Schedule I - Condensed Financial Information of Registrant (Balance Sheet) (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Current assets        
Cash and cash equivalents $ 573,600 $ 1,730,335 $ 1,364,953 $ 2,282,155
Short-term intercompany receivables 0 0    
Prepaid expenses and other 329,197 397,574    
Total current assets 1,713,412 3,748,186    
Investments in and advances to affiliates   0    
Intangible assets, net 822,124 980,369    
Deferred income taxes, net 5,767 26,713    
Long-term intercompany receivables 0 0    
Other assets 456,355 477,306    
Total assets 5,430,591 8,679,954    
Current liabilities        
Short-term intercompany payables 0 0    
Accrued expenses and other 562,988 959,059    
Total current liabilities 1,709,380 2,286,590    
Long-term intercompany payables 0 0    
Other long-term liabilities 299,571 227,028    
Total liabilities 2,801,862 8,324,567    
External Liabilities Subject To Compromise 4,593,493      
Intercompany Liabilities Subject To Compromise 0      
Liabilities Subject to Compromise 4,593,493 0    
Total stockholders' equity (1,964,764) 355,387    
Total liabilities and stockholders' equity 5,430,591 8,679,954    
NII Holdings Inc. (Parent) [Member]        
Current assets        
Cash and cash equivalents 106,747 356,314 735,022 1,042,358
Short-term intercompany receivables 27,803 31,803    
Prepaid expenses and other 7,942 6,832    
Total current assets 142,492 394,949    
Investments in and advances to affiliates 0 1,867,753    
Intangible assets, net 18,000 18,000    
Deferred income taxes, net 0 16,025    
Long-term intercompany receivables 1,393,109 1,474,658    
Other assets 947 29,381    
Total assets 1,554,548 3,800,766    
Current liabilities        
Short-term intercompany payables 0 464,798    
Accrued expenses and other 0 0    
Total current liabilities 0 464,798    
Long-term intercompany payables 0 2,950,226    
Other long-term liabilities 100 30,329    
Other Liabilities, Noncurrent (Including Long-Term Debt) 1,629 30,355    
Total liabilities 1,629 3,445,379    
External Liabilities Subject To Compromise 30,584 0    
Intercompany Liabilities Subject To Compromise 3,487,099 0    
Liabilities Subject to Compromise 3,517,683 0    
Total stockholders' equity (1,964,764) 355,387    
Total liabilities and stockholders' equity $ 1,554,548 $ 3,800,766