CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - 9 months ended Sep. 30, 2017 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Earnings (Deficit)
Balance (in shares) at Dec. 31, 2016		110,212,547		349,760
Balance, beginning of period at Dec. 31, 2016	$ 133,000	$ 110	$ 161,261	$ (2,216)	$ (26,155)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	$ 15,232		15,232
Exercise of stock options (in shares)	2,417,769	1,097,933		(1,319,836)
Exercise of stock options	$ 11,590	$ 1	(2,697)	$ 14,286
Issuance of restricted stock (in shares)		1,393,446		(1,630,093)
Issuance of restricted stock	0	$ 1	(13,108)	$ 13,107
Restricted stock shares canceled/forfeited	0		2,717	$ (2,717)
Restricted stock shares cancelled/forfeited (in shares)				283,198
Shares issued for services performed	$ 166		41	$ 125
Shares issued for services performed (in shares)	(17,539)			(17,539)
Share repurchase (in shares)				3,644,327
Share repurchase	$ (44,032)			$ (44,032)
Shares repurchased for tax withholding (in shares)				358,861
Shares repurchased for tax withholding	(3,337)			$ (3,337)
Net income	29,853				29,853
Balance (in shares) at Sep. 30, 2017		112,703,926		1,668,678
Balance, end of period at Sep. 30, 2017	$ 142,472	$ 112	$ 163,446	$ (24,784)	$ 3,698