Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies (DetailsTextuals)

 v2.3.0.11
Summary of Significant Accounting Policies (DetailsTextuals) (USD $)
 3 Months Ended 6 Months Ended
Jun. 30, 2011
Jun. 30, 2010
Jun. 30, 2011
Jun. 30, 2010
Jun. 22, 2011
Mar. 31, 2011
Dec. 31, 2010
Mar. 31, 2010
Dec. 31, 2009
Summary of Significant Accounting Policies (Textuals) [Abstract]                  
Cash and cash equivalents $ 380,382,000 $ 519,818,000 $ 380,382,000 $ 519,818,000   $ 503,019,000 $ 539,221,000 $ 659,824,000 $ 699,629,000
Cash equivalents 318,200,000   318,200,000       460,800,000    
Cash and cash equivalents held in domestic bank accounts 363,700,000   363,700,000       509,600,000    
Cash and cash equivalents held in foreign bank accounts 16,700,000   16,700,000       29,600,000    
Total allowances for doubtful accounts 7,300,000   7,300,000       7,300,000    
Allowances for doubtful accounts, Current 6,086,000   6,086,000       6,105,000    
Current retainage balances 103,300,000   103,300,000       119,400,000    
Non-current retainage balances 15,500,000   15,500,000       8,000,000    
Unbilled receivables 152,900,000   152,900,000       103,500,000    
Decrease in fair value of reporting units considered, for impairment calculation             10.00%    
Acquired ownership interest in HEP         39.00%        
Initial capital contribution for acquisition of HEP 35,000,000   35,000,000            
Agreed amount of loan to indirect parent of LLC 4,000,000                
Change orders and/or claims 48,100,000   48,100,000       83,100,000    
Fiber optic deferred revenue 47,000,000   47,000,000       44,400,000    
Fiber Optic Licensing terms, minimum in years 5 years 5 years 5 years 5 years          
Fiber Optic Licensing terms, maximum in years 25 years 25 years 25 years 25 years          
Fiber optic non-current deferred revenue 37,600,000   37,600,000       34,700,000    
Unrecognized tax benefits related to uncertain tax positions 55,900,000   55,900,000            
Increase (decrease) in unrecognized tax benefits related to uncertain tax positions from last fiscal year     5,300,000            
Interest expense (income) and penalties 1,000,000 1,000,000 1,800,000 2,000,000          
Estimated amount believed to be reasonably possible for unrecognized tax benefits to decrease over the next 12 months related to uncertain tax positions due to the expiration of certain statutes of limitations $ 8,700,000   $ 8,700,000