v3.26.1
Investments (Tables)
 12 Months Ended
Dec. 31, 2025
EBP 005  
EBP, Master Trust [Line Items]  
Schedule of Master Trust Net Assets
The following table is a summary, at fair value, of the net assets of the master trust by investment type as of December 31, 2025 and 2024: 
20252024
Master Trust BalancesPlan's Interest in Master Trust BalancesMaster Trust BalancesPlan's Interest in Master Trust Balances
Allegheny Technologies Incorporated Master Trust:
Common collective trusts$681,459,280 $193,253,854 $611,412,373 $174,443,223 
Registered investment companies452,989,632 99,069,806 385,843,440 77,386,014 
Pooled separate accounts151,624,798 43,371,551 140,662,433 37,328,857 
Corporate common stock93,113,165 35,172,294 68,021,722 28,527,659 
Cash4,805,431 1,789,769 3,451,804 1,240,311 
Total investments at fair value$1,383,992,306 $372,657,274 $1,209,391,772 $318,926,064 
Plan's interest in master trust27 %26 %
The following table is a summary, at contract value, of the net assets of the Allegheny Technologies Incorporated Master Trust by investment type as of December 31, 2025 and 2024: 
20252024
Master Trust BalancesPlan's Interest in Master Trust BalancesMaster Trust BalancesPlan's Interest in Master Trust Balances
Allegheny Technologies Incorporated Master Trust:
Synthetic investment contracts$113,818,599 $42,391,411 $120,666,597 $43,208,303 
Total investments at contract value$113,818,599 $42,391,411 $120,666,597 $43,208,303 
Investment income attributable to the master trust for the year ended December 31, 2025 was as follows: 

Allegheny Technologies Incorporated Master Trust
Net appreciation in fair value of investments$235,511,834 
Investment income from investments at fair value14,683,788 
Investment income from investments at contract value3,532,110 
Administrative expenses and other, net(115,396)
Total investment income$253,612,336