Stockholders' Equity - Summary of Stock Option Activity (Details) - Stock Option [Member]	3 Months Ended
	Mar. 31, 2021 $ / shares shares
Number of Options Outstanding, Beginning Balance | shares	134,931,000
Number of Options Outstanding, granted | shares	5,000,000
Number of Options Outstanding, canceled | shares	(37,221,000)
Number of Options Outstanding, Ending Balance | shares	102,710,000
Number of Options Exercisable, Ending Balance | shares	72,043,000
Weighted- Average Exercise Price Options Outstanding, Beginning Balance | $ / shares	$ 4.71
Weighted- Average Exercise Price Options Outstanding, granted | $ / shares	0.53
Weighted- Average Exercise Price Options Outstanding, canceled | $ / shares	5.16
Weighted- Average Exercise Price Options Outstanding, Ending Balance | $ / shares	4.00
Weighted- Average Exercise Price Options Exercisable, Ending Balance | $ / shares	$ 3.56