Loans and Leases - Quality of Loans Held for Investment (Details) - USD ($) $ in Millions		Mar. 31, 2022		Dec. 31, 2021		Mar. 31, 2021
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans Receivable	[1]	$ 46,703		$ 45,681
Multi-Family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans Receivable		35,751		34,603
Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans Receivable		6,701		6,698
One-to-Four Family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans Receivable		145		160
Acquisition, Development, and Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans Receivable		237		209
Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual Loans						$ 2
Total Loans Receivable	[3]	3,863	[2]	4,006	[4]
Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans Receivable		6		5
Non-Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual Loans		63		33
Total Loans Receivable		46,703		45,681
Non-Covered Loans | Financing Receivable, 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		34		67
Non-Covered Loans | Total Past Due Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		97		100
Non-Covered Loans | Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		46,606		45,581
Non-Covered Loans | Multi-Family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual Loans		22		10
Total Loans Receivable		35,751		34,603
Non-Covered Loans | Multi-Family | Financing Receivable, 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		23		57
Non-Covered Loans | Multi-Family | Total Past Due Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		45		67
Non-Covered Loans | Multi-Family | Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		35,706		34,536
Non-Covered Loans | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual Loans		35		16
Total Loans Receivable		6,701		6,698
Non-Covered Loans | Commercial Real Estate | Financing Receivable, 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		4		2
Non-Covered Loans | Commercial Real Estate | Total Past Due Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		39		18
Non-Covered Loans | Commercial Real Estate | Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		6,662		6,680
Non-Covered Loans | One-to-Four Family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual Loans				1
Total Loans Receivable		145		160
Non-Covered Loans | One-to-Four Family | Financing Receivable, 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		7		8
Non-Covered Loans | One-to-Four Family | Total Past Due Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		7		9
Non-Covered Loans | One-to-Four Family | Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		138		151
Non-Covered Loans | Acquisition, Development, and Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans Receivable		237		209
Non-Covered Loans | Acquisition, Development, and Construction | Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		237		209
Non-Covered Loans | Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual Loans	[6]	6	[5]	6	[7]
Total Loans Receivable	[6]	3,863	[5]	4,006	[7]
Non-Covered Loans | Commercial and Industrial | Total Past Due Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	[6]	6	[5]	6	[7]
Non-Covered Loans | Commercial and Industrial | Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	[6]	3,857	[5]	4,000	[7]
Non-Covered Loans | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans Receivable		6		5
Non-Covered Loans | Other | Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		$ 6		$ 5

[1] Excludes accrued interest receivable of $200 million and $199 million at March 31, 2022 and December 31, 2021, respectively, which is included in other assets in the Consolidated Statements of Condition.

[2] Includes lease financing receivables, all of which were classified as Pass.

[3] Includes specialty finance loans and leases of $3.3 billion and $3.5 billion, respectively, at March 31, 2022 and December 31, 2021, and other C&I loans of $548 million and $527 million, respectively, at March 31, 2022 and December 31, 2021.

[4] Includes lease financing receivables, all of which were classified as Pass.

[5] Includes $5 million of taxi medallion-related loans that were 90 days or more past due. There were no taxi medallion-related loans that were 30 to 89 days past due.

[6] Includes lease financing receivables, all of which were current.

[7] Includes $6 million of taxi medallion-related loans that were 90 days or more past due. There were no taxi medallion-related loans that were 30 to 89 days past due.