Restructuring Activities - Restructuring and severance costs for our reportable segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2020
Restructuring Cost and Reserve [Line Items]
Severance and benefits		$ 1,105	$ 1,105
Lease impairment and other costs			351
Total restructuring and severance costs			1,456
Restructuring costs were recorded to restructuring charges	$ 619
Agriculture and Weather Analytics
Restructuring Cost and Reserve [Line Items]
Restructuring costs were recorded to restructuring charges	$ 837
Segment income: | Roadway Sensors
Restructuring Cost and Reserve [Line Items]
Severance and benefits			110
Total restructuring and severance costs			110
Segment income: | Transportation Systems
Restructuring Cost and Reserve [Line Items]
Severance and benefits			43
Total restructuring and severance costs			43
Segment income: | Agriculture and Weather Analytics
Restructuring Cost and Reserve [Line Items]
Severance and benefits			524
Lease impairment and other costs			313
Total restructuring and severance costs			837
Corporate
Restructuring Cost and Reserve [Line Items]
Severance and benefits			428
Lease impairment and other costs			38
Total restructuring and severance costs			$ 466