CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Total
Balances at Dec. 31, 2018	$ 213	$ 3,813,678	$ (10,165)	$ (1,877,759)	$ 1,925,967
Increase (Decrease) in Stockholders' Equity
Issuance of shares of Common Stock upon exercise of stock options and settlement of employee restricted stock units	1	15,480			15,481
Issuance of shares of Common Stock for services rendered		104			104
Stock compensation		40,690			40,690
Adoption of ASU No. 2016-02				95	95
Other comprehensive income			918		918
Net income (loss)				102,312	102,312
Balances at Mar. 31, 2019	214	3,869,952	(9,247)	(1,775,352)	2,085,567
Balances at Dec. 31, 2019	216	4,044,490	(15,542)	(1,430,758)	2,598,406	[1]
Increase (Decrease) in Stockholders' Equity
Issuance of shares of Common Stock upon exercise of stock options and settlement of employee restricted stock units	1	14,618			14,619
Issuance of shares of Common Stock for services rendered		145			145
Stock compensation		42,758			42,758
Other comprehensive income			2,435		2,435
Net income (loss)				(720,642)	(720,642)
Balances at Mar. 31, 2020	$ 217	$ 4,102,011	$ (13,107)	$ (2,151,400)	$ 1,937,721

[1] The condensed consolidated balance sheet at December 31, 2019 has been derived from the audited consolidated financial statements at that date.