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Business Combinations - Narrative (Details) |  | 3 Months Ended | 6 Months Ended |
--- | --- | --- | --- | ---
Jan. 03, 2022 USD ($) $ / shares shares | Jun. 30, 2022 USD ($) $ / shares shares | Jun. 30, 2021 USD ($) | Jun. 30, 2022 USD ($) $ / shares shares | Jun. 30, 2021 USD ($) | Dec. 31, 2021 $ / shares
Business Acquisition [Line Items] |  |  |  |  |  |
Preferred stock, par value (in dollars per share) | $ / shares |  | $ 0.01 |  | $ 0.01 |  | $ 0.01
Preferred stock, non-callable period, extended term | 5 years |  |  |  |  |
Gain on acquisition |  | $ 0 |  | $ 431,000,000 | $ 0 |
Pro forma adjustment |  | 255,000,000 | $ 153,000,000 | 526,000,000 | $ 300,000,000 |
CIT Group Inc. |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Business combination, number of fractional shares purchased (in shares) | shares | 8,800 |  |  |  |  |
Business combination, payment to purchase fractional shares | $ 7,000,000 |  |  |  |  |
Consideration for stock-based compensation | 81,000,000 |  |  |  |  |
Gain on acquisition | 431,000,000 |  |  |  |  |
Initial PCD ACL | $ 272,000,000 |  |  |  |  |
Business combination, pro forma information, earnings or loss of acquiree since acquisition date, actual |  |  |  | 266,000,000 |  |
CIT Group Inc. | Provision for Credit Losses |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Pro forma adjustment |  |  |  | 513,000,000 |  |
CIT Group Inc. | Acquisition-related Costs |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Pro forma adjustment |  | $ 34,000,000 |  | 169,000,000 |  |
CIT Group Inc. | Interest income |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Business combination, pro forma information, revenue of acquiree since acquisition date, actual |  |  |  | 728,000,000 |  |
CIT Group Inc. | Noninterest income |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Business combination, pro forma information, revenue of acquiree since acquisition date, actual |  |  |  | $ 607,000,000 |  |
Class A Common Stock |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Common stock, par value (in dollars per share) | $ / shares | $ 1.00 | $ 1 |  | $ 1 |  | $ 1
Class A Common Stock | CIT Group Inc. |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Common stock, terms of conversion, conversion ratio | 0.062 |  |  |  |  |
Business acquisition, equity interest Issued or issuable (in shares) | shares | 6,140,010 |  |  |  |  |
Sale of stock (in dollars per share) | $ / shares | $ 859.76 |  |  |  |  |
Equity consideration | $ 5,279,000,000 |  |  |  |  |
Series A Preferred Stock |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Preferred stock, par value (in dollars per share) | $ / shares |  | $ 0.01 |  | $ 0.01 |  |
Preferred stock, dividend rate |  |  |  | 5.375% |  |
Preferred stock, shares outstanding (in shares) | shares |  | 345,000 |  | 345,000 |  |
Liquidation preference per share (in dollars per share) | $ / shares |  | $ 1,000 |  | $ 1,000 |  |
Total Liquidation Preference |  | $ 345,000,000 |  | $ 345,000,000 |  |
Series B Preferred Stock |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Preferred stock, par value (in dollars per share) | $ / shares |  | $ 0.01 |  | $ 0.01 |  |
Preferred stock, dividend rate |  |  |  | 5.80% |  |
Preferred stock, shares outstanding (in shares) | shares | 325,000 | 325,000 |  | 325,000 |  |
Liquidation preference per share (in dollars per share) | $ / shares | $ 1,000 | $ 1,000 |  | $ 1,000 |  |
Total Liquidation Preference | $ 325,000,000 | $ 325,000,000 |  | $ 325,000,000 |  |
Series C Preferred Stock |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Preferred stock, par value (in dollars per share) | $ / shares |  | $ 0.01 |  | $ 0.01 |  |
Preferred stock, dividend rate |  |  |  | 5.625% |  |
Preferred stock, shares outstanding (in shares) | shares | 8,000,000 | 8,000,000 |  | 8,000,000 |  |
Liquidation preference per share (in dollars per share) | $ / shares | $ 25 | $ 25 |  | $ 25 |  |
Total Liquidation Preference | $ 200,000,000 | $ 200,000,000 |  | $ 200,000,000 |  |
Preferred Stock | CIT Group Inc. |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Equity consideration | $ 541,000,000 |  |  |  |  |
CIT Group Inc. |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Common stock, par value (in dollars per share) | $ / shares | $ 0.01 |  |  |  |  |
CIT Group Inc. | Series A Preferred Stock |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Preferred stock, par value (in dollars per share) | $ / shares | $ 0.01 |  |  |  |  |
CIT Group Inc. | Series B Preferred Stock |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Common stock, terms of conversion, conversion ratio | 1 |  |  |  |  |
Preferred stock, par value (in dollars per share) | $ / shares | $ 0.01 |  |  |  |  |
Preferred stock, dividend rate | 5.625% |  |  |  |  |
CIT Group Inc. | Series C Preferred Stock |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Common stock, terms of conversion, conversion ratio | 1 |  |  |  |  |

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- Definition Value of the difference between preference in liquidation and the par or stated values of the preferred shares. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(d)) -URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 13 -Subparagraph (h) -URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644 + Details
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- Definition Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 13 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644 + Details
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- Definition Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction. + References No definition available. + Details
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