PENSION PLANS AND RETIREMENT BENEFITS (Tables)

6 Months Ended

Jun. 30, 2021

Retirement Benefits [Abstract]

Components of Net Periodic Benefit (Income) Cost

	Pension Benefits				Other Postretirement Benefits
	Three Months Ended June 30,				Three Months Ended June 30,
	2021		2020		2021		2020
Components of Net Periodic Benefit (Income) Cost	($ in millions)
Service cost	$	2.8	$	2.7	$	0.3	$	0.4
Interest cost	12.8		18.8		0.3		0.3
Expected return on plans’ assets	(35.0)		(35.6)		—		—
Amortization of prior service cost	(0.2)		—		0.1		—
Recognized actuarial loss	13.2		11.1		0.6		0.5
Net periodic benefit (income) cost	$	(6.4)	$	(3.0)	$	1.3	$	1.2

	Pension Benefits				Other Postretirement Benefits
	Six Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Components of Net Periodic Benefit (Income) Cost	($ in millions)
Service cost	$	5.8	$	5.7	$	0.7	$	0.7
Interest cost	25.6		37.5		0.6		0.7
Expected return on plans’ assets	(71.1)		(71.2)		—		—
Amortization of prior service cost	(0.3)		—		0.1		—
Recognized actuarial loss	26.3		22.3		1.3		1.2
Net periodic benefit (income) cost	$	(13.7)	$	(5.7)	$	2.7	$	2.6