XML 53 R41.htm IDEA: XBRL DOCUMENT v3.3.1.900
Asset Retirement Obligations (Tables)
 12 Months Ended
Dec. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]  
Schedule of Asset Retirement Obligations [Table Text Block]
AROs consist of the following (in millions):
 
As of December 31,
 
2015
 
2014
Trojan decommissioning activities
$
43

 
$
41

Utility plant
97

 
64

Non-utility property
11

 
11

Asset retirement obligations
$
151

 
$
116

 
 
 
 
Schedule of Change in Asset Retirement Obligation [Table Text Block]
The following is a summary of the changes in the Company’s AROs (in millions):

 
Years Ended December 31,
 
2015
 
2014
 
2013
Balance as of beginning of year
$
116

 
$
100

 
$
94

Liabilities incurred
2

 
15

 
4

Liabilities settled
(4
)
 
(3
)
 
(4
)
Accretion expense
7

 
6

 
6

Revisions in estimated cash flows
30

 
(2
)
 
—

Balance as of end of year
$
151

 
$
116

 
$
100