CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in	Treasury Stock	Accumulated Deficit
Balance, beginning of period at Dec. 31, 2012	$ 20,007	$ 88	$ 89,627	$ (25)	$ (69,683)
Balance, beginning of period (in shares) at Dec. 31, 2012		88,423,169		50,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	6,010		6,010
Exercise of stock options	1,981	$ 2	1,979
Exercise of stock options (in shares)		1,958,674
Exercise of warrants	2,108	$ 2	2,106
Exercise of warrants (in shares)		1,844,352
Common stock issued for 5% convertible note	$ 5,272	$ 5	5,267
Common stock issued for 5% convertible note (in shares)	5,272,004	5,272,004
Common stock issued for earn - out liability	$ 5,792	$ 1	5,791
Common stock issued for earn-out liability (in shares)	1,174,915	1,174,915
Issuance of restricted stock	$ 0
Issuance of restricted stock (in shares)		2,500
Public offering of common stock, net of expenses	36,510	$ 6	36,504
Public offering of common stock, net of expenses (in shares)		5,750,000
Shares issued for services performed	0
Net income (loss)	(4,112)				(4,112)
Balance, end of period at Dec. 31, 2013	73,568	$ 104	147,284	$ (25)	(73,795)
Balance, end of period (in shares) at Dec. 31, 2013		104,425,614		50,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	11,453		11,453
Exercise of stock options	2,470	$ 2	2,468
Exercise of stock options (in shares)		1,653,690
Exercise of warrants	1,113	$ 1	1,112
Exercise of warrants (in shares)		1,242,416
Common stock issued for 5% convertible note	0
Common stock issued for earn - out liability	0
Issuance of restricted stock	0	$ 1	(1)
Issuance of restricted stock (in shares)		1,438,569
Shares issued for services performed	$ 117		117
Shares issued for services performed (in shares)	15,958	15,958
Stock repurchase	$ (5,612)			$ (5,612)
Stock repurchase (in shares)				936,636
Net income (loss)	6,220				6,220
Balance, end of period at Dec. 31, 2014	89,329	$ 108	162,433	$ (5,637)	(67,575)
Balance, end of period (in shares) at Dec. 31, 2014		108,776,247		986,636
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	16,896		16,896
Tax benefit of share-based compensation expense	7,757		7,757
Exercise of stock options	$ 4,629	$ 1	(9,792)	$ 14,420
Exercise of stock options (in shares)	2,220,881	647,656		(1,573,225)
Exercise of warrants	$ 46		(379)	$ 425
Exercise of warrants (in shares)				(42,400)
Common stock issued for 5% convertible note	0
Common stock issued for earn - out liability	0
Issuance of restricted stock	0		(14,547)	$ 14,547
Issuance of restricted stock (in shares)		34,250		(1,940,009)
Restricted stock shares canceled/forfeited	$ 0		652	$ (652)
Restricted stock shares canceled/forfeited (in shares)	69,949	(2,058)
Shares issued for services performed	$ 164		113	$ 51
Shares issued for services performed (in shares)	16,493	11,321		(5,172)
Stock repurchase	$ (40,279)			$ (40,279)
Stock repurchase (in shares)	4,610,000			4,610,166
Net income (loss)	$ 29,446				29,446
Balance, end of period at Dec. 31, 2015	$ 107,988	$ 109	$ 163,133	$ (17,125)	$ (38,129)
Balance, end of period (in shares) at Dec. 31, 2015		109,467,416		2,105,945