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Investment Securities Available-For-Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Contractual maturities of investments in debt securities available-for-sale, Amortized Cost
Due in one year or less	$ 105,859
Due after one year through five years	948,501
Due after five years through ten years	157,760
Due after ten years	470
Mortgage-backed securities	663,441
Total debt securities available-for-sale	1,876,031	$ 1,173,268
Contractual maturities of investments in debt securities available-for-sale, Fair Value
Due in one year or less	106,732
Due after one year through five years	940,267
Due after five years through ten years	155,850
Due after ten years	465
Mortgage-backed securities	659,727
Total debt securities available-for-sale	1,863,041	1,197,467
Accrued interest receivable on investment securities available-for-sale	4,800	3,840
U.S. Treasury and Federal agencies securities
Contractual maturities of investments in debt securities available-for-sale, Amortized Cost
Total debt securities available-for-sale	1,093,780	610,195
Contractual maturities of investments in debt securities available-for-sale, Fair Value
Total debt securities available-for-sale	1,084,006	619,482
U.S. States and political subdivisions securities
Contractual maturities of investments in debt securities available-for-sale, Amortized Cost
Total debt securities available-for-sale	95,700	78,812
Contractual maturities of investments in debt securities available-for-sale, Fair Value
Total debt securities available-for-sale	95,701	81,127
Mortgage-backed securities - Federal agencies
Contractual maturities of investments in debt securities available-for-sale, Amortized Cost
Total debt securities available-for-sale	663,441	442,748
Contractual maturities of investments in debt securities available-for-sale, Fair Value
Total debt securities available-for-sale	659,727	453,789
Corporate debt securities
Contractual maturities of investments in debt securities available-for-sale, Amortized Cost
Total debt securities available-for-sale	22,510	40,813
Contractual maturities of investments in debt securities available-for-sale, Fair Value
Total debt securities available-for-sale	23,009	42,369
Foreign government and other securities
Contractual maturities of investments in debt securities available-for-sale, Amortized Cost
Total debt securities available-for-sale	600	700
Contractual maturities of investments in debt securities available-for-sale, Fair Value
Total debt securities available-for-sale	$ 598	$ 700

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