Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Nov. 30, 2019	Nov. 30, 2018	Nov. 30, 2019	Nov. 30, 2018
Disaggregation Of Revenue [Line Items]
Net sales	$ 110,112	$ 129,637	$ 293,812	$ 339,359
Corporate, Non-Segment [Member]
Disaggregation Of Revenue [Line Items]
Net sales	75	257	341	683
Automotive [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Net sales	29,985	45,053	86,472	124,705
Automotive [Member] | Operating Segments [Member] | OEM Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	10,628	24,472	37,391	70,782
Automotive [Member] | Operating Segments [Member] | Aftermarket Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	19,357	20,581	49,081	53,923
Consumer Electronics [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Net sales	79,914	83,927	206,601	213,159
Consumer Electronics [Member] | Operating Segments [Member] | Premium Audio Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	53,250	49,666	128,056	121,707
Consumer Electronics [Member] | Operating Segments [Member] | Other Consumer Electronic Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	26,664	34,261	78,545	91,452
Biometrics [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Net sales	138	400	398	812
Biometrics [Member] | Operating Segments [Member] | Biometric Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	$ 138	$ 400	$ 398	$ 812