Commitments and Contingent Liabilities (Tables)

3 Months Ended

Mar. 31, 2026

Commitments and Contingencies Disclosure [Abstract]

Schedule of Fair Value, Off-balance Sheet Risks

The following table provides details of Northern Trust's off-balance sheet financial instruments as of March 31, 2026 and December 31, 2025.

TABLE 64: SUMMARY OF OFF-BALANCE SHEET FINANCIAL INSTRUMENTS

	MARCH 31, 2026						DECEMBER 31, 2025
(In Millions)	ONE YEAR AND LESS		OVER ONE YEAR		TOTAL		ONE YEAR AND LESS		OVER ONE YEAR		TOTAL
Undrawn Commitments(1)	$	11,240.4	$	17,543.9	$	28,784.3	$	10,959.6	$	18,154.7	$	29,114.3
Standby Letters of Credit and Financial Guarantees(2)(3)	147,476.1		701.2		148,177.3		148,883.9		671.0		149,554.9
Commercial Letters of Credit	25.5		—		25.5		18.1		0.1		18.2
Securities Lent with Indemnification	177,081.7		—		177,081.7		170,738.8		—		170,738.8
Total Off-Balance Sheet Financial Instruments	$	335,823.7	$	18,245.1	$	354,068.8	$	330,600.4	$	18,825.8	$	349,426.2

(1) These amounts exclude $116.1 million and $175.1 million of commitments participated to others at March 31, 2026 and December 31, 2025, respectively.

(2) These amounts include $69.3 million and $68.1 million of standby letters of credit secured by cash deposits or participated to others as of March 31, 2026 and December 31, 2025, respectively.

(3) These amounts include a $146.6 billion and $147.8 billion guarantee to the FICC under the sponsored member program, without taking into consideration the related collateral, as of March 31, 2026 and December 31, 2025, respectively.