Equity (Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning	$ (92)	$ (169)	$ (188)
Other comprehensive income (loss) before reclassifications	84	63	(3)
Amounts reclassified from AOCI	7	11	24
Total other comprehensive income, net of tax	91	74	21
Less other comprehensive loss attributable to noncontrolling interests	(1)	7	1
Acquisition of Gulf Power			(1)
AOCI Impact of Disposal of a Business		10
Accumulated other comprehensive loss, ending	0	(92)	(169)
AOCI Including Portion Attributable to Noncontrolling Interest, Net Of Tax	6
Net Unrealized Gains (Losses) on Cash Flow Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning	8	(27)	(55)
Other comprehensive income (loss) before reclassifications	0	0	0
Amounts reclassified from AOCI	6	12	29
Total other comprehensive income, net of tax	6	12	29
Less other comprehensive loss attributable to noncontrolling interests	0	0	0
Acquisition of Gulf Power			(1)
AOCI Impact of Disposal of a Business		23
Accumulated other comprehensive loss, ending	14	8	(27)
AOCI Including Portion Attributable to Noncontrolling Interest, Net Of Tax	0
Net Unrealized Gains (Losses) on Available for Sale Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning	20	11	(7)
Other comprehensive income (loss) before reclassifications	(11)	12	20
Amounts reclassified from AOCI	(4)	(3)	(2)
Total other comprehensive income, net of tax	(15)	9	18
Less other comprehensive loss attributable to noncontrolling interests	0	0	0
Acquisition of Gulf Power			0
AOCI Impact of Disposal of a Business		0
Accumulated other comprehensive loss, ending	5	20	11
AOCI Including Portion Attributable to Noncontrolling Interest, Net Of Tax	0
Defined Benefit Pension and Other Benefits Plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning	(75)	(114)	(65)
Other comprehensive income (loss) before reclassifications	95	37	(46)
Amounts reclassified from AOCI	5	2	(3)
Total other comprehensive income, net of tax	100	39	(49)
Less other comprehensive loss attributable to noncontrolling interests	0	0	0
Acquisition of Gulf Power			0
AOCI Impact of Disposal of a Business		0
Accumulated other comprehensive loss, ending	25	(75)	(114)
AOCI Including Portion Attributable to Noncontrolling Interest, Net Of Tax	0
Net Unrealized Gains (Losses) on Foreign Currency Translation
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning	(49)	(42)	(63)
Other comprehensive income (loss) before reclassifications	(1)	13	22
Amounts reclassified from AOCI	0	0	0
Total other comprehensive income, net of tax	(1)	13	22
Less other comprehensive loss attributable to noncontrolling interests	(1)	7	1
Acquisition of Gulf Power			0
AOCI Impact of Disposal of a Business		(13)
Accumulated other comprehensive loss, ending	(49)	(49)	(42)
AOCI Including Portion Attributable to Noncontrolling Interest, Net Of Tax	6
Other Comprehensive Income (Loss) Related to Equity Method Investees
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning	4	3	2
Other comprehensive income (loss) before reclassifications	1	1	1
Amounts reclassified from AOCI	0	0	0
Total other comprehensive income, net of tax	1	1	1
Less other comprehensive loss attributable to noncontrolling interests	0	0	0
Acquisition of Gulf Power			0
AOCI Impact of Disposal of a Business		0
Accumulated other comprehensive loss, ending	5	$ 4	$ 3
AOCI Including Portion Attributable to Noncontrolling Interest, Net Of Tax	$ 0