BORROWINGS - Schedule of Subordinated Debt (Details)	3 Months Ended
Mar. 31, 2021 USD ($)
Debt Instrument [Line Items]
Aggregate Principal Amount Issued	$ 558,000,000
Net Proceeds	560,000,000
Carrying Value	$ 547,000,000
2.20% Senior Notes due February 24, 2023 [Member]
Debt Instrument [Line Items]
Interest Rate	2.20%
Aggregate Principal Amount Issued	$ 300,000,000
Net Proceeds	298,000,000
Carrying Value	$ 299,000,000
4.95% Fixed-To-Floating Rate Subordinated Notes due 2029 [Member]
Debt Instrument [Line Items]
Interest Rate	4.95%
Aggregate Principal Amount Issued	$ 120,000,000
Net Proceeds	118,000,000
Carrying Value	$ 118,000,000
4.875% Subordinated Notes due 2025 [Member]
Debt Instrument [Line Items]
Interest Rate	4.875%
Aggregate Principal Amount Issued	$ 100,000,000
Net Proceeds	98,000,000
Carrying Value	$ 99,000,000
7.625% Subordinated Notes due August 12, 2023 [Member] \| Yadkin Financial Corporation (YDKN) [Member]
Debt Instrument [Line Items]
Interest Rate	7.625%
Aggregate Principal Amount Issued	$ 38,000,000
Net Proceeds	46,000,000
Carrying Value	$ 31,000,000

Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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