Securities Purchased Under Agreements to Resell and Securities Sold Under Agreements to Repurchase (Tables)

12 Months Ended

Dec. 31, 2019

Investments, Debt and Equity Securities [Abstract]

Securities Purchased under Agreements to Resell

($ In Millions)	2019			2018
Balance at December 31	$	707.8		$	1,031.2
Average Balance During the Year	835.0			1,478.3
Average Interest Rate Earned During the Year	2.10		%	2.22		%
Maximum Month-End Balance During the Year	$	1,290.0		$	1,942.0

Securities Sold under Agreements to Repurchase

($ In Millions)	2019			2018
Balance at December 31	$	489.7		$	168.3
Average Balance During the Year	339.0			525.2
Average Interest Rate Paid During the Year	1.89		%	1.48		%
Maximum Month-End Balance During the Year	$	489.7		$	981.3

Transfer of Certain Financial Assets Accounted for as Secured Borrowings

	Remaining Contractual Maturity of the Agreements
($ In Millions)	Overnight and Continuous
Repurchase Agreements	December 31, 2019		December 31, 2018
U.S. Treasury and Agency Securities	$	489.7	$	168.3
Total Borrowings	489.7		168.3
Gross Amount of Recognized Liabilities for Repurchase Agreements in Note 28	489.7		168.3
Amounts related to agreements not included in Note 28	—		—