LONG-TERM BORROWINGS - Schedule of Subordinated Debt (Detail) - USD ($)	3 Months Ended	12 Months Ended
Sep. 30, 2022	Dec. 31, 2022
Debt Instrument [Line Items]
Aggregate Principal Amount Issued		$ 964,000,000
Net Proceeds		963,000,000
Carrying Value		951,000,000
Senior Notes
Debt Instrument [Line Items]
Aggregate Principal Amount Issued		650,000,000
Net Proceeds		645,000,000
Carrying Value		648,000,000
Other Subordinated Debt
Debt Instrument [Line Items]
Aggregate Principal Amount Issued		314,000,000
Net Proceeds		318,000,000
Carrying Value		$ 303,000,000
2.200% Senior Notes due February 24, 2023
Debt Instrument [Line Items]
Interest Rate	2.20%
2.200% Senior Notes due February 24, 2023 \| Senior Notes
Debt Instrument [Line Items]
Interest Rate		2.20%
Aggregate Principal Amount Issued		$ 300,000,000
Net Proceeds		298,000,000
Carrying Value		$ 300,000,000
5.150% Senior Notes due August 25, 2025
Debt Instrument [Line Items]
Interest Rate	5.15%
Aggregate Principal Amount Issued	$ 350,000,000
Net Proceeds	$ 347,400,000
5.150% Senior Notes due August 25, 2025 \| Senior Notes
Debt Instrument [Line Items]
Interest Rate		5.15%
Aggregate Principal Amount Issued		$ 350,000,000
Net Proceeds		347,000,000
Carrying Value		$ 348,000,000
4.950% Fixed-To-Floating Rate Subordinated Notes due 2029 \| Other Subordinated Debt
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
4.950% Fixed-To-Floating Rate Subordinated Notes due 2029 \| LIBOR \| Other Subordinated Debt
Debt Instrument [Line Items]
Basis points		2.40%
4.875% Subordinated Notes due 2025 \| Other Subordinated Debt
Debt Instrument [Line Items]
Interest Rate		4.875%
Aggregate Principal Amount Issued		$ 100,000,000
Net Proceeds		98,000,000
Carrying Value		$ 100,000,000
7.625% Subordinated Notes due August 12, 2013 \| Other Subordinated Debt
Debt Instrument [Line Items]
Interest Rate		7.625%
Aggregate Principal Amount Issued		$ 38,000,000
Net Proceeds		46,000,000
Carrying Value		$ 29,000,000
6.00% Fixed-To-Floating Rate Subordinated Notes due December 6, 2028 \| Other Subordinated Debt
Debt Instrument [Line Items]
Interest Rate		6.00%
Aggregate Principal Amount Issued		$ 25,000,000
Net Proceeds		26,000,000
Carrying Value		$ 25,000,000
6.00% Fixed-To-Floating Rate Subordinated Notes due December 6, 2028 \| LIBOR \| Other Subordinated Debt
Debt Instrument [Line Items]
Basis points		3.02%
5.00% Fixed-To-Floating Rate Subordinated Note due May 29, 2030 \| Other Subordinated Debt
Debt Instrument [Line Items]
Interest Rate		5.00%
Aggregate Principal Amount Issued		$ 25,000,000
Net Proceeds		24,000,000
Carrying Value		$ 24,000,000
5.00% Fixed-To-Floating Rate Subordinated Note due May 29, 2030 \| SOFR \| Other Subordinated Debt
Debt Instrument [Line Items]
Basis points		4.64%
6.00% Fixed-To-Floating Rate Subordinated Note due May 15, 2028 \| Other Subordinated Debt
Debt Instrument [Line Items]
Interest Rate		6.00%
Aggregate Principal Amount Issued		$ 6,000,000
Net Proceeds		6,000,000
Carrying Value		$ 6,000,000
6.00% Fixed-To-Floating Rate Subordinated Note due May 15, 2028 \| LIBOR \| Other Subordinated Debt
Debt Instrument [Line Items]
Basis points		3.50%

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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- Definition

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

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- Definition

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

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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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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The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

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