Consolidated Statements of Shareholder's Equity - USD ($) $ in Millions	Total	Capital stock	Additional paid-in capital	Accumulated other comprehensive (loss) income	Retained earnings
Balance at Mar. 31, 2023	$ 16,509	$ 915	$ 2	$ (57)	$ 15,649
Net income	1,131				1,131
Other comprehensive income (loss), net of tax	0
Balance at Dec. 31, 2023	17,640	915	2	(57)	16,780
Balance at Sep. 30, 2023	17,049	915	2	(87)	16,219
Net income	561				561
Other comprehensive income (loss), net of tax	30			30
Balance at Dec. 31, 2023	17,640	915	2	(57)	16,780
Balance at Mar. 31, 2024	16,982	915	2	(65)	16,130
Net income	1,215				1,215
Other comprehensive income (loss), net of tax	(2)			(2)
Balance at Dec. 31, 2024	18,195	915	2	(67)	17,345
Balance at Sep. 30, 2024	17,787	915	2	(46)	16,916
Net income	429				429
Other comprehensive income (loss), net of tax	(21)			(21)
Balance at Dec. 31, 2024	$ 18,195	$ 915	$ 2	$ (67)	$ 17,345