Line of Credit - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2019	Mar. 29, 2018	Jan. 04, 2016
Line Of Credit Facility [Line Items]
Line of credit	$ 37,000,000		$ 37,000,000		$ 11,000,000
Remaining borrowing capacity	263,000,000		263,000,000
Interest expense	253,000	$ 516,000	758,000	$ 1,657,000
Amortization of debt issuance costs	177,000	$ 177,000	532,000	$ 532,000
Revolving Credit Facility
Line Of Credit Facility [Line Items]
Maximum borrowing capacity	$ 400,000,000		$ 400,000,000			$ 300,000,000	$ 250,000,000
Additional borrowing capacity						$ 100,000,000
Credit agreement maturity date			Mar. 29, 2023
Letter of Credit
Line Of Credit Facility [Line Items]
Maximum borrowing capacity							10,000,000
Swing-Line Loans
Line Of Credit Facility [Line Items]
Maximum borrowing capacity							$ 10,000,000