Amount of affordable housing tax credits and other tax benefits recognized.

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Amount of investment in qualified affordable housing projects.

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Amount of commitment or contingent commitments to qualified affordable housing project investments.

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Investments in Qualified Affordable Housing Projects and Federal Historic Projects - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Remaining unfunded equity contributions	$ 138.5		$ 138.5		$ 131.3
Qualified Affordable Housing Projects
Schedule of Equity Method Investments [Line Items]
Amortization expense	5.1	$ 2.5	10.4	$ 5.0
Tax credits and other benefits	6.3	$ 3.0	12.9	$ 6.0
Remaining investment amount	225.2		225.2		195.8
Federal Historical Projects and Ohio Historical Preservation Projects
Schedule of Equity Method Investments [Line Items]
Remaining investment amount	54.0		54.0		$ 43.6
Federal Historical Projects
Schedule of Equity Method Investments [Line Items]
Amortization expense	0.2		0.4
Tax credits and other benefits	$ 0.3		0.6
Ohio Historical Preservation Projects
Schedule of Equity Method Investments [Line Items]
Tax credits and other benefits			$ 0.4