Selected Quarterly Financial Data (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]
Revenues	$ 153,386	$ 165,625	$ 190,944	$ 184,063	$ 186,057	$ 202,428	$ 199,140	$ 253,420	$ 694,018	$ 841,045	$ 1,116,843
Gross Profit	25,247	57,262	81,279	82,228	82,905	97,763	102,769	148,769	246,016	432,206	673,512
Operating (Loss) Income	(195,865)	(75,980)	(91,166)	(25,415)	(121,601)	8,760	14,244	75,713	(388,426)	(22,884)	322,858
Net (Loss) Income, Amount	$ (215,038)	$ (70,140)	$ (87,984)	$ (28,747)	$ (65,217)	$ (2,897)	$ 2,537	$ 41,027	$ (401,909)	$ (24,550)	$ 184,243
Net (Loss) Income, Per Basic Share (in Dollars per share)	$ (1.71)	$ (0.56)	$ (0.70)	$ (0.23)	$ (0.52)	$ (0.02)	$ 0.02	$ 0.33	$ (3.21)	$ (0.20)	$ 1.50
Net (Loss) Income, Per Diluted Share (in Dollars per share)	$ (1.71)	$ (0.56)	$ (0.70)	$ (0.23)	$ (0.52)	$ (0.02)	$ 0.02	$ 0.33	$ (3.21)	$ (0.20)	$ 1.47