v3.3.0.814
Quarterly Financial Information (Unaudited) (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2015
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Jun. 30, 2015
Jun. 30, 2014
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Quarterly Financial Information                            
Total operating revenues   $ 100,718 $ 71,583 $ 57,441 $ 36,532 $ 22,942 $ 16,994 $ 11,980 $ 6,318          
Total operating expenses $ 51,333 42,758 34,840 33,653 20,965 37,797 7,864 6,216 4,178 $ 103,255 $ 54,618 $ 132,216 $ 56,055 $ 5,354
Operating income (loss) $ 36,760 57,960 36,743 23,788 15,567 (14,855) 9,130 5,764 2,140 $ 70,673 $ 39,355 134,058 2,179 (4,707)
Net income (loss)   $ 55,898 $ 34,288 $ 22,380 $ 15,309 $ (14,904) $ 9,078 $ 5,720 $ 2,121     $ 127,875 $ 2,015 $ (4,715)