Collaborative Arrangements (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Collaborative Arrangements [Line Items] | |||
| Pipeline fees | $ 17,249 | $ 3,625 | $ 0 |
| Prepaid pipeline fees | $ 6,400 | ||
| Prepaid Expenses | |||
| Collaborative Arrangements [Line Items] | |||
| Prepaid pipeline fees | $ 4,100 | ||