Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Mar. 31, 2014
Segment Reporting Information [Abstract]
Net sales	$ 377.3	$ 364.2	$ 769.8	$ 740.0
Gross profit	56.7	57.2	124.4	119.1
Gross profit as % of sales (in hundredths)	15.00%	15.70%	16.20%	16.10%
Operating income	7.9	10.6	32.0	29.6
Total assets	1,012.2		1,012.2		1,032.3
Operating Segments [Member]
Segment Reporting Information [Abstract]
Net sales	381.9	367.7	778.9	747.7
Gross profit	56.5	57.1	123.8	118.8
Gross profit as % of sales (in hundredths)	14.80%	15.50%	15.90%	15.90%
Operating income	15.3	17.6	45.7	43.2
Operating Segments [Member] | North America [Member]
Segment Reporting Information [Abstract]
Net sales	143.8	146.0	295.5	294.7
Gross profit	20.9	25.0	49.0	50.5
Gross profit as % of sales (in hundredths)	14.50%	17.10%	16.60%	17.10%
Operating income	7.9	11.7	24.0	26.0
Total assets	225.4		225.4		218.1
Operating Segments [Member] | Europe [Member]
Segment Reporting Information [Abstract]
Net sales	146.4	138.9	305.0	285.1
Gross profit	16.7	14.7	38.9	34.0
Gross profit as % of sales (in hundredths)	11.40%	10.60%	12.80%	11.90%
Operating income	4.6	3.3	15.0	11.3
Total assets	336.9		336.9		367.9
Operating Segments [Member] | South America [Member]
Segment Reporting Information [Abstract]
Net sales	27.2	31.8	52.4	66.2
Gross profit	3.6	5.8	7.1	11.9
Gross profit as % of sales (in hundredths)	13.40%	18.20%	13.60%	18.00%
Operating income	0.3	2.5	0.1	5.1
Total assets	73.2		73.2		80.1
Operating Segments [Member] | Asia [Member]
Segment Reporting Information [Abstract]
Net sales	19.0	16.2	39.8	34.5
Gross profit	2.1	1.8	5.7	4.1
Gross profit as % of sales (in hundredths)	11.10%	10.70%	14.30%	11.80%
Operating income	(0.7)	(1.1)	0.2	(1.4)
Total assets	92.7		92.7		92.8
Operating Segments [Member] | Building HVAC [Member]
Segment Reporting Information [Abstract]
Net sales	45.5	34.8	86.2	67.2
Gross profit	13.2	9.8	23.1	18.3
Gross profit as % of sales (in hundredths)	29.20%	28.10%	26.90%	27.20%
Operating income	3.2	1.2	6.4	2.2
Total assets	150.5		150.5		132.7
Corporate and Eliminations [Member]
Segment Reporting Information [Abstract]
Net sales	(4.6)	(3.5)	(9.1)	(7.7)
Gross profit	0.2	0.1	0.6	0.3
Gross profit as % of sales (in hundredths)	0.00%	0.00%	0.00%	0.00%
Operating income	(7.4)	(7.0)	(13.7)	(13.6)
Total assets	$ 133.5		$ 133.5		$ 140.7