v3.26.1
Restructuring Costs (Restructuring Activities) (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Restructuring Reserve [Roll Forward]      
Liability at beginning of period $ 129 $ 117 $ 117
Restructuring charges 45 32 222
Cash payments (79)   (205)
Non-cash charges (1)   (5)
Liability at end of period 94   129
Severance      
Restructuring Reserve [Roll Forward]      
Liability at beginning of period 99 75 75
Restructuring charges 32   174
Cash payments (68)   (150)
Non-cash charges 0   0
Liability at end of period 63   99
Real Estate Related Costs      
Restructuring Reserve [Roll Forward]      
Liability at beginning of period 30 42 42
Restructuring charges 5   32
Cash payments (3)   (39)
Non-cash charges (1)   (5)
Liability at end of period 31   30
Information Technology      
Restructuring Reserve [Roll Forward]      
Liability at beginning of period 0 0 0
Restructuring charges 0   0
Cash payments 0   0
Non-cash charges 0   0
Liability at end of period 0   0
Consulting and Other Outside Services      
Restructuring Reserve [Roll Forward]      
Liability at beginning of period 0 $ 0 0
Restructuring charges 8   16
Cash payments (8)   (16)
Non-cash charges 0   0
Liability at end of period $ 0   $ 0