ON Semiconductor (ON) 10-Q 2 Aug 21 2021 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jul. 02, 2021	Jul. 28, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jul. 2, 2021
Document Transition Report	false
Entity File Number	001-39317
Entity Registrant Name	ON SEMICONDUCTOR CORP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-3840979
Entity Address, Address Line One	5005 E. McDowell Road
Entity Address, City or Town	Phoenix
Entity Address, State or Province	AZ
Entity Address, Postal Zip Code	85008
City Area Code	602
Local Phone Number	244-6600
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	ON
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		430,532,211
Central Index Key	0001097864
Current Fiscal Year End	--12-31
Document Fiscal Period	Q2
Document Fiscal Year	2021
Amendment	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Jul. 02, 2021	Dec. 31, 2020
Assets
Cash and cash equivalents	$ 1,091.1	$ 1,080.7
Receivables, net	669.1	676
Inventories	1,309.3	1,251.4
Other current assets	160.4	176
Total current assets	3,229.9	3,184.1
Property, plant and equipment, net	2,457.8	2,512.3
Goodwill	1,663.4	1,663.4
Intangible assets, net	416.3	469
Deferred tax assets	429.9	429
Other assets	397.1	410.2
Total assets	8,594.4	8,668
Liabilities, Non-Controlling Interest and Stockholders’ Equity
Accounts payable	610.2	572.9
Accrued expenses and other current liabilities	643.6	570
Current portion of long-term debt	201.3	531.6
Total current liabilities	1,455.1	1,674.5
Long-term debt	2,907.1	2,959.7
Deferred tax liabilities	49.8	57.3
Other long-term liabilities	378	418.4
Total liabilities	4,790	5,109.9
Commitments and contingencies (Note 9)
ON Semiconductor Corporation stockholders’ equity:
Common stock ($0.01 par value, 1,250,000,000 shares authorized, 599,397,171 and 570,766,439 issued, 430,532,211 and 411,842,629 outstanding, respectively)	6	5.7
Additional paid-in capital	4,470.3	4,133.1
Accumulated other comprehensive loss	(52.2)	(57.6)
Accumulated earnings	1,699.5	1,425.5
Less: Treasury stock, at cost: 168,864,960 and 158,923,810 shares, respectively	(2,339.2)	(1,968.2)
Total ON Semiconductor Corporation stockholders’ equity	3,784.4	3,538.5
Non-controlling interest	20	19.6
Total stockholders' equity	3,804.4	3,558.1
Total liabilities and stockholders' equity	$ 8,594.4	$ 8,668

Consolidated Balance Sheets - P

Consolidated Balance Sheets - Parenthetical - $ / shares	Jul. 02, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,250,000,000	1,250,000,000
Common stock, shares issued (in shares)	599,397,171	570,766,439
Common stock, shares outstanding (in shares)	430,532,211	411,842,629
Treasury stock, shares (in shares)	168,864,960	158,923,810

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Income Statement [Abstract]
Revenue	$ 1,669.9	$ 1,213.5	$ 3,151.6	$ 2,491.4
Cost of revenue (exclusive of amortization shown below)	1,029.8	839.2	1,990.3	1,714.4
Gross profit	640.1	374.3	1,161.3	777
Operating expenses:
Research and development	166.3	156.1	339.9	327.1
Selling and marketing	76.1	65.6	155	142.4
General and administrative	73.2	62.9	145.6	134.1
Amortization of acquisition-related intangible assets	24.8	29.1	49.8	61.4
Restructuring, asset impairments and other charges, net	17.5	16.2	60	49
Intangible asset impairment	0	1.3	2.9	1.3
Total operating expenses	357.9	331.2	753.2	715.3
Operating income	282.2	43.1	408.1	61.7
Other income (expense), net:
Interest expense	(33.1)	(41.9)	(66.5)	(84.4)
Interest income	0.2	1.5	0.6	3.4
Loss on debt refinancing and prepayment	(26.2)	0	(26.2)	0
Other income (expense)	(1.1)	(2.8)	3.4	(2.7)
Other income (expense), net	(60.2)	(43.2)	(88.7)	(83.7)
Income (loss) before income taxes	222	(0.1)	319.4	(22)
Income tax (provision) benefit	(37.9)	(0.8)	(45)	7.4
Net income (loss)	184.1	(0.9)	274.4	(14.6)
Less: Net income attributable to non-controlling interest	0	(0.5)	(0.4)	(0.8)
Net income (loss) attributable to ON Semiconductor Corporation	184.1	(1.4)	274	(15.4)
Comprehensive income (loss), net of tax:
Net income (loss)	184.1	(0.9)	274.4	(14.6)
Foreign currency translation adjustments	(0.2)	(0.1)	(2.5)	0.5
Effects of cash flow hedges	3.9	(1)	7.9	(13.8)
Other comprehensive income (loss), net of tax	3.7	(1.1)	5.4	(13.3)
Comprehensive income (loss)	187.8	(2)	279.8	(27.9)
Comprehensive income attributable to non-controlling interest	0	(0.5)	(0.4)	(0.8)
Comprehensive income (loss) attributable to ON Semiconductor Corporation	$ 187.8	$ (2.5)	$ 279.4	$ (28.7)
Net income (loss) per share of common stock attributable to ON Semiconductor Corporation:
Basic (in dollars per share)	$ 0.43	$ 0	$ 0.65	$ (0.04)
Diluted (in dollars per share)	$ 0.42	$ 0	$ 0.62	$ (0.04)
Weighted-average shares of common stock outstanding:
Basic (in shares)	427.7	410.1	420.5	410.3
Diluted (in shares)	443.6	410.1	444.5	410.3

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Earnings	Treasury Stock	Non-Controlling Interest
Balance, beginning (in shares) at Dec. 31, 2019		565,562,607				(154,249,943)
Balance, beginning at Dec. 31, 2019	$ 3,324.1	$ 5.7	$ 3,809.5	$ (54.3)	$ 1,191.3	$ (1,650.5)	$ 22.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued pursuant to the ESPP (in shares)		1,153,803
Shares issued pursuant to the ESPP	11.4		11.4
RSUs and stock grant awards issued (in shares)		2,894,867
RSUs and stock grant awards issued	0	$ 0
Payment of tax withholding for RSUs (in shares)						(940,300)
Payment of tax withholding for RSUs	(16.6)					$ (16.6)
Share-based compensation	33.7		33.7
Repurchase of common stock (in shares)						(3,611,413)
Repurchase of common stock	(65.4)					$ (65.4)
Comprehensive income	(27.9)			(13.3)	(15.4)		0.8
Balance, ending (in shares) at Jul. 03, 2020		569,611,277				(158,801,656)
Balance, ending at Jul. 03, 2020	3,259.3	$ 5.7	3,854.6	(67.6)	1,175.9	$ (1,732.5)	23.2
Balance, beginning (in shares) at Apr. 03, 2020		568,774,542				(158,769,976)
Balance, beginning at Apr. 03, 2020	3,237.6	$ 5.7	3,830.3	(66.5)	1,177.3	$ (1,731.9)	22.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued pursuant to the ESPP (in shares)		666,365
Shares issued pursuant to the ESPP	6.3		6.3
RSUs and stock grant awards issued (in shares)		170,370
RSUs and stock grant awards issued	0	$ 0
Payment of tax withholding for RSUs (in shares)						(31,680)
Payment of tax withholding for RSUs	(0.6)					$ (0.6)
Share-based compensation	18		18
Comprehensive income	(2)			(1.1)	(1.4)		0.5
Balance, ending (in shares) at Jul. 03, 2020		569,611,277				(158,801,656)
Balance, ending at Jul. 03, 2020	3,259.3	$ 5.7	3,854.6	(67.6)	1,175.9	$ (1,732.5)	23.2
Balance, beginning (in shares) at Dec. 31, 2020		570,766,439				(158,923,810)
Balance, beginning at Dec. 31, 2020	3,558.1	$ 5.7	4,133.1	(57.6)	1,425.5	$ (1,968.2)	19.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercisies (in shares)		4,000
Stock option exercises	0		0
Shares issued pursuant to the ESPP (in shares)		461,831
Shares issued pursuant to the ESPP	12.1		12.1
RSUs and stock grant awards issued (in shares)		2,549,977
RSUs and stock grant awards issued	0
Shares issued upon exercise of warrants for 1.00% Notes (in shares)		13,424,951
Shares issued for warrants exercise - 1.00% Notes	0	$ 0.1	(0.1)
Partial settlement - 1.625% Notes (in shares)		5,425,239
Partial settlement - 1.625% Notes	(141.6)	$ 0.1	(141.7)
Partial settlement of warrants - 1.625% Notes (in shares)		6,764,734
Partial settlement of warrants - 1.625% Notes	0	$ 0.1	(0.1)
Partial settlement of bond hedges - 1.625% Notes	0		339			$ (339)
Partial settlement of bond hedges - 1.625% Notes (in shares)						(9,120,930)
Equity component - 0% Notes	136.6		136.6
Warrants and bond hedges, net - 0% Notes	(66.5)		(66.5)
Tax impact of warrants and bond hedges, net	6.5		6.5
Payment of tax withholding for RSUs (in shares)						(820,220)
Payment of tax withholding for RSUs	(32)					$ (32)
Share-based compensation	51.4		51.4
Comprehensive income	279.8			5.4	274		0.4
Balance, ending (in shares) at Jul. 02, 2021		599,397,171				(168,864,960)
Balance, ending at Jul. 02, 2021	3,804.4	$ 6	4,470.3	(52.2)	1,699.5	$ (2,339.2)	20
Balance, beginning (in shares) at Apr. 02, 2021		579,553,444				(159,657,033)
Balance, beginning at Apr. 02, 2021	3,649.6	$ 5.8	4,161	(55.9)	1,515.4	$ (1,996.7)	20
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercisies (in shares)		4,000
Stock option exercises	0
Shares issued pursuant to the ESPP (in shares)		257,416
Shares issued pursuant to the ESPP	6.4		6.4
RSUs and stock grant awards issued (in shares)		280,649
RSUs and stock grant awards issued	0
Shares issued upon exercise of warrants for 1.00% Notes (in shares)		7,111,689
Shares issued for warrants exercise - 1.00% Notes	0
Partial settlement - 1.625% Notes (in shares)		5,425,239
Partial settlement - 1.625% Notes	(141.6)	$ 0.1	(141.7)
Partial settlement of warrants - 1.625% Notes (in shares)		6,764,734
Partial settlement of warrants - 1.625% Notes	0	$ 0.1	(0.1)
Partial settlement of bond hedges - 1.625% Notes	0		339			$ (339)
Partial settlement of bond hedges - 1.625% Notes (in shares)						(9,120,930)
Equity component - 0% Notes	136.6		136.6
Warrants and bond hedges, net - 0% Notes	(66.5)		(66.5)
Tax impact of warrants and bond hedges, net	6.5		6.5
Payment of tax withholding for RSUs (in shares)						(86,997)
Payment of tax withholding for RSUs	(3.5)					$ (3.5)
Share-based compensation	29.1		29.1
Comprehensive income	187.8			3.7	184.1		0
Balance, ending (in shares) at Jul. 02, 2021		599,397,171				(168,864,960)
Balance, ending at Jul. 02, 2021	$ 3,804.4	$ 6	$ 4,470.3	$ (52.2)	$ 1,699.5	$ (2,339.2)	$ 20

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020
Cash flows from operating activities:
Net income (loss)	$ 274.4	$ (14.6)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	306.5	315.1
Loss (gain) on sale and disposal of fixed assets	0.3	(2.9)
Loss on debt refinancing and prepayment	26.2	0
Amortization of debt discount and issuance costs	5.1	6
Share-based compensation	51.4	33.7
Non-cash interest on convertible notes	10.6	19.3
Non-cash asset impairment charges	7.5	8.5
Change in deferred tax balances	(4.7)	(12.3)
Other	0	1.8
Changes in assets and liabilities:
Receivables	4.3	37.8
Inventories	(53.5)	(51.5)
Other assets	3.5	3.5
Accounts payable	32	2.3
Accrued expenses and other current liabilities	61.4	(23)
Other long-term liabilities	(18.5)	(3.2)
Net cash provided by operating activities	706.5	320.5
Cash flows from investing activities:
Purchase of property, plant and equipment	(181.8)	(205.6)
Deposits and proceeds from sale of property, plant and equipment	6.6	0.9
Deposits utilized (made) for purchase of property, plant and equipment	(2.8)	0.5
Purchase of business, net of cash acquired	0	(4.5)
Settlement of purchase price from previous acquisition	0	26
Net cash used in investing activities	(178)	(182.7)
Cash flows from financing activities:
Proceeds for the issuance of common stock under the ESPP	12.3	11.4
Payment of tax withholding for RSUs	(32)	(16.6)
Repurchase of common stock	0	(65.4)
Issuance and borrowings under debt agreements	787.3	1,165
Reimbursement of debt issuance costs	2.7	0
Payment of debt issuance costs	(3.5)	0
Repayment of borrowings under debt agreements	(1,214.7)	(60.3)
Payment for purchase of bond hedges	(160.3)	0
Proceeds from issuance of warrants	93.8	0
Payments related to prior acquisition	(2.3)	(5.5)
Net cash provided by (used in) financing activities	(516.7)	1,028.6
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(0.8)	0.1
Net increase in cash, cash equivalents and restricted cash	11	1,166.5
Beginning cash, cash equivalents and restricted cash	1,081.5	894.2
Ending cash, cash equivalents and restricted cash	$ 1,092.5	$ 2,060.7

Background and Basis of Present

Background and Basis of Presentation	6 Months Ended
	Jul. 02, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background and Basis of Presentation	Note 1: Background and Basis of Presentation ON Semiconductor Corporation, together with its wholly and majority-owned subsidiaries ("ON Semiconductor," "we," "us," "our" or the "Company"), uses a thirteen-week fiscal quarter accounting period for the first three fiscal quarters of each year, with the second quarter of 2021 having ended on July 2, 2021 and each fiscal year ending on December 31. The quarters ended July 2, 2021 and July 3, 2020 each contained 91 days. The six months ended July 2, 2021 and July 3, 2020 contained 183 and 185 days, respectively. As of July 2, 2021, the Company was organized into the following three operating and reportable segments: the Power Solutions Group ("PSG"), the Advanced Solutions Group ("ASG") and the Intelligent Sensing Group ("ISG"). The accompanying unaudited financial statements as of and for the quarter and six months ended July 2, 2021 have been prepared in accordance with generally accepted accounting principles in the United States of America ("GAAP"). Accordingly, the unaudited financial statements do not include all of the information and footnotes required by GAAP for audited financial statements. The balance sheet as of December 31, 2020 was derived from the Company's audited financial statements, but does not include all disclosures required by GAAP for audited financial statements. In the opinion of the Company's management, the interim information includes all adjustments, which include normal recurring adjustments, necessary for a fair statement of the results for the interim periods. Certain reclassifications have been made to prior period amounts to conform to current-period presentation. The footnote disclosures related to the interim financial information included herein are also unaudited. Such financial information should be read in conjunction with the consolidated financial statements and related notes thereto for the year ended December 31, 2020 included in the Company's Annual Report on Form 10-K for the year ended December 31, 2020, which was filed with the SEC on February 16, 2021 (the "2020 Form 10-K"). Use of Estimates The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amount of assets and liabilities at the date of the financial statements and the reported amount of revenue and expenses during the reporting period. Management evaluates these estimates and judgments on an ongoing basis and bases its estimates on experience, current and expected future conditions, third-party evaluations and various other assumptions that management believes are reasonable under the circumstances. Significant estimates have been used by management in conjunction with the following: (i) future payouts for customer incentives and amounts subject to allowances and returns; (ii) valuation and obsolescence relating to inventories; (iii) variable and share-based compensation; and (iv) measurement of valuation allowances against deferred tax assets and evaluations of uncertain tax positions. Additionally, during periods where it becomes applicable, significant estimates will be used by management in determining the future cash flows used to assess and test for impairment of long-lived assets and goodwill and in assumptions used in connection with business combinations. Actual results may differ from the estimates and assumptions used in the consolidated financial statements.

Revenue and Segment Information

Revenue and Segment Information	6 Months Ended
	Jul. 02, 2021
Segment Reporting [Abstract]
Revenue and Segment Information	Note 2: Revenue and Segment Information The Company is organized into three operating and reportable segments consisting of PSG, ASG and ISG. These segments represent the Company’s view of the business, and its gross profit is used to evaluate the performance of the Company’s segments, the progress of major initiatives and the allocation of resources. Gross profit is exclusive of the amortization of acquisition-related intangible assets. Revenue and gross profit for the Company’s operating and reportable segments are as follows (in millions): PSG ASG ISG Total For the quarter ended July 2, 2021: Revenue from external customers $ 846.6 $ 607.6 $ 215.7 $ 1,669.9 Gross profit $ 314.3 $ 252.3 $ 73.5 $ 640.1 For the quarter ended July 3, 2020: Revenue from external customers $ 618.4 $ 426.7 $ 168.4 $ 1,213.5 Gross profit (1) $ 172.4 $ 151.4 $ 50.5 $ 374.3 For the six months ended July 2, 2021: Revenue from external customers $ 1,593.6 $ 1,139.1 $ 418.9 $ 3,151.6 Gross profit $ 560.8 $ 459.1 $ 141.4 $ 1,161.3 For the six months ended July 3, 2020: Revenue from external customers $ 1,242.3 $ 893.8 $ 355.3 $ 2,491.4 Gross profit (1) $ 355.0 $ 309.2 $ 112.8 $ 777.0 (1) Beginning in the first quarter of 2021, the Company started including unallocated manufacturing costs as part of segment operating results to determine segment gross profit. As a result, the prior-period amounts have been reclassified to conform to current-period presentation. The Company had one customer, a distributor, whose purchases accounted for approximately 14% and 12% of the Company's total revenue for the quarter and six months ended July 2, 2021. Revenue for the Company's operating and reportable segments disaggregated into geographic locations based on sales billed from the respective country and sales channels are as follows (in millions): Quarter Ended July 2, 2021 PSG ASG ISG Total Geographic Location Singapore $ 273.1 $ 226.8 $ 33.1 $ 533.0 Hong Kong 261.0 144.3 44.0 449.3 United Kingdom 147.4 84.9 44.2 276.5 United States 108.1 76.4 41.1 225.6 Other 57.0 75.2 53.3 185.5 Total $ 846.6 $ 607.6 $ 215.7 $ 1,669.9 Sales Channel Distributors $ 611.1 $ 344.3 $ 140.5 $ 1,095.9 Direct Customers 235.5 263.3 75.2 574.0 Total $ 846.6 $ 607.6 $ 215.7 $ 1,669.9 Six Months Ended July 2, 2021 PSG ASG ISG Total Geographic Location Singapore $ 547.6 $ 428.5 $ 65.9 $ 1,042.0 Hong Kong 457.1 244.8 89.6 791.5 United Kingdom 290.1 167.5 87.8 545.4 United States 183.4 146.6 79.9 409.9 Other 115.4 151.7 95.7 362.8 Total $ 1,593.6 $ 1,139.1 $ 418.9 $ 3,151.6 Sales Channel Distributors $ 1,135.0 $ 633.2 $ 261.7 $ 2,029.9 Direct Customers 458.6 505.9 157.2 1,121.7 Total $ 1,593.6 $ 1,139.1 $ 418.9 $ 3,151.6 Quarter Ended July 3, 2020 PSG ASG ISG Total Geographic Location Singapore $ 243.4 $ 157.4 $ 38.6 $ 439.4 Hong Kong 190.4 95.7 37.2 323.3 United Kingdom 75.8 42.4 22.7 140.9 United States 56.2 63.5 32.1 151.8 Other 52.6 67.7 37.8 158.1 Total $ 618.4 $ 426.7 $ 168.4 $ 1,213.5 Sales Channel Distributors $ 436.9 $ 231.3 $ 103.8 $ 772.0 Direct Customers 181.5 195.4 64.6 441.5 Total $ 618.4 $ 426.7 $ 168.4 $ 1,213.5 Six Months Ended July 3, 2020 PSG ASG ISG Total Geographic Location Singapore $ 437.7 $ 330.0 $ 80.0 $ 847.7 Hong Kong 382.4 187.6 69.5 639.5 United Kingdom 180.9 119.2 67.8 367.9 United States 128.9 140.8 66.6 336.3 Other 112.4 116.2 71.4 300.0 Total $ 1,242.3 $ 893.8 $ 355.3 $ 2,491.4 Sales Channel Distributors $ 823.2 $ 444.9 $ 207.2 $ 1,475.3 Direct Customers 419.1 448.9 148.1 1,016.1 Total $ 1,242.3 $ 893.8 $ 355.3 $ 2,491.4 The Company operates in various geographic locations. Sales to customers have little correlation with the location of manufacturers. Accordingly, the Company does not present operating profit by geographical location. The Company does not discretely allocate assets to its operating segments, nor does management evaluate operating segments using discrete asset information. The Company’s consolidated assets are not specifically ascribed to its individual reportable segments. Rather, assets used in operations are generally shared across the Company’s operating and reportable segments. Property, plant and equipment, net, by geographic location, is summarized as follows (in millions): As of July 2, 2021 December 31, 2020 United States $ 703.8 $ 686.6 South Korea 440.5 455.5 Philippines 367.8 386.6 China 218.4 229.6 Czech Republic 205.0 216.1 Japan 211.7 209.3 Malaysia 184.5 190.2 Other 126.1 138.4 Total $ 2,457.8 $ 2,512.3

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jul. 02, 2021
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	Note 3: Recent Accounting Pronouncements Pending adoption: ASU 2020-06 - Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity ( " ASU 2020-06 " )

Restructuring, Asset Impairment

Restructuring, Asset Impairments and Other, Net	6 Months Ended
	Jul. 02, 2021
Restructuring Charges [Abstract]
Restructuring, Asset Impairments and Other, Net	Note 4: Restructuring, Asset Impairments and Other, Net Details of restructuring, asset impairments and other charges, net are as follows (in millions): Restructuring Asset Impairments Other Total Quarter ended July 2, 2021 2021 Involuntary Separation Program $ 21.1 $ — $ — $ 21.1 Other — 0.1 (3.7) (3.6) Total $ 21.1 $ 0.1 $ (3.7) $ 17.5 Restructuring Asset Impairments Other Total Six months ended July 2, 2021 2021 Involuntary Separation Program $ 54.1 $ — $ — $ 54.1 Other — 3.3 2.6 5.9 Total $ 54.1 $ 3.3 $ 2.6 $ 60.0 A summary of changes in accrued restructuring from December 31, 2020 to July 2, 2021 is as follows (in millions): As of As of December 31, 2020 Charges Usage July 2, 2021 Employee separation charges $ 6.2 $ 54.1 $ (28.8) $ 31.5 Total $ 6.2 $ 54.1 $ (28.8) $ 31.5 2021 Involuntary Separation Program On March 4, 2021, as part of its ongoing efforts to realign its investments to focus on growth drivers and key markets and to streamline its operations, the Company announced its plans to implement certain employee terminations during the first half of 2021 (the "ISP"). During the first quarter of 2021, the Company notified approximately 500 employees of their employment termination, and incurred severance costs and other benefit costs amounting to $33.0 million. During the second quarter of 2021, the Company notified an additional 227 employees of their employment termination, and incurred severance costs and other benefit costs amounting to $21.1 million. The Company paid approximately $28.8 million of the aggregate expense and had $31.5 million accrued as of July 2, 2021, and expects to pay a majority of the remaining accrued expense during the second half of 2021.

Balance Sheet Information and O

Balance Sheet Information and Other	6 Months Ended
	Jul. 02, 2021
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Information and Other	Note 5: Balance Sheet Information and Other Goodwill There was no change in the balance of goodwill from December 31, 2020 to July 2, 2021. Goodwill is tested for impairment annually on the first day of the fourth quarter or more frequently if events or changes in circumstances (each, a "triggering event") would more likely than not reduce the carrying value of goodwill below its fair value. Management did not identify any triggering events during the quarter ended July 2, 2021 that would require an interim impairment analysis. Inventory Details of Inventory included in the Company’s Consolidated Balance Sheets are as follows (in millions): As of July 2, 2021 December 31, 2020 Inventories: Raw materials $ 150.3 $ 135.7 Work in process 844.8 829.7 Finished goods 314.2 286.0 $ 1,309.3 $ 1,251.4 Defined Benefit Plans The Company recognizes the aggregate amount of all overfunded plans as assets and the aggregate amount of all underfunded plans as liabilities in its financial statements. As of July 2, 2021, the net assets for the overfunded plans totaled $8.5 million. The total accrued pension liability for underfunded plans was $148.4 million, of which the current portion of $0.4 million was classified as accrued expenses and other current liabilities. As of December 31, 2020, the net funded status for all the plans was a liability of $141.9 million, of which the current portion of $0.3 million was classified as accrued expenses and other current liabilities. The components of the net periodic pension expense were as follows (in millions): Quarters Ended Six Months Ended July 2, 2021 July 3, 2020 July 2, 2021 July 3, 2020 Service cost $ 3.0 $ 2.7 $ 6.1 $ 5.4 Interest cost 1.1 1.1 2.2 2.3 Expected return on plan assets (1.6) (1.5) (3.3) (3.1) Curtailment loss — (1.6) 1.9 (1.6) Total net periodic pension cost $ 2.5 $ 0.7 $ 6.9 $ 3.0 Leases Operating lease arrangements are comprised primarily of real estate and equipment agreements. The components of lease expense were as follows (in millions): Quarters Ended Six Months Ended July 2, 2021 July 3, 2020 July 2, 2021 July 3, 2020 Operating lease $ 9.8 $ 9.1 $ 19.7 $ 18.2 Variable lease 1.0 0.7 1.9 1.8 Short-term lease 0.5 1.2 1.2 2.4 Total lease expense $ 11.3 $ 11.0 $ 22.8 $ 22.4 The lease liabilities recognized in the Consolidated Balance Sheets are as follows (in millions): As of July 2, 2021 December 31, 2020 Accrued expenses and other current liabilities $ 32.9 $ 32.2 Other long-term liabilities 104.2 115.7 Total lease liabilities $ 137.1 $ 147.9 Operating right-of-use ("ROU") assets as of July 2, 2021 and December 31, 2020 amounted to $129.3 million and $136.3 million, respectively, and are included in other assets in the Consolidated Balance Sheets. As of July 2, 2021, the weighted-average remaining lease-term was 6.6 years and the weighted-average discount rate was 4.8%. Supplemental Disclosure of Cash Flow Information Certain of the Company's cash and non-cash activities were as follows (in millions): Six Months Ended July 2, 2021 July 3, 2020 Non-cash investing activities: Capital expenditures in accounts payable and other long-term liabilities $ 160.0 $ 152.8 Sale of property in exchange of note receivable 1.0 4.7 ROU assets obtained in exchange of lease liabilities 11.0 49.0 Cash paid for: Interest expense $ 52.6 $ 58.4 Income taxes 43.7 15.5 Operating lease payments in operating cash flows 20.8 18.3 Reconciliation of the captions in the Consolidated Balance Sheets to the Consolidated Statements of Cash Flows (in millions) As of July 2, 2021 December 31, 2020 July 3, 2020 December 31, 2019 Consolidated Balance Sheets: Cash and cash equivalents $ 1,091.1 $ 1,080.7 $ 2,060.4 $ 894.2 Restricted cash (included in other current assets) 1.4 0.8 0.3 — Cash, cash equivalents and restricted cash in Consolidated Statements of Cash Flows $ 1,092.5 $ 1,081.5 $ 2,060.7 $ 894.2

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jul. 02, 2021
Debt Disclosure [Abstract]
Long-Term Debt	Note 6: Long-Term Debt The Company's long-term debt consists of the following (annualized interest rates, in millions): As of July 2, 2021 December 31, 2020 Amended Credit Agreement: Revolving Credit Facility due 2024, interest payable monthly at —% and 1.90%, respectively $ — $ 700.0 Term Loan "B" Facility due 2026, interest payable monthly at 2.10% and 2.15%, respectively 1,606.3 1,614.5 0% Notes due 2027 805.0 — 3.875% Notes due 2028 (1) 700.0 700.0 1.625% Notes due 2023 (2) 202.6 575.0 Gross long-term debt, including current portion $ 3,313.9 $ 3,589.5 Less: Debt discount (3) (167.2) (69.7) Less: Debt issuance costs (4) (38.3) (28.5) Net long-term debt, including current portion $ 3,108.4 $ 3,491.3 Less: Current portion of long-term debt (201.3) (531.6) Net long-term debt $ 2,907.1 $ 2,959.7 (1) Interest is payable on March 1 and September 1 of each year at 3.875% annually. (2) Interest is payable on April 15 and October 15 of each year at 1.625% annually. (3) Debt discount of $8.3 million and $9.0 million for the Term Loan "B" Facility, $136.8 million and zero for the 0% Notes, $6.2 million and $6.5 million for the 3.875% Notes, $15.9 million and $54.2 million for the 1.625% Notes, in each case as of July 2, 2021 and December 31, 2020, respectively. (4) Debt issuance costs of $19.3 million and $21.0 million for the Term Loan "B" Facility, $15.4 million and zero for the 0% Notes, $2.1 million and $2.3 million for the 3.875% Notes and $1.5 million and $5.2 million for the 1.625% Notes, in each case as of July 2, 2021 and December 31, 2020, respectively. Expected maturities of gross long-term debt (including current portion - see 1.625% Notes section below) as of July 2, 2021 were as follows (in millions): Period Expected Maturities Remainder of 2021 $ 210.8 2022 16.3 2023 16.3 2024 16.3 2025 16.3 Thereafter 3,037.9 Total $ 3,313.9 The Company was in compliance with its covenants under all debt agreements as of July 2, 2021. 0% Convertible Senior Notes due 2027 On May 19, 2021, the Company completed a private offering of $805.0 million aggregate principal amount of its 0% Convertible Senior Notes due 2027 (the "0% Notes"), the proceeds of which were used to repurchase a portion of the 1.625% Notes in privately negotiated note repurchase or exchange transactions, repay a portion of the Revolving Credit Facility, pay the net cost of the related convertible note hedges after such costs were offset by the proceeds from the sale of warrants, and general corporate purposes. The 0% Notes were issued under an indenture (the "0% Indenture") by and among the Company, the guarantors party thereto, and Wells Fargo Bank, National Association, as trustee, which provides, among other things, that the 0% Notes will mature on May 1, 2027, unless earlier repurchased or redeemed by the Company or converted pursuant to their terms. On or after February 1, 2027, until the close of business on the second scheduled trading day immediately preceding May 1, 2027, holders may convert their 0% Notes at any time. The 0% Notes are the Company’s senior unsecured obligations and are fully and unconditionally guaranteed, on a joint and several basis, by each of the Company’s subsidiaries that is a borrower or guarantor under the Company’s Amended Credit Agreement. The Company may satisfy any conversion elections by paying cash up to the aggregate principal amount of the 0% Notes to be converted, and paying or delivering, as the case may be, cash, shares of common stock or a combination of cash and shares of common stock, at the Company’s election, in respect of the remainder, if any, of its conversion obligation in excess of the aggregate principal amount of the 0% Notes to be converted. The initial conversion rate of the 0% Notes is 18.8796 shares of common stock per $1,000 principal amount, which is equivalent to an initial conversion price of approximately $52.97 per share of common stock. The Company may redeem for cash all or any portion of the 0% Notes, at the Company’s option, on or after May 1, 2024, if the last reported sale price of the Company’s common stock has been at least 130% of the conversion price then in effect for at least 20 trading days during any consecutive 30 trading-day period. Prior to February 1, 2027, the holders may convert their 0% Notes under the following circumstances: (i) during any calendar quarter commencing after the calendar quarter ending on June 30, 2021 (and only during such calendar quarter), if the last reported sale price of the Company’s common stock for at least 20 trading days during the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (ii) during the five The conversion rate is subject to adjustment upon the occurrence of certain specified events as set forth in the 0% Indenture. The maximum number of shares of common stock issuable in connection with the conversion is 21.7 million. In accordance with the accounting guidance on embedded conversion features, the Company valued and bifurcated the conversion option, representing the debt discount, from the respective host debt instrument and recorded $139.9 million to stockholders’ equity. The Company also incurred issuance costs of $19.0 million, of which $15.7 million was capitalized as debt issuance costs and $3.3 million was allocated to the conversion option and recorded to stockholders’ equity. The debt discount and debt issuance costs are being amortized at an effective interest rate of 3.2% over the contractual term of the 0% Notes. In addition, the Company entered into convertible note hedge transactions with respect to the common stock with the initial purchasers or their affiliates ("Counterparties"). The convertible note hedges cover, subject to customary anti-dilution adjustments, the number of shares of common stock that initially underlie the 0% Notes, and are expected to reduce the potential dilution to the common stock and/or offset potential cash payments in excess of the principal amount upon conversion. The Company paid $160.3 million in cash for the convertible note hedges, that was recorded to stockholders’ equity. The Company also entered into warrant transactions with the Counterparties, whereby the Company sold warrants to acquire, subject to anti-dilution adjustments, the same number of shares of the Company’s common stock covered by the convertible note hedges at an initial strike price of $74.34 per share, which represents a 100% premium over the closing price of $37.17 per share on May 11, 2021. The maximum number of shares of common stock issuable in connection with the warrants is 30.4 million. The Company received $93.8 million in cash for the sale of warrants, that was recorded to stockholders’ equity. Partial exchange or repurchase and/or exchange of the 1.625% Notes On May 11, 2021, contemporaneously with the issuance of the 0% Notes, the Company entered into separate privately negotiated transactions with certain holders of the 1.625% Notes to repurchase or exchange, as applicable, $372.4 million in aggregate principal amount of the 1.625% Notes for a total consideration of $506.5 million in cash and 5.4 million shares of the Company’s common stock. The repurchases and exchanges resulted in a loss on debt prepayment of $26.2 million based on the fair value of the debt component, while the remainder of the consideration amounting to $141.6 million attributable to the equity component was recorded to stockholders’ equity. Separately, the Company received 9.1 million shares into treasury by terminating a portion of the convertible note hedge transactions that were originally entered at the time of issuance of the 1.625% Notes in a notional amount corresponding to the principal amount of the 1.625% Notes repurchased or exchanged. The fair market value of these shares amounting to $339.0 million was recorded to additional paid-in capital and treasury stock, with no overall impact to equity. Additionally, the Company terminated a portion of the warrant transactions originally entered at the time of issuance of the 1.625% Notes and issued 6.8 million shares with respect to a number of shares of common stock equal to the notional shares underlying such 1.625% Notes repurchased or exchanged. The remaining outstanding principal amount of the 1.625% Notes, amounting to $185.2 million, net of unamortized discount and issuance costs continues to be classified as a current portion of long-term debt as of July 2, 2021. Pursuant to the indenture governing the 1.625% Notes, because the last reported sale price of the Company’s common stock for at least 20 trading days during the period of 30 consecutive trading days ending on June 30, 2021 was greater than or equal to $26.94 (130% of the conversion price) on each applicable trading day, the holders have the right to surrender any portion of their 1.625% Notes (in minimum denominations of $1,000 in principal amount or an integral multiple thereof) for conversion during the calendar quarter ending September 30, 2021, and only during such calendar quarter. Ninth Amendment to the Amended Credit Agreement On May 10, 2021, in anticipation of the issuance of the 0% Notes, the Company entered into the Ninth Amendment to the Amended Credit Agreement ("Ninth Amendment"). The Ninth Amendment provided for, among other things, modifications to the Amended Credit Agreement to permit the issuance of the 0% Notes and the repurchase or exchange of the 1.625% Notes, remove the availability of borrowings in currencies other than U.S. dollars in light of the unavailability of LIBO Rate for such other currencies beginning December 31, 2021, provide for increased capacity to dispose of certain assets, make investments and incur certain types of indebtedness and liens, increase the threshold for real estate properties required to be mortgaged to secure the facility, increase the ability to incur incremental debt facilities and remove certain conditions applicable to the incurrence of incremental facilities. There was no impact to the consolidated financial statements due to the Ninth Amendment. Repayments under the Revolving Credit Facility During the quarter ended July 2, 2021, the Company repaid the entire outstanding balance under the Revolving Credit Facility of $550.0 million using a portion of the net proceeds from the issuance of the 0% Notes and cash generated from operations. During the quarter ended April 2, 2021, the Company repaid $150.0 million of the outstanding balance under the Revolving Credit Facility using cash generated from operations. As of July 2, 2021, the Company had approximately $1.97 billion available under the Revolving Credit Facility for future borrowings, except for amounts utilized for the letters of credit.

Earnings Per Share and Equity

Earnings Per Share and Equity	6 Months Ended
	Jul. 02, 2021
Earnings Per Share [Abstract]
Earnings Per Share and Equity	Note 7: Earnings Per Share and Equity Earnings Per Share Net income (loss) per share of common stock attributable to ON Semiconductor Corporation is calculated as follows (in millions, except per share data): Quarters Ended Six Months Ended July 2, 2021 July 3, 2020 July 2, 2021 July 3, 2020 Net income (loss) attributable to ON Semiconductor Corporation $ 184.1 $ (1.4) $ 274.0 $ (15.4) Basic weighted-average shares of common stock outstanding 427.7 410.1 420.5 410.3 Dilutive effect of share-based awards 2.0 — 2.4 — Dilutive effect of convertible notes and warrants 13.9 — 21.6 — Diluted weighted-average shares of common stock outstanding 443.6 410.1 444.5 410.3 Net income (loss) per share of common stock attributable to ON Semiconductor Corporation: Basic $ 0.43 $ 0.00 $ 0.65 $ (0.04) Diluted $ 0.42 $ 0.00 $ 0.62 $ (0.04) Basic income (loss) per share of common stock is computed by dividing net income (loss) attributable to the Company by the weighted-average number of shares of common stock outstanding during the period. To calculate the diluted weighted-average shares of common stock outstanding, the treasury stock method has been applied to calculate the number of incremental shares from the assumed issuance of shares relating to RSUs. The excluded number of anti-dilutive share-based awards was approximately 0.4 million and 3.6 million for the quarters ended July 2, 2021 and July 3, 2020, respectively, and 0.6 million and 3.1 million for the six months ended July 2, 2021 and July 3, 2020, respectively. The dilutive impact related to the 0% Notes and 1.625% Notes has been determined in accordance with the net share settlement requirements. While the 0% Notes are convertible into cash up to the par value, in accordance with their terms, the Company has assumed the 1.625% Notes to be convertible into cash up to the par value in accordance with the existing accounting standards. The excess over par value for the 0% Notes and 1.625% Notes, if applicable, has been assumed to be convertible into common stock. Prior to conversion, the convertible note hedges are not considered for purposes of the earnings per share calculations, as their effect would be anti-dilutive. Upon conversion, the convertible note hedges are expected to offset the dilutive effect of the 0% Notes and 1.625% Notes when the stock price is above $52.97 and $20.72 per share, respectively. The dilutive impact of the warrants issued concurrently with the issuance of the 0% Notes, 1.625% Notes and 1.00% Notes with exercise prices of $74.34, $30.70 and $25.96 respectively, has been included in the calculation of diluted weighted-average common shares outstanding, if applicable. All of the warrants issued in connection with the 1.00% Notes were settled during the quarter and six months ended July 2, 2021. Equity 1.00% Notes Warrants Settlement At the time of issuance of the 1.00% Notes, the Company sold 37.3 million warrants to bank counterparties whereby the holders of the warrants had the option to purchase the equivalent number of shares of the Company’s common stock at a price of $25.96 per share from the Company beginning in March 2021. During the quarter ended July 2, 2021, the warrant holders exercised the remaining 18.6 million warrants and the Company settled them by issuing 7.1 million shares of common stock on a net-share basis. The warrant holders had previously exercised 18.7 million warrants during the quarter ended April 2, 2021, and the Company settled them by issuing 6.3 million shares of common stock on a net-share basis. Share Repurchase Program Under the Company's share repurchase program announced on November 15, 2018 (the "Share Repurchase Program"), the Company may repurchase up to $1.5 billion (exclusive of fees, commissions and other expenses) of the Company's common stock from December 1, 2018 through December 31, 2022. There were no repurchases during the quarters ended July 2, 2021 and July 3, 2020 under the Share Repurchase Program. There were no repurchases during the six months ended July 2, 2021, while the repurchases amounted to $65.3 million during the six months ended July 3, 2020. As of July 2, 2021, the authorized amount remaining under the Share Repurchase Program was $1,295.8 million. Activity under the Share Repurchase Program during the quarter and six months ended July 2, 2021 and July 3, 2020 was as follows (in millions, except per share data): Quarters Ended Six Months Ended July 2, 2021 July 3, 2020 July 2, 2021 July 3, 2020 Number of repurchased shares (1) — — — 3.6 Aggregate purchase price $ — $ — $ — $ 65.3 Fees, commissions and other expenses — — — 0.1 Total cash used for share repurchases $ — $ — $ — $ 65.4 Weighted-average purchase price per share (2) $ — $ — $ — $ 18.08 (1) None of these shares had been reissued or retired as of July 2, 2021, but may be reissued or retired at a later date. (2) Exclusive of fees, commissions and other expenses. Shares for Restricted Stock Units Tax Withholding The amounts remitted for employee withholding taxes during the quarter and six months ended July 2, 2021 were $3.5 million and $32.0 million, respectively, for which the Company withheld approximately 0.1 million and 0.8 million shares of common stock, respectively, that were underlying the RSUs that vested. The amounts remitted during the quarter and six months ended July 3, 2020 were $0.6 million and $16.6 million, respectively, for which the Company withheld less than 0.1 million and approximately 0.9 million shares of common stock, respectively, that were underlying the RSUs that vested. None of these shares had been reissued or retired as of July 2, 2021, but may be reissued or retired by the Company at a later date. Non-Controlling Interest in Leshan-Phoenix Semiconductor Company Limited (“Leshan”) The results of Leshan have been consolidated in the Company's financial statements. As of December 31, 2020, the non-controlling interest balance was $19.6 million and along with the $0.4 million share of the earnings for the six months ended July 2, 2021, increased to $20.0 million as of July 2, 2021. Stockholders' Rights Plan On June 7, 2020, the Company's Board of Directors authorized and declared a dividend of one preferred share purchase right (a "Right") for each outstanding share of common stock to the stockholders of record on June 18, 2020. The Rights, which continued to have a de minimis value from the time they were issued, expired on June 7, 2021.

Share-Based Compensation

Share-Based Compensation	6 Months Ended
	Jul. 02, 2021
Share-based Payment Arrangement [Abstract]
Share-Based Compensation	Note 8: Share-Based Compensation Total share-based compensation expense related to the Company's RSUs, stock grant awards and the ESPP was recorded within the Consolidated Statements of Operations and Comprehensive Income as follows (in millions): Quarters Ended Six Months Ended July 2, 2021 July 3, 2020 July 2, 2021 July 3, 2020 Cost of revenue $ 4.9 $ 2.8 $ 8.2 $ 5.3 Research and development 7.3 4.4 13.0 8.5 Selling and marketing 4.5 3.1 8.8 6.1 General and administrative 12.4 7.7 21.4 13.8 Share-based compensation expense $ 29.1 $ 18.0 $ 51.4 $ 33.7 Income tax benefit (6.1) (3.8) (10.8) (7.1) Share-based compensation expense, net of taxes $ 23.0 $ 14.2 $ 40.6 $ 26.6 As of July 2, 2021, total unrecognized expected share-based compensation expense, net of estimated forfeitures, related to non-vested RSUs with service, performance and market conditions was $125.7 million, which is expected to be recognized over a weighted-average period of 1.6 years. The remaining outstanding stock options, which were insignificant, were exercised during the quarter and six months ended July 2, 2021. Upon option exercise, vesting of RSUs, stock grant awards or completion of a purchase under the ESPP, the Company issues new shares of common stock. The annualized pre-vesting forfeiture rate for RSUs was estimated to be 6% for the quarter ended July 2, 2021 and 5% for the quarter and six months ended July 3, 2020. Shares Available On May 20, 2021, the Company's stockholders approved certain amendments to the Amended and Restated SIP to extend the expiration date from 2022 to 2031 and to increase the number of shares of common stock subject to all awards by 22.5 million, from 87.0 million to 109.5 million. On the same day, the stockholders also approved an amendment to the ESPP, which increased the number of shares available to be issued pursuant to the ESPP by 6.0 million, from 28.5 million to 34.5 million. As of July 2, 2021 and December 31, 2020, there was an aggregate of 41.8 million and 16.5 million shares of common stock, respectively, available for grant under the Amended and Restated SIP. As of July 2, 2021 and December 31, 2020, there was an aggregate of 8.5 million and 3.0 million shares of common stock, respectively, available for issuance under the ESPP. Restricted Stock Units RSUs generally vest ratably over three years for awards with service conditions and over two Number of Shares Weighted-Average Grant Date Fair Value Per Share Non-vested RSUs at December 31, 2020 11.3 $ 20.73 Granted 2.3 41.18 Released (2.6) 21.46 Forfeited (4.1) 21.57 Non-vested RSUs at July 2, 2021 6.9 26.70

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jul. 02, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 9: Commitments and Contingencies Environmental Contingencies There are no new material environmental contingencies subsequent to the filing of the 2020 Form 10-K. Financing Contingencies In the ordinary course of business, the Company provides standby letters of credit or other guarantee instruments to certain parties initiated by either the Company or its subsidiaries, as required for transactions, including, but not limited to, material purchase commitments, agreements to mitigate collection risk, leases, utilities or customs guarantees. As of July 2, 2021, the Company's Revolving Credit Facility included $15.0 million available for the issuance of letters of credit. There were $0.9 million in letters of credit outstanding under the Revolving Credit Facility as of July 2, 2021, which reduced the Company's borrowing capacity. As of July 2, 2021, the Company also had outstanding guarantees and letters of credit outside of its Revolving Credit Facility totaling $8.6 million. As part of obtaining financing in the ordinary course of business, the Company issued guarantees related to certain of its subsidiaries, which totaled $0.9 million as of July 2, 2021. Based on historical experience and information currently available, the Company believes that it will not be required to make payments under the standby letters of credit or guarantee arrangements for the foreseeable future. Indemnification Contingencies There are no new material indemnification contingencies subsequent to the filing of the 2020 Form 10-K. Legal Matters The Company is currently involved in a variety of legal matters that arise in the ordinary course of business. Based on information currently available, the Company is not involved in any pending or threatened legal proceedings that it believes could reasonably be expected to have a material adverse effect on its financial condition, results of operations or liquidity. The litigation process is inherently uncertain, and the Company cannot guarantee that the outcome of any litigation matter will be favorable to the Company. Intellectual Property Matters The Company faces risk of exposure from claims of infringement of the IP rights of others. In the ordinary course of business, the Company receives letters asserting that the Company’s products or components breach another party’s rights. Such letters may request royalty payments from the Company, that the Company cease and desist using certain IP or other remedies.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jul. 02, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 10: Fair Value Measurements Fair Value of Financial Instruments The following table summarizes the Company's financial assets and liabilities, excluding pension assets, measured at fair value on a recurring basis (in millions): As of Fair Value Hierarchy Description July 2, 2021 Level 1 Level 2 Level 3 Assets: Cash and cash equivalents: Demand and time deposits $ 8.4 $ 8.4 $ — $ — As of Fair Value Hierarchy Description December 31, 2020 Level 1 Level 2 Level 3 Assets: Cash and cash equivalents: Demand and time deposits $ 8.5 $ 8.5 $ — $ — Other The carrying amounts of other current assets and liabilities, such as accounts receivable and accounts payable, approximate fair value based on the short-term nature of these instruments. Fair Value of Long-Term Debt, including Current Portion The carrying amounts and fair values of the Company’s long-term borrowings were as follows (in millions): As of July 2, 2021 December 31, 2020 Carrying Fair Value Carrying Fair Value Long-term debt, including current portion (1) Convertible notes $ 838.0 $ 1,222.5 $ 515.6 $ 967.1 Other long-term debt 2,270.4 2,272.6 2,975.7 2,966.8 (1) Carrying amounts shown are net of debt discount and debt issuance costs. The fair values of the 3.875% Notes, 1.625% Notes and 0% Notes were estimated based on market prices in active markets (Level 1). The fair value of other long-term debt was estimated based on discounting the remaining principal and interest payments using current market rates for similar debt (Level 2).

Financial Instruments

Financial Instruments	6 Months Ended
	Jul. 02, 2021
Investments, All Other Investments [Abstract]
Financial Instruments	Note 11: Financial Instruments Foreign Currencies As a multinational business, the Company engages in transactions that are denominated in a variety of currencies. When appropriate, the Company uses forward foreign currency contracts to reduce its overall exposure to the effects of currency fluctuations on its results of operations and cash flows. The Company’s policy prohibits trading in currencies for which there are no underlying exposures and entering into trades for any currency to intentionally increase the underlying exposure. The Company primarily hedges existing assets and liabilities associated with transactions currently on its balance sheet, which are undesignated hedges for accounting purposes. As of July 2, 2021 and December 31, 2020, the Company had net outstanding foreign exchange contracts with notional amounts of $318.8 million and $263.4 million, respectively. Such contracts were obtained through financial institutions and were scheduled to mature within one The following summarizes the Company’s net foreign exchange positions in U.S. Dollars (in millions): As of July 2, 2021 December 31, 2020 Buy (Sell) Notional Amount Buy (Sell) Notional Amount Japanese Yen $ 89.1 $ 89.1 $ 71.2 $ 71.2 Philippine Peso 67.9 67.9 57.2 57.2 Euro 65.4 65.4 47.7 47.7 Korean Won 43.3 43.3 34.4 34.4 Malaysian Ringgit 16.4 16.4 11.7 11.7 Chinese Yuan 12.0 12.0 17.7 17.7 Other Currencies - Buy 15.6 15.6 12.4 12.4 Other Currencies - Sell (9.1) 9.1 (11.1) 11.1 $ 300.6 $ 318.8 $ 241.2 $ 263.4 Amounts receivable or payable under the contracts are included in other current assets or accrued expenses and other current liabilities in the accompanying Consolidated Balance Sheets. During the quarters ended July 2, 2021 and July 3, 2020, realized and unrealized foreign currency transactions totaled a loss of $1.6 million and a loss of $3.2 million, respectively. During the six months ended July 2, 2021 and July 3, 2020, realized and unrealized foreign currency transactions totaled a gain of $2.4 million and a loss of $3.4 million, respectively. The realized and unrealized foreign currency transactions are included in other income (expense) in the Company's Consolidated Statements of Operations and Comprehensive Income. Cash Flow Hedges All derivatives are recognized on the Company’s Consolidated Balance Sheets at their fair value and classified based on the applicable instrument's maturity date. Foreign Currency Risk The purpose of the foreign currency hedging activities is to protect the Company from the risk that the eventual cash flows resulting from transactions in foreign currencies will be adversely affected by changes in exchange rates. During the quarter ended July 2, 2021, the Company entered into an insignificant forward contract that is designated as a foreign currency cash flow hedge of a forecasted payment denominated in a currency other than U.S. Dollars. Interest Rate Risk The Company uses interest rate swap contracts to mitigate its exposure to interest rate fluctuations. During the quarter ended July 2, 2021, the Company entered into interest rate swap agreements for notional amounts totaling $500.0 million, effective as of December 30, 2022 and December 29, 2023, with maturity dates of December 29, 2023 and December 31, 2024, respectively. The Company did not identify any ineffectiveness with respect to the notional amounts of the interest rate swap contracts effective as of July 2, 2021 and July 3, 2020, amounting to $1.5 billion and $2.25 billion, respectively. Other As of July 2, 2021, the Company had no outstanding commodity derivatives, currency swaps or options relating to either its debt instruments or investments. The Company does not hedge the value of its equity investments in its subsidiaries or affiliated

Income Taxes

Income Taxes	6 Months Ended
	Jul. 02, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Note 12: Income Taxes The Company recognizes interest and penalties related to uncertain tax positions in tax expense on the Company's Consolidated Statements of Operations and Comprehensive Income. The Company had approximately $1.9 million and $4.6 million of net interest and penalties accrued as of July 2, 2021 and July 3, 2020, respectively. It is reasonably possible that $41.1 million of its uncertain tax positions will be reduced in the next 12 months due to settlement with tax authorities or expiration of the applicable statute of limitations. The Company maintains a partial valuation allowance on its U.S. state deferred tax assets and a valuation allowance on foreign net operating losses and tax credits in certain foreign jurisdictions, a substantial portion of which relate to Japan net operating losses, which are projected to expire prior to utilization. Tax years prior to 2017 are generally not subject to examination by the United States Internal Revenue Service (the "IRS") except for items involving tax attributes that have been carried forward to tax years with statutes of limitations that remain open. The Company is currently under IRS examination for the 2017 tax year. For state tax returns, the Company is generally not subject to income tax examinations for tax years prior to 2016. The Company is also subject to routine examinations by various foreign tax jurisdictions in which it operates. With respect to jurisdictions outside the United States, the Company is generally not subject to examination for tax years prior to 2011. The Company believes that adequate provisions have been made for any adjustments that may result from tax examinations. However, the outcome of tax audits cannot be predicted with certainty. If any issues addressed in the Company’s tax audits are resolved in a manner not consistent with the Company's expectations, the Company could be required to adjust its provision for income taxes in the period such resolution occurs.

Changes in Accumulated Other Co

Changes in Accumulated Other Comprehensive Loss	6 Months Ended
	Jul. 02, 2021
Equity [Abstract]
Changes in Accumulated Other Comprehensive Loss	Note 13: Changes in Accumulated Other Comprehensive Loss Amounts comprising the Company's accumulated other comprehensive loss and reclassifications are as follows (in millions): Currency Translation Adjustments Effects of Cash Flow Hedges Total Balance as of December 31, 2020 $ (40.6) $ (17.0) $ (57.6) Other comprehensive income (loss) prior to reclassifications (2.5) 17.3 14.8 Amounts reclassified from accumulated other comprehensive loss — (9.4) (9.4) Net current period other comprehensive income (loss) (1) (2.5) 7.9 5.4 Balance as of July 2, 2021 $ (43.1) $ (9.1) $ (52.2) (1) Effects of cash flow hedges are net of tax expense of $2.4 million for the six months ended July 2, 2021. Amounts reclassified from accumulated other comprehensive loss to the specific caption within Consolidated Statements of Operations and Comprehensive Income were as follows: Amounts Reclassified from Accumulated Other Comprehensive Loss Quarters Ended Six Months Ended July 2, 2021 July 3, 2020 July 2, 2021 July 3, 2020 To caption Interest rate swaps $ 4.8 $ 5.0 $ 9.4 $ 6.9 Interest expense Total reclassifications $ 4.8 $ 5.0 $ 9.4 $ 6.9

Background and Basis of Prese_2

Background and Basis of Presentation (Policies)	6 Months Ended
	Jul. 02, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amount of assets and liabilities at the date of the financial statements and the reported amount of revenue and expenses during the reporting period. Management evaluates these estimates and judgments on an ongoing basis and bases its estimates on experience, current and expected future conditions, third-party evaluations and various other assumptions that management believes are reasonable under the circumstances. Significant estimates have been used by management in conjunction with the following: (i) future payouts for customer incentives and amounts subject to allowances and returns; (ii) valuation and obsolescence relating to inventories; (iii) variable and share-based compensation; and (iv) measurement of valuation allowances against deferred tax assets and evaluations of uncertain tax positions. Additionally, during periods where it becomes applicable, significant estimates will be used by management in determining the future cash flows used to assess and test for impairment of long-lived assets and goodwill and in assumptions used in connection with business combinations. Actual results may differ from the estimates and assumptions used in the consolidated financial statements.
Recent Accounting Pronouncements	Pending adoption: ASU 2020-06 - Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity ( " ASU 2020-06 " )

Revenue and Segment Informati_2

Revenue and Segment Information (Tables)	6 Months Ended
	Jul. 02, 2021
Segment Reporting [Abstract]
Revenues and Gross Profit From Reportable Segments	Revenue and gross profit for the Company’s operating and reportable segments are as follows (in millions): PSG ASG ISG Total For the quarter ended July 2, 2021: Revenue from external customers $ 846.6 $ 607.6 $ 215.7 $ 1,669.9 Gross profit $ 314.3 $ 252.3 $ 73.5 $ 640.1 For the quarter ended July 3, 2020: Revenue from external customers $ 618.4 $ 426.7 $ 168.4 $ 1,213.5 Gross profit (1) $ 172.4 $ 151.4 $ 50.5 $ 374.3 For the six months ended July 2, 2021: Revenue from external customers $ 1,593.6 $ 1,139.1 $ 418.9 $ 3,151.6 Gross profit $ 560.8 $ 459.1 $ 141.4 $ 1,161.3 For the six months ended July 3, 2020: Revenue from external customers $ 1,242.3 $ 893.8 $ 355.3 $ 2,491.4 Gross profit (1) $ 355.0 $ 309.2 $ 112.8 $ 777.0 (1) Beginning in the first quarter of 2021, the Company started including unallocated manufacturing costs as part of segment operating results to determine segment gross profit. As a result, the prior-period amounts have been reclassified to conform to current-period presentation.
Disaggregation of Revenue	Revenue for the Company's operating and reportable segments disaggregated into geographic locations based on sales billed from the respective country and sales channels are as follows (in millions): Quarter Ended July 2, 2021 PSG ASG ISG Total Geographic Location Singapore $ 273.1 $ 226.8 $ 33.1 $ 533.0 Hong Kong 261.0 144.3 44.0 449.3 United Kingdom 147.4 84.9 44.2 276.5 United States 108.1 76.4 41.1 225.6 Other 57.0 75.2 53.3 185.5 Total $ 846.6 $ 607.6 $ 215.7 $ 1,669.9 Sales Channel Distributors $ 611.1 $ 344.3 $ 140.5 $ 1,095.9 Direct Customers 235.5 263.3 75.2 574.0 Total $ 846.6 $ 607.6 $ 215.7 $ 1,669.9 Six Months Ended July 2, 2021 PSG ASG ISG Total Geographic Location Singapore $ 547.6 $ 428.5 $ 65.9 $ 1,042.0 Hong Kong 457.1 244.8 89.6 791.5 United Kingdom 290.1 167.5 87.8 545.4 United States 183.4 146.6 79.9 409.9 Other 115.4 151.7 95.7 362.8 Total $ 1,593.6 $ 1,139.1 $ 418.9 $ 3,151.6 Sales Channel Distributors $ 1,135.0 $ 633.2 $ 261.7 $ 2,029.9 Direct Customers 458.6 505.9 157.2 1,121.7 Total $ 1,593.6 $ 1,139.1 $ 418.9 $ 3,151.6 Quarter Ended July 3, 2020 PSG ASG ISG Total Geographic Location Singapore $ 243.4 $ 157.4 $ 38.6 $ 439.4 Hong Kong 190.4 95.7 37.2 323.3 United Kingdom 75.8 42.4 22.7 140.9 United States 56.2 63.5 32.1 151.8 Other 52.6 67.7 37.8 158.1 Total $ 618.4 $ 426.7 $ 168.4 $ 1,213.5 Sales Channel Distributors $ 436.9 $ 231.3 $ 103.8 $ 772.0 Direct Customers 181.5 195.4 64.6 441.5 Total $ 618.4 $ 426.7 $ 168.4 $ 1,213.5 Six Months Ended July 3, 2020 PSG ASG ISG Total Geographic Location Singapore $ 437.7 $ 330.0 $ 80.0 $ 847.7 Hong Kong 382.4 187.6 69.5 639.5 United Kingdom 180.9 119.2 67.8 367.9 United States 128.9 140.8 66.6 336.3 Other 112.4 116.2 71.4 300.0 Total $ 1,242.3 $ 893.8 $ 355.3 $ 2,491.4 Sales Channel Distributors $ 823.2 $ 444.9 $ 207.2 $ 1,475.3 Direct Customers 419.1 448.9 148.1 1,016.1 Total $ 1,242.3 $ 893.8 $ 355.3 $ 2,491.4
Summary of Property, Plant and Equipment by Geographic Location	Property, plant and equipment, net, by geographic location, is summarized as follows (in millions): As of July 2, 2021 December 31, 2020 United States $ 703.8 $ 686.6 South Korea 440.5 455.5 Philippines 367.8 386.6 China 218.4 229.6 Czech Republic 205.0 216.1 Japan 211.7 209.3 Malaysia 184.5 190.2 Other 126.1 138.4 Total $ 2,457.8 $ 2,512.3

Restructuring, Asset Impairme_2

Restructuring, Asset Impairments and Other, Net - (Tables)	6 Months Ended
	Jul. 02, 2021
Restructuring Charges [Abstract]
Schedule of Activity Included in Restructuring, Asset Impairments, and Other, Net	Details of restructuring, asset impairments and other charges, net are as follows (in millions): Restructuring Asset Impairments Other Total Quarter ended July 2, 2021 2021 Involuntary Separation Program $ 21.1 $ — $ — $ 21.1 Other — 0.1 (3.7) (3.6) Total $ 21.1 $ 0.1 $ (3.7) $ 17.5 Restructuring Asset Impairments Other Total Six months ended July 2, 2021 2021 Involuntary Separation Program $ 54.1 $ — $ — $ 54.1 Other — 3.3 2.6 5.9 Total $ 54.1 $ 3.3 $ 2.6 $ 60.0
Schedule of Changes in Accrued Restructuring Reserve	A summary of changes in accrued restructuring from December 31, 2020 to July 2, 2021 is as follows (in millions): As of As of December 31, 2020 Charges Usage July 2, 2021 Employee separation charges $ 6.2 $ 54.1 $ (28.8) $ 31.5 Total $ 6.2 $ 54.1 $ (28.8) $ 31.5

Balance Sheet Information and_2

Balance Sheet Information and Other - (Tables)	6 Months Ended
	Jul. 02, 2021
Balance Sheet Related Disclosures [Abstract]
Schedule of Inventory	Details of Inventory included in the Company’s Consolidated Balance Sheets are as follows (in millions): As of July 2, 2021 December 31, 2020 Inventories: Raw materials $ 150.3 $ 135.7 Work in process 844.8 829.7 Finished goods 314.2 286.0 $ 1,309.3 $ 1,251.4
Schedule of Net Periodic Pension Expense	The components of the net periodic pension expense were as follows (in millions): Quarters Ended Six Months Ended July 2, 2021 July 3, 2020 July 2, 2021 July 3, 2020 Service cost $ 3.0 $ 2.7 $ 6.1 $ 5.4 Interest cost 1.1 1.1 2.2 2.3 Expected return on plan assets (1.6) (1.5) (3.3) (3.1) Curtailment loss — (1.6) 1.9 (1.6) Total net periodic pension cost $ 2.5 $ 0.7 $ 6.9 $ 3.0
Schedule of Components of Lease Expense	The components of lease expense were as follows (in millions): Quarters Ended Six Months Ended July 2, 2021 July 3, 2020 July 2, 2021 July 3, 2020 Operating lease $ 9.8 $ 9.1 $ 19.7 $ 18.2 Variable lease 1.0 0.7 1.9 1.8 Short-term lease 0.5 1.2 1.2 2.4 Total lease expense $ 11.3 $ 11.0 $ 22.8 $ 22.4 The lease liabilities recognized in the Consolidated Balance Sheets are as follows (in millions): As of July 2, 2021 December 31, 2020 Accrued expenses and other current liabilities $ 32.9 $ 32.2 Other long-term liabilities 104.2 115.7 Total lease liabilities $ 137.1 $ 147.9
Schedule of Cash and Non-cash Activities	Certain of the Company's cash and non-cash activities were as follows (in millions): Six Months Ended July 2, 2021 July 3, 2020 Non-cash investing activities: Capital expenditures in accounts payable and other long-term liabilities $ 160.0 $ 152.8 Sale of property in exchange of note receivable 1.0 4.7 ROU assets obtained in exchange of lease liabilities 11.0 49.0 Cash paid for: Interest expense $ 52.6 $ 58.4 Income taxes 43.7 15.5 Operating lease payments in operating cash flows 20.8 18.3
Schedule of Cash and Cash Equivalents	Reconciliation of the captions in the Consolidated Balance Sheets to the Consolidated Statements of Cash Flows (in millions) As of July 2, 2021 December 31, 2020 July 3, 2020 December 31, 2019 Consolidated Balance Sheets: Cash and cash equivalents $ 1,091.1 $ 1,080.7 $ 2,060.4 $ 894.2 Restricted cash (included in other current assets) 1.4 0.8 0.3 — Cash, cash equivalents and restricted cash in Consolidated Statements of Cash Flows $ 1,092.5 $ 1,081.5 $ 2,060.7 $ 894.2
Schedule of Restrictions on Cash and Cash Equivalents	Reconciliation of the captions in the Consolidated Balance Sheets to the Consolidated Statements of Cash Flows (in millions) As of July 2, 2021 December 31, 2020 July 3, 2020 December 31, 2019 Consolidated Balance Sheets: Cash and cash equivalents $ 1,091.1 $ 1,080.7 $ 2,060.4 $ 894.2 Restricted cash (included in other current assets) 1.4 0.8 0.3 — Cash, cash equivalents and restricted cash in Consolidated Statements of Cash Flows $ 1,092.5 $ 1,081.5 $ 2,060.7 $ 894.2

Long-Term Debt - (Tables)

Long-Term Debt - (Tables)	6 Months Ended
	Jul. 02, 2021
Debt Disclosure [Abstract]
Schedule of Long-Term Debt	The Company's long-term debt consists of the following (annualized interest rates, in millions): As of July 2, 2021 December 31, 2020 Amended Credit Agreement: Revolving Credit Facility due 2024, interest payable monthly at —% and 1.90%, respectively $ — $ 700.0 Term Loan "B" Facility due 2026, interest payable monthly at 2.10% and 2.15%, respectively 1,606.3 1,614.5 0% Notes due 2027 805.0 — 3.875% Notes due 2028 (1) 700.0 700.0 1.625% Notes due 2023 (2) 202.6 575.0 Gross long-term debt, including current portion $ 3,313.9 $ 3,589.5 Less: Debt discount (3) (167.2) (69.7) Less: Debt issuance costs (4) (38.3) (28.5) Net long-term debt, including current portion $ 3,108.4 $ 3,491.3 Less: Current portion of long-term debt (201.3) (531.6) Net long-term debt $ 2,907.1 $ 2,959.7 (1) Interest is payable on March 1 and September 1 of each year at 3.875% annually. (2) Interest is payable on April 15 and October 15 of each year at 1.625% annually. (3) Debt discount of $8.3 million and $9.0 million for the Term Loan "B" Facility, $136.8 million and zero for the 0% Notes, $6.2 million and $6.5 million for the 3.875% Notes, $15.9 million and $54.2 million for the 1.625% Notes, in each case as of July 2, 2021 and December 31, 2020, respectively. (4) Debt issuance costs of $19.3 million and $21.0 million for the Term Loan "B" Facility, $15.4 million and zero for the 0% Notes, $2.1 million and $2.3 million for the 3.875% Notes and $1.5 million and $5.2 million for the 1.625% Notes, in each case as of July 2, 2021 and December 31, 2020, respectively.
Schedule of Annual Maturities Relating To Long-Term Debt	Expected maturities of gross long-term debt (including current portion - see 1.625% Notes section below) as of July 2, 2021 were as follows (in millions): Period Expected Maturities Remainder of 2021 $ 210.8 2022 16.3 2023 16.3 2024 16.3 2025 16.3 Thereafter 3,037.9 Total $ 3,313.9

Earnings Per Share and Equity -

Earnings Per Share and Equity - (Tables)	6 Months Ended
	Jul. 02, 2021
Earnings Per Share [Abstract]
Summary of Earnings Per Share	Net income (loss) per share of common stock attributable to ON Semiconductor Corporation is calculated as follows (in millions, except per share data): Quarters Ended Six Months Ended July 2, 2021 July 3, 2020 July 2, 2021 July 3, 2020 Net income (loss) attributable to ON Semiconductor Corporation $ 184.1 $ (1.4) $ 274.0 $ (15.4) Basic weighted-average shares of common stock outstanding 427.7 410.1 420.5 410.3 Dilutive effect of share-based awards 2.0 — 2.4 — Dilutive effect of convertible notes and warrants 13.9 — 21.6 — Diluted weighted-average shares of common stock outstanding 443.6 410.1 444.5 410.3 Net income (loss) per share of common stock attributable to ON Semiconductor Corporation: Basic $ 0.43 $ 0.00 $ 0.65 $ (0.04) Diluted $ 0.42 $ 0.00 $ 0.62 $ (0.04)
Schedule of Share Repurchase Program	Activity under the Share Repurchase Program during the quarter and six months ended July 2, 2021 and July 3, 2020 was as follows (in millions, except per share data): Quarters Ended Six Months Ended July 2, 2021 July 3, 2020 July 2, 2021 July 3, 2020 Number of repurchased shares (1) — — — 3.6 Aggregate purchase price $ — $ — $ — $ 65.3 Fees, commissions and other expenses — — — 0.1 Total cash used for share repurchases $ — $ — $ — $ 65.4 Weighted-average purchase price per share (2) $ — $ — $ — $ 18.08 (1) None of these shares had been reissued or retired as of July 2, 2021, but may be reissued or retired at a later date. (2) Exclusive of fees, commissions and other expenses.

Share-Based Compensation - (Tab

Share-Based Compensation - (Tables)	6 Months Ended
	Jul. 02, 2021
Share-based Payment Arrangement [Abstract]
Summary Of Share-Based Compensation Expense	Total share-based compensation expense related to the Company's RSUs, stock grant awards and the ESPP was recorded within the Consolidated Statements of Operations and Comprehensive Income as follows (in millions): Quarters Ended Six Months Ended July 2, 2021 July 3, 2020 July 2, 2021 July 3, 2020 Cost of revenue $ 4.9 $ 2.8 $ 8.2 $ 5.3 Research and development 7.3 4.4 13.0 8.5 Selling and marketing 4.5 3.1 8.8 6.1 General and administrative 12.4 7.7 21.4 13.8 Share-based compensation expense $ 29.1 $ 18.0 $ 51.4 $ 33.7 Income tax benefit (6.1) (3.8) (10.8) (7.1) Share-based compensation expense, net of taxes $ 23.0 $ 14.2 $ 40.6 $ 26.6
Summary Of Restricted Stock Units Transactions	A summary of the RSU transactions for the six months ended July 2, 2021 is as follows (in millions, except per share data): Number of Shares Weighted-Average Grant Date Fair Value Per Share Non-vested RSUs at December 31, 2020 11.3 $ 20.73 Granted 2.3 41.18 Released (2.6) 21.46 Forfeited (4.1) 21.57 Non-vested RSUs at July 2, 2021 6.9 26.70

Fair Value Measurements - (Tabl

Fair Value Measurements - (Tables)	6 Months Ended
	Jul. 02, 2021
Fair Value Disclosures [Abstract]
Summary of Fair Value of Assets and Liabilities	The following table summarizes the Company's financial assets and liabilities, excluding pension assets, measured at fair value on a recurring basis (in millions): As of Fair Value Hierarchy Description July 2, 2021 Level 1 Level 2 Level 3 Assets: Cash and cash equivalents: Demand and time deposits $ 8.4 $ 8.4 $ — $ — As of Fair Value Hierarchy Description December 31, 2020 Level 1 Level 2 Level 3 Assets: Cash and cash equivalents: Demand and time deposits $ 8.5 $ 8.5 $ — $ —
Summary of Fair Value, by Balance Sheet Grouping	The carrying amounts and fair values of the Company’s long-term borrowings were as follows (in millions): As of July 2, 2021 December 31, 2020 Carrying Fair Value Carrying Fair Value Long-term debt, including current portion (1) Convertible notes $ 838.0 $ 1,222.5 $ 515.6 $ 967.1 Other long-term debt 2,270.4 2,272.6 2,975.7 2,966.8 (1) Carrying amounts shown are net of debt discount and debt issuance costs.

Financial Instruments - (Tables

Financial Instruments - (Tables)	6 Months Ended
	Jul. 02, 2021
Investments, All Other Investments [Abstract]
Schedule of Net Foreign Exchange Positions	The following summarizes the Company’s net foreign exchange positions in U.S. Dollars (in millions): As of July 2, 2021 December 31, 2020 Buy (Sell) Notional Amount Buy (Sell) Notional Amount Japanese Yen $ 89.1 $ 89.1 $ 71.2 $ 71.2 Philippine Peso 67.9 67.9 57.2 57.2 Euro 65.4 65.4 47.7 47.7 Korean Won 43.3 43.3 34.4 34.4 Malaysian Ringgit 16.4 16.4 11.7 11.7 Chinese Yuan 12.0 12.0 17.7 17.7 Other Currencies - Buy 15.6 15.6 12.4 12.4 Other Currencies - Sell (9.1) 9.1 (11.1) 11.1 $ 300.6 $ 318.8 $ 241.2 $ 263.4

Changes in Accumulated Other _2

Changes in Accumulated Other Comprehensive Loss - (Tables)	6 Months Ended
	Jul. 02, 2021
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Loss	Amounts comprising the Company's accumulated other comprehensive loss and reclassifications are as follows (in millions): Currency Translation Adjustments Effects of Cash Flow Hedges Total Balance as of December 31, 2020 $ (40.6) $ (17.0) $ (57.6) Other comprehensive income (loss) prior to reclassifications (2.5) 17.3 14.8 Amounts reclassified from accumulated other comprehensive loss — (9.4) (9.4) Net current period other comprehensive income (loss) (1) (2.5) 7.9 5.4 Balance as of July 2, 2021 $ (43.1) $ (9.1) $ (52.2) (1) Effects of cash flow hedges are net of tax expense of $2.4 million for the six months ended July 2, 2021. Amounts reclassified from accumulated other comprehensive loss to the specific caption within Consolidated Statements of Operations and Comprehensive Income were as follows: Amounts Reclassified from Accumulated Other Comprehensive Loss Quarters Ended Six Months Ended July 2, 2021 July 3, 2020 July 2, 2021 July 3, 2020 To caption Interest rate swaps $ 4.8 $ 5.0 $ 9.4 $ 6.9 Interest expense Total reclassifications $ 4.8 $ 5.0 $ 9.4 $ 6.9

Background and Basis of Prese_3

Background and Basis of Presentation (Details) - segment	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Fiscal period duration	91 days	91 days	183 days	185 days
Number of operating segments			3
Number of reportable segments			3

Revenue and Segment Informati_3

Revenue and Segment Information Additional Information (Details) - segment	3 Months Ended	6 Months Ended
	Jul. 02, 2021	Jul. 02, 2021
Segment Reporting Information [Line Items]
Number of operating segments		3
Number of reportable segments		3
One Customer | Revenue from Contract with Customer Benchmark | Customer Concentration Risk
Segment Reporting Information [Line Items]
Concentration risk, percentage	14.00%	12.00%

Revenue and Segment Informati_4

Revenue and Segment Information - Segment Information Of Revenues, Gross Profit And Operating Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Segment Reporting Information [Line Items]
Revenue	$ 1,669.9	$ 1,213.5	$ 3,151.6	$ 2,491.4
Gross profit	640.1	374.3	1,161.3	777
PSG
Segment Reporting Information [Line Items]
Revenue	846.6	618.4	1,593.6	1,242.3
Gross profit	314.3	172.4	560.8	355
ASG
Segment Reporting Information [Line Items]
Revenue	607.6	426.7	1,139.1	893.8
Gross profit	252.3	151.4	459.1	309.2
ISG
Segment Reporting Information [Line Items]
Revenue	215.7	168.4	418.9	355.3
Gross profit	$ 73.5	$ 50.5	$ 141.4	$ 112.8

Revenue and Segment Informati_5

Revenue and Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Segment Reporting Information [Line Items]
Revenue	$ 1,669.9	$ 1,213.5	$ 3,151.6	$ 2,491.4
Distributors
Segment Reporting Information [Line Items]
Revenue	1,095.9	772	2,029.9	1,475.3
Direct Customers
Segment Reporting Information [Line Items]
Revenue	574	441.5	1,121.7	1,016.1
Singapore
Segment Reporting Information [Line Items]
Revenue	533	439.4	1,042	847.7
Hong Kong
Segment Reporting Information [Line Items]
Revenue	449.3	323.3	791.5	639.5
United Kingdom
Segment Reporting Information [Line Items]
Revenue	276.5	140.9	545.4	367.9
United States
Segment Reporting Information [Line Items]
Revenue	225.6	151.8	409.9	336.3
Other
Segment Reporting Information [Line Items]
Revenue	185.5	158.1	362.8	300
PSG
Segment Reporting Information [Line Items]
Revenue	846.6	618.4	1,593.6	1,242.3
PSG | Distributors
Segment Reporting Information [Line Items]
Revenue	611.1	436.9	1,135	823.2
PSG | Direct Customers
Segment Reporting Information [Line Items]
Revenue	235.5	181.5	458.6	419.1
PSG | Singapore
Segment Reporting Information [Line Items]
Revenue	273.1	243.4	547.6	437.7
PSG | Hong Kong
Segment Reporting Information [Line Items]
Revenue	261	190.4	457.1	382.4
PSG | United Kingdom
Segment Reporting Information [Line Items]
Revenue	147.4	75.8	290.1	180.9
PSG | United States
Segment Reporting Information [Line Items]
Revenue	108.1	56.2	183.4	128.9
PSG | Other
Segment Reporting Information [Line Items]
Revenue	57	52.6	115.4	112.4
ASG
Segment Reporting Information [Line Items]
Revenue	607.6	426.7	1,139.1	893.8
ASG | Distributors
Segment Reporting Information [Line Items]
Revenue	344.3	231.3	633.2	444.9
ASG | Direct Customers
Segment Reporting Information [Line Items]
Revenue	263.3	195.4	505.9	448.9
ASG | Singapore
Segment Reporting Information [Line Items]
Revenue	226.8	157.4	428.5	330
ASG | Hong Kong
Segment Reporting Information [Line Items]
Revenue	144.3	95.7	244.8	187.6
ASG | United Kingdom
Segment Reporting Information [Line Items]
Revenue	84.9	42.4	167.5	119.2
ASG | United States
Segment Reporting Information [Line Items]
Revenue	76.4	63.5	146.6	140.8
ASG | Other
Segment Reporting Information [Line Items]
Revenue	75.2	67.7	151.7	116.2
ISG
Segment Reporting Information [Line Items]
Revenue	215.7	168.4	418.9	355.3
ISG | Distributors
Segment Reporting Information [Line Items]
Revenue	140.5	103.8	261.7	207.2
ISG | Direct Customers
Segment Reporting Information [Line Items]
Revenue	75.2	64.6	157.2	148.1
ISG | Singapore
Segment Reporting Information [Line Items]
Revenue	33.1	38.6	65.9	80
ISG | Hong Kong
Segment Reporting Information [Line Items]
Revenue	44	37.2	89.6	69.5
ISG | United Kingdom
Segment Reporting Information [Line Items]
Revenue	44.2	22.7	87.8	67.8
ISG | United States
Segment Reporting Information [Line Items]
Revenue	41.1	32.1	79.9	66.6
ISG | Other
Segment Reporting Information [Line Items]
Revenue	$ 53.3	$ 37.8	$ 95.7	$ 71.4

Revenue and Segment Informati_6

Revenue and Segment Information - Summary of Property, Plant and Equipment by Geographic Location (Details) - USD ($) $ in Millions	Jul. 02, 2021	Dec. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	$ 2,457.8	$ 2,512.3
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	703.8	686.6
South Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	440.5	455.5
Philippines
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	367.8	386.6
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	218.4	229.6
Czech Republic
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	205	216.1
Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	211.7	209.3
Malaysia
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	184.5	190.2
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	$ 126.1	$ 138.4

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020	Dec. 31, 2022	May 19, 2021	May 11, 2021	May 10, 2021
Debt Instrument [Line Items]
Dilutive effect of convertible notes and warrants (in shares)	13.9	0	21.6	0
Forecast | Cumulative Effect, Period of Adoption, Adjustment
Debt Instrument [Line Items]
Interest expense					$ 29
Dilutive effect of convertible notes and warrants (in shares)					9.8
1.625% Notes | Convertible Debt
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)	1.625%		1.625%			1.625%	1.625%	1.625%
0% Notes | Convertible Debt
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)	0.00%		0.00%			0.00%	0.00%	0.00%

Restructuring, Asset Impairme_3

Restructuring, Asset Impairments and Other, Net - Schedule of Activity Included in Restructuring, Asset Impairments, and Other, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 21.1		$ 54.1
Asset Impairments	0.1		3.3
Other	(3.7)		2.6
Total	17.5	$ 16.2	60	$ 49
Other
Restructuring Cost and Reserve [Line Items]
Restructuring	0		0
Asset Impairments	0.1		3.3
Other	(3.7)		2.6
Total	(3.6)		5.9
2021 Involuntary Separation Program | Workforce Reduction
Restructuring Cost and Reserve [Line Items]
Restructuring	21.1		54.1
Asset Impairments	0		0
Other	0		0
Total	$ 21.1		$ 54.1

Restructuring, Asset Impairme_4

Restructuring, Asset Impairments and Other, Net - Summary of Changes in Accrued Restructuring Charges (Details) $ in Millions	6 Months Ended
	Jul. 02, 2021USD ($)
Restructuring Reserve [Roll Forward]
Balance at Beginning of Period	$ 6.2
Charges	54.1
Usage	(28.8)
Balance at End of Period	31.5
Employee separation charges
Restructuring Reserve [Roll Forward]
Balance at Beginning of Period	6.2
Charges	54.1
Usage	(28.8)
Balance at End of Period	$ 31.5

Restructuring, Asset Impairme_5

Restructuring, Asset Impairments and Other, Net - Narrative (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021USD ($)employee	Apr. 02, 2021USD ($)employee	Jul. 02, 2021USD ($)	Dec. 31, 2020USD ($)
Restructuring Cost and Reserve [Line Items]
Payments for restructuring			$ 28.8
Restructuring reserve accrued	$ 31.5		31.5	$ 6.2
2021 Involuntary Separation Program
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | employee	227	500
Severance costs	$ 21.1	$ 33
Payments for restructuring			28.8
Restructuring reserve accrued	$ 31.5		$ 31.5

Balance Sheet Information and_3

Balance Sheet Information and Other - Narrative (Details) - USD ($)	6 Months Ended
	Jul. 02, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Changes in goodwill	$ 0
Net assets for overfunded plans	8,500,000
Accrued pension liability	148,400,000	$ 141,900,000
Current portion accrued pension liability	400,000	300,000
Operating ROU assets	$ 129,300,000	$ 136,300,000
Remaining Lease Term (in years)	6 years 7 months 6 days
Discount Rate (as a percent)	4.80%

Balance Sheet Information and_4

Balance Sheet Information and Other - Inventory (Details) - USD ($) $ in Millions	Jul. 02, 2021	Dec. 31, 2020
Inventories:
Raw materials	$ 150.3	$ 135.7
Work in process	844.8	829.7
Finished goods	314.2	286
Inventories	$ 1,309.3	$ 1,251.4

Balance Sheet Information and_5

Balance Sheet Information and Other - Pension Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Balance Sheet Related Disclosures [Abstract]
Service cost	$ 3	$ 2.7	$ 6.1	$ 5.4
Interest cost	1.1	1.1	2.2	2.3
Expected return on plan assets	(1.6)	(1.5)	(3.3)	(3.1)
Curtailment loss	0	(1.6)	1.9	(1.6)
Total net periodic pension cost	$ 2.5	$ 0.7	$ 6.9	$ 3

Balance Sheet Information and_6

Balance Sheet Information and Other - Lease Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Operating lease	$ 9.8	$ 9.1	$ 19.7	$ 18.2
Variable lease	1	0.7	1.9	1.8
Short-term lease	0.5	1.2	1.2	2.4
Total lease expense	11.3	$ 11	22.8	$ 22.4
Accrued expenses and other current liabilities	32.9		32.9		$ 32.2
Other long-term liabilities	104.2		104.2		115.7
Total lease liabilities	$ 137.1		$ 137.1		$ 147.9
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesCurrent		us-gaap:AccruedLiabilitiesCurrent		us-gaap:AccruedLiabilitiesCurrent
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other long-term liabilities		Other long-term liabilities		Other long-term liabilities

Balance Sheet Information and_7

Balance Sheet Information and Other - Cash and Non-cash Activity (Details) - USD ($) $ in Millions	6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020
Non-cash investing activities:
Capital expenditures in accounts payable and other long-term liabilities	$ 160	$ 152.8
Sale of property in exchange of note receivable	1	4.7
ROU assets obtained in exchange of lease liabilities	11	49
Cash paid for:
Interest expense	52.6	58.4
Income taxes	43.7	15.5
Operating lease payments in operating cash flows	$ 20.8	$ 18.3

Balance Sheet Information and_8

Balance Sheet Information and Other - Summary of Cash and Cash Equivalents (Details) - USD ($) $ in Millions	Jul. 02, 2021	Dec. 31, 2020	Jul. 03, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Cash and cash equivalents	$ 1,091.1	$ 1,080.7	$ 2,060.4	$ 894.2
Restricted cash (included in other current assets)	1.4	0.8	0.3	0
Cash, cash equivalents and restricted cash in Consolidated Statements of Cash Flows	$ 1,092.5	$ 1,081.5	$ 2,060.7	$ 894.2

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Millions	Jul. 02, 2021	May 19, 2021	May 11, 2021	May 10, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt	$ 3,313.9				$ 3,589.5
Less: Debt discount	(167.2)				(69.7)
Less: Debt issuance costs	(38.3)				(28.5)
Net long-term debt, including current portion	3,108.4				3,491.3
Less: Current portion of long-term debt	(201.3)				(531.6)
Net long-term debt	2,907.1				2,959.7
Senior Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	$ 0				$ 700
Debt instrument, interest rate (as a percent)	0.00%				1.90%
Term Loan B Facility
Debt Instrument [Line Items]
Long-term debt	$ 1,606.3				$ 1,614.5
Less: Debt discount	(8.3)				(9)
Less: Debt issuance costs	$ (19.3)				$ (21)
Debt instrument, interest rate (as a percent)	2.10%				2.15%
0% Notes | Convertible Debt
Debt Instrument [Line Items]
Long-term debt	$ 805				$ 0
Less: Debt discount	(136.8)				0
Less: Debt issuance costs	$ (15.4)				0
Debt instrument, interest rate (as a percent)	0.00%	0.00%	0.00%	0.00%
3.875% Notes | Notes Payable
Debt Instrument [Line Items]
Long-term debt	$ 700				700
Less: Debt discount	(6.2)				(6.5)
Less: Debt issuance costs	$ (2.1)				(2.3)
Debt instrument, interest rate (as a percent)	3.875%
1.625% Notes | Convertible Debt
Debt Instrument [Line Items]
Long-term debt	$ 202.6				575
Less: Debt discount	(15.9)				(54.2)
Less: Debt issuance costs	(1.5)				$ (5.2)
Less: Current portion of long-term debt	$ (185.2)
Debt instrument, interest rate (as a percent)	1.625%	1.625%	1.625%	1.625%

Long-Term Debt - Annual Maturit

Long-Term Debt - Annual Maturities Relating To Long-Term Debt (Details) $ in Millions	Jul. 02, 2021USD ($)
Long-term Debt, Fiscal Year Maturity [Abstract]
Remainder of 2021	$ 210.8
2022	16.3
2023	16.3
2024	16.3
2025	16.3
Thereafter	3,037.9
Total	$ 3,313.9

Long-Term Debt - 0% Convertible

Long-Term Debt - 0% Convertible Senior Notes (Details) $ / shares in Units, shares in Millions	May 19, 2021USD ($)day$ / sharesshares	Jul. 02, 2021USD ($)$ / shares	Jul. 02, 2021USD ($)day$ / shares	Jul. 03, 2020USD ($)	May 11, 2021$ / shares	May 10, 2021
Debt Instrument [Line Items]
Debt issuance costs allocated to conversion option		$ 136,600,000	$ 136,600,000
Payment for purchase of bond hedges			160,300,000	$ 0
Share price | $ / shares					$ 37.17
Proceeds from issuance of warrants			$ 93,800,000	$ 0
0% Notes Warrants
Debt Instrument [Line Items]
Price per unit (in dollars per unit) | $ / shares	$ 74.34	$ 74.34	$ 74.34
Premium over closing share price	100.00%
Number of warrants (in shares) | shares	30.4
Proceeds from issuance of warrants	$ 93,800,000
Convertible Debt | 0% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)	0.00%	0.00%	0.00%		0.00%	0.00%
Aggregate principal amount	$ 805,000,000
Conversion rate	0.0188796
Conversion price per share (in dollars per share) | $ / shares	$ 52.97	$ 52.97	$ 52.97
Threshold percentage of stock price trigger (greater than or equal to)	130.00%
Threshold trading days | day	20
Threshold consecutive trading days | day	30
Maximum shares issuable (in shares) | shares	21.7
Equity component of debt instrument	$ 139,900,000
Debt issuance costs	19,000,000
Debt issuance costs capitalized	15,700,000
Debt issuance costs allocated to conversion option	$ 3,300,000
Effective interest rate	3.20%
Convertible Debt | 0% Notes | Embedded Derivative Financial Instruments
Debt Instrument [Line Items]
Payment for purchase of bond hedges	$ 160,300,000
Convertible Debt | 0% Notes | Debt Conversion One
Debt Instrument [Line Items]
Threshold percentage of stock price trigger (greater than or equal to)	130.00%
Threshold trading days | day	20
Threshold consecutive trading days | day	30
Convertible Debt | 0% Notes | Debt Conversion Two
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)	0.00%
Threshold consecutive trading days | day	5
Period immediately following consecutive trading days (in business days)	5 days
Ratio of trading price per 1000 principal amount (as a percent) (less than)	0.98
Convertible Debt | 1.625% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)	1.625%	1.625%	1.625%		1.625%	1.625%
Conversion price per share (in dollars per share) | $ / shares		$ 20.72	$ 20.72
Threshold percentage of stock price trigger (greater than or equal to)			130.00%
Threshold trading days | day			20
Threshold consecutive trading days | day			30

Long-Term Debt - Partial exchan

Long-Term Debt - Partial exchange or repurchase of the 1.625% Notes (Details) $ / shares in Units, shares in Millions, $ in Millions	Jul. 02, 2021USD ($)$ / shares	May 19, 2021day	May 11, 2021USD ($)shares	Jul. 02, 2021USD ($)	Jul. 03, 2020USD ($)	Jul. 02, 2021USD ($)day	Jul. 03, 2020USD ($)	May 10, 2021	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
Loss on debt refinancing and prepayment				$ (26.2)	$ 0	$ (26.2)	$ 0
Partial settlement - 1.625% Notes				(141.6)		(141.6)
Settlement of bond hedges, APIC impact				0		0
Current portion of long-term debt	$ 201.3			201.3		201.3			$ 531.6
Additional Paid-in Capital
Debt Instrument [Line Items]
Partial settlement - 1.625% Notes				(141.7)		(141.7)
Settlement of bond hedges, APIC impact				$ (339)		$ (339)
1.625% Notes Warrants
Debt Instrument [Line Items]
Number of warrants (in shares) | shares			6.8
Convertible Debt | 1.625% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)	1.625%	1.625%	1.625%	1.625%		1.625%		1.625%
Face amount repurchased or exchanged			$ 372.4
Cash consideration for repurchase or exchange of convertible debt			$ 506.5
Equity consideration for repurchase or exchange of convertible debt (in shares) | shares			5.4
Loss on debt refinancing and prepayment			$ 26.2
Partial settlement - 1.625% Notes			141.6
Current portion of long-term debt	$ 185.2			$ 185.2		$ 185.2
Threshold trading days | day						20
Threshold consecutive trading days | day						30
Stock price trigger (in dollars per share) | $ / shares	$ 26.94
Threshold percentage of stock price trigger (greater than or equal to)						130.00%
Convertible Debt | 1.625% Notes | Additional Paid-in Capital
Debt Instrument [Line Items]
Settlement of bond hedges, APIC impact			$ (339)
Convertible Debt | 1.625% Notes | Embedded Derivative Financial Instruments
Debt Instrument [Line Items]
Shares received into treasury (in shares) | shares			9.1
Value of shares received into treasury			$ 339
Convertible Debt | 0% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)	0.00%	0.00%	0.00%	0.00%		0.00%		0.00%
Threshold trading days | day		20
Threshold consecutive trading days | day		30
Threshold percentage of stock price trigger (greater than or equal to)		130.00%

Long-Term Debt - Ninth Amendmen

Long-Term Debt - Ninth Amendment and Repayment of Revolving Credit Facility (Details) - USD ($) $ in Millions	3 Months Ended
	Jul. 02, 2021	Apr. 02, 2021	May 19, 2021	May 11, 2021	May 10, 2021	Dec. 31, 2020
Senior Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)	0.00%					1.90%
Repayments of revolving credit facility	$ 550	$ 150
Remaining borrowing capacity	$ 1,970
0% Notes | Convertible Debt
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)	0.00%		0.00%	0.00%	0.00%

Earnings Per Share and Equity_2

Earnings Per Share and Equity - Summary of earnings per share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Earnings Per Share [Abstract]
Net income (loss) attributable to ON Semiconductor Corporation	$ 184.1	$ (1.4)	$ 274	$ (15.4)
Basic weighted average shares of common stock outstanding (in shares)	427.7	410.1	420.5	410.3
Dilutive effect of share-based awards (in shares)	2	0	2.4	0
Dilutive effect of convertible notes and warrants (in shares)	13.9	0	21.6	0
Diluted weighted-average shares of common stock outstanding (in shares)	443.6	410.1	444.5	410.3
Net income (loss) per share of common stock attributable to ON Semiconductor Corporation:
Basic (in dollars per share)	$ 0.43	$ 0	$ 0.65	$ (0.04)
Diluted (in dollars per share)	$ 0.42	$ 0	$ 0.62	$ (0.04)

Earnings Per Share and Equity_3

Earnings Per Share and Equity - Narrative (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jul. 02, 2021	Apr. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020	May 19, 2021	May 11, 2021	May 10, 2021	Dec. 31, 2020	Nov. 15, 2018
Dividends Payable [Line Items]
Anti-dilutive shares	400,000		3,600,000	600,000	3,100,000
Aggregate purchase price				$ 0	$ 65,400,000
Payments of tax withholding for restricted shares	$ 3,500,000		$ 600,000	$ 32,000,000	$ 16,600,000
Common stock withheld underlying restricted stock units (in shares)	100,000		100,000	800,000	900,000
Treasury shares reissued or retired during period (in shares)				0
Non-controlling interest	$ 20,000,000			$ 20,000,000					$ 19,600,000
Non-controlling interest share of earnings	$ 0		$ 500,000	$ 400,000	$ 800,000
0% Notes Warrants
Dividends Payable [Line Items]
Price per unit (in dollars per unit)	$ 74.34			$ 74.34		$ 74.34
Number of warrants (in shares)						30,400,000
1.625% Notes Warrants
Dividends Payable [Line Items]
Price per unit (in dollars per unit)	30.70			30.70
Number of warrants (in shares)							6,800,000
1.00% Notes Warrants
Dividends Payable [Line Items]
Price per unit (in dollars per unit)	$ 25.96			$ 25.96
Number of warrants (in shares)	37,300,000			37,300,000
Warrants exercised (in shares)	18,600,000	18,700,000
Stock issued for settlement of warrants (in shares)	7,100,000	6,300,000
Convertible Debt | 0% Notes
Dividends Payable [Line Items]
Debt instrument, interest rate (as a percent)	0.00%			0.00%		0.00%	0.00%	0.00%
Conversion price per share (in dollars per share)	$ 52.97			$ 52.97		$ 52.97
Convertible Debt | 1.625% Notes
Dividends Payable [Line Items]
Debt instrument, interest rate (as a percent)	1.625%			1.625%		1.625%	1.625%	1.625%
Conversion price per share (in dollars per share)	$ 20.72			$ 20.72
Convertible Debt | 1.00% Notes
Dividends Payable [Line Items]
Debt instrument, interest rate (as a percent)	1.00%			1.00%
Share Repurchase Program
Dividends Payable [Line Items]
Stock repurchase program, authorized amount										$ 1,500,000,000
Number of repurchased shares (in shares)	0		0	0	3,600,000
Aggregate purchase price	$ 0		$ 0	$ 0	$ 65,300,000
Remaining authorized amount available for repurchase	$ 1,295,800,000			$ 1,295,800,000

Earnings Per Share and Equity_4

Earnings Per Share and Equity - Schedule of Share Repurchase Program (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate purchase price			$ 0	$ 65,400,000
Fees, commissions and other expenses	$ 0	$ 0	0	100,000
Total cash used for share repurchases	$ 0	$ 0	$ 0	$ 65,400,000
Treasury shares reissued or retired during period (in shares)			0
Share Repurchase Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of repurchased shares (in shares)	0	0	0	3,600,000
Aggregate purchase price	$ 0	$ 0	$ 0	$ 65,300,000
Weighted-average purchase price per share (in dollars per share )	$ 0	$ 0	$ 0	$ 18.08

Share-Based Compensation - Summ

Share-Based Compensation - Summary Of Share-Based Compensation (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 29.1	$ 18	$ 51.4	$ 33.7
Income tax benefit	(6.1)	(3.8)	(10.8)	(7.1)
Share-based compensation expense, net of taxes	23	14.2	40.6	26.6
Cost of revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	4.9	2.8	8.2	5.3
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	7.3	4.4	13	8.5
Selling and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	4.5	3.1	8.8	6.1
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 12.4	$ 7.7	$ 21.4	$ 13.8

Share-Based Compensation - Narr

Share-Based Compensation - Narrative (Details) - USD ($) shares in Millions, $ in Millions	May 20, 2021	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020	May 19, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of additional shares authorized (in shares)	22.5
Number of shares authorized (in shares)	109.5					87
Amended And Restated Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate of common stock available for grant (in shares)		41.8		41.8			16.5
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized share-based compensation expense on non-vested stock options		$ 125.7		$ 125.7
Period For Recognition (in years)				1 year 7 months 6 days
Options pre-vesting forfeitures rate		6.00%	5.00%		5.00%
Service Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum award vesting period (in years)				3 years
Performance or Market Based Restricted Stock Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum award vesting period (in years)				2 years
Performance or Market Based Restricted Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum award vesting period (in years)				3 years
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of additional shares authorized (in shares)	6
Number of shares authorized (in shares)	34.5					28.5
Aggregate of common stock available for grant (in shares)		8.5		8.5			3

Share-Based Compensation - Su_2

Share-Based Compensation - Summary Of Restricted Stock Units Transactions (Details) - Restricted Stock Units shares in Millions	6 Months Ended
	Jul. 02, 2021$ / sharesshares
Number of Shares
Nonvested shares restricted stock units, beginning (in shares) | shares	11.3
Restricted stock units granted (in shares) | shares	2.3
Restricted stock units released (in shares) | shares	(2.6)
Restricted stock units forfeited (in shares) | shares	(4.1)
Nonvested shares restricted stock units, ending (in shares) | shares	6.9
Weighted-Average Grant Date Fair Value Per Share
Weighted Average Grant Date Fair Value, Nonvested, beginning (in dollars per share) | $ / shares	$ 20.73
Weighted Average Grant Date Fair Value, Granted (in dollars per share) | $ / shares	41.18
Weighted-Average Grant Date Fair Value, Released (in dollars per share) | $ / shares	21.46
Weighted Average Grant Date Fair Value, Forfeited (in dollars per share) | $ / shares	21.57
Weighted Average Grant Date Fair Value, Nonvested, ending (in dollars per share) | $ / shares	$ 26.70

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Millions	Jul. 02, 2021USD ($)
Loss Contingencies [Line Items]
Outstanding guarantees and letters of credit	$ 8.6
Guarantees	0.9
Revolving Credit Facility | Senior Revolving Credit Facility
Loss Contingencies [Line Items]
Current borrowing capacity	15
Letter of Credit | Senior Revolving Credit Facility
Loss Contingencies [Line Items]
Credit commitment outstanding	$ 0.9

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Fair Value of Assets and Liabilities (Details) - Fair Value, Measurements, Recurring - Demand and time deposits - USD ($) $ in Millions	Jul. 02, 2021	Dec. 31, 2020
Level 1
Assets:
Cash and cash equivalents	$ 8.4	$ 8.5
Level 2
Assets:
Cash and cash equivalents	0	0
Level 3
Assets:
Cash and cash equivalents	0	0
Estimate of Fair Value
Assets:
Cash and cash equivalents	$ 8.4	$ 8.5

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Fair Value, by Balance Sheet Grouping (Details) - USD ($) $ in Millions	Jul. 02, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	$ 3,313.9	$ 3,589.5
Convertible notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	838	515.6
Fair Value	1,222.5	967.1
Other long-term debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	2,270.4	2,975.7
Fair Value	$ 2,272.6	$ 2,966.8

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details)	Jul. 02, 2021	May 19, 2021	May 11, 2021	May 10, 2021
Notes Payable | 3.875% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)	3.875%
Convertible Debt | 1.625% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)	1.625%	1.625%	1.625%	1.625%
Convertible Debt | 0% Notes
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)	0.00%	0.00%	0.00%	0.00%

Financial Instruments - Narrati

Financial Instruments - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Foreign currency transaction gain (loss) realized	$ (1,600,000)	$ (3,200,000)	$ 2,400,000	$ (3,400,000)
Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Notional Amount	318,800,000		$ 318,800,000		$ 263,400,000
Foreign currency exchange contracts | Minimum
Derivatives, Fair Value [Line Items]
Derivative, term of contract (in months)			1 month
Foreign currency exchange contracts | Maximum
Derivatives, Fair Value [Line Items]
Derivative, term of contract (in months)			3 months
Interest Rate Swap
Derivatives, Fair Value [Line Items]
Notional Amount	1,500,000,000	$ 2,250,000,000	$ 1,500,000,000	$ 2,250,000,000
Interest Rate Swap 1
Derivatives, Fair Value [Line Items]
Notional Amount	$ 500,000,000		$ 500,000,000

Financial Instruments - Schedul

Financial Instruments - Schedule of Net Foreign Exchange Positions (Details) - Foreign currency exchange contracts - USD ($) $ in Millions	Jul. 02, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Buy (Sell)	$ 300.6	$ 241.2
Notional Amount	318.8	263.4
Other Currencies - Buy
Derivatives, Fair Value [Line Items]
Buy (Sell)	15.6	12.4
Notional Amount	15.6	12.4
Other Currencies - Sell
Derivatives, Fair Value [Line Items]
Buy (Sell)	(9.1)	(11.1)
Notional Amount	9.1	11.1
Japanese Yen
Derivatives, Fair Value [Line Items]
Buy (Sell)	89.1	71.2
Notional Amount	89.1	71.2
Philippine Peso
Derivatives, Fair Value [Line Items]
Buy (Sell)	67.9	57.2
Notional Amount	67.9	57.2
Euro
Derivatives, Fair Value [Line Items]
Buy (Sell)	65.4	47.7
Notional Amount	65.4	47.7
Korean Won
Derivatives, Fair Value [Line Items]
Buy (Sell)	43.3	34.4
Notional Amount	43.3	34.4
Malaysian Ringgit
Derivatives, Fair Value [Line Items]
Buy (Sell)	16.4	11.7
Notional Amount	16.4	11.7
Chinese Yuan
Derivatives, Fair Value [Line Items]
Buy (Sell)	12	17.7
Notional Amount	$ 12	$ 17.7

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	Jul. 02, 2021	Jul. 03, 2020
Income Tax Disclosure [Abstract]
Unrecognized tax benefits, income tax penalties and interest accrued	$ 1.9	$ 4.6
Possible reduction in unrecognized tax benefits in next twelve months	$ 41.1

Changes in Accumulated Other _3

Changes in Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning	$ 3,649.6	$ 3,237.6	$ 3,558.1	$ 3,324.1
Other comprehensive income (loss) prior to reclassifications			14.8
Amounts reclassified from accumulated other comprehensive loss			(9.4)
Other comprehensive income (loss), net of tax	3.7	(1.1)	5.4	(13.3)
Balance, ending	3,804.4	3,259.3	3,804.4	3,259.3
Cash flow hedge, tax			2.4
Currency Translation Adjustments
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning			(40.6)
Other comprehensive income (loss) prior to reclassifications			(2.5)
Amounts reclassified from accumulated other comprehensive loss			0
Other comprehensive income (loss), net of tax			(2.5)
Balance, ending	(43.1)		(43.1)
Effects of Cash Flow Hedges
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning			(17)
Other comprehensive income (loss) prior to reclassifications			17.3
Amounts reclassified from accumulated other comprehensive loss			(9.4)
Other comprehensive income (loss), net of tax			7.9
Balance, ending	(9.1)		(9.1)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning	(55.9)	(66.5)	(57.6)	(54.3)
Balance, ending	$ (52.2)	$ (67.6)	$ (52.2)	$ (67.6)

Changes in Accumulated Other _4

Changes in Accumulated Other Comprehensive Loss - Reclassifications from Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest expense	$ (1.1)	$ (2.8)	$ 3.4	$ (2.7)
Net income (loss)	184.1	(0.9)	274.4	(14.6)
Interest rate swaps
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net income (loss)	4.8	5	9.4	6.9
Effects of Cash Flow Hedges | Interest rate swaps
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest expense	$ 4.8	$ 5	$ 9.4	$ 6.9