Securities - Amortized Cost and Fair Value and Allowance for Credit Loss on Securities Held-to-Maturity (Details) - USD ($) $ in Thousands		Dec. 31, 2025	Mar. 31, 2025		Dec. 31, 2024	Jun. 30, 2024		Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost		$ 781,760	$ 781,760	[1]		$ 690,837	[1]
Unrealized gains			8,004			4,604
Unrealized losses			54,072			65,200
Fair value		$ 735,692	735,692			630,241
Allowance			422		$ 439	483		$ 498	$ 485	$ 0
Net carrying value			781,338			690,354
U.S. Treasury Securities [Member]
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost	[1]		20,836			23,785
Unrealized gains			0			0
Unrealized losses			1,036			1,749
Fair value			19,800			22,036
Allowance			0			0
Net carrying value			20,836			23,785
State and Political Subdivisions [Member]
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost	[1]		459,108			450,343
Unrealized gains			7,029			4,541
Unrealized losses			35,414			40,235
Fair value			430,723			414,649
Allowance			41			44
Net carrying value			459,067			450,299
Mortgage-backed Securities-Residential [Member]
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost	[1]		135,874			48,033
Unrealized gains			916			51
Unrealized losses			2,670			3,314
Fair value			134,120			44,770
Allowance			0			0
Net carrying value			135,874			48,033
Mortgage-backed Securities-Multi-family [Member]
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost	[1]		139,845			143,363
Unrealized gains			0			0
Unrealized losses			13,242			17,397
Fair value			126,603			125,966
Allowance			0			0
Net carrying value			139,845			143,363
Corporate Debt Securities [Member]
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost	[1]		26,068			25,282
Unrealized gains			59			12
Unrealized losses			1,710			2,505
Fair value			24,417			22,789
Allowance			380			438
Net carrying value			25,688			24,844
Other Securities [Member]
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost	[1]		29			31
Unrealized gains			0			0
Unrealized losses			0			0
Fair value			29			31
Allowance			1			1
Net carrying value			$ 28			$ 30

[1] Amortized cost excludes accrued interest receivable of $6.0 million and $4.1 million at March 31, 2025 and June 30, 2024, respectively, which is included in accrued interest receivable in the consolidated statements of financial condition.