Earnings Per Share - Narrative (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares	12,241,000	25,266,000	11,058,000	24,734,000
Employee Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares	5,375,000	5,440,000	5,141,000	5,414,000
Warrant to purchase shares of common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares	6,866,000	19,826,000	5,917,000	19,320,000