|
Fair Value Measurements (Carrying Amounts and Estimated Fair Values of Long-Term Debt Instrument) (Details) (USD $)
In Thousands, unless otherwise specified |
Dec. 31, 2014
|
Dec. 31, 2013
|
|---|---|---|
| Carrying amount | $ 5,385,099 | $ 5,441,009 |
| Long-term estimated fair value | 2,710,778 | 3,493,289 |
| Equipment Financing [Member] | ||
| Carrying amount | 689,930 | 653,557 |
| Long-term estimated fair value | 620,125 | 620,173 |
| NII Capital Corp [Member] | ||
| Carrying amount | 2,750,000 | 2,729,321 |
| Long-term estimated fair value | 648,500 | 1,227,950 |
| Convertible Notes [Member] | ||
| Carrying amount | 345,169 | 448,169 |
| Long-term estimated fair value | 275,653 | 373,796 |
| NII International Telecom [Member] | ||
| Carrying amount | 1,600,000 | 1,609,962 |
| Long-term estimated fair value | $ 1,166,500 | $ 1,271,370 |