Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	$ 1,242,760	$ 977,830
Unrealized Gains	35,201	43,354
Unrealized Losses	(7,141)	(440)
Fair Value	1,270,820	1,020,744
US Government Agencies Debt Securities [Member]
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	115,492	92,710
Unrealized Gains	3,965	5,105
Unrealized Losses	(366)	(1)
Fair Value	119,091	97,814
Mortgage Backed Securities - Residential
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	574,048	346,606
Unrealized Gains	6,056	8,794
Unrealized Losses	(5,165)	(279)
Fair Value	574,939	355,121
Mortgage Backed Securities - Commercial
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	15,591	17,931
Unrealized Gains	336	559
Unrealized Losses	0	0
Fair Value	15,927	18,490
Collateralized Mortgage Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	160,643	209,556
Unrealized Gains	2,397	4,761
Unrealized Losses	(772)	(157)
Fair Value	162,268	214,160
State and Municipal Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	345,263	285,837
Unrealized Gains	18,664	20,294
Unrealized Losses	(770)	0
Fair Value	363,157	306,131
Taxable Municipal Bonds
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	31,067	22,440
Unrealized Gains	539	702
Unrealized Losses	(68)	(3)
Fair Value	31,538	23,139
US Treasury Securities
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	656	2,750
Unrealized Gains	0	3
Unrealized Losses	0	0
Fair Value	656	2,753
Collateralized Debt Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	0	0
Unrealized Gains	3,244	3,136
Unrealized Losses	0	0
Fair Value	$ 3,244	$ 3,136