Borrowed Funds - Additional Information (Details)		12 Months Ended
	Nov. 04, 2002 USD ($) Age $ / shares shares	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Accrued interest		$ 18,000,000	$ 19,000,000
Interest expense		286,000,000	302,000,000	$ 318,000,000
Federal funds purchased outstanding amount		0	0
Federal funds purchased, average balance		$ 81,000,000	$ 180,000,000
Federal fund purchased Weighted average interest rate		0.09%	0.49%
Federal fund purchased, interest expenses		$ 0	$ 1,000,000	0
Junior subordinated debentures		361,000,000	360,000,000
Gross proceeds of BONUSES, debt		2,072,000,000	6,925,000,000	4,786,000,000
Subordinated notes outstanding		296,000,000	296,000,000
Interest expense on subordinated notes		18,000,000	18,000,000	18,000,000
Repurchase Agreements
Debt Instrument [Line Items]
Accrued interest		2,000,000	2,000,000
Interest expense		18,000,000	18,000,000	18,000,000
Short-term debt outstanding amount		0	0
Federal Home Loan Bank Advances
Debt Instrument [Line Items]
Interest expense		233,000,000	246,000,000	259,000,000
BONUSESSM units | New York Community Capital Trust V (BONUSESSM Units)
Debt Instrument [Line Items]
Public offering of Bifurcated Option Note Unit Securities ("BONUSES units") | shares	5,500,000
Public offering of units, offering price per share | $ / shares	$ 50.00
Warrants and capital securities non-callable period	5 years
Gross proceeds of BONUSES, debt	$ 275,000,000.0
Difference between the assigned value and the stated liquidation amount of the capital securities is treated as an original issue discount	$ 92,400,000
Original issue discount amortized amount		65,000,000
BONUSESSM units | New York Community Capital Trust V (BONUSESSM Units) | Capital Units
Debt Instrument [Line Items]
Warrant to purchase, number of shares | Age	2.4953
Warrant to purchase, total number of shares | shares	13,700,000
Warrant to purchase, exercise price per share | $ / shares	$ 20.04
Capital security, term (in years)	49 years
Capital security, coupon or distribution rate	6.00%
Capital security, per share liquidation amount | $ / shares	$ 50.00
Gross proceeds of BONUSES	$ 182,600,000
BONUSESSM units | New York Community Capital Trust V (BONUSESSM Units) | Warrant
Debt Instrument [Line Items]
Gross proceeds of BONUSES	$ 92,400,000
Junior Subordinated Debt
Debt Instrument [Line Items]
Interest expense		18,000,000	19,000,000	$ 22,000,000
FHLB - NY
Debt Instrument [Line Items]
Unused line of credit		8,400,000,000	7,300,000,000
Overnight FHLB advances		0	0
Line of credit, average balance		$ 6,000,000	$ 2,000,000
Line of credit, weighted average interest rate		0.36%	1.20%