OTHER COMPREHENSIVE INCOME (Tables)

12 Months Ended

Dec. 31, 2023

OTHER COMPREHENSIVE INCOME [Abstract]

Accumulated Other Comprehensive Income, Net of Tax

in millions	2023	2022	2021
AOCI
Cash flow hedges	$          (19.4)	$         (21.0)	$         (22.5)
Pension and postretirement plans	(124.4)	(133.7)	(130.2)
Total	$        (143.8)	$       (154.7)	$       (152.7)

Changes in Accumulated Other Comprehensive Income, Net of Tax

		Pension and
	Cash Flow	Postretirement
in millions	Hedges	Benefit Plans	Total
AOCI
Balances at December 31, 2020	$          (24.0)	$       (157.3)	$       (181.3)
Other comprehensive income (loss)
before reclassifications	0.0	13.4	13.4
Amounts reclassified from AOCI	1.5	13.7	15.2
Net OCI changes	1.5	27.1	28.6
Balances at December 31, 2021	$          (22.5)	$       (130.2)	$       (152.7)
Other comprehensive income (loss)
before reclassifications	0.0	(6.5)	(6.5)
Amounts reclassified from AOCI	1.5	3.0	4.5
Net OCI changes	1.5	(3.5)	(2.0)
Balances at December 31, 2022	$          (21.0)	$       (133.7)	$       (154.7)
Other comprehensive income (loss)
before reclassifications	0.0	4.2	4.2
Amounts reclassified from AOCI	1.6	5.1	6.7
Net OCI changes	1.6	9.3	10.9
Balances at December 31, 2023	$          (19.4)	$       (124.4)	$       (143.8)

Amounts Reclassified from Accumulated Other Comprehensive Income to Earnings

in millions	2023	2022	2021
Amortization of Cash Flow Hedge Losses
Interest expense	$             2.1	$            2.0	$            2.0
Benefit from income taxes	(0.5)	(0.5)	(0.5)
Total	$             1.6	$            1.5	$            1.5
Amortization of Pension and Postretirement Plan
Actuarial Loss and Prior Service Cost
Other nonoperating expense	$             6.9	$            4.0	$          18.5
Benefit from income taxes	(1.8)	(1.0)	(4.8)
Total	$             5.1	$            3.0	$          13.7
Total reclassifications from AOCI to earnings	$             6.7	$            4.5	$          15.2