Income Taxes (Tables)

9 Months Ended

Sep. 30, 2020

Income Tax Disclosure [Abstract]

Reconciliation Between Actual Federal Income Tax Benefit and Amount Computed at Indicated Statutory Rate

The following table sets forth the reconciliation between actual federal income tax expense and the amount computed at the indicated statutory rate for the three and nine months ended September 30, 2020 and 2019:

($ millions)	Three months ended September 30								Nine months ended September 30
	2020				2019				2020				2019
Amount at statutory rate	$	3.1	21.0	%	$	2.7	21.0	%	$	(18.4)	21.0	%	$	14.0	21.0	%
Tax-exempt interest and dividends received deduction	(0.6)		(4.1)		(0.7)		(5.3)		(1.7)		1.9		(2.1)		(3.1)
Other, net	0.7		4.5		(0.8)		(6.3)		1.2		(1.4)		0.1		—
Federal income tax expense (benefit)	3.2		21.4	%	1.2		9.4	%	(18.9)		21.5	%	$	12.0	17.9	%