Management's Statement: Reclassification (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Fuel, purchased power and cost of natural gas sold	$ 71,629	$ 90,200	$ 259,508	$ 339,942
Operations and maintenance	117,308	124,950	242,774	248,534
Taxes - property and production	14,381	13,142	28,499	26,467
Operating Expenses	$ 259,981	279,887	$ 643,846	717,566
Scenario, Adjustment
Fuel, purchased power and cost of natural gas sold		400		1,300
Operations and maintenance		0		(300)
Taxes - property and production		0		(200)
Other operating expenses		(400)		(800)
Operating Expenses		$ 0		$ 0