Borrowings - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)
Borrowings Due October 2023.
Class of Stock [Line Items]
Long-Term Debt, Gross	$ 150.0
Interest rate	5.11%
Other Borrowings Due December 2023
Class of Stock [Line Items]
Long-Term Debt, Gross	$ 150.0
Interest rate	5.69%
Borrowings Due April 2024
Class of Stock [Line Items]
Long-Term Debt, Gross	$ 200.0
Interest rate	4.75%
VRB Subordinated - 6% | Subordinated Debt
Class of Stock [Line Items]
Interest rate	6.00%
Current Coupon Rate	6.00%
VRB Subordinated - 6% | SOFR | Subordinated Debt
Class of Stock [Line Items]
Basis spread on variable rate	3.78%
VRB Subordinated - 5% | Subordinated Debt
Class of Stock [Line Items]
Interest rate	5.00%
Current Coupon Rate	5.00%
VRB Subordinated - 5% | SOFR | Subordinated Debt
Class of Stock [Line Items]
Basis spread on variable rate	4.90%