Fair Value Measurements (Details 2) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair value measurements
Investment securities available-for-sale	$ 1,622,600	$ 1,775,128
Assets:
Mortgages held for sale	1,442	3,914
U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	922,866	998,598
U.S. States and political subdivisions securities
Fair value measurements
Investment securities available-for-sale	92,564	122,762
Mortgage-backed securities - Federal agencies
Fair value measurements
Investment securities available-for-sale	598,252	637,058
Corporate debt securities
Fair value measurements
Investment securities available-for-sale	8,329	16,131
Foreign government and other securities
Fair value measurements
Investment securities available-for-sale	589	579
Total
Fair value measurements
Investment securities available-for-sale	1,622,600	1,775,128
Assets:
Mortgages held for sale	1,442	3,914
Level 1
Fair value measurements
Investment securities available-for-sale	541,461	573,679
Assets:
Mortgages held for sale	0	0
Level 2
Fair value measurements
Investment securities available-for-sale	1,079,978	1,199,985
Assets:
Mortgages held for sale	1,442	3,914
Level 3
Fair value measurements
Investment securities available-for-sale	1,161	1,464
Assets:
Mortgages held for sale	0	0
Recurring \| Total
Fair value measurements
Investment securities available-for-sale	1,622,600	1,775,128
Assets:
Mortgages held for sale	1,442	3,914
Accrued income and other assets	22,704	24,838
Total	1,646,746	1,803,880
Liabilities:
Accrued expenses and other liabilities	23,140	25,307
Total	23,140	25,307
Recurring \| Total \| U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	922,866	998,598
Recurring \| Total \| U.S. States and political subdivisions securities
Fair value measurements
Investment securities available-for-sale	92,564	122,762
Recurring \| Total \| Mortgage-backed securities - Federal agencies
Fair value measurements
Investment securities available-for-sale	598,252	637,058
Recurring \| Total \| Corporate debt securities
Fair value measurements
Investment securities available-for-sale	8,329	16,131
Recurring \| Total \| Foreign government and other securities
Fair value measurements
Investment securities available-for-sale	589	579
Recurring \| Level 1
Fair value measurements
Investment securities available-for-sale	541,461	573,679
Assets:
Mortgages held for sale	0	0
Accrued income and other assets	0	0
Total	541,461	573,679
Liabilities:
Accrued expenses and other liabilities	0	0
Total	0	0
Recurring \| Level 1 \| U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	541,461	573,679
Recurring \| Level 1 \| U.S. States and political subdivisions securities
Fair value measurements
Investment securities available-for-sale	0	0
Recurring \| Level 1 \| Mortgage-backed securities - Federal agencies
Fair value measurements
Investment securities available-for-sale	0	0
Recurring \| Level 1 \| Corporate debt securities
Fair value measurements
Investment securities available-for-sale	0	0
Recurring \| Level 1 \| Foreign government and other securities
Fair value measurements
Investment securities available-for-sale	0	0
Recurring \| Level 2
Fair value measurements
Investment securities available-for-sale	1,079,978	1,199,985
Assets:
Mortgages held for sale	1,442	3,914
Accrued income and other assets	22,704	24,838
Total	1,104,124	1,228,737
Liabilities:
Accrued expenses and other liabilities	23,140	25,307
Total	23,140	25,307
Recurring \| Level 2 \| U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	381,405	424,919
Recurring \| Level 2 \| U.S. States and political subdivisions securities
Fair value measurements
Investment securities available-for-sale	91,403	121,298
Recurring \| Level 2 \| Mortgage-backed securities - Federal agencies
Fair value measurements
Investment securities available-for-sale	598,252	637,058
Recurring \| Level 2 \| Corporate debt securities
Fair value measurements
Investment securities available-for-sale	8,329	16,131
Recurring \| Level 2 \| Foreign government and other securities
Fair value measurements
Investment securities available-for-sale	589	579
Recurring \| Level 3
Fair value measurements
Investment securities available-for-sale	1,161	1,464
Assets:
Mortgages held for sale	0	0
Accrued income and other assets	0	0
Total	1,161	1,464
Liabilities:
Accrued expenses and other liabilities	0	0
Total	0	0
Recurring \| Level 3 \| U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	0	0
Recurring \| Level 3 \| U.S. States and political subdivisions securities
Fair value measurements
Investment securities available-for-sale	1,161	1,464
Recurring \| Level 3 \| Mortgage-backed securities - Federal agencies
Fair value measurements
Investment securities available-for-sale	0	0
Recurring \| Level 3 \| Corporate debt securities
Fair value measurements
Investment securities available-for-sale	0	0
Recurring \| Level 3 \| Foreign government and other securities
Fair value measurements
Investment securities available-for-sale	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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