Accumulated Other Comprehensive Income (Tables)

3 Months Ended

Mar. 31, 2023

Equity [Abstract]

Schedule of Accumulated Other Comprehensive Income

The following table presents the changes in the accumulated balances for each component of AOCI (in millions of dollars):

	Quarter Ended March 31,
	2023			2022
Defined Benefit Plans:
Beginning balance	$	2.8		$	(21.4	)
Amortization of net actuarial (gain) loss1		(0.3	)		—
Amortization of prior service cost1		1.2			1.2
Less: income tax expense2		(0.2	)		(0.3	)
Other comprehensive income, net of tax		0.7			0.9
Ending balance	$	3.5		$	(20.5	)
Cash Flow Hedges:
Beginning balance	$	0.4		$	17.7
Unrealized (loss) gain on cash flow hedges		(2.6	)		42.3
Less: income tax benefit (expense)		0.6			(10.0	)
Net unrealized (loss) gain on cash flow hedges		(2.0	)		32.3
Reclassification of unrealized loss (gain) upon settlement of cash flow hedges		0.2			(19.9	)
Less: income tax benefit2		—			4.7
Net loss (gain) reclassified from AOCI to Net income		0.2			(15.2	)
Other comprehensive (loss) income, net of tax		(1.8	)		17.1
Ending balance3	$	(1.4	)	$	34.8
Total AOCI ending balance	$	2.1		$	14.3

1Amounts amortized out of AOCI related to pension and other postretirement benefits were included within Net periodic postretirement benefit cost (see Note 3).

2Income tax amounts reclassified out of AOCI were included as a component of Income tax provision.

3As of March 31, 2023, we estimate a net mark-to-market loss before tax of $3.0 million in AOCI will be reclassified into Net income upon settlement within the next 12 months.