v3.26.1
Fair Value Measurements (Tables)
12 Months Ended
Dec. 31, 2025
Community Financial System, Inc. 401(k) Employee Stock Ownership Plan  
Fair Value Measurements  
Schedule of financial assets that were accounted for at fair value on a recurring basis

As of December 31, 2025

  ​ ​ ​

  ​ ​ ​

  ​ ​ ​

  ​ ​ ​

Total Fair

Level 1

Level 2

Level 3

Value

Mutual funds

$

368,463,156

$

$

$

368,463,156

Common stock of plan sponsor

 

83,352,180

 

 

 

83,352,180

Self-directed brokerage

 

 

8,046,915

 

 

8,046,915

Total assets at fair value

$

451,815,336

$

8,046,915

$

 

459,862,251

Investments valued using Net Asset Value (a)

 

  ​

 

  ​

 

  ​

 

13,659,977

$

473,522,228

As of December 31, 2024

  ​ ​ ​

  ​ ​ ​

  ​ ​ ​

  ​ ​ ​

Total Fair

Level 1

Level 2

Level 3

Value

Mutual funds

$

327,318,655

$

$

$

327,318,655

Common stock of plan sponsor

 

87,776,467

 

 

 

87,776,467

Self-directed brokerage

 

 

7,073,868

 

 

7,073,868

Total assets at fair value

$

415,095,122

$

7,073,868

$

 

422,168,990

Investments valued using Net Asset Value (a)

 

  ​

 

  ​

 

  ​

 

14,869,236

$

437,038,226

(a)

In accordance with ASC Subtopic 820-10, certain investments that were measured at net asset value per share (or its equivalents) as a practical expedient have not been classified in the fair value hierarchy.