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, 2020			1,000
Balance at Dec. 31, 2020		$ 1,411	$ 0	$ 1,111	$ 301	$ (1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 4	28			28
Balance (shares) at Mar. 31, 2021			1,000
Balance at Mar. 31, 2021		$ 1,439	$ 0	1,111	329	(1)
Balance (shares) at Dec. 31, 2021	76,000,000	1,000	1,000
Balance at Dec. 31, 2021	$ 46,694	$ 1,535	$ 0	1,111	425	(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ (129)	28			28
Contributions		$ 130		130
Balance (shares) at Mar. 31, 2022	76,000,000	1,000	1,000
Balance at Mar. 31, 2022	$ 46,530	$ 1,693	$ 0	$ 1,241	$ 453	$ (1)