REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Jul. 28, 2018	Jul. 29, 2017
Disaggregation of Revenue [Line Items]
Net Sales	$ 223.4	$ 201.2
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales	213.6
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales	9.8
UNITED STATES
Disaggregation of Revenue [Line Items]
Net Sales	104.7
MALTA
Disaggregation of Revenue [Line Items]
Net Sales	38.9
CHINA
Disaggregation of Revenue [Line Items]
Net Sales	28.9
CANADA
Disaggregation of Revenue [Line Items]
Net Sales	20.8
EGYPT
Disaggregation of Revenue [Line Items]
Net Sales	12.7
BELGIUM
Disaggregation of Revenue [Line Items]
Net Sales	8.3
Other Countries [Member]
Disaggregation of Revenue [Line Items]
Net Sales	9.1
Automotive [Member]
Disaggregation of Revenue [Line Items]
Net Sales	175.3	156.5
Automotive [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales	165.5
Automotive [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales	9.8
Automotive [Member] | UNITED STATES
Disaggregation of Revenue [Line Items]
Net Sales	77.3
Automotive [Member] | MALTA
Disaggregation of Revenue [Line Items]
Net Sales	30.5
Automotive [Member] | CHINA
Disaggregation of Revenue [Line Items]
Net Sales	20.0
Automotive [Member] | CANADA
Disaggregation of Revenue [Line Items]
Net Sales	20.8
Automotive [Member] | EGYPT
Disaggregation of Revenue [Line Items]
Net Sales	12.7
Automotive [Member] | BELGIUM
Disaggregation of Revenue [Line Items]
Net Sales	8.3
Automotive [Member] | Other Countries [Member]
Disaggregation of Revenue [Line Items]
Net Sales	5.7
Interface
Disaggregation of Revenue [Line Items]
Net Sales	29.0	29.4
Interface | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales	29.0
Interface | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Interface | UNITED STATES
Disaggregation of Revenue [Line Items]
Net Sales	19.4
Interface | MALTA
Disaggregation of Revenue [Line Items]
Net Sales	6.1
Interface | CHINA
Disaggregation of Revenue [Line Items]
Net Sales	0.1
Interface | CANADA
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Interface | EGYPT
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Interface | BELGIUM
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Interface | Other Countries [Member]
Disaggregation of Revenue [Line Items]
Net Sales	3.4
Power Products [Member]
Disaggregation of Revenue [Line Items]
Net Sales	18.8	15.2
Power Products [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales	18.8
Power Products [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Power Products [Member] | UNITED STATES
Disaggregation of Revenue [Line Items]
Net Sales	7.7
Power Products [Member] | MALTA
Disaggregation of Revenue [Line Items]
Net Sales	2.3
Power Products [Member] | CHINA
Disaggregation of Revenue [Line Items]
Net Sales	8.8
Power Products [Member] | CANADA
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Power Products [Member] | EGYPT
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Power Products [Member] | BELGIUM
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Power Products [Member] | Other Countries [Member]
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Other Segments [Member]
Disaggregation of Revenue [Line Items]
Net Sales	0.3	$ 0.1
Other Segments [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales	0.3
Other Segments [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Other Segments [Member] | UNITED STATES
Disaggregation of Revenue [Line Items]
Net Sales	0.3
Other Segments [Member] | MALTA
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Other Segments [Member] | CHINA
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Other Segments [Member] | CANADA
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Other Segments [Member] | EGYPT
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Other Segments [Member] | BELGIUM
Disaggregation of Revenue [Line Items]
Net Sales	0.0
Other Segments [Member] | Other Countries [Member]
Disaggregation of Revenue [Line Items]
Net Sales	$ 0.0