Revenue Recognition - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018	Apr. 01, 2018
Disaggregation Of Revenue [Line Items]
Total net revenue	$ 39,659	$ 41,987	$ 40,722	$ 38,389	$ 36,618	$ 36,014	$ 34,203	$ 34,007	$ 160,757	$ 140,842	$ 127,360
Revenue recognized									37,000	33,100
Transfers to accounts receivable									2,800	4,600
Capitalized contract cost, net	$ 3,200				$ 3,300				3,200	3,300		$ 1,900
Sales commissions and fees									4,700	4,500
Capitalized contract cost, amortization									1,400	1,100
Products [Member]
Disaggregation Of Revenue [Line Items]
Total net revenue									44,230	39,003	33,699
Support, Maintenance, Subscription Services, and Professional Services [Member]
Disaggregation Of Revenue [Line Items]
Total net revenue									$ 116,500	$ 101,800	$ 93,700