XML 82 R22.htm IDEA: XBRL DOCUMENT v2.4.0.6
Asset Retirement Obligations
12 Months Ended
Dec. 31, 2011
Asset Retirement Obligations [Abstract]  
Asset Retirement Obligations
14. Asset Retirement Obligations

Our asset retirement obligations are related primarily to past TEL operations. The following table illustrates the 2011, 2010, and 2009 activity associated with our asset retirement obligations.

 

     Years Ended December 31  
     2011      2010     2009  

Asset retirement obligations, beginning of year

   $ 2,975       $ 3,031      $ 3,009   

Liabilities incurred

     100         0        2,000   

Accretion expense

     165         139        168   

Liabilities settled

     0         0        (1,539

Changes in expected cash flows and timing

     57         (195     (607
  

 

 

    

 

 

   

 

 

 

Asset retirement obligations, end of year

   $ 3,297       $ 2,975      $ 3,031