Investments - Neumora Therapeutics, Inc. (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Schedule of Equity Method Investments [Line Items]
Equity securities	$ 4,188	$ 4,514
Unrealized gain (loss) on equity method investment	$ (21)	$ 98	$ (165)
Neumora Therapeutics, Inc.
Schedule of Equity Method Investments [Line Items]
Ownership percentage	21.90%	23.20%
Equity securities	$ 375	$ 603
Unrealized gain (loss) on equity method investment	$ (228)	$ 238	$ 105
Neumora Therapeutics, Inc. | Maximum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	5.00%
Neumora Therapeutics, Inc. | Minimum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	10.00%