Supplemental Cash Flow Disclosures - Non-cash Investing and Financing Activities (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash paid during the year for:
Interest	$ 16,396,000	$ 15,624,000	$ 33,964,000
Income taxes	34,326,000	22,374,000	25,914,000
Non-cash investing and financing activities:
Real Estate Owned, Transfer to Real Estate Owned	2,852,000	3,163,000	3,865,000
Fair value of loans transferred from held to maturity to available for sale	61,892,000	73,697,000	37,305,000
Transfer of Loans Held-for-sale to Portfolio Loans	1,485,000	0	4,335,000
Gross (decrease) increase in market value adjustment to securities available for sale	(131,840,000)	(29,908,000)	19,911,000
Gross decrease in market value adjustment to derivatives	(31,574,000)	(3,356,000)	(4,467,000)
Investments Committed to Purchase, Not Yet Paid	0	0	(34,185,000)
Increase in Commitment to Limited Partnership	0	7,565,000	0
Other Significant Noncash Transaction, Consideration Received	1,973,000	0	(384,000)
Treasury stock reissued	$ 1,947,000	$ 2,042,000	$ 1,594,000