Long-Term Debt (Schedule of Long-Term Debt Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 15, 2021	Jun. 14, 2021	Dec. 31, 2020	Sep. 26, 2019	Mar. 05, 2018	Oct. 10, 2017
Debt Instrument [Line Items]
Total PSE long-term debt	$ 6,857,160
Long Term Debt, Reconciliation, Fair Value Adjustment	(156,849)			$ (165,357)
Long-term Debt, term loan					$ 210,000
Long-term Line of Credit, Noncurrent	33,300			14,700
Unamortized discount on senior notes	(7,404)			(4,947)
Long-term Debt, Excluding Current Maturities	6,203,766			5,892,440
Current maturities of long-term debt	450,000			526,412
Short-term debt	140,000			373,800
$210M Term Loan Due 2022
Debt Instrument [Line Items]
Long-term Debt, term loan	$ 0			210,000
Working Capital Needs
Debt Instrument [Line Items]
Current borrowing capacity of line of credit							$ 800,000
Senior Secured Note | 5.625% Senior Secured Note Due 2022
Debt Instrument [Line Items]
Stated interest rate percent	5.625%
Total PSE long-term debt	$ 0			450,000
Senior Secured Note | 3.650% Senior Secured Note Due 2025 [Member]
Debt Instrument [Line Items]
Stated interest rate percent	3.65%
Total PSE long-term debt	$ 400,000			400,000
Senior Secured Note | 6.000% Senior Secured Note Due 2021
Debt Instrument [Line Items]
Stated interest rate percent			6.00%
Current maturities of long-term debt			$ 500,000
Senior Secured Note | 4.100% Senior Secured Note Due 2030
Debt Instrument [Line Items]
Stated interest rate percent	4.10%
Total PSE long-term debt	$ 650,000			650,000
Senior Secured Note | 2.379% Senior Secured Note Due 2028
Debt Instrument [Line Items]
Stated interest rate percent	2.379%		2.379%
Total PSE long-term debt	$ 500,000		$ 500,000	0
Long-term Debt, Term			7 years
Subsidiaries [Member]
Debt Instrument [Line Items]
Total PSE long-term debt	4,823,860
Unamortized discount on senior notes	(39,141)			(35,816)
Long-term Debt, Excluding Current Maturities	4,784,719			4,338,044
Current maturities of long-term debt	0			2,412
Short-term debt	$ 140,000			373,800
Subsidiaries [Member] | Working Capital Needs
Debt Instrument [Line Items]
Current borrowing capacity of line of credit							$ 800,000
Subsidiaries [Member] | Senior Notes and First Mortgage Bonds | 7.150% Series Due 2025
Debt Instrument [Line Items]
Stated interest rate percent	7.15%
Total PSE long-term debt	$ 15,000			15,000
Subsidiaries [Member] | Senior Notes and First Mortgage Bonds | 7.200% Series Due 2025
Debt Instrument [Line Items]
Stated interest rate percent	7.20%
Total PSE long-term debt	$ 2,000			2,000
Subsidiaries [Member] | Pollution Control Bonds | 3.900% Series Due 2031
Debt Instrument [Line Items]
Stated interest rate percent	3.90%
Total PSE long-term debt	$ 138,460			138,460
Subsidiaries [Member] | Pollution Control Bonds | 4.000% Series Due 2031
Debt Instrument [Line Items]
Stated interest rate percent	4.00%
Total PSE long-term debt	$ 23,400			23,400
Subsidiaries [Member] | Senior Secured Note | 7.020% Series Due 2027
Debt Instrument [Line Items]
Stated interest rate percent	7.02%
Total PSE long-term debt	$ 300,000			300,000
Subsidiaries [Member] | Senior Secured Note | 7.000% Series Due 2029
Debt Instrument [Line Items]
Stated interest rate percent	7.00%
Total PSE long-term debt	$ 100,000			100,000
Subsidiaries [Member] | Senior Secured Note | 5.483% Series Due 2035
Debt Instrument [Line Items]
Stated interest rate percent	5.483%
Total PSE long-term debt	$ 250,000			250,000
Subsidiaries [Member] | Senior Secured Note | 6.724% Series Due 2036
Debt Instrument [Line Items]
Stated interest rate percent	6.724%
Total PSE long-term debt	$ 250,000			250,000
Subsidiaries [Member] | Senior Secured Note | 6.274% Series Due 2037
Debt Instrument [Line Items]
Stated interest rate percent						6.274%
Total PSE long-term debt	$ 300,000			300,000
Subsidiaries [Member] | Senior Secured Note | 5.757% Series Due 2039
Debt Instrument [Line Items]
Stated interest rate percent	5.757%
Total PSE long-term debt	$ 350,000			350,000
Subsidiaries [Member] | Senior Secured Note | 5.795% Series Due 2040
Debt Instrument [Line Items]
Stated interest rate percent	5.795%
Total PSE long-term debt	$ 325,000			325,000
Subsidiaries [Member] | Senior Secured Note | 5.764% Series Due 2040
Debt Instrument [Line Items]
Stated interest rate percent	5.764%
Total PSE long-term debt	$ 250,000			250,000
Subsidiaries [Member] | Senior Secured Note | 4.434% Series Due 2041
Debt Instrument [Line Items]
Stated interest rate percent	4.434%
Total PSE long-term debt	$ 250,000			250,000
Subsidiaries [Member] | Senior Secured Note | 5.638% Series Due 2041
Debt Instrument [Line Items]
Stated interest rate percent	5.638%
Total PSE long-term debt	$ 300,000			300,000
Subsidiaries [Member] | Senior Secured Note | 4.300% Series Due 2045
Debt Instrument [Line Items]
Stated interest rate percent	4.30%
Total PSE long-term debt	$ 425,000			425,000
Subsidiaries [Member] | Senior Secured Note | 4.223% Series Due 2048
Debt Instrument [Line Items]
Stated interest rate percent	4.223%
Total PSE long-term debt	$ 600,000			600,000
Subsidiaries [Member] | Senior Secured Note | 3.250% Senior Secured Note Due 2049 [Member]
Debt Instrument [Line Items]
Stated interest rate percent	3.25%
Total PSE long-term debt	$ 450,000			450,000
Subsidiaries [Member] | Senior Secured Note | 4.700% Series Due 2051
Debt Instrument [Line Items]
Stated interest rate percent	4.70%
Total PSE long-term debt	$ 45,000			45,000
Subsidiaries [Member] | Senior Secured Note | 2.893% Senior Secured Note Due 2051
Debt Instrument [Line Items]
Stated interest rate percent	2.893%	2.893%
Total PSE long-term debt	$ 450,000	$ 450,000		$ 0
Long-term Debt, Term		30 years