Derivative Financial Instruments - Information about Interest Rate Swap Agreements (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Notional Amount	$ 15,200,000	$ 17,400,000
Average Maturity (in years)	2 years 7 months 6 days	1 year 7 months 6 days
Estimated Fair Value Gain (Loss)	$ 11,250	$ (7,892)
Interest Payments On Variable Rate Commercial Real Estate Loans [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Notional Amount	$ 12,700,000	$ 15,900,000
Average Maturity (in years)	2 years	1 year 4 months 24 days
Weighted-Average Rate, Fixed	3.10%	1.91%
Weighted-Average Rate, Variable	4.82%	4.38%
Estimated Fair Value Gain (Loss)	$ 5,890	$ (7,059)
Fixed Rate Long-Term Borrowings [Member] | Fair Value Hedges [Member]
Derivative [Line Items]
Notional Amount	$ 2,500,000	$ 1,500,000
Average Maturity (in years)	5 years 8 months 12 days	3 years 3 months 18 days
Weighted-Average Rate, Fixed	3.05%	2.98%
Weighted-Average Rate, Variable	5.06%	4.52%
Estimated Fair Value Gain (Loss)	$ 5,360	$ (833)