Pension and Postretirement Health Care (Tables)

9 Months Ended

Sep. 30, 2018

Retirement Benefits [Abstract]

Net Periodic Pension Expense (Benefit)

The following tables set forth the net periodic pension and postretirement benefit expense for Northern Trust’s U.S. and non-U.S. pension plans, supplemental pension plan, and postretirement health care plan for the three and nine months ended September 30, 2018 and 2017.

Table 61: Net Periodic Pension Expense (Benefit)

Net Periodic Pension Expense U.S. Plan	Three Months Ended September 30,						Nine Months Ended September 30,
(In Millions)	2018			2017			2018			2017
Service Cost	$	10.4		$	9.6		$	31.1		$	28.8
Interest Cost	11.1			11.4			33.3			34.4
Expected Return on Plan Assets	(22.1		)	(23.4		)	(66.2		)	(70.4		)
Amortization
Net Actuarial Loss	7.0			4.7			21.1			14.3
Prior Service Cost	(0.1		)	(0.1		)	(0.3		)	(0.3		)
Net Periodic Pension Expense	$	6.3		$	2.2		$	19.0		$	6.8

Net Periodic Pension Expense Non-U.S. Plans	Three Months Ended September 30,						Nine Months Ended September 30,
(In Millions)	2018			2017			2018			2017
Service Cost	$	0.4		$	—		$	1.2		$	—
Interest Cost	1.0			1.0			3.0			2.9
Expected Return on Plan Assets	(1.1		)	(1.1		)	(3.3		)	(3.3		)
Settlement Expense	—			0.7			0.4			0.9
Net Actuarial Loss Amortization	0.3			0.4			0.9			1.0
Net Periodic Pension Expense	$	0.6		$	1.0		$	2.2		$	1.5

Net Periodic Pension Expense Supplemental Plan	Three Months Ended September 30,				Nine Months Ended September 30,
(In Millions)	2018		2017		2018		2017
Service Cost	$	1.0	$	1.0	$	3.2	$	2.8
Interest Cost	1.3		1.3		4.0		3.9
Amortization
Net Actuarial Loss	1.9		1.5		5.5		4.3
Prior Service Cost	0.1		0.1		0.2		0.1
Net Periodic Pension Expense	$	4.3	$	3.9	$	12.9	$	11.1

Net Periodic Postretirement Expense Postretirement Health Care Plan	Three Months Ended September 30,				Nine Months Ended September 30,
(In Millions)	2018		2017		2018		2017
Service Cost	$	—	$	0.1	$	—	$	0.1
Interest Cost	0.3		0.3		1.0		1.1
Net Periodic Postretirement Expense	$	0.3	$	0.4	$	1.0	$	1.2