XML 69 R56.htm IDEA: XBRL DOCUMENT v3.7.0.1
Asset Retirement Obligations (Tables)
 12 Months Ended
Dec. 31, 2016
Asset Retirement Obligation Disclosure [Abstract]  
Reconciliations of the Company's ARO liability
Reconciliations of the Company’s asset retirement obligations are as follows:
 
December 31,
 
2016
 
2015
 
(Dollars in millions)
Balance at beginning of year
$
712.1

 
$
752.5

Liabilities incurred or acquired
—

 
1.3

Liabilities settled or disposed
(41.5
)
 
(53.3
)
Accretion expense
45.7

 
42.7

Revisions to estimates
42.5

 
(31.1
)
Balance at end of year
$
758.8

 
$
712.1

Less: Current portion (included in "Accounts payable and accrued expenses")
41.0

 
25.5

Noncurrent obligation (included in "Asset retirement obligations")
$
717.8

 
$
686.6

Balance at end of year — active locations
$
651.1

 
$
656.8

Balance at end of year — closed or inactive locations
$
107.7

 
$
55.3