Deposits - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2022	Dec. 31, 2021
Statistical Disclosure for Banks [Abstract]
Time deposits with a denomination of $250,000 or more	$ 1,600	$ 593
California \| Deposits \| Geographic Concentration Risk
Deposit Liability [Line Items]
Concentration risk, percentage	41.20%
North Carolina \| Deposits \| Geographic Concentration Risk
Deposit Liability [Line Items]
Concentration risk, percentage	29.20%	50.80%
South Carolina \| Deposits \| Geographic Concentration Risk
Deposit Liability [Line Items]
Concentration risk, percentage	13.10%	22.70%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
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