REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Oct. 27, 2018	Oct. 28, 2017	Oct. 27, 2018	Oct. 28, 2017
Disaggregation of Revenue [Line Items]
Net Sales	$ 264.0	$ 230.1	$ 487.4	$ 431.3
Goods Transferred at a Point in Time
Disaggregation of Revenue [Line Items]
Net Sales	256.0		469.6
Goods Transferred Over Time
Disaggregation of Revenue [Line Items]
Net Sales	8.0		17.8
U.S.
Disaggregation of Revenue [Line Items]
Net Sales	136.3		241.0
Malta
Disaggregation of Revenue [Line Items]
Net Sales	37.0		75.9
China
Disaggregation of Revenue [Line Items]
Net Sales	31.7		60.5
Canada
Disaggregation of Revenue [Line Items]
Net Sales	26.8		47.6
Egypt
Disaggregation of Revenue [Line Items]
Net Sales	12.9		25.6
Belgium
Disaggregation of Revenue [Line Items]
Net Sales	8.7		17.0
Other
Disaggregation of Revenue [Line Items]
Net Sales	10.6		19.8
Automotive
Disaggregation of Revenue [Line Items]
Net Sales	201.6	186.7	376.9	343.2
Automotive | Goods Transferred at a Point in Time
Disaggregation of Revenue [Line Items]
Net Sales	193.6		359.1
Automotive | Goods Transferred Over Time
Disaggregation of Revenue [Line Items]
Net Sales	8.0		17.8
Automotive | U.S.
Disaggregation of Revenue [Line Items]
Net Sales	96.7		174.0
Automotive | Malta
Disaggregation of Revenue [Line Items]
Net Sales	29.6		60.1
Automotive | China
Disaggregation of Revenue [Line Items]
Net Sales	22.5		42.5
Automotive | Canada
Disaggregation of Revenue [Line Items]
Net Sales	24.3		45.1
Automotive | Egypt
Disaggregation of Revenue [Line Items]
Net Sales	12.9		25.6
Automotive | Belgium
Disaggregation of Revenue [Line Items]
Net Sales	8.7		17.0
Automotive | Other
Disaggregation of Revenue [Line Items]
Net Sales	6.9		12.6
Industrial
Disaggregation of Revenue [Line Items]
Net Sales	47.4	24.7	79.6	50.5
Industrial | Goods Transferred at a Point in Time
Disaggregation of Revenue [Line Items]
Net Sales	47.4		79.6
Industrial | Goods Transferred Over Time
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Industrial | U.S.
Disaggregation of Revenue [Line Items]
Net Sales	24.9		37.0
Industrial | Malta
Disaggregation of Revenue [Line Items]
Net Sales	7.4		15.7
Industrial | China
Disaggregation of Revenue [Line Items]
Net Sales	9.1		17.9
Industrial | Canada
Disaggregation of Revenue [Line Items]
Net Sales	2.5		2.5
Industrial | Egypt
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Industrial | Belgium
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Industrial | Other
Disaggregation of Revenue [Line Items]
Net Sales	3.5		6.5
Medical
Disaggregation of Revenue [Line Items]
Net Sales	0.3	0.0	0.6	0.1
Medical | Goods Transferred at a Point in Time
Disaggregation of Revenue [Line Items]
Net Sales	0.3		0.6
Medical | Goods Transferred Over Time
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Medical | U.S.
Disaggregation of Revenue [Line Items]
Net Sales	0.3		0.6
Medical | Malta
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Medical | China
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Medical | Canada
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Medical | Egypt
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Medical | Belgium
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Medical | Other
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Interface
Disaggregation of Revenue [Line Items]
Net Sales	14.7	$ 18.7	30.3	$ 37.5
Interface | Goods Transferred at a Point in Time
Disaggregation of Revenue [Line Items]
Net Sales	14.7		30.3
Interface | Goods Transferred Over Time
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Interface | U.S.
Disaggregation of Revenue [Line Items]
Net Sales	14.4		29.4
Interface | Malta
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.1
Interface | China
Disaggregation of Revenue [Line Items]
Net Sales	0.1		0.1
Interface | Canada
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Interface | Egypt
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Interface | Belgium
Disaggregation of Revenue [Line Items]
Net Sales	0.0		0.0
Interface | Other
Disaggregation of Revenue [Line Items]
Net Sales	$ 0.2		$ 0.7