XML 68 R34.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Defined Benefit Pension and Other Postretirement Plans (Tables)
 3 Months Ended
Dec. 31, 2019
Retirement Benefits [Abstract]  
Components of Net Periodic Pension Expense and Other Postretirement Benefit Costs Net periodic pension cost and other postretirement benefit cost include the following components:
 
 
Pension Benefits
 
Other Postretirement Benefits
Three Months Ended December 31,
 
2019
 
2018
 
2019
 
2018
Service cost
 
$
2.8

 
$
2.5

 
$
0.1

 
$
—

Interest cost
 
5.8

 
6.8

 
0.2

 
0.2

Expected return on assets
 
(9.4
)
 
(9.0
)
 
(0.2
)
 
(0.2
)
Amortization of:
 
 
 
 
 
 
 
 
Prior service cost (benefit)
 
0.1

 
0.1

 
(0.1
)
 
(0.1
)
Actuarial loss
 
3.7

 
1.9

 
—

 
—

Net benefit cost (benefit)
 
3.0

 
2.3

 
—

 
(0.1
)
Change in associated regulatory liabilities
 
—

 
—

 
(0.3
)
 
(0.3
)
Net benefit cost (benefit) after change in regulatory liabilities
 
$
3.0

 
$
2.3

 
$
(0.3
)
 
$
(0.4
)