Short-Term Borrowings (Tables)

12 Months Ended

Dec. 31, 2016

Debt Disclosure [Abstract]

Schedule of Short-term Debt

The following table presents information about these U.S. government securities and the carrying value of the related repurchase agreements, including accrued interest, as of December 31, 2016. The table excludes repurchase agreements collateralized by securities purchased under resale agreements and collateralized by trading account assets.

	U.S. Government Securities Sold				Repurchase Agreements(1)
(In millions)	Amortized Cost		Fair Value		Amortized Cost
Overnight maturity	$	4,490	$	4,491	$	4,400

⁽¹⁾ Collateralized by investment securities

The following tables present information with respect to the amounts outstanding and weighted-average interest rates of the primary components of our short-term borrowings as of and for the years ended December 31:

	Securities Sold Under Repurchase Agreements									Federal Funds Purchased
(Dollars in millions)	2016			2015			2014			2016			2015			2014
Balance as of December 31	$	4,400		$	4,499		$	8,925		$	—		$	6		$	21
Maximum outstanding as of any month-end	5,572			10,977			10,955			29			29			29
Average outstanding during the year	4,113			8,875			8,817			31			21			20
Weighted-average interest rate as of year-end	.040		%	.020		%	.005		%	.00		%	.03		%	.01		%
Weighted-average interest rate for the year	.02			.01			.00			.17			.01			.00

	Tax-Exempt Investment Program									Corporate Commercial Paper Program(1)
(Dollars in millions)	2016			2015			2014			2015			2014
Balance as of December 31	$	1,158		$	1,748		$	1,870		$	—		$	2,485
Maximum outstanding as of any month-end	1,726			1,865			1,938			2,919			2,485
Average outstanding during the year	1,512			1,807			1,903			1,897			2,136
Weighted-average interest rate as of year-end	.67		%	.03		%	.06		%	.00		%	.16		%
Weighted-average interest rate for the year	.36			.06			.08			.26			.17

⁽¹⁾ We phased out our commercial paper program prior to December 31, 2015.