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Securities - Amortized Cost and Estimated Fair Value of Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Available for sale:
Available for sale, amortized cost	$ 1,497,458	$ 971,595
Available for sale, gross unrealized gains	21,896	33,972
Available for sale, gross unrealized losses	(14,626)	(893)
Available for sale, fair value	1,504,728	1,004,674
Available for sale, allowance for credit losses	0	0
Available-for-sale, net carrying amount	1,504,728	1,004,674
Held to maturity:
Held to maturity, fair value	25,117	41,205
Held to maturity, allowance for credit losses	(167)	(66)	$ 0
Held to maturity, net carrying amount	22,767	38,128
Securities carried at fair value through income:
Securities carried at fair value through income, fair value	7,497	11,554
State and municipal securities
Available for sale:
Available for sale, amortized cost	394,046	420,559
Available for sale, gross unrealized gains	14,095	21,884
Available for sale, gross unrealized losses	(2,323)	(258)
Available for sale, fair value	405,818	442,185
Available for sale, allowance for credit losses	0	0
Available-for-sale, net carrying amount	405,818	442,185
Held to maturity:
Held to maturity, amortized cost	22,934	38,194
Held to maturity, gross unrealized gains	2,183	3,011
Held to maturity, gross unrealized losses	0	0
Held to maturity, fair value	25,117	41,205
Held to maturity, allowance for credit losses	(167)	(66)
Held to maturity, net carrying amount	22,767	38,128
Securities carried at fair value through income:
Securities carried at fair value through income, amortized cost	7,375	10,618
Securities carried at fair value through income, fair value	7,497	11,554
Securities carried at fair value through income, net carrying amount	7,497	11,554
Corporate bonds
Available for sale:
Available for sale, amortized cost	80,498	64,313
Available for sale, gross unrealized gains	2,509	1,762
Available for sale, gross unrealized losses	(273)	(137)
Available for sale, fair value	82,734	65,938
Available for sale, allowance for credit losses	0	0
Available-for-sale, net carrying amount	82,734	65,938
U.S. government and agency securities
Available for sale:
Available for sale, amortized cost	98,892	851
Available for sale, gross unrealized gains	2	3
Available for sale, gross unrealized losses	(1,236)	(5)
Available for sale, fair value	97,658	849
Available for sale, allowance for credit losses	0	0
Available-for-sale, net carrying amount	97,658	849
Commercial mortgage-backed securities
Available for sale:
Available for sale, amortized cost	65,691	10,814
Available for sale, gross unrealized gains	0	266
Available for sale, gross unrealized losses	(1,448)	0
Available for sale, fair value	64,243	11,080
Available for sale, allowance for credit losses	0	0
Available-for-sale, net carrying amount	64,243	11,080
Residential mortgage-backed securities
Available for sale:
Available for sale, amortized cost	559,655	207,742
Available for sale, gross unrealized gains	3,751	7,441
Available for sale, gross unrealized losses	(5,605)	(232)
Available for sale, fair value	557,801	214,951
Available for sale, allowance for credit losses	0	0
Available-for-sale, net carrying amount	557,801	214,951
Commercial collateralized mortgage obligations
Available for sale:
Available for sale, amortized cost	20,000
Available for sale, gross unrealized gains	2
Available for sale, gross unrealized losses	(330)
Available for sale, fair value	19,672
Available for sale, allowance for credit losses	0
Available-for-sale, net carrying amount	19,672
Residential collateralized mortgage obligations
Available for sale:
Available for sale, amortized cost	196,691	193,865
Available for sale, gross unrealized gains	460	1,739
Available for sale, gross unrealized losses	(3,411)	(261)
Available for sale, fair value	193,740	195,343
Available for sale, allowance for credit losses	0	0
Available-for-sale, net carrying amount	193,740	195,343
Asset-backed securities
Available for sale:
Available for sale, amortized cost	81,985	73,451
Available for sale, gross unrealized gains	1,077	877
Available for sale, gross unrealized losses	0	0
Available for sale, fair value	83,062	74,328
Available for sale, allowance for credit losses	0	0
Available-for-sale, net carrying amount	$ 83,062	$ 74,328

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