Medical Claims Payable - Reconciliation of the Beginning and Ending Balances for Medical Claims Payable (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Gross medical claims payable, beginning of year	$ 15,580	$ 15,865	$ 15,348
Ceded medical claims payable, beginning of year	(13)	(7)	(6)
Net medical claims payable, beginning of year	15,567	15,858	15,342
Business combinations and purchase adjustments	344	143	0
Net incurred medical claims:
Current year	145,566	125,370	121,798
Prior years redundancies	(1,290)	(1,731)	(1,571)
Total net incurred medical claims	144,276	123,639	120,227
Net payments attributable to:
Current year medical claims	130,265	110,930	107,146
Prior years medical claims	13,141	13,143	12,565
Total net payments	143,406	124,073	119,711
Net medical claims payable, end of year	16,781	15,567	15,858
Ceded medical claims payable, end of year	48	13	7
Gross medical claims payable, end of year	$ 16,829	$ 15,580	$ 15,865