SEGMENT INFORMATION - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Jan. 30, 2016	Jan. 31, 2015	Jan. 30, 2016	Jan. 31, 2015
Segment Reporting Information [Line Items]
Net sales to unaffiliated customers	$ 184.6	$ 206.0	$ 596.3	$ 653.8
Income (loss) from operations	21.5	34.7	78.4	97.7
Interest income, net	(0.2)	(0.2)	(0.7)	(0.4)
Other income, net	(1.0)	(0.3)	(1.5)	(0.2)
Income before income taxes	22.7	35.2	80.6	98.3
Operating Segments
Segment Reporting Information [Line Items]
Net sales	(184.6)	(206.0)	(596.3)	(653.8)
Transfers between segments
Segment Reporting Information [Line Items]
Net sales	0.0	0.0	0.0	0.0
Automotive
Segment Reporting Information [Line Items]
Net sales to unaffiliated customers	138.5	141.1	452.8	463.4
Income (loss) from operations	28.7	29.5	99.7	92.8
Automotive \| Operating Segments
Segment Reporting Information [Line Items]
Net sales	(141.0)	(142.6)	(459.1)	(466.5)
Automotive \| Transfers between segments
Segment Reporting Information [Line Items]
Net sales	(2.5)	(1.5)	(6.3)	(3.1)
Interface
Segment Reporting Information [Line Items]
Net sales to unaffiliated customers	34.8	36.9	104.3	121.4
Income (loss) from operations	0.5	3.8	2.6	15.7
Interface \| Operating Segments
Segment Reporting Information [Line Items]
Net sales	(35.2)	(37.4)	(105.4)	(123.1)
Interface \| Transfers between segments
Segment Reporting Information [Line Items]
Net sales	(0.4)	(0.5)	(1.1)	(1.7)
Power Products
Segment Reporting Information [Line Items]
Net sales to unaffiliated customers	11.3	26.1	39.1	63.9
Income (loss) from operations	1.2	9.3	4.7	17.9
Power Products \| Operating Segments
Segment Reporting Information [Line Items]
Net sales	(11.4)	(26.3)	(39.6)	(64.3)
Power Products \| Transfers between segments
Segment Reporting Information [Line Items]
Net sales	(0.1)	(0.2)	(0.5)	(0.4)
Other
Segment Reporting Information [Line Items]
Net sales to unaffiliated customers	0.1	1.8	0.1	5.1
Income (loss) from operations	(2.1)	(1.2)	(6.2)	(4.1)
Other \| Operating Segments
Segment Reporting Information [Line Items]
Net sales	(0.2)	(1.9)	(0.3)	(5.3)
Other \| Transfers between segments
Segment Reporting Information [Line Items]
Net sales	(0.1)	(0.1)	(0.2)	(0.2)
Eliminations/Corporate
Segment Reporting Information [Line Items]
Net sales to unaffiliated customers	(0.1)	0.1	0.0	0.0
Income (loss) from operations	(6.8)	(6.7)	(22.4)	(24.6)
Eliminations/Corporate \| Operating Segments
Segment Reporting Information [Line Items]
Net sales	3.2	2.2	8.1	5.4
Eliminations/Corporate \| Transfers between segments
Segment Reporting Information [Line Items]
Net sales	$ 3.1	$ 2.3	$ 8.1	$ 5.4

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Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
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-Section S99
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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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