Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Amount
U.S. federal statutory tax		$ (2,564)	$ (421)	$ (1,054)
Valuation allowance		3,145	1,150	1,199
Federal audit settlement		(490)
Research and development credits		(409)	(472)	(204)
State income tax provision, net of effects on U.S. federal tax		(223)	(75)	(90)
Tax on non-U.S. activities		113	35	64
Impact of subsidiary shares purchased from noncontrolling interests			(29)
Other provision adjustments		47	49	116
Total income tax (benefit)/expense		$ (381)	$ 237	$ 31
Rate
U.S. federal statutory tax		21.00%	21.00%	21.00%
Valuation allowance		(25.80%)	(57.30%)	(23.90%)
Federal audit settlement		4.00%
Research and development credits		3.30%	23.60%	4.10%
State income tax provision, net of effects on U.S. federal tax		1.80%	3.70%	1.80%
Tax on non-U.S. activities		(0.90%)	(1.80%)	(1.30%)
Impact of subsidiary shares purchased from noncontrolling interests			1.50%
Other provision adjustments		(0.30%)	(2.50%)	(2.30%)
Effective income tax rate		3.10%	(11.80%)	(0.60%)
Effective income tax rate reconciliation, tax contingency, amount	$ 490
Deferred tax assets, valuation allowance expense	$ 155