Employee Benefits (Tables)

12 Months Ended

Dec. 31, 2019

Retirement Benefits [Abstract]

Plan Status of U.S. Plan, Non-U.S. Plans and Supplemental Plan

The following tables set forth the status, amounts included in AOCI, and net periodic pension expense of the U.S. Qualified Plan, Non-U.S. Pension Plans, and U.S. Non-Qualified Plan for 2019, 2018, and 2017. Prior service costs are being amortized on a straight-line basis over 11 years for the U.S. Qualified Plan and 10 years for the U.S. Non-Qualified Plan.

TABLE 114: EMPLOYEE BENEFIT PLAN STATUS

	U.S. QUALIFIED PLAN						NON-U.S. PENSION PLANS						U.S. NON-QUALIFIED PLAN
($ In Millions)	2019			2018			2019			2018			2019			2018
Accumulated Benefit Obligation	$	1,181.9		$	980.6		$	204.7		$	178.4		$	131.5		$	120.9
Projected Benefit Obligation	1,323.4			1,092.0			211.1			183.5			149.2			135.6
Plan Assets at Fair Value	1,601.2			1,380.1			190.1			166.7			—			—
Funded Status at December 31	$	277.8		$	288.1		$	(21.0	)	$	(16.8	)	$	(149.2	)	$	(135.6	)
Weighted-Average Assumptions:
Discount Rates	3.37		%	4.47		%	1.40		%	2.16		%	3.37		%	4.47		%
Rate of Increase in Compensation Level	4.97			4.39			1.50			1.75			4.97			4.39
Expected Long-Term Rate of Return on Assets	5.25			6.00			1.72			2.39			N/A			N/A

The following tables set forth the postretirement health care plan status and amounts included in AOCI at December 31, 2019 and 2018, the net periodic postretirement benefit cost of the plan for 2019 and 2018, and the change in the accumulated postretirement benefit obligation during 2019 and 2018.

TABLE 122: POSTRETIREMENT HEALTH CARE PLAN STATUS

	DECEMBER 31,
(In Millions)	2019		2018
Accumulated Postretirement Benefit Obligation at Measurement Date:
Retirees and Dependents	$	25.2	$	23.5
Actives Eligible for Benefits	3.6		4.6
Net Postretirement Benefit Obligation	$	28.8	$	28.1

Amount Included in Accumulated Other Comprehensive Income

	U.S. QUALIFIED PLAN						NON-U.S. PENSION PLANS				U.S. NON-QUALIFIED PLAN
(In Millions)	2019			2018			2019		2018		2019		2018
Net Actuarial Loss	$	426.7		$	435.4		$	46.5	$	41.2	$	82.5	$	65.8
Prior Service (Benefit) Cost	(1.0		)	(1.4		)	3.0		3.6		0.2		0.4
Gross Amount in Accumulated Other Comprehensive Income	425.7			434.0			49.5		44.8		82.7		66.2
Income Tax Effect	105.7			108.5			6.2		6.0		20.4		16.4
Net Amount in Accumulated Other Comprehensive Income	$	320.0		$	325.5		$	43.3	$	38.8	$	62.3	$	49.8

	DECEMBER 31,
(In Millions)	2019			2018
Net Actuarial (Gain) Loss	$	(5.4	)	$	(6.5	)
Prior Service Cost	—			—
Gross Amount in Accumulated Other Comprehensive Income	(5.4		)	(6.5		)
Income Tax Effect	(1.4		)	(2.2		)
Net Amount in Accumulated Other Comprehensive Income	$	(4.0	)	$	(4.3	)

Components of Company's Net Periodic Benefit Cost

	U.S. QUALIFIED PLAN									NON-U.S. PENSION PLANS									U.S. NON-QUALIFIED PLAN
($ In Millions)	2019			2018			2017			2019			2018			2017			2019			2018			2017
Service Cost	$	41.6		$	41.4		$	38.3		$	2.0		$	1.7		$	0.4		$	4.1		$	4.3		$	3.7
Interest Cost	47.2			44.3			45.9			3.9			4.0			4.0			5.8			5.3			5.2
Expected Return on Plan Assets	(86.9		)	(88.2		)	(93.8		)	(4.4		)	(4.4		)	(4.5		)	—			N/A			N/A
Settlement Expense	—			—			—			—			0.5			1.1			—			—			—
Amortization:
Net Actuarial Loss	17.2			28.2			19.0			0.6			0.9			1.3			5.6			7.4			5.7
Prior Service (Benefit) Cost	(0.4		)	(0.4		)	(0.4		)	0.3			0.2			0.1			0.2			0.2			0.2
Net Periodic Pension Expense	$	18.7		$	25.3		$	9.0		$	2.4		$	2.9		$	2.4		$	15.7		$	17.2		$	14.8
Weighted-Average Assumptions:
Discount Rates	4.47		%	3.79		%	4.46		%	2.16		%	2.08		%	2.33		%	4.47		%	3.79		%	4.46		%
Rate of Increase in Compensation Level	4.39			4.39			4.39			1.75			1.75			1.75			4.39			4.39			4.39
Expected Long-Term Rate of Return on Assets	6.00			6.00			6.75			2.39			2.61			3.13			N/A			N/A			N/A

	FOR THE YEAR ENDED DECEMBER 31,
(In Millions)	2019			2018		2017
Service Cost	$	—		$	—	$	0.1
Interest Cost	1.2			1.3		1.4
Expected Return on Plan Assets	—			—		—
Amortization
Net Gain	(1.1		)	—		—
Prior Service Benefit	—			—		—
Net Periodic Postretirement Expense	$	0.1		$	1.3	$	1.5

Change in Benefit Obligation, Postretirement Health Care, and in Accumulated Postretirement Benefit Obligation

	U.S. QUALIFIED PLAN						NON-U.S. PENSION PLANS						U.S. NON-QUALIFIED PLAN
(In Millions)	2019			2018			2019			2018			2019			2018
Beginning Balance	$	1,092.0		$	1,209.9		$	183.5		$	198.3		$	135.6		$	144.5
Service Cost	41.6			41.4			2.0			1.7			4.1			4.3
Interest Cost	47.2			44.3			3.9			4.0			5.8			5.3
Employee Contributions	—			—			0.6			0.4			—			—
Plan Amendment	—			—			(0.4		)	1.3			—			—
Actuarial Loss (Gain)	213.3			(112.4		)	20.9			(9.3		)	22.0			(9.7		)
Settlement	—			—			—			(2.7		)	—			—
Benefits Paid	(70.7		)	(91.2		)	(3.6		)	(1.1		)	(18.3		)	(8.8		)
Foreign Exchange Rate Changes	—			—			4.2			(9.1		)	—			—
Ending Balance	$	1,323.4		$	1,092.0		$	211.1		$	183.5		$	149.2		$	135.6

	FOR THE YEAR ENDED DECEMBER 31,
(In Millions)	2019			2018
Beginning Balance	$	28.1		$	34.4
Service Cost	—			—
Interest Cost	1.2			1.3
Actuarial Loss (Gain)	0.2			(6.7		)
Net Claims Paid	(0.7		)	(0.9		)
Ending Balance	$	28.8		$	28.1

Estimated Future Benefit Payments

(In Millions)	TOTAL POSTRETIREMENT MEDICAL BENEFITS
2020	$	2.5
2021	2.4
2022	2.3
2023	2.2
2024	2.1
2025-2029	9.6

(In Millions)	U.S. QUALIFIED PLAN		NON-U.S.PENSION PLANS		U.S. NON-QUALIFIED PLAN
2020	$	81.0	$	3.9	$	15.0
2021	82.9		4.2		16.7
2022	84.3		4.2		18.4
2023	91.1		4.6		20.3
2024	89.6		4.9		16.2
2025-2029	469.7		29.9		60.8

Change in Plan Assets

	U.S. QUALIFIED PLAN						NON-U.S PENSION PLANS
(In Millions)	2019			2018			2019			2018
Fair Value of Assets at Beginning of Period	$	1,380.1		$	1,506.4		$	166.7		$	178.7
Actual Return on Assets	291.8			(85.1		)	18.6			(2.3		)
Employer Contributions	—			50.0			3.1			2.6
Employee Contributions	—			—			0.6			0.4
Settlement	—			—			—			(2.7		)
Benefits Paid	(70.7		)	(91.2		)	(3.6		)	(1.1		)
Foreign Exchange Rate Changes	—			—			4.7			(8.9		)
Fair Value of Assets at End of Period	$	1,601.2		$	1,380.1		$	190.1		$	166.7

Fair Values of U.S. Pension Plan Assets by Major Asset Category, and their Level within Fair Value Hierarchy

The following table presents the fair values of Northern Trust’s U.S. Qualified Plan assets, by major asset category, and their level within the fair value hierarchy defined by GAAP as of December 31, 2019 and 2018.

TABLE 120: FAIR VALUE OF U.S. QUALIFIED PLAN ASSETS

	DECEMBER 31, 2019
(In Millions)	LEVEL 1		LEVEL 2		LEVEL 3		TOTAL
Domestic Common Stock	$	12.3	$	—	$	—	$	12.3
Domestic Corporate Bonds	—		254.6		—		254.6
Foreign Corporate Bonds	—		45.0		—		45.0
U.S. Government Obligations	—		168.3		—		168.3
Non-U.S. Government Obligations	—		18.8		—		18.8
Domestic Municipal and Provincial Bonds	—		23.1		—		23.1
Foreign Municipal and Provincial Bonds	—		0.3		—		0.3
Collective Trust Funds	—		866.6		—		866.6
Mutual Funds	112.8		—		—		112.8
Northern Trust Private Equity Funds	—		—		20.3		20.3
Northern Trust Hedge Funds	—		—		30.2		30.2
Real Estate Funds	—		—		46.3		46.3
Cash and Other	2.6		—		—		2.6
Total Assets at Fair Value	$	127.7	$	1,376.7	$	96.8	$	1,601.2

	DECEMBER 31, 2018
(In Millions)	LEVEL 1		LEVEL 2		LEVEL 3		TOTAL
Domestic Common Stock	$	27.7	$	—	$	—	$	27.7
Domestic Corporate Bonds	—		227.6		—		227.6
Foreign Corporate Bonds	—		34.2		—		34.2
U.S. Government Obligations	—		155.5		—		155.5
Non-U.S. Government Obligations	—		15.1		—		15.1
Domestic Municipal and Provincial Bonds	—		22.7		—		22.7
Foreign Municipal and Provincial Bonds	—		2.0		—		2.0
Collective Trust Funds	—		745.8		—		745.8
Mutual Funds	92.4		—		—		92.4
Exchange Traded Fund	0.1		—		—		0.1
Northern Trust Private Equity Funds	—		—		25.5		25.5
Northern Trust Hedge Funds	—		—		29.2		29.2
Cash and Other	2.3		—		—		2.3
Total Assets at Fair Value	$	122.5	$	1,202.9	$	54.7	$	1,380.1

Changes in Level 3 U.S. Pension Plan Assets

The following table presents the changes in Level 3 assets for the years ended December 31, 2019 and 2018.

TABLE 121: CHANGE IN U.S. QUALIFIED PLAN LEVEL 3 ASSETS

	PRIVATE EQUITY FUNDS						HEDGE FUNDS						REAL ESTATE FUNDS
(In Millions)	2019			2018			2019			2018			2019		2018
Fair Value at January 1	$	25.5		$	29.3		$	29.2		$	44.6		$	—	$	—
Actual Return on Plan Assets(1)	(2.8		)	(1.5		)	1.2			(2.7		)	0.2		—
Realized Gain	7.4			8.7			—			2.4			—		—
Purchases	0.1			0.3			—			—			46.1		—
Sales	(9.9		)	(11.3		)	(0.2		)	(15.1		)	—		—
Fair Value at December 31	$	20.3		$	25.5		$	30.2		$	29.2		$	46.3	$	—

(1) The return on plan assets represents the change in the unrealized gain (loss) on assets still held at December 31.