Description of Business and Summary of Significant Accounting Policies - Acquisitions and Divestitures (Details) - USD ($) $ in Thousands				3 Months Ended		6 Months Ended
	Dec. 07, 2020	May 05, 2020	Apr. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Significant accounting policies
Restructuring charges			$ 1,500	$ 0	$ 0	$ 0	$ 619
TrafficCast International
Significant accounting policies
Consideration transferred, liabilities	$ 1,700
Consideration transferred, assets	16,000
Payments to acquire businesses, gross	15,000
Security hold back	1,000
Business combination, contingent consideration arrangements, range of outcomes, value, high	$ 1,000
Consideration transferred, earn out term	2 years
Agriculture and Weather Analytics segment
Significant accounting policies
Restructuring charges			$ 1,500
Held for sale | Agriculture and Weather Analytics segment
Significant accounting policies
Total purchase consideration		$ 12,000
Proceeds from divestiture of businesses		10,500
Amount held in escrow from divestiture of business		1,500
Amount receivable from sale of segment		50
Held for sale | Agriculture and Weather Analytics segment | 12-month anniversaries of the closing date
Significant accounting policies
Amount receivable from sale of segment		$ 1,450