Stockholders' Equity - Fair Value of Employee Stock Options (Parenthetical) (Detail) - shares	3 Months Ended	9 Months Ended
Dec. 31, 2019	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of options granted	0	342,500

Gross number of share options (or share units) granted during the period.

No definition available.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration