Net Income (Loss) per Share - Basic and Diluted Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Net income (loss) attributable to ION	$ (25,342)	$ 56,069	$ (60,356)	$ 805
Weighted average number of common shares outstanding (in shares)	11,415	10,979	11,008	10,975
Effect of dilutive stock awards	0	1	0	2
Weighted average number of diluted common shares outstanding (in shares)	11,415	10,980	11,008	10,977
Basic net income (loss) per share (in dollars per share)	$ (2.22)	$ 5.11	$ (5.48)	$ 0.07
Diluted net income (loss) per share (in dollars per share)	$ (2.22)	$ 5.11	$ (5.48)	$ 0.07