Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2025

EBP 002

EBP, Investment, Fair Value and NAV [Line Items]

Investments

The following tables present Plan investments, including those measured and recorded at fair value on a recurring basis, as well as their levels within the fair value hierarchy, each as of December 31, 2025 and 2024:

Description	Level 1		Level 2		Level 3		Balance as of December 31,
							2025
Fair value of investments in the fair value hierarchy:
Northern Trust common stock funds	$	270,853,326	$	—	$	—	$	270,853,326
Mutual funds	101,751,231		—		—		101,751,231
Collective trust funds	—		3,192,944,512		—		3,192,944,512
Total fair value of investments in the fair value hierarchy	372,604,557		3,192,944,512		—		3,565,549,069
Stable value portfolio measured at contract value(1)	—		—		—		171,427,516
Total investments	$	372,604,557	$	3,192,944,512	$	—	$	3,736,976,585

Description	Level 1		Level 2		Level 3		Balance as of December 31,
							2024
Fair value of investments in the fair value hierarchy:
Northern Trust common stock funds	$	232,116,478	$	—	$	—	$	232,116,478
Mutual funds	82,444,860		—		—		82,444,860
Collective trust funds	—		2,838,812,747		—		2,838,812,747
Total fair value of investments in the fair value hierarchy	314,561,338		2,838,812,747		—		3,153,374,085
Stable value portfolio measured at contract value(1)	—		—		—		161,070,016
Total investments	$	314,561,338	$	2,838,812,747	$	—	$	3,314,444,101

(1) The investments in fully benefit-responsive investment contracts through the Stable Value Portfolio are measured at contract value and have not been categorized in the fair value hierarchy.