Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net income (loss)	$ (17,331)	$ (104,893)	$ (80,887)	$ (155,939)
Denominator:
Weighted-average common shares outstanding, Basic (in shares)	111,315	107,897	110,633	108,324
Effect of potential dilutive common shares	0	0	0	0
Denominator:
Weighted-average common shares outstanding, Diluted (in shares)	111,315	107,897	110,633	108,324
Earnings per share, basic	$ (0.16)	$ (0.97)	$ (0.73)	$ (1.44)
Earnings per share, diluted	$ (0.16)	$ (0.97)	$ (0.73)	$ (1.44)