v3.26.1
Allowance for Expected Credit Losses - Premiums receivable (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Credit Loss [Abstract]        
Balance at beginning of period $ 6,526 $ 6,607 $ 5,723 $ 5,634
Balance at end of period 7,160 7,067 7,160 7,067
Allowance for Expected Credit Losses        
Balance at beginning of period 39 43 43 45
Change for provision of expected credit losses [1] 2 3 (2) 1
Balance at end of period 41 46 41 46
Premium receivable, write-offs during the period $ 0 $ 1 $ 0 $ 1
[1] Amounts deemed uncollectible are written-off in operating expenses. For the 2026 second quarter and 2025 second quarter, amounts written off were nil and $1 million, respectively. For the six months ended June 30, 2026 and 2025 period, amounts written off were nil and $1 million, respectively.