Pension and Other Postretirement Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2018

Retirement Benefits [Abstract]

Components of Net Periodic Benefit Expense (Income) [Table Text Block]

	Pension						Other Postretirement
Components of Net Periodic Benefit Cost	2018			2017			2018			2017
Millions
Quarter Ended September 30,
Service Cost		$2.7			$2.6			$1.2			$1.1
Non-Service Cost Components (a)
Interest Cost	7.4			8.1			1.8			2.0
Expected Return on Plan Assets	(11.1		)	(10.6		)	(2.7		)	(2.6		)
Amortization of Prior Service Credits	—			—			(0.4		)	(0.5		)
Amortization of Net Loss	3.0			2.5			0.2			—
Net Periodic Benefit Cost		$2.0			$2.6			$0.1		—
Nine Months Ended September 30,
Service Cost		$8.2			$7.7			$3.7			$3.3
Non-Service Cost Components (a)
Interest Cost	22.2			24.4			5.4			5.8
Expected Return on Plan Assets	(33.2		)	(31.8		)	(8.2		)	(7.9		)
Amortization of Prior Service Credits	—			—			(1.3		)	(1.5		)
Amortization of Net Loss	9.0			7.4			0.6			0.2
Net Periodic Benefit Cost (Income)		$6.2			$7.7			$0.2		$(0.1)

(a)

These components of net periodic benefit cost are included in the line item “Other” under Other Income (Expense) on the Consolidated Statement of Income.