BUSINESS SEGMENTS - Segment Operating Income Results (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 29, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Dec. 29, 2017	Dec. 30, 2016	Jan. 01, 2016
Segment Reporting Information [Line Items]
Amortization of intangible assets										$ (36.1)	$ (37.6)	$ (25.4)
Impairment of intangible assets										(5.7)	0.0	0.0
Network and Security Solutions [Member]
Segment Reporting Information [Line Items]
Amortization of intangible assets										(14.4)	(14.1)	(14.7)
Electrical and Electronic Solutions [Member]
Segment Reporting Information [Line Items]
Amortization of intangible assets										(8.4)	(8.5)	(6.3)	[1]
Utility Power Solutions [Member]
Segment Reporting Information [Line Items]
Amortization of intangible assets										(13.3)	(15.0)	(3.9)	[1]
Corporate [Member]
Segment Reporting Information [Line Items]
Amortization of intangible assets	[2]									0.0	0.0	0.0
Operating Income (Loss) [Member]
Segment Reporting Information [Line Items]
Amortization of intangible assets		$ (9.0)	$ (9.1)	$ (9.0)	$ (9.0)	$ (9.0)	$ (9.4)	$ (9.5)	$ (9.7)	(36.1)	(37.6)	(24.9)
UK pension settlement								(9.6)			(9.6)	(0.4)
Restructuring charges								(5.6)		0.0	(5.4)	(8.2)
Acquisition and integration costs		(1.5)	$ (0.8)			$ (0.8)	$ (0.7)	(1.4)	$ (2.2)	(2.3)	(5.1)	(13.2)
Impairment of intangible assets		$ (5.7)								(5.7)
Write-off of capitalized software												(3.1)
Latin America bad debt provision								$ (7.6)			(7.6)	(11.7)
Dilapidation provision												(1.7)
Items impacting operating expense and operating income										(44.1)	(65.3)	(63.2)
Operating Income (Loss) [Member] | Network and Security Solutions [Member]
Segment Reporting Information [Line Items]
Amortization of intangible assets										(14.4)	(14.1)	(14.7)
UK pension settlement											0.0	0.0
Restructuring charges										0.0	(1.7)	(2.4)
Acquisition and integration costs										0.0	0.0	0.0
Impairment of intangible assets										(5.7)
Write-off of capitalized software												0.0
Latin America bad debt provision											(3.9)	(10.7)
Dilapidation provision												0.0
Items impacting operating expense and operating income										(20.1)	(19.7)	(27.8)
Operating Income (Loss) [Member] | Electrical and Electronic Solutions [Member]
Segment Reporting Information [Line Items]
Amortization of intangible assets										(8.4)	(8.5)	(6.3)
UK pension settlement											0.0	0.0
Restructuring charges										0.5	(1.3)	(3.2)
Acquisition and integration costs										0.0	0.0	0.0
Impairment of intangible assets										0.0
Write-off of capitalized software												0.0
Latin America bad debt provision											(3.7)	(1.0)
Dilapidation provision												0.0
Items impacting operating expense and operating income										(7.9)	(13.5)	(10.5)
Operating Income (Loss) [Member] | Utility Power Solutions [Member]
Segment Reporting Information [Line Items]
Amortization of intangible assets										(13.3)	(15.0)	(3.9)
UK pension settlement											0.0	0.0
Restructuring charges										(0.1)	(2.1)	(0.1)
Acquisition and integration costs										0.0	(0.3)	(0.2)
Impairment of intangible assets										0.0
Write-off of capitalized software												0.0
Latin America bad debt provision											0.0	0.0
Dilapidation provision												0.0
Items impacting operating expense and operating income										(13.4)	(17.4)	(4.2)
Operating Income (Loss) [Member] | Corporate [Member]
Segment Reporting Information [Line Items]
Amortization of intangible assets										0.0	0.0	0.0
UK pension settlement											(9.6)	(0.4)
Restructuring charges										(0.4)	(0.3)	(2.5)
Acquisition and integration costs										(2.3)	(4.8)	(13.0)
Impairment of intangible assets										0.0
Write-off of capitalized software												(3.1)
Latin America bad debt provision											0.0	0.0
Dilapidation provision												(1.7)
Items impacting operating expense and operating income										$ (2.7)	$ (14.7)	$ (20.7)

[1] At the beginning of the fourth quarter of 2015, the Company acquired Power Solutions which is reported in both the EES and UPS business segments. For further information, see Note 3. "Business Combinations".

[2] Corporate "Total assets" primarily consists of cash and cash equivalents, deferred tax assets, and corporate fixed assets.