v3.19.2
Retirement Benefits (Tables)
 6 Months Ended
Jun. 30, 2019
Retirement Benefits [Abstract]  
Pension Plans and Postretirement Plans Components of the net periodic benefit costs for the three and six months ended June 30, 2019 and 2018 are presented in the following tables.
Three Months Ended
June 30, 2019
Southern
Company
 
Alabama
Power
 
Georgia
Power
 
Mississippi
Power
 
Southern Power
 
Southern Company Gas
 
(in millions)
Pension Plans
Service cost
$
73

 
$
17

 
$
18

 
$
3

 
$
1

 
$
6

Interest cost
123

 
29

 
39

 
5

 
2

 
9

Expected return on plan assets
(221
)
 
(52
)
 
(73
)
 
(10
)
 
(3
)
 
(15
)
Amortization:
 
 
 
 
 
 
 
 
 
 
 
Prior service costs
1

 
1

 
1

 
—

 
—

 
—

Regulatory asset
—

 
—

 
—

 
—

 
—

 
4

Net (gain)/loss
30

 
9

 
11

 
2

 
—

 
—

Net periodic pension cost (income)
$
6

 
$
4

 
$
(4
)
 
$
—

 
$
—

 
$
4

Postretirement Benefits
Service cost
$
4

 
$
1

 
$
1

 
$
—

 
$
—

 
$
—

Interest cost
17

 
4

 
6

 
1

 
—

 
3

Expected return on plan assets
(17
)
 
(7
)
 
(6
)
 
(1
)
 
—

 
(1
)
Amortization:
 
 
 
 
 
 
 
 
 
 
 
Prior service costs
1

 
1

 
—

 
—

 
—

 
—

Regulatory asset
—

 
—

 
—

 
—

 
—

 
1

Net (gain)/loss
—

 
—

 
—

 
—

 
—

 
(1
)
Net periodic postretirement benefit cost
$
5

 
$
(1
)
 
$
1

 
$
—

 
$
—

 
$
2

Six Months Ended
June 30, 2019
Southern
Company
 
Alabama
Power
 
Georgia
Power
 
Mississippi
Power
 
Southern Power
 
Southern Company Gas
 
(in millions)
Pension Plans
Service cost
$
146

 
$
34

 
$
37

 
$
6

 
$
3

 
$
12

Interest cost
246

 
57

 
78

 
11

 
3

 
18

Expected return on plan assets
(442
)
 
(103
)
 
(146
)
 
(20
)
 
(5
)
 
(30
)
Amortization:
 
 
 
 
 
 
 
 
 
 
 
Prior service costs
1

 
1

 
1

 
—

 
—

 
(1
)
Regulatory asset
—

 
—

 
—

 
—

 
—

 
7

Net (gain)/loss
60

 
18

 
22

 
3

 
—

 
1

Net periodic pension cost (income)
$
11

 
$
7

 
$
(8
)
 
$
—

 
$
1

 
$
7

Postretirement Benefits
Service cost
$
9

 
$
2

 
$
2

 
$
—

 
$
—

 
$
1

Interest cost
34

 
8

 
13

 
2

 
—

 
5

Expected return on plan assets
(33
)
 
(13
)
 
(12
)
 
(1
)
 
—

 
(3
)
Amortization:
 
 
 
 
 
 
 
 
 
 
 
Prior service costs
2

 
2

 
—

 
—

 
—

 
—

Regulatory asset
—

 
—

 
—

 
—

 
—

 
3

Net (gain)/loss
(1
)
 
—

 
—

 
—

 
—

 
(2
)
Net periodic postretirement benefit cost
$
11

 
$
(1
)
 
$
3

 
$
1

 
$
—

 
$
4

Three Months Ended
June 30, 2018
Southern
Company
 
Alabama
Power
 
Georgia
Power
 
Mississippi
Power
 
Southern Power
 
Southern Company Gas
 
(in millions)
Pension Plans
Service cost
$
89


$
20


$
21


$
4


$
2


$
8

Interest cost
116


25


35


5


2


9

Expected return on plan assets
(235
)

(53
)

(74
)

(10
)

(2
)

(17
)
Amortization:
 
 
 
 
 
 
 
 
 
 
 
Prior service costs
1


1


1


—


—


—

Regulatory asset
—

 
—

 
—

 
—

 
—

 
4

Net (gain)/loss
54


13


17


2


—


3

Net periodic pension cost (income)
$
25


$
6


$
—


$
1


$
2


$
7

Postretirement Benefits
Service cost
$
6

 
$
2

 
$
1

 
$
1

 
$
—

 
$
—

Interest cost
18

 
4

 
7

 
1

 
—

 
3

Expected return on plan assets
(17
)
 
(7
)
 
(7
)
 
(1
)
 
—

 
(2
)
Amortization:
 
 
 
 
 
 
 
 
 
 
 
Prior service costs
1

 
1

 
1

 
—

 
—

 
—

Regulatory asset
—

 
—

 
—

 
—

 
—

 
2

Net (gain)/loss
4

 
1

 
2

 
—

 
—

 
—

Net periodic postretirement benefit cost
$
12

 
$
1

 
$
4

 
$
1

 
$
—

 
$
3


Six Months Ended
June 30, 2018
Southern
Company
 
Alabama
Power
 
Georgia
Power
 
Mississippi
Power
 
Southern Power
 
Southern Company Gas
 
(in millions)
Pension Plans
Service cost
$
179

 
$
39

 
$
43

 
$
8

 
$
4

 
$
16

Interest cost
232

 
50

 
70

 
10

 
3

 
19

Expected return on plan assets
(471
)
 
(104
)
 
(148
)
 
(20
)
 
(5
)
 
(35
)
Amortization:
 
 
 
 
 
 
 
 
 
 
 
Prior service costs
2

 
1

 
1

 
—

 
—

 
(1
)
Regulatory asset
—

 
—

 
—

 
—

 
—

 
7

Net (gain)/loss
107

 
27

 
34

 
5

 
1

 
6

Net periodic pension cost (income)
$
49

 
$
13

 
$
—

 
$
3

 
$
3

 
$
12

Postretirement Benefits
Service cost
$
12

 
$
3

 
$
3

 
$
1

 
$
—

 
$
1

Interest cost
37

 
8

 
14

 
2

 
—

 
5

Expected return on plan assets
(34
)
 
(13
)
 
(13
)
 
(1
)
 
—

 
(4
)
Amortization:
 
 
 
 
 
 
 
 
 
 
 
Prior service costs
3

 
2

 
1

 
—

 
—

 
—

Regulatory asset
—

 
—

 
—

 
—

 
—

 
3

Net (gain)/loss
7

 
1

 
4

 
—

 
—

 
—

Net periodic postretirement benefit cost
$
25

 
$
1

 
$
9

 
$
2

 
$
—

 
$
5