Consolidated Statements of Comprehensive Income - GAS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net Income (Loss)	$ 2,309	$ 3,103	$ 4,744
Qualifying hedges:
Changes in fair value, net of tax	(49)	10	(115)
Reclassification adjustment for amounts included in net income, net of tax	96	(40)	57
Pension and other postretirement benefit plans:
Benefit plan net gain (loss), net of tax	98	(55)	(64)
Current period change	158	(75)	(118)
Comprehensive Income (Loss) Attributable to Parent	2,551	3,044	4,621
Southern Company Gas
Net Income (Loss)	539	590	585
Qualifying hedges:
Changes in fair value, net of tax	17	(21)	(5)
Reclassification adjustment for amounts included in net income, net of tax	(11)	7	2
Pension and other postretirement benefit plans:
Benefit plan net gain (loss), net of tax	40	(15)	(16)
Current period change	46	(29)	(19)
Comprehensive Income (Loss) Attributable to Parent	$ 585	$ 561	$ 566