Pension and Other Postretirement Benefits (Tables)

6 Months Ended

Dec. 31, 2016

Compensation and Retirement Disclosure [Abstract]

Schedule of components of the net periodic benefit cost

The components of the net periodic benefit cost related to the Company’s pension and other postretirement benefits for the three and six months ended December 31, 2016 and 2015 were as follows:

Three months ended December 31,	Pension Plans						Other Postretirement Plans
($ in millions)	2016			2015			2016			2015
Service cost	$	7.7		$	7.8		$	0.9		$	0.8
Interest cost	12.4			14.4			2.3			2.5
Expected return on plan assets	(16.6		)	(16.4		)	(1.7		)	(1.7		)
Amortization of net loss	9.5			6.8			0.8			0.7
Amortization of prior service cost (benefit)	0.5			0.1			(1.6		)	(1.6		)
Net periodic benefit costs	$	13.5		$	12.7		$	0.7		$	0.7

Six months ended December 31,	Pension Plans						Other Postretirement Plans
($ in millions)	2016			2015			2016			2015
Service cost	$	16.0		$	15.6		$	1.8		$	1.7
Interest cost	25.3			28.8			4.6			5.2
Expected return on plan assets	(31.9		)	(32.9		)	(3.4		)	(3.5		)
Amortization of net loss	18.9			13.7			1.6			1.4
Amortization of prior service cost (benefit)	0.8			0.2			(3.2		)	(3.3		)
Curtailment charge	0.5			—			—			—
Net periodic benefit costs	$	29.6		$	25.4		$	1.4		$	1.5