Grants and other liabilities (Details) $ in Thousands |
12 Months Ended | |||
|---|---|---|---|---|
|
Dec. 31, 2017
USD ($)
Type
|
Dec. 31, 2016
USD ($)
|
Dec. 31, 2015
USD ($)
|
Oct. 02, 2013
USD ($)
|
|
| Grants and other liabilities [Abstract] | ||||
| Grants | $ 1,225,877 | $ 1,297,755 | ||
| Number of grant types | Type | 2 | |||
| Other liabilities | $ 410,183 | 314,290 | ||
| Grant and other non-current liabilities | 1,636,060 | 1,612,045 | ||
| Income from grants | 59,707 | 59,085 | $ 67,859 | |
| Solana and Mojave [Member] | ||||
| Grants and other liabilities [Abstract] | ||||
| Income from grants | 59,800 | 57,000 | ||
| U.S. Department of Treasury [Member] | ||||
| Grants and other liabilities [Abstract] | ||||
| Grants | 771,000 | 803,000 | ||
| Federal Financing Bank [Member] | ||||
| Grants and other liabilities [Abstract] | ||||
| Grants | 452,000 | 492,000 | ||
| Liberty Interactive Corporation [Member] | ||||
| Grants and other liabilities [Abstract] | ||||
| Grant and other non-current liabilities | $ 352,000 | $ 263,000 | ||
| Class A membership investment | $ 300,000 | |||