferred Income			2,365
Multifamily | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		0
Multifamily | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		0
Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		8,383
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		31,662
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		28,022
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		17,289
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		21,172
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		66,560
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		173,088
Loans and Leases Receivable, Net of Deferred Income		173,088	178,424
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff		0
Commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		8,383
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		31,662
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		28,022
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		17,289
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		21,172
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		61,344
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		167,872
Loans and Leases Receivable, Net of Deferred Income			170,534
Commercial real estate | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		694
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		694
Loans and Leases Receivable, Net of Deferred Income			701
Commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		4,522
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		4,522
Loans and Leases Receivable, Net of Deferred Income			7,189
Commercial real estate | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		0
Commercial real estate | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		0
Business
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		8,454
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		42,152
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		57,054
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		11,037
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		594
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		44,057
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	[1]	163,348
Loans and Leases Receivable, Net of Deferred Income		163,348	166,908	[1]
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff		0
Business | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		8,454
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		42,152
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		49,728
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		11,037
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		401
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		42,070
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		153,842
Loans and Leases Receivable, Net of Deferred Income			154,056
Business | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		7,326
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		16
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		7,342
Loans and Leases Receivable, Net of Deferred Income			5,719
Business | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		193
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		1,971
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		2,164
Loans and Leases Receivable, Net of Deferred Income			7,133
Business | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		0
Business | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		0
One-to-four family
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		1,610
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		3,876
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		13,562
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		1,448
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		9,127
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		35,903
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		65,526
Loans and Leases Receivable, Net of Deferred Income		65,526	65,808
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff		0
One-to-four family | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		1,610
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		3,876
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		13,562
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		1,448
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		9,127
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		31,778
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		61,401
Loans and Leases Receivable, Net of Deferred Income			60,629
One-to-four family | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		4,125
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		4,125
Loans and Leases Receivable, Net of Deferred Income			5,179
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		7,769
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		804
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		17
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		30
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		1,137
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	[2]	9,757
Loans and Leases Receivable, Net of Deferred Income		9,757	7,639	[2]
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff		95
Consumer | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		7,769
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		803
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		17
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		30
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		1,137
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		9,756
Loans and Leases Receivable, Net of Deferred Income			7,639
Consumer | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year		1
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year		0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		$ 1
Loans and Leases Receivable, Net of Deferred Income			$ 0

[1] (1) Includes PPP loans and business overdrafts

[2] 2) Includes personal loans and consumer overdrafts