Loans and Leases - Loans Held for Investment by Credit Quality Indicator (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	$ 6,046
2022	19,108
2021	13,748
2020	10,982
2019	7,301
Prior To 2019	15,575
Revolving Loans	9,711
Revolving Loans Converted to Term Loans	76
Total	82,547		$ 69,001
Financing Receivable, Excluding Accrued Interest, Allowance For Credit Loss, Writeoff, By Origination Year [Abstract]
Total	(5)	$ (3)
Mortgage Loans:
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	947
2022	14,351
2021	11,070
2020	9,431
2019	6,030
Prior To 2019	14,488
Revolving Loans	280
Revolving Loans Converted to Term Loans	8
Total	56,605		54,473
Financing Receivable, Excluding Accrued Interest, Allowance For Credit Loss, Writeoff, By Origination Year [Abstract]
2023	0
2022	0
2021	0
2020	0
2019	0
Prior To 2019	(2)
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total	(2)	(3)
Mortgage Loans: | Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	935
2022	14,349
2021	10,976
2020	9,217
2019	5,531
Prior To 2019	12,800
Revolving Loans	279
Revolving Loans Converted to Term Loans	5
Total	54,092		52,195
Mortgage Loans: | Special mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0
2022	0
2021	80
2020	168
2019	262
Prior To 2019	833
Revolving Loans	1
Revolving Loans Converted to Term Loans	0
Total	1,344		1,106
Mortgage Loans: | Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	12
2022	2
2021	14
2020	46
2019	237
Prior To 2019	855
Revolving Loans	0
Revolving Loans Converted to Term Loans	3
Total	1,169		1,172
Mortgage Loans: | Doubtful
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total			0
Mortgage Loans: | Multi-family
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	38,004		38,130
Mortgage Loans: | Multi-family | Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	36,497		36,622
Mortgage Loans: | Multi-family | Special mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	926		864
Mortgage Loans: | Multi-family | Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	581		644
Mortgage Loans: | Multi-family | Doubtful
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total			0
Mortgage Loans: | Commercial real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	10,464		8,526
Mortgage Loans: | Commercial real estate | Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	9,567		7,871
Mortgage Loans: | Commercial real estate | Special mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	403		230
Mortgage Loans: | Commercial real estate | Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	494		425
Mortgage Loans: | Commercial real estate | Doubtful
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total			0
Mortgage Loans: | One-to-four family first mortgage
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	5,934		5,821
Mortgage Loans: | One-to-four family first mortgage | Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	5,832		5,710
Mortgage Loans: | One-to-four family first mortgage | Special mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	8		8
Mortgage Loans: | One-to-four family first mortgage | Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	94		103
Mortgage Loans: | One-to-four family first mortgage | Doubtful
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total			0
Mortgage Loans: | Acquisition, development, and construction
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	2,203		1,996
Mortgage Loans: | Acquisition, development, and construction | Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	2,196		1,992
Mortgage Loans: | Acquisition, development, and construction | Special mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	7		4
Mortgage Loans: | Acquisition, development, and construction | Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	0		0
Mortgage Loans: | Acquisition, development, and construction | Doubtful
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total			0
Other Loans:
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	5,099
2022	4,757
2021	2,678
2020	1,551
2019	1,271
Prior To 2019	1,087
Revolving Loans	9,431
Revolving Loans Converted to Term Loans	68
Total	25,942		14,528
Financing Receivable, Excluding Accrued Interest, Allowance For Credit Loss, Writeoff, By Origination Year [Abstract]
2023	0
2022	0
2021	0
2020	0
2019	0
Prior To 2019	(3)
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total	(3)	$ 0
Other Loans: | Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	5,095
2022	4,728
2021	2,667
2020	1,519
2019	1,246
Prior To 2019	1,025
Revolving Loans	9,389
Revolving Loans Converted to Term Loans	61
Total	25,730		14,446
Other Loans: | Special mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	3
2022	13
2021	3
2020	3
2019	18
Prior To 2019	17
Revolving Loans	11
Revolving Loans Converted to Term Loans	0
Total	68		18
Other Loans: | Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	1
2022	16
2021	8
2020	29
2019	7
Prior To 2019	45
Revolving Loans	31
Revolving Loans Converted to Term Loans	7
Total	144		64
Other Loans: | Doubtful
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total			0
Other Loans: | Commercial and industrial loans and lease financing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	23,357		12,276
Other Loans: | Commercial and industrial loans and lease financing | Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	23,164		12,208
Other Loans: | Commercial and industrial loans and lease financing | Special mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	68		18
Other Loans: | Commercial and industrial loans and lease financing | Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	125		50
Other Loans: | Commercial and industrial loans and lease financing | Doubtful
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total			0
Other Loans: | Other
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	2,585		2,252
Other Loans: | Other | Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	2,566		2,238
Other Loans: | Other | Special mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	0		0
Other Loans: | Other | Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total	$ 19		14
Other Loans: | Other | Doubtful
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total			$ 0