Annual report pursuant to Section 13 and 15(d)

Supplemental Quarterly Financial Information (unaudited) (Details)

v3.10.0.1
Supplemental Quarterly Financial Information (unaudited) (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]                      
Total operating revenues $ 161,895 $ 161,214 $ 137,075 $ 127,440 $ 118,214 $ 84,614 $ 82,283 $ 81,363 $ 587,624 $ 366,474 $ 200,851
Income from operations 58,333 72,811 67,400 60,986 54,028 31,426 23,743 32,249 259,530 141,446 (47,477)
Net income 156,194 37,931 50,474 55,761 22,824 17,081 33,390 47,129 300,360 120,424 (91,813)
Income available to common shares $ 154,370 $ 36,108 $ 48,650 $ 53,937 $ 21,001 $ 15,257 $ 31,566 $ 45,305 $ 293,065 $ 113,129 $ (99,108)
Basic income per share (in dollars per share) $ 0.68 $ 0.16 $ 0.23 $ 0.27 $ 0.10 $ 0.08 $ 0.16 $ 0.23 $ 1.35 $ 0.56 $ (0.78)
Diluted income per share (in dollars per share) $ 0.68 $ 0.16 $ 0.23 $ 0.27 $ 0.10 $ 0.08 $ 0.16 $ 0.22 $ 1.35 $ 0.56 $ (0.78)