Pension And Other Postretirement Benefits
9 Months Ended
Sep. 30, 2015
Pension and Other Postretirement Benefit Expense [Abstract]  
Pension And Other Postretirement Benefits
Pension and Other Postretirement Benefits
CPG provides defined contribution plans and noncontributory defined benefit retirement plans that cover employees of subsidiaries of Columbia OpCo. Prior to the Separation, employees of subsidiaries of Columbia OpCo were covered by defined contribution plans and noncontributory defined benefit retirement plans provided by NiSource. Benefits under the defined benefit retirement plans reflect the employees’ compensation, years of service and age at retirement. Additionally, CPG provides health care and life insurance benefits for certain retired employees of subsidiaries of Columbia OpCo. The majority of employees may become eligible for these benefits if they reach retirement age while working for subsidiaries of Columbia OpCo. The expected cost of such benefits is accrued during the employees’ years of service. Current rates charged to customers of subsidiaries of Columbia OpCo include postretirement benefit costs. Cash contributions are remitted to grantor trusts.
Subsidiaries of Columbia OpCo are participants in the consolidated CPG defined benefit retirement plans (the Plans) and, therefore, subsidiaries of Columbia OpCo are allocated a ratable portion of CPG’s grantor trusts for the Plans in which its employees and retirees participate. As a result, the Partnership follows multiple employer accounting under the provisions of GAAP.
As of July 1, 2015, in connection with the Separation, accrued pension and postretirement benefit obligations for subsidiaries of Columbia OpCo participants and related plan assets were transferred from NiSource to CPG. This event required a remeasurement of benefit obligations in accordance with ASC 715, Compensation - Retirement Benefits. Certain of subsidiaries of Columbia OpCo's actuarial assumptions were updated in connection with the remeasurement. As of July 1, 2015, subsidiaries of Columbia OpCo selected discount rates of 4.04% and 4.26% for determining the pension and postretirement benefit obligations, respectively. For the postretirement plans, subsidiaries of Columbia OpCo assumed a health care cost trend rate of 8.73% for the remainder of 2015, trending to 4.50% by 2022. Subsidiaries of Columbia OpCo also selected an estimated long-term rate of return assumption of 8.10% for pension plan assets and 7.96% for postretirement plan assets. These assumptions were used in the determination of the net periodic benefit cost and obligation for the period from July 1, 2015 through December 31, 2015.
For the nine months ended September 30, 2015, subsidiaries of Columbia OpCo have made no contributions to its pension plans and contributed $3.0 million to its other postretirement benefit plans.
The following table provides the components of the subsidiaries of Columbia OpCo's allocation of net periodic benefits cost for the three and nine months ended September 30, 2015 and 2014:

Pension Benefits
 
Other Postretirement
Benefits
Three Months Ended September 30, (in millions)
2015
 
2014
 
2015
 
2014
 
 
 
Predecessor
 
 
 
Predecessor
Components of Net Periodic Benefit Cost (Income)
 
 
 
 
 
 
 
Service cost
$
1.4

 
$
1.3

 
$
0.2

 
$
0.3

Interest cost
3.3

 
3.4

 
1.0

 
1.1

Expected return on assets
(5.8
)
 
(6.0
)
 
(4.4
)
 
(4.2
)
Amortization of prior service (credit) cost
(0.3
)
 
(0.2
)
 

 
0.1

Recognized actuarial loss (gain)
2.1

 
1.6

 
(0.1
)
 
(0.1
)
Total Net Periodic Benefit Cost (Income)
$
0.7

 
$
0.1

 
$
(3.3
)
 
$
(2.8
)
 
Pension Benefits
 
Other Postretirement
Benefits
Nine Months Ended September 30, (in millions)
2015
 
2014
 
2015
 
2014
 
 
 
Predecessor
 
 
 
Predecessor
Components of Net Periodic Benefit Cost (Income)
 
 
 
 
 
 
 
Service cost
$
4.0

 
$
3.7

 
$
0.8

 
$
0.8

Interest cost
9.4

 
10.3

 
3.0

 
3.5

Expected return on assets
(18.0
)
 
(17.9
)
 
(13.0
)
 
(12.3
)
Amortization of prior service (credit) cost
(0.7
)
 
(0.7
)
 

 
0.1

Recognized actuarial loss (gain)
6.2

 
4.9

 
(0.1
)
 
(0.1
)
Total Net Periodic Benefit Cost (Income)
$
0.9

 
$
0.3

 
$
(9.3
)
 
$
(8.0
)