CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (in thousands, except share data and dividends per share) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Cash dividends per share	$ 0.10
Balances, Common Stock, Shares, Outstanding, Beginning at Dec. 31, 2018		112,241,966
Balances, Total Stockholders' Equity, Beginning at Dec. 31, 2018	$ 2,920,322	$ 1,122	$ 1,765,738	$ 1,165,842	$ (12,380)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(187,001)			(187,001)
Other comprehensive income (loss)	1,061				1,061
Cash dividends	(11,254)			(11,254)
Issuance of common stock under Employee Stock Purchase Plan (Shares)		314,868
Issuance of common stock under Employee Stock Purchase Plan (Amount)	3,209	$ 3	3,206
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Shares)		334,399
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Amount)	(1,661)	$ 4	(1,665)
Stock-based compensation expense (Shares)		96,719
Stock-based compensation expense (Amount)	24,318	$ 1	24,317
Balances, Common Stock, Shares, Outstanding, Ending at Dec. 31, 2019		112,987,952
Balances, Total Stockholders' Equity, Ending at Dec. 31, 2019	$ 2,748,994	$ 1,130	1,791,596	967,587	(11,319)
Cash dividends per share	$ 0.02
Increase (Decrease) in Stockholders' Equity
Net income (loss)	$ (764,614)			(764,614)
Other comprehensive income (loss)	(2,279)				(2,279)
Cash dividends	(2,276)			(2,276)
Issuance of common stock under Employee Stock Purchase Plan (Shares)		464,757
Issuance of common stock under Employee Stock Purchase Plan (Amount)	1,464	$ 4	1,460
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Shares)		1,022,019
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Amount)	(1,560)	$ 10	(1,570)
Stock-based compensation expense (Shares)		267,576
Stock-based compensation expense (Amount)	14,999	$ 3	14,996
Issuance of warrants	21,520		21,520
Other	$ (88)		(88)
Balances, Common Stock, Shares, Outstanding, Ending at Dec. 31, 2020	114,742,304	114,742,304
Balances, Total Stockholders' Equity, Ending at Dec. 31, 2020	$ 2,016,160	$ 1,147	1,827,914	200,697	(13,598)
Cash dividends per share	$ 0.02
Increase (Decrease) in Stockholders' Equity
Net income (loss)	$ 36,229			36,229
Other comprehensive income (loss)	749				749
Cash dividends	(2,393)			(2,393)
Issuance of common stock under Employee Stock Purchase Plan (Shares)		313,773
Issuance of common stock under Employee Stock Purchase Plan (Amount)	2,639	$ 3	2,636
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Shares)		827,572
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Amount)	(9,072)	$ 9	(9,081)
Stock-based compensation expense (Shares)		60,510
Stock-based compensation expense (Amount)	18,819	$ 1	18,818
Issuance of common stock through cashless exercise of Warrants (Shares)		5,918,089
Issuance of common stock through cashless exercise of Warrants (Amount)	$ 0	$ 59	(59)
Balances, Common Stock, Shares, Outstanding, Ending at Dec. 31, 2021	121,862,248	121,862,248
Balances, Total Stockholders' Equity, Ending at Dec. 31, 2021	$ 2,063,131	$ 1,219	$ 1,840,228	$ 234,533	$ (12,849)