Loans and Leases - Summary of Financial Effects of Troubled Debt Restructurings (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) Investment	Dec. 31, 2020 USD ($) Investment	Dec. 31, 2019 USD ($) Investment
Financing Receivable Modifications [Line Items]
Number of loans classified as a non-accrual TDRs | Investment	3	43	73
Pre-Modification Recorded Investment	$ 12	$ 24	$ 35
Post-Modification Recorded Investment	$ 12	23	31
Trouble debt restructuring, charge-off amount		$ 1	$ 4
Commercial Real Estate
Financing Receivable Modifications [Line Items]
Number of loans classified as a non-accrual TDRs | Investment	2	1
Pre-Modification Recorded Investment	$ 4	$ 15
Post-Modification Recorded Investment	$ 4	$ 15
Weighted Average Interest Rate, Pre-Modification	6.00%	8.00%
Weighted Average Interest Rate, Post-Modification	3.55%	3.50%
Multi-Family
Financing Receivable Modifications [Line Items]
Number of loans classified as a non-accrual TDRs | Investment	1
Pre-Modification Recorded Investment	$ 8
Post-Modification Recorded Investment	$ 8
Weighted Average Interest Rate, Pre-Modification	3.13%
Weighted Average Interest Rate, Post-Modification	3.25%
Commercial and Industrial
Financing Receivable Modifications [Line Items]
Number of loans classified as a non-accrual TDRs | Investment		42	72
Pre-Modification Recorded Investment		$ 9	$ 35
Post-Modification Recorded Investment		$ 8	$ 31
Weighted Average Interest Rate, Pre-Modification		2.36%	4.31%
Weighted Average Interest Rate, Post-Modification		2.23%	4.37%
Trouble debt restructuring, charge-off amount		$ 1	$ 4
One-to-Four Family
Financing Receivable Modifications [Line Items]
Number of loans classified as a non-accrual TDRs | Investment			1
Weighted Average Interest Rate, Pre-Modification			5.50%
Weighted Average Interest Rate, Post-Modification			5.50%