Investments and Fair Value Measurements (Details) - USD ($)	Jun. 30, 2020	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Marketable securities	$ 14,970,000	$ 2,997,000
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	69,987,000	18,390,000
Total liabilities	0	0
Money Market Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	4,988,000	11,348,000
Commercial Paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	48,382,000	7,042,000
Cash and cash equivalents	41,600,000	4,000,000.0
Marketable securities	6,800,000	3,000,000.0
Municipal Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	16,617,000
Cash and cash equivalents	8,400,000
Marketable securities	8,200,000
Quoted Market Prices for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	4,988,000	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	4,988,000	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) | Municipal Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	0
Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	64,999,000	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	48,382,000	7,042,000
Significant Other Observable Inputs (Level 2) | Municipal Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	16,617,000
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) | Municipal Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	$ 0