Derivatives (Tables)

3 Months Ended

Mar. 31, 2018

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Energy-Related Derivatives

At March 31, 2018, the net volume of energy-related derivative contracts for natural gas positions for the Southern Company system, together with the longest hedge date over which the respective entity is hedging its exposure to the variability in future cash flows for forecasted transactions and the longest non-hedge date for derivatives not designated as hedges, were as follows:

	Net Purchased mmBtu	Longest Hedge Date	Longest Non-Hedge Date
	(in millions)
Southern Company(*)	670	2021	2026
Alabama Power	74	2021	—
Georgia Power	167	2021	—
Gulf Power	17	2020	—
Mississippi Power	59	2021	—
Southern Power	14	2020	2018
Southern Company Gas(*)	339	2020	2026

(*) Southern Company's and Southern Company Gas' derivative instruments include both long and short natural gas positions. A long position is a contract to purchase natural gas and a short position is a contract to sell natural gas. Southern Company Gas' volume represents the net of long natural gas positions of 3.6 billion mmBtu and short natural gas positions of 3.3 billion mmBtu as of March 31, 2018, which is also included in Southern Company's total volume.

Schedule of Interest Rate Derivatives

At March 31, 2018, the following interest rate derivatives were outstanding:

	Notional Amount		Interest Rate Received	Weighted Average Interest Rate Paid	Hedge Maturity Date	Fair Value Gain (Loss) at March 31, 2018
	(in millions)					(in millions)
Fair Value Hedges of Existing Debt
Southern Company(*)	$	300	2.75%	3-month LIBOR + 0.92%	June 2020	$	(5	)
Southern Company(*)	1,500		2.35%	1-month LIBOR + 0.87%	July 2021	(50		)
Georgia Power	250		5.40%	3-month LIBOR + 4.02%	June 2018	(1		)
Georgia Power	500		1.95%	3-month LIBOR + 0.76%	December 2018	(4		)
Georgia Power	200		4.25%	3-month LIBOR + 2.46%	December 2019	(2		)
Southern Company Consolidated	$	2,750				$	(62	)

(*) Represents the Southern Company parent entity.

Schedule of Foreign Currency Derivatives

At March 31, 2018, the following foreign currency derivatives were outstanding:

	Pay Notional		Pay Rate	Receive Notional		Receive Rate	Hedge Maturity Date	Fair Value Gain (Loss) at March 31, 2018
	(in millions)			(in millions)				(in millions)
Cash Flow Hedges of Existing Debt
Southern Power	$	677	2.95%	€	600	1.00%	June 2022	$	83
Southern Power	564		3.78%	500		1.85%	June 2026	77
Total	$	1,241		€	1,100			$	160

Fair Value of Energy-Related Derivatives and Interest Rate Derivatives

The fair value of energy-related derivatives, interest rate derivatives, and foreign currency derivatives was reflected in the balance sheets as follows:

	As of March 31, 2018						As of December 31, 2017
Derivative Category and Balance Sheet Location	Assets			Liabilities			Assets			Liabilities
	(in millions)						(in millions)
Southern Company
Derivatives designated as hedging instruments for regulatory purposes
Energy-related derivatives:
Other current assets/Other current liabilities	$	7		$	28		$	10		$	43
Other deferred charges and assets/Other deferred credits and liabilities	4			27			7			24
Total derivatives designated as hedging instruments for regulatory purposes	$	11		$	55		$	17		$	67
Derivatives designated as hedging instruments in cash flow and fair value hedges
Energy-related derivatives:
Other current assets/Other current liabilities	$	3		$	3		$	3		$	14
Other deferred charges and assets/Other deferred credits and liabilities	1			1			—			—
Interest rate derivatives:
Other current assets/Other current liabilities	—			14			1			4
Other deferred charges and assets/Other deferred credits and liabilities	—			47			—			34
Foreign currency derivatives:
Other current assets/Other current liabilities	—			22			—			23
Other deferred charges and assets/Other deferred credits and liabilities	182			—			129			—
Total derivatives designated as hedging instruments in cash flow and fair value hedges	$	186		$	87		$	133		$	75
Derivatives not designated as hedging instruments
Energy-related derivatives:
Other current assets/Other current liabilities	$	283		$	299		$	380		$	437
Other deferred charges and assets/Other deferred credits and liabilities	234			284			170			215
Total derivatives not designated as hedging instruments	$	517		$	583		$	550		$	652
Gross amounts recognized	$	714		$	725		$	700		$	794
Gross amounts offset(a)	$	(336	)	$	(559	)	$	(405	)	$	(598	)
Net amounts recognized in the Balance Sheets(b)	$	378		$	166		$	295		$	196

	As of March 31, 2018						As of December 31, 2017
Derivative Category and Balance Sheet Location	Assets			Liabilities			Assets			Liabilities
	(in millions)						(in millions)
Alabama Power
Derivatives designated as hedging instruments for regulatory purposes
Energy-related derivatives:
Other current assets/Other current liabilities	$	2		$	3		$	2		$	6
Other deferred charges and assets/Other deferred credits and liabilities	1			5			2			4
Total derivatives designated as hedging instruments for regulatory purposes	$	3		$	8		$	4		$	10
Gross amounts recognized	$	3		$	8		$	4		$	10
Gross amounts offset	$	(2	)	$	(2	)	$	(4	)	$	(4	)
Net amounts recognized in the Balance Sheets	$	1		$	6		$	—		$	6
Georgia Power
Derivatives designated as hedging instruments for regulatory purposes
Energy-related derivatives:
Other current assets/Other current liabilities	$	3		$	6		$	2		$	9
Other deferred charges and assets/Other deferred credits and liabilities	2			12			4			10
Total derivatives designated as hedging instruments for regulatory purposes	$	5		$	18		$	6		$	19
Derivatives designated as hedging instruments in cash flow and fair value hedges
Interest rate derivatives:
Other current assets/Other current liabilities	$	—		$	6		$	—		$	4
Other deferred charges and assets/Other deferred credits and liabilities	—			2			—			1
Total derivatives designated as hedging instruments in cash flow and fair value hedges	$	—		$	8		$	—		$	5
Gross amounts recognized	$	5		$	26		$	6		$	24
Gross amounts offset	$	(5	)	$	(5	)	$	(6	)	$	(6	)
Net amounts recognized in the Balance Sheets	$	—		$	21		$	—		$	18
Gulf Power
Derivatives designated as hedging instruments for regulatory purposes
Energy-related derivatives:
Other current assets/Other current liabilities	$	—		$	11		$	—		$	14
Other deferred charges and assets/Other deferred credits and liabilities	—			6			—			7
Total derivatives designated as hedging instruments for regulatory purposes	$	—		$	17		$	—		$	21
Gross amounts recognized	$	—		$	17		$	—		$	21
Gross amounts offset	$	—		$	—		$	—		$	—
Net amounts recognized in the Balance Sheets	$	—		$	17		$	—		$	21

	As of March 31, 2018						As of December 31, 2017
Derivative Category and Balance Sheet Location	Assets			Liabilities			Assets			Liabilities
	(in millions)						(in millions)
Mississippi Power
Derivatives designated as hedging instruments for regulatory purposes
Energy-related derivatives:
Other current assets/Other current liabilities	$	1		$	4		$	1		$	6
Other deferred charges and assets/Other deferred credits and liabilities	1			4			1			3
Total derivatives designated as hedging instruments for regulatory purposes	$	2		$	8		$	2		$	9
Derivatives designated as hedging instruments in cash flow and fair value hedges
Interest rate derivatives:
Other current assets/Other current liabilities	$	—		$	—		$	1		$	—
Total derivatives designated as hedging instruments in cash flow and fair value hedges	$	—		$	—		$	1		$	—
Gross amounts recognized	$	2		$	8		$	3		$	9
Gross amounts offset	$	(2	)	$	(2	)	$	(2	)	$	(2	)
Net amounts recognized in the Balance Sheets	$	—		$	6		$	1		$	7
Southern Power
Derivatives designated as hedging instruments in cash flow and fair value hedges
Energy-related derivatives:
Other current assets/Other current liabilities	$	3		$	2		$	3		$	11
Other deferred charges and assets/Other deferred credits and liabilities	1			1			—			—
Foreign currency derivatives:
Other current assets/Other current liabilities	—			22			—			23
Other deferred charges and assets/Other deferred credits and liabilities	182			—			129			—
Total derivatives designated as hedging instruments in cash flow and fair value hedges	$	186		$	25		$	132		$	34
Derivatives not designated as hedging instruments
Energy-related derivatives:
Other current assets/Other current liabilities	$	—		$	—		$	—		$	2
Gross amounts recognized	$	186		$	25		$	132		$	36
Gross amounts offset	$	(1	)	$	(1	)	$	(3	)	$	(3	)
Net amounts recognized in the Balance Sheets	$	185		$	24		$	129		$	33

	As of March 31, 2018						As of December 31, 2017
Derivative Category and Balance Sheet Location	Assets			Liabilities			Assets			Liabilities
	(in millions)						(in millions)
Southern Company Gas
Derivatives designated as hedging instruments for regulatory purposes
Energy-related derivatives:
Assets from risk management activities/Liabilities from risk management activities-current	$	1		$	4		$	5		$	8
Derivatives designated as hedging instruments in cash flow and fair value hedges
Energy-related derivatives:
Assets from risk management activities/Liabilities from risk management activities-current	$	—		$	1		$	—		$	3
Derivatives not designated as hedging instruments
Energy-related derivatives:
Assets from risk management activities/Liabilities from risk management activities-current	$	283		$	299		$	379		$	434
Other deferred charges and assets/Other deferred credits and liabilities	234			284			170			215
Total derivatives not designated as hedging instruments	$	517		$	583		$	549		$	649
Gross amounts of recognized	$	518		$	588		$	554		$	660
Gross amounts offset(a)	$	(325	)	$	(548	)	$	(390	)	$	(583	)
Net amounts recognized in the Balance Sheets(b)	$	193		$	40		$	164		$	77

(a) Gross amounts offset include cash collateral held on deposit in broker margin accounts of $223 million and $193 million as of March 31, 2018 and December 31, 2017, respectively.

(b) Net amounts of derivative instruments outstanding exclude premium and intrinsic value associated with weather derivatives of $4 million and $11 million as of March 31, 2018 and December 31, 2017, respectively.

Pre-tax Effects of Unrealized Derivative Gains (Losses) Arising from Energy-Related Derivative Instruments

At March 31, 2018 and December 31, 2017, the pre-tax effects of unrealized derivative gains (losses) arising from energy-related derivative instruments designated as regulatory hedging instruments and deferred were as follows:

Regulatory Hedge Unrealized Gain (Loss) Recognized in the Balance Sheet at March 31, 2018
Derivative Category and Balance Sheet Location	Southern Company(*)			Alabama Power			Georgia Power			Gulf Power			Mississippi Power			Southern Company Gas(*)
	(in millions)
Energy-related derivatives:
Other regulatory assets, current	$	(20	)	$	(1	)	$	(3	)	$	(11	)	$	(3	)	$	(2	)
Other regulatory assets, deferred	(23		)	(4		)	(10		)	(6		)	(3		)	—
Other regulatory liabilities, current	7			—			—			—			—			7
Total energy-related derivative gains (losses)	$	(36	)	$	(5	)	$	(13	)	$	(17	)	$	(6	)	$	5

(*) Fair value gains and losses recorded in regulatory assets and liabilities include cash collateral held on deposit in broker margin accounts of $8 million at March 31, 2018.

Regulatory Hedge Unrealized Gain (Loss) Recognized in the Balance Sheet at December 31, 2017
Derivative Category and Balance Sheet Location	Southern Company(*)			Alabama Power			Georgia Power			Gulf Power			Mississippi Power			Southern Company Gas(*)
	(in millions)
Energy-related derivatives:
Other regulatory assets, current	$	(34	)	$	(4	)	$	(7	)	$	(14	)	$	(5	)	$	(4	)
Other regulatory assets, deferred	(18		)	(3		)	(6		)	(7		)	(2		)	—
Other regulatory liabilities, current	7			—			—			—			—			7
Other regulatory liabilities, deferred	1			1			—			—			—			—
Total energy-related derivative gains (losses)	$	(44	)	$	(6	)	$	(13	)	$	(21	)	$	(7	)	$	3

(*) Fair value gains and losses recorded in regulatory assets and liabilities include cash collateral held on deposit in broker margin accounts of $6 million at December 31, 2017.

Pre-tax Effects of Interest Rate Derivatives, Designated as Cash Flow Hedging Instruments

For the three months ended March 31, 2018 and 2017, the pre-tax effects of cash flow hedge accounting on accumulated OCI were as follows:

Derivatives in Cash Flow Hedging Relationships	Gain (Loss) Recognized in OCI on Derivative						Gain (Loss) Reclassified from Accumulated OCI into Income
							Statements of Income Location	Amount
	2018			2017				2018			2017
	(in millions)							(in millions)
Southern Company
Energy-related derivatives	$	12		$	(11	)	Depreciation and amortization	$	1		$	(4	)
							Cost of natural gas	(2		)	—
Interest rate derivatives	(2		)	1			Interest expense, net of amounts capitalized	(5		)	(5		)
Foreign currency derivatives	53			(4		)	Interest expense, net of amounts capitalized	(5		)	(6		)
							Other income (expense), net(*)	36			17
Total	$	63		$	(14	)		$	25		$	2
Southern Power
Energy-related derivatives	$	11		$	(8	)	Depreciation and amortization	$	1		$	(4	)
Foreign currency derivatives	53			(4		)	Interest expense, net of amounts capitalized	(5		)	(6		)
							Other income (expense), net(*)	36			17
Total	$	64		$	(12	)		$	32		$	7

(*) The reclassification from accumulated OCI into other income (expense), net completely offsets currency gains and losses arising from changes in the U.S. currency exchange rates used to record the euro-denominated notes.

Schedule of Cash Flow Hedging Instruments, Statements of Financial Performance and Financial Position, Location

For the three months ended March 31, 2018 and 2017, the pre-tax effects of cash flow and fair value hedge accounting on income were as follows:

Location and Amount of Gain (Loss) Recognized in Income on Cash Flow and Fair Value Hedging Relationships	For the Three Months Ended March 31,
	2018			2017
	(in millions)
Southern Company
Depreciation and amortization	$	769		$	716
Gain (loss) on cash flow hedges
Energy-related derivatives	1			(4		)
Interest expense, net of amounts capitalized	(458		)	(416		)
Gain (loss) on cash flow hedges
Interest rate derivatives	(5		)	(5		)
Foreign currency derivatives	(5		)	(6		)
Gain (loss) on fair value hedges(a)
Interest rate derivatives	(24		)	(8		)
Other income (expense), net	60			48
Gain (loss) on cash flow hedges(b)
Foreign currency derivatives	36			17
Southern Power
Depreciation and amortization	$	114		$	119
Gain (loss) on cash flow hedges
Energy-related derivatives	1			(4		)
Interest expense, net of amounts capitalized	(47		)	(50		)
Gain (loss) on cash flow hedges
Foreign currency derivatives	(5		)	(6		)
Other income (expense), net	3			(1		)
Gain (loss) on cash flow hedges(b)
Foreign currency derivatives	36			17

(a) For fair value hedges presented above, changes in the fair value of the derivative contracts are equal to changes in the fair value of the underlying debt and have no impact on income.

(b) The reclassification from accumulated OCI into other income (expense), net completely offsets currency gains and losses arising from changes in the U.S. currency exchange rates used to record the euro-denominated notes.

Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location

As of March 31, 2018 and December 31, 2017, the following amounts were recorded on the balance sheets related to cumulative basis adjustments for fair value hedges:

	Carrying Amount of the Hedged Item						Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item
Balance Sheet Location of Hedged Items	As of March 31, 2018			As of December 31, 2017			As of March 31, 2018		As of December 31, 2017
	(in millions)						(in millions)
Southern Company
Securities due within one year	$	(745	)	$	(746	)	$	4	$	3
Long-term Debt	(2,533		)	(2,553		)	57		35
Georgia Power
Securities due within one year	$	(745	)	$	(746	)	$	4	$	3
Long-term Debt	(497		)	(498		)	2		1

Pre-tax Effect of Interest Rate and Energy Related Derivatives

For the three months ended March 31, 2018 and 2017, the pre-tax effects of energy-related derivatives not designated as hedging instruments on the statements of income were as follows:

		Gain (Loss)
		Three Months Ended March 31,
Derivatives in Non-Designated Hedging Relationships	Statements of Income Location	2018			2017
		(in millions)
Southern Company
Energy-related derivatives:	Natural gas revenues(*)	$	(15	)	$	50
	Cost of natural gas	2			(3		)
Total derivatives in non-designated hedging relationships		$	(13	)	$	47
Southern Company Gas
Energy-related derivatives:	Natural gas revenues(*)	$	(15	)	$	50
	Cost of natural gas	2			(3		)
Total derivatives in non-designated hedging relationships		$	(13	)	$	47

(*) Excludes gains (losses) recorded in natural gas revenues associated with weather derivatives of an immaterial amount and $14 million for the three months ended March 31, 2018 and 2017, respectively.