Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2018

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs

	Three months ended						Six months ended
In millions	June 30, 2018			June 30, 2017			June 30, 2018			June 30, 2017
Service cost	$	1.0		$	2.9		$	2.1		$	5.8
Interest cost	3.0			4.1			6.0			8.2
Expected return on plan assets	(2.2		)	(2.9		)	(4.5		)	(5.8		)
Net periodic benefit cost	$	1.8		$	4.1		$	3.6		$	8.2