Fair Value Measurements (Details 2) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair value measurements
Investment securities available-for-sale	$ 1,197,467	$ 1,040,583
Assets:
Mortgages held for sale	12,885	20,277
U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	619,482	526,964
U.S. States and political subdivisions securities
Fair value measurements
Investment securities available-for-sale	81,127	84,505
Mortgage-backed securities - Federal agencies
Fair value measurements
Investment securities available-for-sale	453,789	375,389
Corporate debt securities
Fair value measurements
Investment securities available-for-sale	42,369	53,025
Foreign government and other securities
Fair value measurements
Investment securities available-for-sale	700	700
Total
Fair value measurements
Investment securities available-for-sale	1,197,467	1,040,583
Assets:
Mortgages held for sale	12,885	20,277
Level 1
Fair value measurements
Investment securities available-for-sale	80,285	80,393
Assets:
Mortgages held for sale	0	0
Level 2
Fair value measurements
Investment securities available-for-sale	1,115,030	957,898
Assets:
Mortgages held for sale	12,885	20,277
Level 3
Fair value measurements
Investment securities available-for-sale	2,152	2,292
Assets:
Mortgages held for sale	0	0
Recurring \| Total
Fair value measurements
Investment securities available-for-sale	1,197,467	1,040,583
Assets:
Mortgages held for sale	12,885	20,277
Total	1,257,006	1,082,835
Liabilities:
Total	47,681	22,352
Recurring \| Total \| Interest rate swap contracts
Assets:
Accrued income and other assets	46,654	21,975
Liabilities:
Accrued expenses and other liabilities	47,681	22,352
Recurring \| Total \| U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	619,482	526,964
Recurring \| Total \| U.S. States and political subdivisions securities
Fair value measurements
Investment securities available-for-sale	81,127	84,505
Recurring \| Total \| Mortgage-backed securities - Federal agencies
Fair value measurements
Investment securities available-for-sale	453,789	375,389
Recurring \| Total \| Corporate debt securities
Fair value measurements
Investment securities available-for-sale	42,369	53,025
Recurring \| Total \| Foreign government and other securities
Fair value measurements
Investment securities available-for-sale	700	700
Recurring \| Level 1
Fair value measurements
Investment securities available-for-sale	80,285	80,393
Assets:
Mortgages held for sale	0	0
Total	80,285	80,393
Liabilities:
Total	0	0
Recurring \| Level 1 \| Interest rate swap contracts
Assets:
Accrued income and other assets	0	0
Liabilities:
Accrued expenses and other liabilities	0	0
Recurring \| Level 1 \| U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	80,285	80,393
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	1,115,030	957,898
Assets:
Mortgages held for sale	12,885	20,277
Total	1,174,569	1,000,150
Liabilities:
Total	47,681	22,352
Recurring \| Level 2 \| Interest rate swap contracts
Assets:
Accrued income and other assets	46,654	21,975
Liabilities:
Accrued expenses and other liabilities	47,681	22,352
Recurring \| Level 2 \| U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	539,197	446,571
Recurring \| Level 2 \| U.S. States and political subdivisions securities
Fair value measurements
Investment securities available-for-sale	78,975	82,213
Recurring \| Level 2 \| Mortgage-backed securities - Federal agencies
Fair value measurements
Investment securities available-for-sale	453,789	375,389
Recurring \| Level 2 \| Corporate debt securities
Fair value measurements
Investment securities available-for-sale	42,369	53,025
Recurring \| Level 2 \| Foreign government and other securities
Fair value measurements
Investment securities available-for-sale	700	700
Recurring \| Level 3
Fair value measurements
Investment securities available-for-sale	2,152	2,292
Assets:
Mortgages held for sale	0	0
Total	2,152	2,292
Liabilities:
Total	0	0
Recurring \| Level 3 \| Interest rate swap contracts
Assets:
Accrued income and other assets	0	0
Liabilities:
Accrued expenses and other liabilities	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	2,152	2,292
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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