Short-Term Borrowings (Tables)

12 Months Ended

Dec. 31, 2020

Debt Disclosure [Abstract]

Schedule of Short-term Debt

The following table presents 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:

(Dollars in millions)	Securities Sold Under Repurchase Agreements									Tax-Exempt Investment Program									Other
	2020			2019			2018			2020			2019			2018			2020			2019			2018
Balance as of December 31	$	3,413		$	1,102		$	1,082		$	616		$	823		$	931		$	3,302		$	—		$	2,000
Maximum outstanding as of any month-end	5,373			4,125			3,441			823			931			1,078			25,665			—			2,000
Average outstanding during the year	2,615			1,616			2,048			771			898			1,023			8,251			3			nm
Weighted-average interest rate as of year-end	.00		%	.00		%	1.38		%	.23		%	1.75		%	1.74		%	1.35		%	.00		%	2.68		%
Weighted-average interest rate during the year	.14			1.90			.62			.78			1.51			1.46			1.23			.01			nm

nm Not meaningful

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, 2020.

	U.S. Government Securities Sold				Repurchase Agreements(1)
(In millions)	Amortized Cost		Fair Value		Amortized Cost
Overnight maturity	$	2,992	$	3,981	$	3,413

(1) Collateralized by investment securities.