Fair Value Measurement - Recurring Fair Value Measurements(Details) - USD ($) $ in Millions | Mar. 31, 2018 | Dec. 31, 2017 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Other assets | | $ 2,370 | $ 1,620 |
Fair Value, Measurements, Recurring | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Other assets | [1] | 22 | 15 |
Total | | 6,281 | 4,488 |
Fair Value, Measurements, Recurring | Level 1 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Other assets | [1] | 15 | 15 |
Total | | 15 | 15 |
Fair Value, Measurements, Recurring | Level 2 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Other assets | [1] | 0 | 0 |
Total | | 6,215 | 4,427 |
Fair Value, Measurements, Recurring | Level 3 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Other assets | [1] | 7 | 0 |
Total | | 51 | 46 |
U.S. Government and Federal Agency | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 3,352 | 2,416 |
U.S. Government and Federal Agency | Fair Value, Measurements, Recurring | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 3,352 | 2,416 |
U.S. Government and Federal Agency | Fair Value, Measurements, Recurring | Level 1 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 0 | 0 |
U.S. Government and Federal Agency | Fair Value, Measurements, Recurring | Level 2 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 3,352 | 2,416 |
U.S. Government and Federal Agency | Fair Value, Measurements, Recurring | Level 3 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 0 | 0 |
State and municipal | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 42 | 44 |
State and municipal | Fair Value, Measurements, Recurring | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 42 | 44 |
State and municipal | Fair Value, Measurements, Recurring | Level 1 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 0 | 0 |
State and municipal | Fair Value, Measurements, Recurring | Level 2 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 0 | 0 |
State and municipal | Fair Value, Measurements, Recurring | Level 3 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 42 | 44 |
Residential mortgage-backed | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | [2] | 1,194 | 1,231 |
Residential mortgage-backed | Fair Value, Measurements, Recurring | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 1,194 | 1,231 |
Residential mortgage-backed | Fair Value, Measurements, Recurring | Level 1 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 0 | 0 |
Residential mortgage-backed | Fair Value, Measurements, Recurring | Level 2 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 1,194 | 1,231 |
Residential mortgage-backed | Fair Value, Measurements, Recurring | Level 3 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 0 | 0 |
Asset-backed Securities [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | [3] | 1,669 | 780 |
Asset-backed Securities [Member] | Fair Value, Measurements, Recurring | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 1,669 | 780 |
Asset-backed Securities [Member] | Fair Value, Measurements, Recurring | Level 1 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 0 | 0 |
Asset-backed Securities [Member] | Fair Value, Measurements, Recurring | Level 2 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 1,669 | 780 |
Asset-backed Securities [Member] | Fair Value, Measurements, Recurring | Level 3 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 0 | 0 |
Domestic Corporate Debt Securities [Member] | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 2 | 2 |
Domestic Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 2 | 2 |
Domestic Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring | Level 1 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 0 | 0 |
Domestic Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring | Level 2 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | 0 | 0 |
Domestic Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring | Level 3 | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | |
Debt securities | | $ 2 | $ 2 |
| |
[1] | Other assets primarily relate to equity investments measured at fair value. | |
[2] | All of our residential mortgage-backed securities have been issued by government-sponsored entities and are collateralized by U.S. mortgages. At March 31, 2018 and December 31, 2017, $342 million and $344 million, respectively, are pledged by the Bank as collateral to the Federal Reserve to secure Federal Reserve Discount Window advances. | |
[3] | All of our asset-backed securities are collateralized by credit card loans. | |