AMERICAN TOWER CORP /MA/ | 2013 | FY | 3



The changes in the carrying value of the Company’s asset retirement obligations are as follows (in thousands):
 
2013
 
2012 (1)
Beginning balance as of January 1,
$
435,624

 
$
344,180

Additions
94,651

 
59,747

Accretion expense
34,045

 
25,056

Revisions in estimates (2)
(36,492
)
 
6,641

Settlements
(959
)
 

Balance as of December 31,
$
526,869

 
$
435,624

 
(1)
December 31, 2012 balances have been revised to reflect purchase accounting measurement period adjustments.
(2)
For the year ended December 31, 2013, revisions in estimates include the impact of approximately $19.8 million of foreign currency translation.

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