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Basis of Presentation and Significant Accounting Policies (Tables)
12 Months Ended
Dec. 31, 2011
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Summary of Depreciable Lives for Property and Equipment
The following table summarizes the depreciable lives for property and equipment (in years):

 
 
Depreciable Life
Network equipment:
 
 
Switches
 
10
  Switch power equipment
 
15
  Cell site equipment and site improvements
 
7
  Towers
 
15
  Antennae
 
5
Computer hardware and software
 
3-5
Furniture, fixtures retail and office equipment
 
3-7
Summary of Asset Retirement Obligations
The following table summarizes the Company's asset retirement obligations as of and for the years ended December 31, 2011 and 2010 (in thousands):

 
 
Year Ended December 31,
 
 
2011
 
2010
Asset retirement obligations, beginning of year
 
$
31,663

 
$
25,749

Liabilities incurred
 
193

 
270

Liabilities assumed by STX Wireless in connection with the formation of the joint venture
 
(828
)
 
3,272

Accretion expense
 
3,061

 
2,503

Decommissioned sites
 
(1,170
)
 
(131
)
Asset retirement obligations, end of year
 
$
32,919

 
$
31,663