Securities - Summary of Portfolio of Securities Available for Sale (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022		Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$ 5,612		$ 5,780
Equity Securities, Fair Value	15		16
Total Securities, Amortized Cost	5,978	[1]	5,850	[2]
Total Securities, Gross Unrealized Gain	21	[1]	62	[2]
Total Securities, Gross Unrealized Loss	372	[1]	116	[2]
Total Securities, Fair Value	5,627	[1]	5,796	[2]
Mortgage-Related Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,806		2,819
Gross Unrealized Gain	4		31
Gross Unrealized Loss	194		60
Fair Value	2,616		2,790
Mortgage-Related Securities | GSE Certificates
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,126		1,102
Gross Unrealized Gain	3		20
Gross Unrealized Loss	66		15
Fair Value	1,063		1,107
Mortgage-Related Securities | GSE CMOs
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,680		1,717
Gross Unrealized Gain	1		11
Gross Unrealized Loss	128		45
Fair Value	1,553		1,683
Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,156		3,015
Gross Unrealized Gain	17		31
Gross Unrealized Loss	177		56
Fair Value	2,996		2,990
Debt Securities | U.S. Treasury Obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	144		45
Fair Value	144		45
Debt Securities | GSE Debentures
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,524		1,524
Gross Unrealized Gain	1		1
Gross Unrealized Loss	152		45
Fair Value	1,373		1,480
Debt Securities | Asset-backed Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	461	[3]	479	[4]
Gross Unrealized Gain	1	[3]	3	[4]
Gross Unrealized Loss	6	[3]	3	[4]
Fair Value	456	[3]	479	[4]
Debt Securities | Municipal Bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	25		25
Gross Unrealized Loss	1
Fair Value	24		25
Debt Securities | Corporate Bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	881		821
Gross Unrealized Gain	8		18
Gross Unrealized Loss	11		1
Fair Value	878		838
Debt Securities | Foreign Notes
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	25		25
Gross Unrealized Gain	1		1
Fair Value	26		26
Debt Securities | Capital Trust Notes
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	96		96
Gross Unrealized Gain	6		8
Gross Unrealized Loss	7		7
Fair Value	95		97
Mortgage Backed Securities And Other Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,962		5,834
Gross Unrealized Gain	21		62
Gross Unrealized Loss	371		116
Fair Value	5,612		5,780
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Equity Securities, Amortized Cost	16		16
Equity Securities, Gross Unrealized Loss	1
Equity Securities, Fair Value	15		16
Equity Securities | Mutual Funds
Schedule of Available-for-sale Securities [Line Items]
Equity Securities, Amortized Cost	16		16
Equity Securities, Gross Unrealized Loss	1
Equity Securities, Fair Value	$ 15		$ 16

[1] Excludes accrued interest receivable of $15 million included in other assets in the Consolidated Statements of Condition.

[2] Excludes accrued interest receivable of $15 million included in other assets in the Consolidated Statements of Condition.

[3] The underlying assets of the asset-backed securities are substantially guaranteed by the U.S. Government.

[4] The underlying assets of the asset-backed securities are substantially guaranteed by the U.S. Government.