CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (UNAUDITED) (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 declared per share	$ 0.05
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)	(177,568)			(177,568)
Other comprehensive income	263				263
Cash dividends declared, per share	(5,612)			(5,612)
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Shares)		2,579
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Amount)	(18)	$ 0	(18)
Stock-based compensation expense (Amount)	5,838		5,838
Balances, Common Stock, Shares, Outstanding, Ending at Mar. 31, 2019		112,244,545
Balances, Total Stockholders' Equity, Ending at Mar. 31, 2019	$ 2,743,225	$ 1,122	1,771,558	982,662	(12,117)
Cash dividends declared 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)	(84,946)
Other comprehensive income	572
Balances, Common Stock, Shares, Outstanding, Ending at Sep. 30, 2019		112,857,163
Balances, Total Stockholders' Equity, Ending at Sep. 30, 2019	2,843,750	$ 1,129	1,784,787	1,069,642	(11,808)
Balances, Common Stock, Shares, Outstanding, Beginning at Mar. 31, 2019		112,244,545
Balances, Total Stockholders' Equity, Beginning at Mar. 31, 2019	2,743,225	$ 1,122	1,771,558	982,662	(12,117)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	50,388			50,388
Other comprehensive income	119				119
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Shares)		290
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Amount)	(2)	$ 0	(2)
Stock-based compensation expense (Shares)		96,719
Stock-based compensation expense (Amount)	6,154	$ 1	6,153
Issuance of common stock under Employee Stock Purchase Plan (Shares)		184,079
Issuance of common stock under Employee Stock Purchase Plan (Amount)	1,959	$ 2	1,957
Other	0		(1)	1
Balances, Common Stock, Shares, Outstanding, Ending at Jun. 30, 2019		112,525,633
Balances, Total Stockholders' Equity, Ending at Jun. 30, 2019	$ 2,801,843	$ 1,125	1,779,665	1,033,051	(11,998)
Cash dividends declared per share	$ 0.05
Increase (Decrease) in Stockholders' Equity
Net income (loss)	$ 42,234			42,234
Other comprehensive income	190				190
Cash dividends declared, per share	(5,643)			(5,643)
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Shares)		331,530
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Amount)	(1,640)	$ 4	(1,644)
Stock-based compensation expense (Amount)	6,766		6,766
Balances, Common Stock, Shares, Outstanding, Ending at Sep. 30, 2019		112,857,163
Balances, Total Stockholders' Equity, Ending at Sep. 30, 2019	$ 2,843,750	$ 1,129	1,784,787	1,069,642	(11,808)
Cash dividends declared per share	$ 0.01
Balances, Common Stock, Shares, Outstanding, Beginning at Dec. 31, 2019	112,987,952	112,987,952
Balances, Total Stockholders' Equity, Beginning at Dec. 31, 2019	$ 2,748,994	$ 1,130	1,791,596	967,587	(11,319)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(411,895)			(411,895)
Other comprehensive income	190				190
Cash dividends declared, per share	(1,130)			(1,130)
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Shares)		730
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Amount)	(3)	$ 0	(3)
Stock-based compensation expense (Amount)	5,561		5,561
Balances, Common Stock, Shares, Outstanding, Ending at Mar. 31, 2020		112,988,682
Balances, Total Stockholders' Equity, Ending at Mar. 31, 2020	$ 2,341,717	$ 1,130	1,797,154	554,562	(11,129)
Cash dividends declared per share	$ 0.02
Balances, Common Stock, Shares, Outstanding, Beginning at Dec. 31, 2019	112,987,952	112,987,952
Balances, Total Stockholders' Equity, Beginning at Dec. 31, 2019	$ 2,748,994	$ 1,130	1,791,596	967,587	(11,319)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(599,439)
Other comprehensive income	$ 1,573
Balances, Common Stock, Shares, Outstanding, Ending at Sep. 30, 2020	114,572,800	114,572,800
Balances, Total Stockholders' Equity, Ending at Sep. 30, 2020	$ 2,185,108	$ 1,146	1,827,836	365,872	(9,746)
Balances, Common Stock, Shares, Outstanding, Beginning at Mar. 31, 2020		112,988,682
Balances, Total Stockholders' Equity, Beginning at Mar. 31, 2020	2,341,717	$ 1,130	1,797,154	554,562	(11,129)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(89,252)			(89,252)
Other comprehensive income	188				188
Stock-based compensation expense (Shares)		267,576
Stock-based compensation expense (Amount)	5,712	$ 3	5,709
Issuance of common stock under Employee Stock Purchase Plan (Shares)		297,013
Issuance of common stock under Employee Stock Purchase Plan (Amount)	947	$ 3	944
Issuance of Warrants	21,520		21,520
Balances, Common Stock, Shares, Outstanding, Ending at Jun. 30, 2020		113,553,271
Balances, Total Stockholders' Equity, Ending at Jun. 30, 2020	$ 2,280,832	$ 1,136	1,825,327	465,310	(10,941)
Cash dividends declared per share	$ 0.01
Increase (Decrease) in Stockholders' Equity
Net income (loss)	$ (98,292)			(98,292)
Other comprehensive income	1,195				1,195
Cash dividends declared, per share	(1,146)			(1,146)
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Shares)		1,019,529
Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Amount)	(1,557)	$ 10	(1,567)
Stock-based compensation expense (Amount)	4,164		4,164
Other	$ (88)		(88)
Balances, Common Stock, Shares, Outstanding, Ending at Sep. 30, 2020	114,572,800	114,572,800
Balances, Total Stockholders' Equity, Ending at Sep. 30, 2020	$ 2,185,108	$ 1,146	$ 1,827,836	$ 365,872	$ (9,746)