BORROWINGS - Schedule of Subordinated Debt (Details)	9 Months Ended
Sep. 30, 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	$ 119,000,000
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	$ 30,000,000

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

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