Derivative Financial Instruments - Amounts Related to Fair Value Hedges (Details) - Fair Value Hedges - Interest Rate Contracts - Net interest income - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized	$ 4	$ 129	$ 208
AFS securities
Derivative Instruments, Gain (Loss) [Line Items]
Amounts related to interest settlements	(5)
Recognized on derivatives	12
Recognized on hedged items	(15)
Net income (expense) recognized	(8)	(16)	(16)
Loans and leases
Derivative Instruments, Gain (Loss) [Line Items]
Amounts related to interest settlements	(2)
Recognized on derivatives	(1)
Recognized on hedged items	2
Net income (expense) recognized	(1)	(3)	(2)
Long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Amounts related to interest settlements	(30)
Recognized on derivatives	(122)
Recognized on hedged items	165
Net income (expense) recognized	$ 13	$ 148	$ 226

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

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Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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Amount of gain (loss) on derivative instrument designated and qualifying as fair value hedge included in assessment of hedge effectiveness, recognized in earnings.

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Total amount of gain (loss) derived from fair value hedges recognized in earnings in the period.

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