v3.26.1
FAIR VALUE MEASUREMENTS (Details) - Reliance, Inc. Master 401(k) Plan - USD ($)
Dec. 31, 2025
Dec. 31, 2024
FAIR VALUE MEASUREMENTS    
Investments, at fair value $ 1,815,672,113 $ 1,624,267,378
Cash and cash equivalents    
FAIR VALUE MEASUREMENTS    
Investments, at fair value 71,423,123 74,205,456
Mutual funds    
FAIR VALUE MEASUREMENTS    
Investments, at fair value 204,750,352 204,803,986
Reliance, Inc. common stock    
FAIR VALUE MEASUREMENTS    
Investments, at fair value 175,684,668 174,570,413
Self-directed brokerage accounts    
FAIR VALUE MEASUREMENTS    
Investments, at fair value 17,198,004 12,149,292
Fair Value, Inputs, Level 1, Level 2, and Level 3    
FAIR VALUE MEASUREMENTS    
Investments, at fair value 469,056,147 465,729,147
Level 1    
FAIR VALUE MEASUREMENTS    
Investments, at fair value 469,056,147 465,729,147
Level 1 | Cash and cash equivalents    
FAIR VALUE MEASUREMENTS    
Investments, at fair value 71,423,123 74,205,456
Level 1 | Mutual funds    
FAIR VALUE MEASUREMENTS    
Investments, at fair value 204,750,352 204,803,986
Level 1 | Reliance, Inc. common stock    
FAIR VALUE MEASUREMENTS    
Investments, at fair value 175,684,668 174,570,413
Level 1 | Self-directed brokerage accounts    
FAIR VALUE MEASUREMENTS    
Investments, at fair value 17,198,004 12,149,292
Fair value at NAV | Commingled funds    
FAIR VALUE MEASUREMENTS    
Investments, at fair value 1,322,012,995 1,128,780,183
Fair value at NAV | Common collective trust    
FAIR VALUE MEASUREMENTS    
Investments, at fair value $ 24,602,971 $ 29,758,048