Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair value measurement
Securities available-for-sale	$ 1,097,093	$ 1,020,744
US Government Agencies Debt Securities [Member]
Fair value measurement
Securities available-for-sale	98,942	97,814
Mortgage Backed Securities - Residential
Fair value measurement
Securities available-for-sale	449,479	355,121
Mortgage Backed Securities - Commercial
Fair value measurement
Securities available-for-sale	16,248	18,490
Collateralized Mortgage Obligations
Fair value measurement
Securities available-for-sale	183,261	214,160
State and Municipal Obligations
Fair value measurement
Securities available-for-sale	321,243	306,131
Collateralized Debt Obligations
Fair value measurement
Securities available-for-sale	3,328	3,136
Fair Value, Inputs, Level 1 [Member]
Fair value measurement
Securities available-for-sale	0	0
Fair Value, Inputs, Level 1 [Member] | US Government Agencies Debt Securities [Member]
Fair value measurement
Securities available-for-sale	0	0
Fair Value, Inputs, Level 1 [Member] | Mortgage Backed Securities - Residential
Fair value measurement
Securities available-for-sale	0	0
Fair Value, Inputs, Level 1 [Member] | Mortgage Backed Securities - Commercial
Fair value measurement
Securities available-for-sale	0	0
Fair Value, Inputs, Level 1 [Member] | Collateralized Mortgage Obligations
Fair value measurement
Securities available-for-sale	0	0
Fair Value, Inputs, Level 1 [Member] | State and Municipal Obligations
Fair value measurement
Securities available-for-sale	0	0
Fair Value, Inputs, Level 1 [Member] | Collateralized Debt Obligations
Fair value measurement
Securities available-for-sale	0	0
Fair Value, Inputs, Level 2 [Member]
Fair value measurement
Securities available-for-sale	1,091,870	1,015,713
Derivative Assets	1,451	2,465
Derivative Liability	(1,451)	(2,465)
Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member]
Fair value measurement
Securities available-for-sale	98,942	97,814
Fair Value, Inputs, Level 2 [Member] | Mortgage Backed Securities - Residential
Fair value measurement
Securities available-for-sale	449,479	355,121
Fair Value, Inputs, Level 2 [Member] | Mortgage Backed Securities - Commercial
Fair value measurement
Securities available-for-sale	16,248	18,490
Fair Value, Inputs, Level 2 [Member] | Collateralized Mortgage Obligations
Fair value measurement
Securities available-for-sale	183,261	214,160
Fair Value, Inputs, Level 2 [Member] | State and Municipal Obligations
Fair value measurement
Securities available-for-sale	319,348	304,236
Fair Value, Inputs, Level 2 [Member] | Collateralized Debt Obligations
Fair value measurement
Securities available-for-sale	0	0
Fair Value, Inputs, Level 3 [Member]
Fair value measurement
Securities available-for-sale	5,223	5,031
Fair Value, Inputs, Level 3 [Member] | US Government Agencies Debt Securities [Member]
Fair value measurement
Securities available-for-sale	0	0
Fair Value, Inputs, Level 3 [Member] | Mortgage Backed Securities - Residential
Fair value measurement
Securities available-for-sale	0	0
Fair Value, Inputs, Level 3 [Member] | Mortgage Backed Securities - Commercial
Fair value measurement
Securities available-for-sale	0	0
Fair Value, Inputs, Level 3 [Member] | Collateralized Mortgage Obligations
Fair value measurement
Securities available-for-sale	0	0
Fair Value, Inputs, Level 3 [Member] | State and Municipal Obligations
Fair value measurement
Securities available-for-sale	1,895	1,895
Fair Value, Inputs, Level 3 [Member] | Collateralized Debt Obligations
Fair value measurement
Securities available-for-sale	$ 3,328	$ 3,136