Accumulated Other Comprehensive Income (Tables)

3 Months Ended

Mar. 31, 2024

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,
	2024			2023
Defined Benefit Plans:
Beginning balance	$	11.0		$	2.8
Amortization of net actuarial gain1		(0.3	)		(0.3	)
Amortization of prior service (credit) cost1		(0.3	)		1.2
Less: income tax benefit (expense)2		0.1			(0.2	)
Other comprehensive (loss) income, net of tax		(0.5	)		0.7
Ending balance	$	10.5		$	3.5
Cash Flow Hedges:
Beginning balance	$	2.1		$	0.4
Unrealized loss on cash flow hedges		(4.2	)		(2.6	)
Less: income tax benefit		1.0			0.6
Net unrealized loss on cash flow hedges		(3.2	)		(2.0	)
Reclassification of unrealized loss upon settlement of cash flow hedges		2.1			0.2
Less: income tax expense2		(0.5	)		—
Net loss reclassified from AOCI to Net income		1.6			0.2
Other comprehensive loss, net of tax		(1.6	)		(1.8	)
Ending balance3	$	0.5		$	(1.4	)
Total AOCI ending balance	$	11.0		$	2.1

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

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

3.As of March 31, 2024, we estimate a net mark-to-market gain before tax of $0.5 million in AOCI will be reclassified into Net income upon settlement within the next 12 months.