Subsequent events	6 Months Ended
	Jun. 30, 2021
Subsequent Events [Abstract]
Subsequent events	Subsequent events. On July 8, 2021, we completed the previously announced acquisition of Effingham County Power, LLC, which owns the Effingham Energy Facility located near Savannah, Georgia, from Effingham County Power Holdings, LLC, an affiliate of the Carlyle Group, Inc. The facility consists of a natural gas-fired combined cycle unit with an aggregate summer planning reserve generation capacity of approximately 511 megawatts. The purchase price was $232,500,000, including working capital and other closing adjustments. We financed the acquisition on an interim basis through the issuance of commercial paper. We have submitted a loan application to the Rural Utilities Service for long-term financing of this acquisition. For any amounts not funded through the Rural Utilities Service, we intend to issue taxable bonds. We expect that any financing from the Rural Utilities Service or through taxable bonds will be secured under our first mortgage indenture.