Long-Term Debt (Schedule of Future Minimum Lease Payments Related to Sale and Leaseback Transactions) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Long-Term Debt, Maturity, Year One	$ 1,379,140
Long-Term Debt, Maturity, Year Two	2,375,720
Long-Term Debt, Maturity, Year Three	1,043,520
Long-Term Debt, Maturity, Year Four	2,177,293
Long-Term Debt, Maturity, Year Five	405,720
Long-Term Debt, Fair Value	25,181,802	$ 22,489,174
Interest Expense, Debt	1,203,588	1,046,164	$ 940,060
Long-Term Debt	27,991,595	25,107,896
System Energy [Member]
Long-Term Debt, Maturity, Year One	200,000
Long-Term Debt, Maturity, Year Two	0
Long-Term Debt, Maturity, Year Three	162,700
Long-Term Debt, Maturity, Year Four	325,000
Long-Term Debt, Maturity, Year Five	0
Long-Term Debt, Fair Value	1,063,946	696,168
Interest Expense, Debt	48,121	48,416	$ 37,381
Long-Term Debt	1,089,736	$ 738,459
Grand Gulf [Member] | System Energy [Member]
Long-Term Debt, Maturity, Year One	17,188
Long-Term Debt, Maturity, Year Two	17,188
Long-Term Debt, Maturity, Year Three	17,188
Long-Term Debt, Maturity, Year Four	17,188
Long-Term Debt, Maturity, Year Five	17,188
Long-Term Debt, Maturity, after Year Five	120,312
Long-Term Debt, Fair Value	206,252
Interest Expense, Debt	172,049
Long-Term Debt	$ 34,203