REGULATORY ASSETS, LIABILITIES, AND BALANCING ACCOUNTS (Current Regulatory Balancing Accounts, Net) (Details) - USD ($) $ in Millions	Oct. 21, 2021	Dec. 31, 2021	Dec. 31, 2020
Regulatory Liabilities [Line Items]
Regulatory balancing accounts		$ 496.0	$ 410.0
Regulatory Balancing Accounts Payable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		1,121.0	1,245.0
Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		2,999.0	2,001.0
Electric distribution | Regulatory Balancing Accounts Payable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		121.0	55.0
Electric transmission | Regulatory Balancing Accounts Payable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		24.0	267.0
Gas distribution and transmission | Regulatory Balancing Accounts Payable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		83.0	76.0
Gas distribution and transmission | Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		0.0	102.0
Energy procurement | Regulatory Balancing Accounts Payable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		211.0	158.0
Energy procurement | Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		310.0	413.0
Public purpose programs | Regulatory Balancing Accounts Payable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		259.0	410.0
Public purpose programs | Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		321.0	292.0
Fire hazard prevention memorandum account | Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		50.0	121.0
Fire risk mitigation memorandum account | Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		14.0	33.0
Wildfire mitigation plan memorandum account | Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		67.0	161.0
Wildfire mitigation balancing account | Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		91.0	27.0
General rate case memorandum accounts | Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		468.0	313.0
Vegetation management balancing account | Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		127.0	115.0
Insurance premium costs
Regulatory Liabilities [Line Items]
Regulatory balancing accounts		82.0
Settlement recovery amount	$ 445.5
Insurance premium costs | Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		605.0	135.0
Wildfire expense memorandum account | Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		440.0	0.0
Residential uncollectibles balancing accounts | Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		127.0	0.0
Nuclear decommissioning adjustment mechanism | Regulatory Balancing Accounts Payable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		137.0	0.0
Other | Regulatory Balancing Accounts Payable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		286.0	279.0
Other | Regulatory Balancing Accounts Receivable
Regulatory Liabilities [Line Items]
Total regulatory balancing accounts		$ 379.0	$ 289.0