CONDENSED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Preferred stock, par value (in USD per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	40,000,000	40,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock outstanding (in shares)	0	0
Common stock, par value (in USD per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares outstanding (in shares)	49,763,176	42,148,247
Common stock, shares issued (in shares)	49,763,176	42,148,247