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


	Quarter Ended March 31,
	2026			2025
Defined Benefit Plans:
Beginning balance	$	22.5		$	19.1
Actuarial loss arising during the period		—			(0.1	)
Amortization of net actuarial gain1		(0.6	)		(0.6	)
Amortization of prior service cost1		0.9			0.9
Less: income tax expense2		(0.1	)		(0.1	)
Other comprehensive income, net of tax		0.2			0.1
Ending balance	$	22.7		$	19.2

Cash Flow Hedges:
Beginning balance	$	4.3		$	1.4
Unrealized gain on cash flow hedges		15.8			8.7
Less: income tax expense		(3.7	)		(2.0	)
Net unrealized gain on cash flow hedges		12.1			6.7
Reclassification of unrealized gain upon settlement of cash flow hedges		(9.3	)		(5.5	)
Less: income tax benefit2		2.2			1.3
Net gain reclassified from AOCI to Net income		(7.1	)		(4.2	)
Other comprehensive income, net of tax		5.0			2.5
Ending balance3	$	9.3		$	3.9

Total AOCI ending balance	$	32.0		$	23.1

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

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

As of March 31, 2026, we estimate a net mark-to-market gain before tax of $13.0 million in AOCI will be reclassified into Net income upon settlement within the next 12 months.