Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 02, 2015	Sep. 26, 2014	Oct. 02, 2015	Sep. 26, 2014
Income Statement [Abstract]
Revenues	$ 904.2	$ 833.5	$ 2,655.5	$ 2,297.6
Cost of revenues (exclusive of amortization shown below)	595.7	552.6	1,742.2	1,490.4
Gross profit	308.5	280.9	913.3	807.2
Operating expenses:
Research and development	104.9	93.4	305.7	255.7
Selling and marketing	52.3	51.1	156.0	143.4
General and administrative	44.9	48.5	136.6	134.2
Amortization of acquisition-related intangible assets	33.6	21.0	101.1	39.6
Restructuring, asset impairments and other, net	3.3	10.1	4.5	20.0
Goodwill and intangible asset impairment	0.1	0.0	3.8	0.0
Total operating expenses	239.1	224.1	707.7	592.9
Operating income	69.4	56.8	205.6	214.3
Other (expense) income, net:
Interest expense	(14.9)	(8.6)	(34.8)	(24.6)
Interest income	0.2	0.2	0.8	0.6
Other	2.1	(1.2)	7.9	(2.1)
Loss on debt extinguishment	0.0	0.0	(0.4)	0.0
Other (expense) income, net	(12.6)	(9.6)	(26.5)	(26.1)
Income before income taxes	56.8	47.2	179.1	188.2
Income tax (provision) benefit	(10.0)	(6.3)	(25.1)	3.7
Net income	46.8	40.9	154.0	191.9
Less: Net income attributable to non-controlling interest	(0.5)	(0.4)	(1.9)	(1.6)
Net income attributable to ON Semiconductor Corporation	46.3	40.5	152.1	190.3
Comprehensive income (loss), net of tax:
Net income	46.8	40.9	154.0	191.9
Foreign currency translation adjustments	0.2	1.9	0.2	1.3
Effects of cash flow hedges	0.4	(1.2)	1.7	1.5
Effects of available-for-sale securities	(1.1)	0.0	(4.5)	0.0
Other comprehensive (loss) income, net of tax of $0.0 million	(0.5)	0.7	(2.6)	2.8
Comprehensive income	46.3	41.6	151.4	194.7
Comprehensive income attributable to non-controlling interest	(0.5)	(0.4)	(1.9)	(1.6)
Comprehensive income attributable to ON Semiconductor Corporation	$ 45.8	$ 41.2	$ 149.5	$ 193.1
Net income per common share attributable to ON Semiconductor Corporation:
Basic (in dollars per share)	$ 0.11	$ 0.09	$ 0.36	$ 0.43
Diluted (in dollars per share)	$ 0.11	$ 0.09	$ 0.35	$ 0.43
Weighted-average common shares outstanding:
Basic (in shares)	413.7	440.7	424.0	440.7
Diluted (in shares)	417.5	444.9	431.3	444.6