Year Ended December 31, |
|||||
2013 |
2012 |
||||
(In millions) |
|||||
Asset retirement obligations as of beginning of period |
$ |
2,095 |
$ |
1,563 | |
Liabilities incurred |
112 | 90 | |||
Liabilities settled |
(83) | (86) | |||
Revision of estimated obligation |
104 | 420 | |||
Liabilities assumed by others |
(28) | (23) | |||
Accretion expense on discounted obligation |
115 | 110 | |||
Foreign currency translation adjustment |
(87) | 21 | |||
Asset retirement obligations as of end of period |
2,228 | 2,095 | |||
Less current portion |
88 | 99 | |||
Asset retirement obligations, long-term |
$ |
2,140 |
$ |
1,996 |