Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2018

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs

	Three months ended						Nine months ended
In millions	September 30, 2018			September 30, 2017			September 30, 2018			September 30, 2017
Service cost	$	1.0		$	2.9		$	3.1		$	8.8
Interest cost	3.0			4.1			9.0			12.3
Expected return on plan assets	(2.2		)	(2.9		)	(6.7		)	(8.7		)
Actuarial loss	2.2			—			2.2			—
Net periodic benefit cost	$	4.0		$	4.1		$	7.6		$	12.4