PENSION PLANS AND RETIREMENT BENEFITS (Tables)

3 Months Ended

Mar. 31, 2016

Compensation and Retirement Disclosure [Abstract]

Components of Net Periodic Benefit (Income) Cost

	Pension Benefits						Other Postretirement Benefits
	Three Months Ended March 31,						Three Months Ended March 31,
	2016			2015			2016		2015
Components of Net Periodic Benefit (Income) Cost	($ in millions)
Service cost	$	3.2		$	1.6		$	0.3	$	0.3
Interest cost	22.4			20.6			0.5		0.6
Expected return on plans’ assets	(39.8		)	(35.6		)	—		—
Recognized actuarial loss	5.3			7.5			0.8		0.9
Curtailments/settlements	—			0.1			—		0.1
Net periodic benefit (income) cost	$	(8.9	)	$	(5.8	)	$	1.6	$	1.9