Consolidated Statements of Changes in Equity (Unaudited) - SPPC - USD ($) $ in Millions	Total	SPPC	SPPC Common Stock	SPPC Additional Paid-in Capital	SPPC Retained Earnings	SPPC Accumulated Other Comprehensive (Loss) Income, Net
Balance (shares) at Dec. 31, 2022			1,000
Balance at Dec. 31, 2022		$ 2,048	$ 0	$ 1,576	$ 473	$ (1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 989	27			27
Balance (shares) at Mar. 31, 2023			1,000
Balance at Mar. 31, 2023		$ 2,075	$ 0	1,576	500	(1)
Balance (shares) at Dec. 31, 2023	76,000,000	1,000	1,000
Balance at Dec. 31, 2023	$ 48,434	$ 2,065	$ 0	1,576	490	(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 653	10			10
Dividends declared		$ (200)			(200)
Balance (shares) at Mar. 31, 2024	76,000,000	1,000	1,000
Balance at Mar. 31, 2024	$ 48,959	$ 1,875	$ 0	$ 1,576	$ 300	$ (1)