Fair Value (Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	$ 649	$ 0
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group	56	105
Loans and Leases Receivable, Net Amount	113,825	110,546
Nonmarketable equity investments	818	418
Deposits	75,744	66,478
Short-term Debt	6,434	8,101
Long-term debt	56,836	66,234
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	649
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group	56	105
Loans and Leases Receivable, Net Amount	113,825	110,546
Nonmarketable equity investments	818	418
Deposits	75,744	66,478
Short-term Debt	6,434	8,101
Long-term debt	56,836	66,234
Portion at Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	658
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group	56	105
Loans and Leases Receivable, Net Amount	114,847	110,737
Nonmarketable equity investments	837	433
Deposits	76,231	66,889
Short-term Debt	6,435	8,102
Long-term debt	59,195	68,175
Portion at Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	0
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group	0	0
Loans and Leases Receivable, Net Amount	0	0
Nonmarketable equity investments	0	0
Deposits	0	0
Short-term Debt	0	0
Long-term debt	0	0
Portion at Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	658
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group	0	0
Loans and Leases Receivable, Net Amount	0	0
Nonmarketable equity investments	787	391
Deposits	0	0
Short-term Debt	0	0
Long-term debt	22,405	23,018
Portion at Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	0
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group	56	105
Loans and Leases Receivable, Net Amount	114,847	110,737
Nonmarketable equity investments	50	42
Deposits	76,231	66,889
Short-term Debt	6,435	8,102
Long-term debt	$ 36,790	$ 45,157

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The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

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No definition available.

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Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

+ References

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Amount, after allowance for bad debt, of loan receivables held-for-sale that are not part of a disposal group. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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