Fair Value Election and Measurement Level 3 Significant Unobservable Input Assumptions (Details) $ in Millions	Jun. 30, 2019 USD ($)		Dec. 31, 2018 USD ($)
level 3 fair value assumptions [Line Items]
Loans Receivable, Fair Value Disclosure	$ 127		$ 163
Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Loans Receivable, Fair Value Disclosure	127		163
Fair Value, Measurements, Recurring [Member]
level 3 fair value assumptions [Line Items]
Loans Receivable, Fair Value Disclosure	127		163
Servicing Asset at Fair Value, Amount	1,717		1,983
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Loans Receivable, Fair Value Disclosure	127		163
Servicing Asset at Fair Value, Amount	1,717		1,983
Fair Value, Measurements, Recurring [Member] | Valuation, Market Approach [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Derivative, Fair Value, Net	24	[1]	13	[2]
Loans Receivable, Fair Value Disclosure	2		5
Fair Value, Measurements, Recurring [Member] | Valuation, Income Approach [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Loans Receivable, Fair Value Disclosure	125		158
Servicing Asset at Fair Value, Amount	$ 1,717		$ 1,983
Pull Through Rate [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Market Approach [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Derivative Asset (Liability) Net, Measurement Input	0.37		0.41
Pull Through Rate [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Market Approach [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Derivative Asset (Liability) Net, Measurement Input	1.00		1.00
Pull Through Rate [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Market Approach [Member] | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Derivative Asset (Liability) Net, Measurement Input	0.81		0.81
MSR Value [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Market Approach [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Derivative Asset (Liability) Net, Measurement Input	0.0024		0.0011
MSR Value [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Market Approach [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Derivative Asset (Liability) Net, Measurement Input	0.0155		0.0165
MSR Value [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Market Approach [Member] | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Derivative Asset (Liability) Net, Measurement Input	0.0099		0.0108
Measurement Input, Credit Spread [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Income Approach [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Loans Held-For-Investment, Measurement Input	0.0062		0.0000
Servicing Asset, Measurement Input	0.01		0.00
Measurement Input, Credit Spread [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Income Approach [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Loans Held-For-Investment, Measurement Input	0.025		0.0250
Servicing Asset, Measurement Input	0.29		1.16
Measurement Input, Credit Spread [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Income Approach [Member] | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Loans Held-For-Investment, Measurement Input	0.0172		0.0164
Servicing Asset, Measurement Input	0.03		0.02
Measurement Input, Prepayment Rate [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Income Approach [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Loans Held-For-Investment, Measurement Input	0.0702		0.07
Servicing Asset, Measurement Input	0.07		0.06
Measurement Input, Prepayment Rate [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Income Approach [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Loans Held-For-Investment, Measurement Input	0.32		0.22
Servicing Asset, Measurement Input	0.31		0.30
Measurement Input, Prepayment Rate [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Income Approach [Member] | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Loans Held-For-Investment, Measurement Input	0.164		0.1239
Servicing Asset, Measurement Input	0.14		0.13
Measurement Input, Default Rate [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Income Approach [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Loans Held-For-Investment, Measurement Input	0.00		0.00
Measurement Input, Default Rate [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Income Approach [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Loans Held-For-Investment, Measurement Input	0.02		0.01
Measurement Input, Default Rate [Member] | Fair Value, Measurements, Recurring [Member] | Valuation, Income Approach [Member] | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]
level 3 fair value assumptions [Line Items]
Loans Held-For-Investment, Measurement Input	0.0051		0.0063

[1] Amount represents the net of IRLC assets and liabilities and includes the derivative liability associated with the Company’s sale of Visa shares. Refer to the “Trading Liabilities and Derivative Instruments” section in Note 20, “Fair Value Election and Measurement,” to the Company's 2018 Annual Report on Form 10-K, for a discussion of valuation assumptions related to the Visa derivative liability.

[2] Amount represents the net of IRLC assets and liabilities and includes the derivative liability associated with the Company’s sale of Visa shares. Refer to the “Trading Liabilities and Derivative Instruments” section in Note 20, “Fair Value Election and Measurement,” to the Company's 2018 Annual Report on Form 10-K, for a discussion of valuation assumptions related to the Visa derivative liability.