Fair Value Measurements (Schedule of Financial Instruments Measured at Other Than Fair Value) (Details) - USD ($) $ in Millions		Mar. 31, 2020		Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities	[1]	$ 288		$ 274
Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities	[1],[2]	288	[3]	274
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		288		274
Net loan receivables		93,574		96,094
Cash and cash equivalents	[4]	10,028		6,924
Restricted cash	[4]	1,183		40
Accrued interest receivables	[4],[5]	1,027		1,044
Time deposits	[6]	34,460		34,910
Long-term borrowings		25,840		26,572
Accrued interest payables	[4],[5]	220		283
Estimated Fair Value [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		13,798		14,383
Estimated Fair Value [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		12,042		12,189
Estimated Fair Value [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		288		274
Estimated Fair Value [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		0		0
Net loan receivables		0		0
Cash and cash equivalents	[4]	10,028		6,924
Restricted cash	[4]	1,183		40
Accrued interest receivables		0		0
Time deposits		0		0
Long-term borrowings		0		0
Accrued interest payables		0		0
Estimated Fair Value [Member] | Level 1 [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		0		0
Estimated Fair Value [Member] | Level 1 [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		0		0
Estimated Fair Value [Member] | Level 1 [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		0		0
Estimated Fair Value [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		288		274
Net loan receivables		0		0
Cash and cash equivalents		0		0
Restricted cash		0		0
Accrued interest receivables	[4],[5]	1,027		1,044
Time deposits	[6]	34,460		34,910
Long-term borrowings		25,689		26,400
Accrued interest payables	[4],[5]	220		283
Estimated Fair Value [Member] | Level 2 [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		13,647		14,211
Estimated Fair Value [Member] | Level 2 [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		12,042		12,189
Estimated Fair Value [Member] | Level 2 [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		288		274
Estimated Fair Value [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		0		0
Net loan receivables		93,574		96,094
Cash and cash equivalents		0		0
Restricted cash		0		0
Accrued interest receivables		0		0
Time deposits		0		0
Long-term borrowings		151		172
Accrued interest payables		0		0
Estimated Fair Value [Member] | Level 3 [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		151		172
Estimated Fair Value [Member] | Level 3 [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		0		0
Estimated Fair Value [Member] | Level 3 [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		0		0
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		279		272
Net loan receivables		86,050		92,511
Cash and cash equivalents	[4]	10,028		6,924
Restricted cash	[4]	1,183		40
Accrued interest receivables	[4],[5]	1,027		1,044
Time deposits	[6]	33,862		34,381
Long-term borrowings		26,098		25,701
Accrued interest payables	[4],[5]	220		283
Carrying Value [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		13,939		14,284
Carrying Value [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		12,159		11,417
Carrying Value [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		$ 279		$ 272

[1] Held-to-maturity investment securities are reported at amortized cost.

[2] Amounts represent residential mortgage-backed securities that were classified as held-to-maturity as they were entered into as a part of the Company's community reinvestment initiatives.

[3] Maturities of residential mortgage-backed securities are reflective of the contractual maturities of the investment.

[4] The carrying values of these assets and liabilities approximate fair value due to the nature of their liquidity (i.e., due or payable in less than one year).

[5] Accrued interest receivable and payable carrying values are presented as part of other assets or accrued expenses and other liabilities, respectively, in the Company's condensed consolidated statements of financial condition.

[6] Excludes deposits without contractually defined maturities for all periods presented.