Commitments and Contingent Liabilities (Details) - USD ($) $ in Thousands			12 Months Ended
	Jun. 30, 2030	Jun. 30, 2025	Dec. 31, 2022
Guarantor Obligations [Line Items]
Within one year			$ 9,422,731
One to three years			400,858
Three to five years			13,643
Over five years			14,872
Total			9,852,104
Deposits Without a Stated Maturity
Guarantor Obligations [Line Items]
Within one year			7,929,683
One to three years			0
Three to five years			0
Over five years			0
Total			7,929,683
Time Deposits
Guarantor Obligations [Line Items]
Within one year			463,393
One to three years			310,218
Three to five years			6,758
Over five years			3,130
Total			783,499
Borrowed Funds
Guarantor Obligations [Line Items]
Within one year			1,010,101
One to three years			69,794
Three to five years			0
Over five years			0
Total			1,079,895
Operating Lease Obligations
Guarantor Obligations [Line Items]
Within one year			6,916
One to three years			12,198
Three to five years			4,717
Over five years			5,436
Total			29,267
Outside Data Processing
Guarantor Obligations [Line Items]
Within one year			3,600
One to three years			1,625
Three to five years			0
Over five years			0
Total			5,225
George Mason Sponsorship
Guarantor Obligations [Line Items]
Within one year			675
One to three years			1,363
Three to five years			1,400
Over five years			5,375
Total			8,813
George Mason Sponsorship | Termination Option One
Guarantor Obligations [Line Items]
Increase (decrease) in contractual obligation, termination option			$ (3,500)
George Mason Sponsorship | Termination Option One | Minimum
Guarantor Obligations [Line Items]
Contractual obligation, option period			11 years
George Mason Sponsorship | Termination Option One | Maximum
Guarantor Obligations [Line Items]
Contractual obligation, option period			15 years
George Mason Sponsorship | Termination Option Two
Guarantor Obligations [Line Items]
Increase (decrease) in contractual obligation, termination option			$ (3,600)
George Mason Sponsorship | Termination Option Two | Minimum
Guarantor Obligations [Line Items]
Contractual obligation, option period			16 years
George Mason Sponsorship | Termination Option Two | Maximum
Guarantor Obligations [Line Items]
Contractual obligation, option period			20 years
George Mason Sponsorship | Forecast
Guarantor Obligations [Line Items]
Option to terminate	15 years	10 years
LIHTC Investments
Guarantor Obligations [Line Items]
Within one year			$ 6,363
One to three years			5,660
Three to five years			768
Over five years			931
Total			13,722
Other Investments
Guarantor Obligations [Line Items]
Within one year			2,000
One to three years			0
Three to five years			0
Over five years			0
Total			$ 2,000