Commitments and Contingencies - CRO contract (Detail) - USD ($)	Mar. 31, 2020	Jan. 31, 2020	Mar. 31, 2019
Commitments and Contingencies [Line Items]
Total	$ 5,597,000
CRO
Commitments and Contingencies [Line Items]
Original contract	6,180,000
Amendment to contract	4,075,000
Total Contract	10,255,000	$ 10,300,000	$ 6,200,000
Initial deposit (included in original contract amount)	861,000
Amendment to deposit	699,000
Expenses incurred applied to deposit	(1,212,000)
Remaining Deposit	348,000
Expenses incurred/accrued (includes expenses applied to deposit)	8,314,000
Total	$ 1,941,000