Fair Values of Assets and Liabilities - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2022		Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	$ 15,456		$ 12,838
Loans Held for Sale	13,811		18,583
Other Assets	73,777	[1]	41,786	[2]
Total Assets	890,459		1,114,587
Other Liabilities	96,948	[1]	34,263	[2]
Total Liabilities	96,948		34,263
Investments, Fair Value Disclosure	787,415		1,041,380
Limited Partnership Investment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets	16,598		14,981
US Government Agencies Residential Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	4,289		5,662
US Government Agency Debt Securities Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	283,253		362,290
Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	461,513		629,974
Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	873		981
Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	8,172		9,524
Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	29,315		32,949
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0		0
Loans Held for Sale	0		0
Other Assets	0	[1]	0	[2]
Total Assets	0		0
Other Liabilities	0	[1]	0	[2]
Total Liabilities	0		0
Investments, Fair Value Disclosure	0		0
Level 1 [Member] | US Government Agencies Residential Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0		0
Level 1 [Member] | US Government Agency Debt Securities Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0		0
Level 1 [Member] | Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0		0
Level 1 [Member] | Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0		0
Level 1 [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0		0
Level 1 [Member] | Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0		0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	14,286		11,668
Loans Held for Sale	13,811		18,583
Other Assets	57,179	[1]	26,805	[2]
Total Assets	872,691		1,098,436
Other Liabilities	96,948	[1]	34,263	[2]
Total Liabilities	96,948		34,263
Investments, Fair Value Disclosure	787,415		1,041,380
Level 2 [Member] | US Government Agencies Residential Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	4,289		5,662
Level 2 [Member] | US Government Agency Debt Securities Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	283,253		362,290
Level 2 [Member] | Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	461,513		629,974
Level 2 [Member] | Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	873		981
Level 2 [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	8,172		9,524
Level 2 [Member] | Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	29,315		32,949
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	1,170		1,170
Loans Held for Sale	0		0
Other Assets	16,598	[1]	14,981	[2]
Total Assets	17,768		16,151
Other Liabilities	0	[1]	0	[2]
Total Liabilities	0		0
Investments, Fair Value Disclosure	0		0
Level 3 [Member] | US Government Agencies Residential Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0		0
Level 3 [Member] | US Government Agency Debt Securities Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0		0
Level 3 [Member] | Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0		0
Level 3 [Member] | Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0		0
Level 3 [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0		0
Level 3 [Member] | Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	$ 0		$ 0

[1] Hedging and non-hedging interest rate derivatives and limited partnership investments

[2] on-hedging interest rate derivatives and limited partnership investments