Securities - Amortized Cost and Fair Value and Allowance for Credit Loss on Securities Held-to-Maturity (Details) - USD ($) $ in Thousands		Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost	[1]	$ 771,344		$ 690,837
Unrealized gains		6,580		4,604
Unrealized losses		58,401		65,200
Fair value		719,523		630,241
Allowance		439	$ 466	483	$ 485	$ 498	$ 0
Net carrying value		770,905		690,354
U.S. Treasury Securities [Member]
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost	[1]	23,820		23,785
Unrealized gains		0		0
Unrealized losses		1,335		1,749
Fair value		22,485		22,036
Allowance		0		0
Net carrying value		23,820		23,785
State and Political Subdivisions [Member]
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost	[1]	458,289		450,343
Unrealized gains		6,480		4,541
Unrealized losses		35,267		40,235
Fair value		429,502		414,649
Allowance		42		44
Net carrying value		458,247		450,299
Mortgage-backed Securities-Residential [Member]
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost	[1]	123,544		48,033
Unrealized gains		72		51
Unrealized losses		4,165		3,314
Fair value		119,451		44,770
Allowance		0		0
Net carrying value		123,544		48,033
Mortgage-backed Securities-Multi-family [Member]
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost	[1]	140,306		143,363
Unrealized gains		0		0
Unrealized losses		15,777		17,397
Fair value		124,529		125,966
Allowance		0		0
Net carrying value		140,306		143,363
Corporate Debt Securities [Member]
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost	[1]	25,355		25,282
Unrealized gains		28		12
Unrealized losses		1,857		2,505
Fair value		23,526		22,789
Allowance		396		438
Net carrying value		24,959		24,844
Other Securities [Member]
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost	[1]	30		31
Unrealized gains		0		0
Unrealized losses		0		0
Fair value		30		31
Allowance		1		1
Net carrying value		$ 29		$ 30

[1] Amortized cost excludes accrued interest receivable of $5.2 million and $4.1 million at December 31, 2024 and June 30, 2024, respectively, which is included in accrued interest receivable in the consolidated statements of financial condition.