Regulatory Capital Requirements (Tables)

12 Months Ended

Dec. 31, 2024

Regulatory Capital Requirements Abstract [Abstract]

Risk-Based Capital Amounts and Ratios for Northern Trust on Consolidated Basis and for Bank

The following table provides capital ratios for the Corporation and the Bank determined by Basel III phased in requirements.

TABLE 122: RISK-BASED AND LEVERAGE CAPITAL AMOUNTS AND RATIOS

	DECEMBER 31, 2024								DECEMBER 31, 2023
($ In Millions)	STANDARDIZED APPROACH				ADVANCED APPROACH				STANDARDIZED APPROACH				ADVANCED APPROACH
	BALANCE		RATIO		BALANCE		RATIO		BALANCE		RATIO		BALANCE		RATIO
Common Equity Tier 1 Capital
Northern Trust Corporation	$	11,038.2	12.4	%	$	11,038.2	14.5	%	$	10,179.4	11.4	%	$	10,179.4	13.4	%
The Northern Trust Company	9,983.8		11.4		9,983.8		13.6		10,806.2		12.2		10,806.2		14.6
Minimum to qualify as well-capitalized:
Northern Trust Corporation	N/A		N/A		N/A		N/A		N/A		N/A		N/A		N/A
The Northern Trust Company	5,703.2		6.5		4,789.1		6.5		5,768.4		6.5		4,808.6		6.5
Tier 1 Capital
Northern Trust Corporation	11,870.2		13.3		11,870.2		15.6		11,023.9		12.3		11,023.9		14.5
The Northern Trust Company	9,983.8		11.4		9,983.8		13.6		10,806.2		12.2		10,806.2		14.6
Minimum to qualify as well-capitalized:
Northern Trust Corporation	5,336.4		6.0		4,555.3		6.0		5,371.6		6.0		4,558.8		6.0
The Northern Trust Company	7,019.4		8.0		5,894.2		8.0		7,099.5		8.0		5,918.3		8.0
Total Capital
Northern Trust Corporation	13,423.2		15.1		13,217.3		17.4		12,733.9		14.2		12,514.7		16.5
The Northern Trust Company	11,241.7		12.8		11,035.8		15.0		12,279.3		13.8		12,060.2		16.3
Minimum to qualify as well-capitalized:
Northern Trust Corporation	8,894.0		10.0		7,592.1		10.0		8,952.7		10.0		7,598.0		10.0
The Northern Trust Company	8,774.2		10.0		7,367.8		10.0		8,874.4		10.0		7,397.9		10.0
Tier 1 Leverage
Northern Trust Corporation	11,870.2		8.1		11,870.2		8.1		11,023.9		8.1		11,023.9		8.1
The Northern Trust Company	9,983.8		6.9		9,983.8		6.9		10,806.2		8.0		10,806.2		8.0
Minimum to qualify as well-capitalized:
Northern Trust Corporation	N/A		N/A		N/A		N/A		N/A		N/A		N/A		N/A
The Northern Trust Company	7,262.3		5.0		7,262.3		5.0		6,764.0		5.0		6,764.0		5.0
Supplementary Leverage
Northern Trust Corporation	N/A		N/A		11,870.2		8.9		N/A		N/A		11,023.9		8.6
The Northern Trust Company	N/A		N/A		9,983.8		7.5		N/A		N/A		10,806.2		8.5
Minimum to qualify as well-capitalized:
Northern Trust Corporation	N/A		N/A		N/A		N/A		N/A		N/A		N/A		N/A
The Northern Trust Company	N/A		N/A		3,974.3		3.0		N/A		N/A		3,825.6		3.0