Selected Quarterly Financial Data (Unaudited) -Summary of Unaudited Quarterly Financial Results (Details) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2019 |
Sep. 30, 2019 |
Jun. 30, 2019 |
Mar. 31, 2019 |
Dec. 31, 2018 |
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Unaudited quarterly financial results | |||||||||||
| Total revenue | $ 218,554 | $ 214,980 | $ 91,360 | $ 87,479 | $ 95,967 | $ 108,082 | $ 104,399 | $ 104,964 | |||
| Operating expenses | 154,357 | 159,407 | 68,635 | 65,354 | 70,210 | 76,272 | 74,715 | 77,696 | $ 447,753 | $ 298,893 | $ 319,461 |
| Income from operations | 64,197 | 55,573 | 22,725 | 22,125 | 25,757 | 31,810 | 29,684 | 27,268 | 164,620 | 114,519 | 90,168 |
| Net income | $ 37,589 | $ 25,992 | $ 14,383 | $ 14,527 | $ 13,915 | $ 20,590 | $ 18,675 | $ 10,524 | $ 92,491 | $ 63,704 | $ 25,826 |
| Basic earnings per share | $ 0.56 | $ 0.38 | $ 0.21 | $ 0.22 | $ 0.21 | $ 0.30 | $ 0.27 | $ 0.17 | $ 1.37 | $ 0.96 | $ 0.47 |
| Diluted earnings per share | $ 0.51 | $ 0.35 | $ 0.20 | $ 0.20 | $ 0.19 | $ 0.29 | $ 0.26 | $ 0.16 | $ 1.26 | $ 0.90 | $ 0.43 |