Retirement Benefits (Tables)

6 Months Ended

Jun. 30, 2019

Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]

Schedule of net pension and retiree health benefit (income) cost

Net pension and retiree health benefit (income) cost included the following components:

	Defined Benefit Pension Plans						Defined Benefit Pension Plans
	Three Months Ended June 30,						Six Months Ended June 30,
	2019			2018			2019			2018
Components of net periodic benefit cost:
Service cost	$	63.5		$	74.9		$	125.4		$	152.5
Interest cost	122.6			111.4			243.3			223.3
Expected return on plan assets	(210.1		)	(210.0		)	(421.2		)	(420.9		)
Amortization of prior service cost	1.5			1.3			3.0			2.4
Recognized actuarial loss	73.1			91.1			142.7			181.1
Net periodic benefit cost	$	50.6		$	68.7		$	93.2		$	138.4

	Retiree Health Benefit Plans						Retiree Health Benefit Plans
	Three Months Ended June 30,						Six Months Ended June 30,
	2019			2018			2019			2018
Components of net periodic benefit income:
Service cost	$	9.4		$	10.9		$	18.2		$	21.6
Interest cost	14.4			13.5			29.0			27.4
Expected return on plan assets	(36.0		)	(43.9		)	(71.9		)	(87.8		)
Amortization of prior service benefit	(15.7		)	(20.4		)	(31.5		)	(40.9		)
Recognized actuarial loss	0.4			2.2			0.9			4.6
Net periodic benefit income	$	(27.5	)	$	(37.7	)	$	(55.3	)	$	(75.1	)