Schedule H, Line 4i – Schedule of Assets (Held At End of Year) (Details) - EBP 002	12 Months Ended
Dec. 31, 2025 USD ($)
EBP, Schedule of Asset Held for Investment [Line Items]
Entity tax identification number	36-1561860
Plan number	002
Participant loan, cost	$ 0
Participant loan, current value	28,087,906
Total Cost	2,442,307,515
Total Current Value	$ 3,760,343,798
Minimum
EBP, Schedule of Asset Held for Investment [Line Items]
Participant loans, interest rates	4.25%
Maximum
EBP, Schedule of Asset Held for Investment [Line Items]
Participant loans, interest rates	9.50%
Collective trust funds
EBP, Schedule of Asset Held for Investment [Line Items]
Cost	$ 2,086,664,827
Current Value	3,192,944,512
Mutual funds
EBP, Schedule of Asset Held for Investment [Line Items]
Cost	89,095,878
Current Value	101,751,231
Stable value portfolio
EBP, Schedule of Asset Held for Investment [Line Items]
Cost	171,427,516
Current Value	166,706,823
Investment, Identifier [Axis]: Collective Trust Funds \| Allspring Core Plus Bond CIT D1
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	6,363,731
Cost	64,337,129
Current Value	67,813,188
Investment, Identifier [Axis]: Collective Trust Funds \| BlackRock LifePath® Index 2030 Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	5,522,908
Cost	83,058,128
Current Value	100,820,695
Investment, Identifier [Axis]: Collective Trust Funds \| BlackRock LifePath® Index 2035 Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	6,146,667
Cost	97,584,756
Current Value	121,999,044
Investment, Identifier [Axis]: Collective Trust Funds \| BlackRock LifePath® Index 2040 Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	5,244,509
Cost	86,512,723
Current Value	112,256,622
Investment, Identifier [Axis]: Collective Trust Funds \| BlackRock LifePath® Index 2045 Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	6,080,411
Cost	103,468,464
Current Value	139,021,305
Investment, Identifier [Axis]: Collective Trust Funds \| BlackRock LifePath® Index 2050 Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	5,034,610
Cost	86,919,475
Current Value	120,400,192
Investment, Identifier [Axis]: Collective Trust Funds \| BlackRock LifePath® Index 2055 Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	3,222,952
Cost	56,246,660
Current Value	78,367,367
Investment, Identifier [Axis]: Collective Trust Funds \| BlackRock LifePath® Index 2060 Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	2,187,641
Cost	38,282,641
Current Value	53,231,206
Investment, Identifier [Axis]: Collective Trust Funds \| BlackRock LifePath® Index 2065 Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	1,105,587
Cost	17,224,755
Current Value	22,096,261
Investment, Identifier [Axis]: Collective Trust Funds \| BlackRock LifePath® Index 2070 Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	127,004
Cost	1,459,990
Current Value	1,532,094
Investment, Identifier [Axis]: Collective Trust Funds \| BlackRock LifePath® Index Retirement Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	5,325,663
Cost	75,415,526
Current Value	84,804,801
Investment, Identifier [Axis]: Collective Trust Funds \| Jennison U.S. Small/Mid Cap Equity Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	987,019
Cost	97,576,839
Current Value	113,605,896
Investment, Identifier [Axis]: Collective Trust Funds \| MFS International Equity Fund Class 3
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	4,154,161
Cost	69,003,008
Current Value	94,382,542
Investment, Identifier [Axis]: Collective Trust Funds \| Northern Collective Short Term Investment Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	22,474,642
Cost	22,474,642
Current Value	22,474,642
Investment, Identifier [Axis]: Collective Trust Funds \| Northern Trust Collective Aggregate Bond Index Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	1,177,165
Cost	125,198,810
Current Value	135,350,474
Investment, Identifier [Axis]: Collective Trust Funds \| Northern Trust Collective All Country World ex-US Investable Market Index Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	1,017,704
Cost	159,737,884
Current Value	257,601,252
Investment, Identifier [Axis]: Collective Trust Funds \| Northern Trust Collective Russell 2000 Index Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	612,432
Cost	76,110,533
Current Value	112,528,202
Investment, Identifier [Axis]: Collective Trust Funds \| Northern Trust Collective S&P 400 Index Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	833,144
Cost	104,929,509
Current Value	172,877,285
Investment, Identifier [Axis]: Collective Trust Funds \| Northern Trust Collective S&P 500 Index Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	3,324,485
Cost	438,749,966
Current Value	1,056,355,076
Investment, Identifier [Axis]: Collective Trust Funds \| Northern Trust Treasury-Inflation Protected Securities Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	391,556
Cost	46,225,383
Current Value	49,872,430
Investment, Identifier [Axis]: Collective Trust Funds \| T. Rowe Price Institutional U.S. Structured Research Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	2,755,540
Cost	236,148,006
Current Value	275,553,938
Investment, Identifier [Axis]: Mutual Funds \| DFA Emerging Markets Core Equity Portfolio
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	1,972,028
Cost	44,016,388
Current Value	57,346,587
Investment, Identifier [Axis]: Mutual Funds \| PIMCO All Asset Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	2,549,224
Cost	29,435,073
Current Value	29,112,132
Investment, Identifier [Axis]: Mutual Funds \| PIMCO International Bond Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	1,540,031
Cost	15,644,417
Current Value	15,292,512
Investment, Identifier [Axis]: Northern Trust common stock funds \| Northern Trust Corporation
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	1,982,966
Cost	95,119,294
Current Value	270,853,326
Investment, Identifier [Axis]: Stable Value Portfolio \| Metropolitan Tower Life Insurance
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	28,281,941
Cost	28,281,941
Current Value	27,521,129
Investment, Identifier [Axis]: Stable Value Portfolio \| Nationwide Life Insurance Company
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	28,756,696
Cost	28,756,696
Current Value	27,982,018
Investment, Identifier [Axis]: Stable Value Portfolio \| Prudential Insurance Company
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	28,627,923
Cost	28,627,923
Current Value	27,874,567
Investment, Identifier [Axis]: Stable Value Portfolio \| RGA Reinsurance Company
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	28,757,628
Cost	28,757,628
Current Value	27,985,846
Investment, Identifier [Axis]: Stable Value Portfolio \| Transamerica Premier Life Insurance Company
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	28,338,907
Cost	28,338,907
Current Value	27,506,956
Investment, Identifier [Axis]: Stable Value Portfolio \| Voya Retirement Insurance
EBP, Schedule of Asset Held for Investment [Line Items]
Par value of shares	28,664,421
Cost	28,664,421
Current Value	$ 27,836,307

The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 12
-Subsection b-2

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EBP, Asset Held For Investment, Cost

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EBP, Asset Held for Investment, Participant Loan, Cost

+ References

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- Definition

Amount of total assets in schedule of asset held for investment of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Includes, but is not limited to, current value of investment, participant loan, and plan interest in master trust.

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- Definition

Current value of investment, excluding plan interest in master trust, in schedule of asset held for investment of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Includes, but is not limited to, derivative, investment measured at net asset value per share as practical expedient, and insurance contract.

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- Definition

Amount, after deemed distribution, of participant loan in schedule of asset held for investment of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

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- Definition

Cost of investment, excluding plan interest in master trust, held by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Includes, but is not limited to, derivative, investment measured at net asset value per share as practical expedient, and insurance contract.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule I))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-02(d))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
-Subsection 10
-Paragraph b
-Subparagraph (4)
-Publisher DOL-EBSA

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
-Subsection 10
-Paragraph b
-Subparagraph (1)(i)(C)
-Publisher DOL-EBSA

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- Definition

Par or maturity value of investment included in asset held for investment schedule by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Includes, but is not limited to, derivative, investment measured at net asset value per share as practical expedient, and insurance contract.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule I))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
-Subsection 10
-Paragraph b
-Subparagraph (3)
-Publisher DOL-EBSA

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
-Subsection 10
-Paragraph b
-Subparagraph (1)(i)(B)
-Publisher DOL-EBSA

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
-Subsection 10
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-Subparagraph (2)(i)(B)
-Publisher DOL-EBSA

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
-Subsection 6
-Paragraph d
-Subparagraph (1)(ii)
-Publisher DOL-EBSA

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- Definition

Interest rate on participant loan in schedule of asset held for investment of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

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- Definition

Plan number of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)), in three-digit numeric format.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule I))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule I))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

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