Stockholders' Equity - Narrative (Details) $ / shares in Units, $ in Millions		3 Months Ended
	Jan. 03, 2022	Mar. 31, 2022 shares	Mar. 12, 2020 USD ($) $ / shares shares
Class of Stock [Line Items]
Depositary shares, shares issued (in shares)			13,800,000
Depository Shares, percentage of preferred stock			0.025
Depository shares, equivalent value per preferred share | $ / shares			$ 1,000
Depositary shares, shares issued, value | $			$ 345
CIT Group Inc.
Class of Stock [Line Items]
Common stock issuance - CIT Merger (in shares)		6,000,000
Class A Common Stock
Class of Stock [Line Items]
Common stock, voting right per share		1
Common stock issuance - CIT Merger (in shares)		6,140,010
Class A Common Stock | CIT Group Inc.
Class of Stock [Line Items]
Common stock, terms of conversion, conversion ratio	0.062
Class B Common Stock
Class of Stock [Line Items]
Common stock, voting right per share		16
Common stock issuance - CIT Merger (in shares)		0
Depositary Shares, Each Representing a 1/40th Interest in a Share of 5.375% Non-Cumulative Perpetual Preferred Stock, Series A
Class of Stock [Line Items]
Dividend		5.375%
Series B Preferred Stock
Class of Stock [Line Items]
Dividend		5.80%
Series B Preferred Stock | CIT Group Inc.
Class of Stock [Line Items]
Dividend	5.625%
Common stock, terms of conversion, conversion ratio	1
Series C Preferred Stock
Class of Stock [Line Items]
Dividend		5.625%
Series C Preferred Stock | CIT Group Inc.
Class of Stock [Line Items]
Common stock, terms of conversion, conversion ratio	1