CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands		Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance at period start (in shares) at Dec. 31, 2017			45,776
Balance at period start at Dec. 31, 2017		$ 447,719	$ 458	$ 593,295	$ (148,178)	$ 2,144
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock in connection with acquisition (in shares)			1,108
Issuance of common stock in connection with acquisition		19,318	$ 11	19,307
Share-based compensation (in shares)			147
Stock-based compensation		6,196	$ 1	6,195
Purchase of common stock for retirement (in shares)			(47)
Purchase of common stock for retirement		(860)		(860)
Other comprehensive loss		529				529
Net income (loss)		39,427			39,427
Balance at period end (in shares) at Dec. 31, 2018			46,984
Balance at period end at Dec. 31, 2018		512,329	$ 470	617,937	(108,751)	2,673
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock in connection with acquisition (in shares)			2,364
Issuance of common stock in connection with acquisition		36,980	$ 23	36,957
Issuance of common stock for convertible notes repurchase, net (in shares)	[1]		3,243
Issuance of common stock for convertible notes repurchase, net	[1]	45,617	$ 32	45,585
Issuance of common stock for employee stock purchase plan (in shares)			68
Issuance of common stock for employee stock purchase plan		1,490	$ 1	1,489
Share-based compensation (in shares)			202
Stock-based compensation		6,213	$ 3	6,210
Purchase of common stock for retirement (in shares)			(54)
Purchase of common stock for retirement		(1,276)		(1,276)
Exercise of stock option / common stock warrants (in shares)			447
Exercise of stock option / common stock warrants		8,171	$ 4	8,167
Other comprehensive loss		(2,091)				(2,091)
Net income (loss)		40,809			40,809
Balance at period end (in shares) at Dec. 31, 2019			53,254
Balance at period end at Dec. 31, 2019		648,242	$ 533	715,069	(67,942)	582
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for employee stock purchase plan (in shares)			145
Issuance of common stock for employee stock purchase plan		1,553	$ 2	1,551
Share-based compensation (in shares)			322
Stock-based compensation		7,109	$ 3	7,106
Purchase of common stock for retirement (in shares)			(69)
Purchase of common stock for retirement		(1,156)	$ (1)	(1,155)
Exercise of stock option / common stock warrants (in shares)			351
Exercise of stock option / common stock warrants		3,936	$ 3	3,933
Other comprehensive loss		(4,324)				(4,324)
Net income (loss)		(409,086)			(409,086)
Balance at period end (in shares) at Dec. 31, 2020			54,003
Balance at period end at Dec. 31, 2020		$ 246,274	$ 540	$ 726,504	$ (477,028)	$ (3,742)

[1] The issuance of common stock for the repurchase of a portion of our 5.00% Convertible Senior Notes during the year ended December 31, 2019, is presented net of a $28.7 million write-off associated with the equity component of the repurchased notes.