v3.25.3
Segments - Reconciliation of Gross Margin to Consolidated Income (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Revenue:        
Premium revenue $ 10,841 $ 9,694 $ 32,337 $ 28,644
Service revenue 21 20 65 60
Revenue from external customers 10,862 9,714 32,402 28,704
Other operating revenues 615 626 1,649 1,447
Total revenue 11,477 10,340 34,051 30,151
Operating expenses:        
Medical care costs 10,044 8,643 29,352 25,425
Cost of service revenue 20 19 58 55
Segment expenses 10,064 8,662 29,410 25,480
Other operating expenses 1,276 1,211 3,698 3,344
Operating income 137 467 943 1,327
Less: interest expense 49 29 140 84
Income before income tax expense 88 438 803 1,243
Medical margin        
Operating expenses:        
Segment margin 797 1,051 2,985 3,219
Service margin        
Operating expenses:        
Segment margin 1 1 7 5
Operating segments | Medicaid        
Revenue:        
Premium revenue 8,015 7,668 24,174 22,538
Service revenue 0 0 0 0
Revenue from external customers 8,015 7,668 24,174 22,538
Operating expenses:        
Medical care costs 7,376 6,938 22,047 20,350
Cost of service revenue 0 0 0 0
Segment expenses 7,376 6,938 22,047 20,350
Operating segments | Medicaid | Medical margin        
Operating expenses:        
Segment margin 639 730 2,127 2,188
Operating segments | Medicaid | Service margin        
Operating expenses:        
Segment margin 0 0 0 0
Operating segments | Medicare        
Revenue:        
Premium revenue 1,610 1,367 4,686 4,250
Service revenue 0 0 0 0
Revenue from external customers 1,610 1,367 4,686 4,250
Operating expenses:        
Medical care costs 1,507 1,225 4,250 3,728
Cost of service revenue 0 0 0 0
Segment expenses 1,507 1,225 4,250 3,728
Operating segments | Medicare | Medical margin        
Operating expenses:        
Segment margin 103 142 436 522
Operating segments | Medicare | Service margin        
Operating expenses:        
Segment margin 0 0 0 0
Operating segments | Marketplace        
Revenue:        
Premium revenue 1,197 659 3,401 1,856
Service revenue 0 0 0 0
Revenue from external customers 1,197 659 3,401 1,856
Operating expenses:        
Medical care costs 1,144 480 2,990 1,347
Cost of service revenue 0 0 0 0
Segment expenses 1,144 480 2,990 1,347
Operating segments | Marketplace | Medical margin        
Operating expenses:        
Segment margin 53 179 411 509
Operating segments | Marketplace | Service margin        
Operating expenses:        
Segment margin 0 0 0 0
Operating segments | Other        
Revenue:        
Premium revenue 19 0 76 0
Service revenue 21 20 65 60
Revenue from external customers 40 20 141 60
Operating expenses:        
Medical care costs 17 0 65 0
Cost of service revenue 20 19 58 55
Segment expenses 37 19 123 55
Operating segments | Other | Medical margin        
Operating expenses:        
Segment margin 2 0 11 0
Operating segments | Other | Service margin        
Operating expenses:        
Segment margin $ 1 $ 1 $ 7 $ 5