Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2014 |
Sep. 30, 2014 |
Jun. 30, 2014 |
Mar. 31, 2014 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Quarterly Financial Information Disclosure [Abstract] | |||||||||||
| Net services revenue | $ 68,341 | $ 15,842 | $ 22,085 | $ 10,971 | $ 47,456 | $ 90,745 | $ 58,975 | $ 12,964 | $ 117,239 | $ 210,140 | $ 504,768 |
| Total operating expenses | 57,423 | 70,685 | 64,342 | 60,833 | 79,026 | 76,001 | 86,167 | 97,599 | 253,283 | 338,793 | 300,666 |
| Income (loss) from operations | 10,918 | (54,843) | (42,257) | (49,862) | (31,570) | 14,744 | (27,192) | (84,635) | (136,044) | (128,653) | 204,102 |
| Net income (loss) | $ 5,447 | $ (32,970) | $ (26,288) | $ (30,445) | $ (17,651) | $ 9,553 | $ (16,799) | $ (54,723) | $ (84,256) | $ (79,620) | $ 130,083 |
| Net income (loss) per common share: | |||||||||||
| Basic (in USD per share) | $ 0.06 | $ (0.34) | $ (0.27) | $ (0.32) | $ (0.18) | $ 0.10 | $ (0.18) | $ (0.57) | $ (0.87) | $ (0.83) | $ 1.36 |
| Diluted (in USD per share) | $ 0.06 | $ (0.34) | $ (0.27) | $ (0.32) | $ (0.18) | $ 0.10 | $ (0.18) | $ (0.57) | $ (0.87) | $ (0.83) | $ 1.34 |