Investment Securities (Amortized Cost and Fair Value of Investment Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item]
Securities available for sale, Amortized Cost	$ 1,098,976	$ 607,665
Securities available for sale, Unrealized Gains	11,337	20,462
Securities available for sale, Unrealized Losses	12,363	68
Securities available for sale	1,097,950	628,059
Securities held to maturity, Amortized Cost	218,140	271,973
Securities held to maturity, Unrealized Gains	6,352	10,062
Securities held to maturity, Unrealized Losses	328
Securities held to maturity, fair value	224,164	282,035
Allowance for credit losses, Amortized Cost	(5)	(7)
Held-to-maturity securities, net , Amortized Cost	218,135	271,966
U.S. Government Agency And Government Sponsored Enterprises [Member]
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item]
Securities available for sale, Amortized Cost	6,253	6,239
Securities available for sale, Unrealized Gains	278	396
Securities available for sale	6,531	6,635
State And Political Subdivisions [Member]
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item]
Securities held to maturity, Amortized Cost	116,812	144,506
Securities held to maturity, Unrealized Gains	2,897	4,478
Securities held to maturity, Unrealized Losses	196
Securities held to maturity, fair value	119,513	148,984
Collateralized Mortgage Obligations [Member] \| Federal National Mortgage Association [Member]
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item]
Securities available for sale, Amortized Cost	17,689	3,047
Securities available for sale, Unrealized Gains	67	97
Securities available for sale, Unrealized Losses	132
Securities available for sale	17,624	3,144
Securities held to maturity, Amortized Cost	21,668	29,988
Securities held to maturity, Unrealized Gains	644	1,075
Securities held to maturity, fair value	22,312	31,063
Collateralized Mortgage Obligations [Member] \| Federal Home Loan Mortgage Corporation [Member]
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item]
Securities available for sale, Amortized Cost	16,318
Securities available for sale, Unrealized Losses	128
Securities available for sale	16,190
Securities held to maturity, Amortized Cost	26,125	35,897
Securities held to maturity, Unrealized Gains	894	1,581
Securities held to maturity, fair value	27,019	37,478
Collateralized Mortgage Obligations [Member] \| Government National Mortgage Association [Member]
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item]
Securities held to maturity, Amortized Cost	5,993	7,864
Securities held to maturity, Unrealized Gains	166	265
Securities held to maturity, fair value	6,159	8,129
Collateralized Mortgage Obligations [Member] \| Privately Issued [Member]
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item]
Securities available for sale, Unrealized Gains	420	435
Securities available for sale	420	435
Mortgage-Backed Securities [Member]
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item]
Securities available for sale, Amortized Cost	1,092,723	601,426
Securities available for sale, Unrealized Gains	11,059	20,066
Securities available for sale, Unrealized Losses	12,363	68
Securities available for sale	1,091,419	621,424
Securities held to maturity, Amortized Cost	101,328	127,467
Securities held to maturity, Unrealized Gains	3,455	5,584
Securities held to maturity, Unrealized Losses	132
Securities held to maturity, fair value	104,651	133,051
Mortgage-Backed Securities [Member] \| Federal National Mortgage Association [Member]
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item]
Securities available for sale, Amortized Cost	575,861	350,627
Securities available for sale, Unrealized Gains	8,847	15,549
Securities available for sale, Unrealized Losses	4,973	44
Securities available for sale	579,735	366,132
Securities held to maturity, Amortized Cost	9,535	10,776
Securities held to maturity, Unrealized Gains	539	703
Securities held to maturity, fair value	10,074	11,479
Mortgage-Backed Securities [Member] \| Federal Home Loan Mortgage Corporation [Member]
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item]
Securities available for sale, Amortized Cost	390,062	225,645
Securities available for sale, Unrealized Gains	1,257	3,155
Securities available for sale, Unrealized Losses	6,195	24
Securities available for sale	385,124	228,776
Securities held to maturity, Amortized Cost	8,835	5,858
Securities held to maturity, Unrealized Gains	203	382
Securities held to maturity, Unrealized Losses	132
Securities held to maturity, fair value	8,906	6,240
Mortgage-Backed Securities [Member] \| Government National Mortgage Association [Member]
Schedule of Debt Securities Available For Sale and Held To Maturity Securities [Line Item]
Securities available for sale, Amortized Cost	92,793	22,107
Securities available for sale, Unrealized Gains	468	830
Securities available for sale, Unrealized Losses	935
Securities available for sale	92,326	22,937
Securities held to maturity, Amortized Cost	29,172	37,084
Securities held to maturity, Unrealized Gains	1,009	1,578
Securities held to maturity, fair value	$ 30,181	$ 38,662

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Debt securities available for sale and held to maturity securities.

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Held-to-maturity securities, net.

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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