CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Earnings/(Deficit)
Balance at Dec. 31, 2017	$ 591,548	$ 436	$ 628,983	$ (6,363)	$ (31,508)
Balance (in shares) at Dec. 31, 2017		43,587,079
Net income	16,617				16,617
Issuance of common stock for debt conversion	0	$ 0	0
Issuance of common stock for debt conversion (in shares)		2
Exercise of stock options and vesting of stock units	3,418	$ 3	3,415
Exercise of stock options and vesting of stock units (in shares)		330,297
Stock-based compensation expense	10,192		10,192
Balance at Dec. 31, 2018	615,568	$ 439	642,590	(11,893)	(15,568)
Balance (in shares) at Dec. 31, 2018		43,917,378
Cumulative effect of accounting changes	(677)				(677)
Translation adjustment	(5,530)			(5,530)
Net income	21,411				21,411
Issuance of common stock for debt conversion	198,757	$ 23	198,734
Issuance of common stock for debt conversion (in shares)		2,316,229
Reduction of equity component from debt conversion, net of tax	(200,079)		(200,079)
Exercise of stock options and vesting of stock units	1,167	$ 3	1,164
Exercise of stock options and vesting of stock units (in shares)		339,329
Issuance of commons stock pursuant to the acquisition	53,938	$ 8	53,930
Issuance of commons stock pursuant to the acquisition, (in shares)		779,221
Tax withholding on vesting of restricted stock units	(490)	$ 0	(490)
Tax withholding on vesting of restricted stock units (in shares)		(5,430)
Equity component of 0.375% senior convertible notes, net of tax	39,070		39,070
Proceeds from issuance of common stock, net of issuance costs	320,713	$ 48	320,665
Proceeds from issuance of common stock, net of issuance costs (in shares)		4,731,531
Stock-based compensation expense	12,847		12,847
Balance at Dec. 31, 2019	1,059,768	$ 521	1,068,431	(15,027)	5,843
Balance (in shares) at Dec. 31, 2019		52,078,258
Cumulative effect of accounting changes	5,843
Translation adjustment	(3,134)			(3,134)
Net income	59,926				59,926
Exercise of stock options and vesting of stock units	8,140	$ 6	8,134
Exercise of stock options and vesting of stock units (in shares)		584,589
Issuance of commons stock pursuant to the acquisition	69,422	$ 4	69,418
Issuance of commons stock pursuant to the acquisition, (in shares)		372,990
Proceeds from issuance of common stock, net of issuance costs	297,775	$ 17	297,758
Proceeds from issuance of common stock, net of issuance costs (in shares)		1,725,000
Stock-based compensation expense	17,007		17,007
Balance at Dec. 31, 2020	1,529,150	$ 548	$ 1,460,748	2,085	$ 65,769
Balance (in shares) at Dec. 31, 2020		54,760,837
Cumulative effect of accounting changes	65,769
Translation adjustment	$ 17,112			$ 17,112