Segment Information (Details) - USD ($) $ in Millions		3 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2021
Segment Information [Abstract]
Net sales		$ 494.6	$ 347.8
Gross profit		$ 73.2	$ 46.1
Gross profit (% of sales)		14.80%	13.30%
Operating income (loss)		$ 8.7	$ (3.2)
Total assets		1,326.9		$ 1,276.7
BHVAC [Member]
Segment Information [Abstract]
Net sales		59.9	47.6
CIS [Member]
Segment Information [Abstract]
Net sales		159.2	122.5
HDE [Member]
Segment Information [Abstract]
Net sales		201.8	123.5
Automotive [Member]
Segment Information [Abstract]
Net sales		86.2	62.1
Segment Total [Member]
Segment Information [Abstract]
Net sales		507.1	355.7
Operating Segments [Member]
Segment Information [Abstract]
Net sales		494.6	347.8
Gross profit		$ 72.8	$ 46.1
Gross profit (% of sales)		14.30%	13.00%
Operating income (loss)		$ 26.3	$ 0.8
Operating Segments [Member] | BHVAC [Member]
Segment Information [Abstract]
Net sales		59.4	47.4
Gross profit		$ 16.2	$ 14.5
Gross profit (% of sales)		27.10%	30.50%
Operating income (loss)		$ 6.8	$ 7.1
Total assets		127.6		110.8
Operating Segments [Member] | CIS [Member]
Segment Information [Abstract]
Net sales		158.2	121.3
Gross profit		$ 20.8	$ 15.5
Gross profit (% of sales)		13.00%	12.60%
Operating income (loss)		$ 6.4	$ 0.0
Total assets		633.5		609.2
Operating Segments [Member] | HDE [Member]
Segment Information [Abstract]
Net sales		191.9	118.3
Gross profit		$ 22.6	$ 11.3
Gross profit (% of sales)		11.20%	9.20%
Operating income (loss)		$ 8.9	$ (2.5)
Total assets		443.9		438.7
Operating Segments [Member] | Automotive [Member]
Segment Information [Abstract]
Net sales		85.1	60.8
Gross profit		$ 13.2	$ 4.8
Gross profit (% of sales)		15.30%	7.70%
Operating income (loss)		$ 4.2	$ (3.8)
Total assets		125.7		124.2
Inter-segment Sales [Member]
Segment Information [Abstract]
Net sales		12.5	7.9
Inter-segment Sales [Member] | BHVAC [Member]
Segment Information [Abstract]
Net sales		0.5	0.2
Inter-segment Sales [Member] | CIS [Member]
Segment Information [Abstract]
Net sales		1.0	1.2
Inter-segment Sales [Member] | HDE [Member]
Segment Information [Abstract]
Net sales		9.9	5.2
Inter-segment Sales [Member] | Automotive [Member]
Segment Information [Abstract]
Net sales		1.1	1.3
Corporate and Eliminations [Member]
Segment Information [Abstract]
Net sales		(12.5)	(7.9)
Gross profit		$ 0.4	$ 0.0
Gross profit (% of sales)		0.00%	0.00%
Operating income (loss)		$ (17.6)	$ (4.0)
Total assets	[1]	(3.8)		(6.2)
Corporate [Member]
Segment Information [Abstract]
Total assets		$ 19.2		$ 17.5

[1] At June 30, 2021 and March 31, 2021, Corporate assets totaled $19.2 million and $17.5 million, respectively and were more than offset by eliminations for intercompany balances, including accounts receivable.