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, 2019			1,000
Balance at Dec. 31, 2019		$ 1,320	$ 0	$ 1,111	$ 210	$ (1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 1,786	38			38
Dividends declared		(20)			(20)
Balance (shares) at Jun. 30, 2020			1,000
Balance at Jun. 30, 2020		1,338	$ 0	1,111	228	(1)
Balance (shares) at Mar. 31, 2020			1,000
Balance at Mar. 31, 2020		1,345	$ 0	1,111	235	(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 1,116	13			13
Dividends declared		(20)			(20)
Balance (shares) at Jun. 30, 2020			1,000
Balance at Jun. 30, 2020		$ 1,338	$ 0	1,111	228	(1)
Balance (shares) at Dec. 31, 2020	76,000,000	1,000	1,000
Balance at Dec. 31, 2020	$ 43,010	$ 1,411	$ 0	1,111	301	(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 2,285	$ 45			45
Balance (shares) at Jun. 30, 2021	76,000,000	1,000	1,000
Balance at Jun. 30, 2021	$ 45,412	$ 1,456	$ 0	1,111	346	(1)
Balance (shares) at Mar. 31, 2021			1,000
Balance at Mar. 31, 2021		1,439		1,111	329	(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 2,281	$ 17			17
Balance (shares) at Jun. 30, 2021	76,000,000	1,000	1,000
Balance at Jun. 30, 2021	$ 45,412	$ 1,456	$ 0	$ 1,111	$ 346	$ (1)