Grants and other liabilities (Details) $ in Thousands |
6 Months Ended | |||
|---|---|---|---|---|
|
Jun. 30, 2018
USD ($)
Type
|
Jun. 30, 2017
USD ($)
|
Dec. 31, 2017
USD ($)
|
Oct. 02, 2013
USD ($)
|
|
| Grants and other liabilities [Abstract] | ||||
| Grants | $ 1,182,650 | $ 1,225,877 | ||
| Other Liabilities | 479,729 | 410,183 | ||
| Grant and other non-current liabilities | $ 1,662,379 | 1,636,060 | ||
| Number of grant types | Type | 2 | |||
| Income from grants | $ 29,719 | $ 29,882 | ||
| Solana and Mojave [Member] | ||||
| Grants and other liabilities [Abstract] | ||||
| Income from grants | 29,600 | $ 29,800 | ||
| U.S. Department of Treasury [Member] | ||||
| Grants and other liabilities [Abstract] | ||||
| Grants | 755,000 | 771,000 | ||
| Federal Financing Bank [Member] | ||||
| Grants and other liabilities [Abstract] | ||||
| Grants | 426,000 | 452,000 | ||
| Liberty Interactive Corporation [Member] | ||||
| Grants and other liabilities [Abstract] | ||||
| Grant and other non-current liabilities | 363,000 | $ 352,000 | ||
| Class A membership investment | $ 300,000 | |||
| Finance lease liabilities | $ 57,000 | |||