Leases - SPPC - Schedule of Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Lessee, Lease, Description [Line Items]
Variable	$ 552	$ 611	$ 592
Operating	136	161	151
Finance lease, amortization	20	23	18
Finance lease, interest expense	36	38	40
Total lease costs	$ 788	$ 848	$ 821
Weighted-average remaining lease term (years):
Operating leases	7 years 4 months 24 days	7 years 7 months 6 days	7 years 4 months 24 days
Finance leases	28 years 1 month 6 days	28 years 1 month 6 days	27 years 6 months
Weighted-average discount rate:
Operating leases	4.10%	4.30%	4.50%
Finance leases	8.60%	8.60%	8.50%
SPPC
Lessee, Lease, Description [Line Items]
Variable	$ 103	$ 86	$ 78
Operating	1	1	2
Finance lease, amortization	5	5	4
Finance lease, interest expense	8	9	9
Total lease costs	$ 117	$ 101	$ 93
Weighted-average remaining lease term (years):
Operating leases	26 years	27 years 4 months 24 days	27 years 2 months 12 days
Finance leases	28 years 2 months 12 days	28 years 4 months 24 days	27 years 9 months 18 days
Weighted-average discount rate:
Operating leases	5.00%	5.00%	5.00%
Finance leases	8.40%	8.20%	8.10%