Asset Retirement Obligations	3 Months Ended
	Mar. 31, 2024
Asset Retirement Obligation [Abstract]
Asset Retirement Obligations	Asset Retirement Obligations. On February 14, 2024, Plant Vogtle Unit No. 4's nuclear reactor achieved self-sustaining nuclear fission, commonly referred to as initial criticality. During the first quarter of 2024, we recognized new nuclear asset retirement obligations totaling $65.1 million. During the three months ended March 31, 2024, no change in cash flow estimates related to existing coal ash related asset retirement obligations was recorded. We expect to periodically receive more refined estimates from Georgia Power regarding closure costs and the timing of expenditures.