Fair Value Measurements (Details 2) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair value measurements
Investment securities available-for-sale	$ 1,083,427	$ 1,040,583
Assets:
Mortgages held for sale	20,990	20,277
U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	568,008	526,964
U.S. States and political subdivisions securities
Fair value measurements
Investment securities available-for-sale	68,733	84,505
Mortgage-backed securities - Federal agencies
Fair value measurements
Investment securities available-for-sale	403,490	375,389
Corporate debt securities
Fair value measurements
Investment securities available-for-sale	42,496	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	1,083,427	1,040,583
Assets:
Mortgages held for sale	20,990	20,277
Level 1
Fair value measurements
Investment securities available-for-sale	76,298	80,393
Assets:
Mortgages held for sale	0	0
Level 2
Fair value measurements
Investment securities available-for-sale	1,003,864	957,898
Assets:
Mortgages held for sale	20,990	20,277
Level 3
Fair value measurements
Investment securities available-for-sale	3,265	2,292
Assets:
Mortgages held for sale	0	0
Recurring basis \| Total
Fair value measurements
Investment securities available-for-sale	1,083,427	1,040,583
Assets:
Mortgages held for sale	20,990	20,277
Total	1,157,444	1,082,835
Liabilities:
Total	53,988	22,352
Recurring basis \| Total \| Interest rate swap contracts
Assets:
Accrued income and other assets	53,027	21,975
Liabilities:
Accrued expenses and other liabilities	53,988	22,352
Recurring basis \| Total \| U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	568,008	526,964
Recurring basis \| Total \| U.S. States and political subdivisions securities
Fair value measurements
Investment securities available-for-sale	68,733	84,505
Recurring basis \| Total \| Mortgage-backed securities - Federal agencies
Fair value measurements
Investment securities available-for-sale	403,490	375,389
Recurring basis \| Total \| Corporate debt securities
Fair value measurements
Investment securities available-for-sale	42,496	53,025
Recurring basis \| Total \| Foreign government and other securities
Fair value measurements
Investment securities available-for-sale	700	700
Recurring basis \| Level 1
Fair value measurements
Investment securities available-for-sale	76,298	80,393
Assets:
Mortgages held for sale	0	0
Total	76,298	80,393
Liabilities:
Total	0	0
Recurring basis \| Level 1 \| Interest rate swap contracts
Assets:
Accrued income and other assets	0	0
Liabilities:
Accrued expenses and other liabilities	0	0
Recurring basis \| Level 1 \| U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	76,298	80,393
Recurring basis \| Level 1 \| U.S. States and political subdivisions securities
Fair value measurements
Investment securities available-for-sale	0	0
Recurring basis \| Level 1 \| Mortgage-backed securities - Federal agencies
Fair value measurements
Investment securities available-for-sale	0	0
Recurring basis \| Level 1 \| Corporate debt securities
Fair value measurements
Investment securities available-for-sale	0	0
Recurring basis \| Level 1 \| Foreign government and other securities
Fair value measurements
Investment securities available-for-sale	0	0
Recurring basis \| Level 2
Fair value measurements
Investment securities available-for-sale	1,003,864	957,898
Assets:
Mortgages held for sale	20,990	20,277
Total	1,077,881	1,000,150
Liabilities:
Total	53,988	22,352
Recurring basis \| Level 2 \| Interest rate swap contracts
Assets:
Accrued income and other assets	53,027	21,975
Liabilities:
Accrued expenses and other liabilities	53,988	22,352
Recurring basis \| Level 2 \| U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	491,710	446,571
Recurring basis \| Level 2 \| U.S. States and political subdivisions securities
Fair value measurements
Investment securities available-for-sale	65,468	82,213
Recurring basis \| Level 2 \| Mortgage-backed securities - Federal agencies
Fair value measurements
Investment securities available-for-sale	403,490	375,389
Recurring basis \| Level 2 \| Corporate debt securities
Fair value measurements
Investment securities available-for-sale	42,496	53,025
Recurring basis \| Level 2 \| Foreign government and other securities
Fair value measurements
Investment securities available-for-sale	700	700
Recurring basis \| Level 3
Fair value measurements
Investment securities available-for-sale	3,265	2,292
Assets:
Mortgages held for sale	0	0
Total	3,265	2,292
Liabilities:
Total	0	0
Recurring basis \| Level 3 \| Interest rate swap contracts
Assets:
Accrued income and other assets	0	0
Liabilities:
Accrued expenses and other liabilities	0	0
Recurring basis \| Level 3 \| U.S. Treasury and Federal agencies securities
Fair value measurements
Investment securities available-for-sale	0	0
Recurring basis \| Level 3 \| U.S. States and political subdivisions securities
Fair value measurements
Investment securities available-for-sale	3,265	2,292
Recurring basis \| Level 3 \| Mortgage-backed securities - Federal agencies
Fair value measurements
Investment securities available-for-sale	0	0
Recurring basis \| Level 3 \| Corporate debt securities
Fair value measurements
Investment securities available-for-sale	0	0
Recurring basis \| 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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