Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2025	Mar. 31, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Class Of Stock [Line Items]
Common stock, shares authorized (in shares)	400,000,000.0		400,000,000.0	400,000,000.0
Issuance of common stock			$ 429	$ 228	$ 25
Sale of stock, number of shares issued in transaction (in shares)	15,800,000	13,600,000
Sale of stock, price per share (in dollars per share)	$ 18.25	$ 11.00	$ 18.25
Sale of stock, consideration received on transaction	$ 288	$ 150
Preferred stock, shares authorized (in shares)	10,000,000.0		10,000,000.0
Preferred stock, par value (in dollars per share)	$ 0.0001		$ 0.0001
Preferred stock, shares outstanding (in shares)	0		0	0
At-the-Market Facility
Class Of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)			1,400,000		200,000
Sale of stock, consideration received on transaction			$ 18		$ 5
Sale of stock, authorized consideration on transaction					$ 200
Gilead | Second Stock Purchase Agreement
Class Of Stock [Line Items]
Issuance of common stock (in shares)					1,000,000.0
Weighted average closing price of our common stock on grant date (in dollars per share)					$ 19.26
Issuance of common stock					$ 20
Gilead | Third Stock Purchase Agreement Amendment
Class Of Stock [Line Items]
Weighted average closing price of our common stock on grant date (in dollars per share)				$ 21.00
Issuance of common stock				$ 320
Premiums earned, net				87
Contract with customer, asset, before allowance for credit loss				228
Capitalized contract cost, gross				$ 5