Investments and Fair Value Measurements (Details) - USD ($)	Sep. 30, 2020	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Marketable securities	$ 17,086,000	$ 2,997,000
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	69,962,000	18,390,000
Total liabilities	0	0
Money Market Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	291,000	11,348,000
Commercial Paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	56,159,000	7,042,000
Cash and cash equivalents	39,600,000	4,000,000.0
Marketable securities	16,600,000	3,000,000.0
Corporate Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	3,000,000
Municipal Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	512,000
US Treasury bills
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	10,000,000
Quoted Market Prices for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	10,291,000	11,348,000
Quoted Market Prices for Identical Assets (Level 1) | Money Market Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	291,000	11,348,000
Quoted Market Prices for Identical Assets (Level 1) | Commercial Paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	0	0
Quoted Market Prices for Identical Assets (Level 1) | Corporate Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	0
Quoted Market Prices for Identical Assets (Level 1) | Municipal Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	0
Quoted Market Prices for Identical Assets (Level 1) | US Treasury bills
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	10,000,000
Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	59,671,000	7,042,000
Significant Other Observable Inputs (Level 2) | Money Market Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	0	0
Significant Other Observable Inputs (Level 2) | Commercial Paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	56,159,000	7,042,000
Significant Other Observable Inputs (Level 2) | Corporate Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	3,000,000
Significant Other Observable Inputs (Level 2) | Municipal Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	512,000
Significant Other Observable Inputs (Level 2) | US Treasury bills
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	0
Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	0	0
Significant Unobservable Inputs (Level 3) | Money Market Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	0	0
Significant Unobservable Inputs (Level 3) | Commercial Paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	0	$ 0
Significant Unobservable Inputs (Level 3) | Corporate Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	0
Significant Unobservable Inputs (Level 3) | Municipal Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	0
Significant Unobservable Inputs (Level 3) | US Treasury bills
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	$ 0