Note 20. Net (Loss) Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net (loss) income	$ (165,615)	$ (416,112)	$ 593,406
Weighted-average common shares outstanding	104,328	102,866	100,886
Effect of restricted and performance stock units and stock purchase plan shares	0	0	929
Weighted-average shares used in computing diluted net (loss) income per share	104,328	102,866	101,815
Net (loss) income per share, basic	$ (1.59)	$ (4.05)	$ 5.88
Net (loss) income per share, diluted	$ (1.59)	$ (4.05)	$ 5.83
Anti-dilutive shares	1,021	753	48