Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Oct. 01, 2020	Jul. 02, 2020	Apr. 02, 2020	Dec. 31, 2019	Sep. 26, 2019	Jun. 27, 2019	Mar. 28, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	$ (154.1)				$ (109.2)				$ (154.1)	$ (109.2)
Class of Stock [Line Items]
Employee Stock Purchase Plan, Number of Allocated Shares	1,000,000								1,000,000
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred Stock, Shares Authorized	10,000,000				10,000,000				10,000,000	10,000,000
Equity, Class of Treasury Stock [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.12	$ 0.12	$ 0.12	$ 0.12	$ 0.04	$ 0.48	$ 0.46
Issued But Unvested Shares (in shares)	1,500,000				1,400,000				1,500,000	1,400,000	1,400,000
Noncontrolling interest	$ 0.5				$ 0.5				$ 0.5	$ 0.5
Payments of Dividends									15.4	50.4	$ 48.0
Basic EPS
(Loss) income available to common shareholders									$ (870.3)	$ 529.7	$ 616.5
(Loss) income available to common shareholders (in shares)									103,900,000	103,600,000	108,000,000.0
Earnings Per Share, Basic	$ (2.85)	$ (1.50)	$ (2.46)	$ (1.57)	$ 0.65	$ 1.27	$ 1.62	$ 1.57	$ (8.38)	$ 5.11	$ 5.71
Income allocated to participating securities									$ 0.0	$ 0.4	$ 0.5
Income allocated to participating securities, shares									0	100,000	100,000
Net (loss) income	$ (295.9)	$ (155.5)	$ (255.9)	$ (163.0)	$ 67.7	$ 131.3	$ 168.0	$ 163.1	$ (870.3)	$ 530.1	$ 617.0
Diluted potential common shares (in shares)										1,000,000.0	1,000,000.0
Diluted EPS
Net income	$ (295.9)	$ (155.5)	$ (255.9)	$ (163.0)	$ 67.7	$ 131.3	$ 168.0	$ 163.1	$ (870.3)	$ 530.1	$ 617.0
Shares									103,900,000	104,700,000	109,100,000
(Loss) earnings per share, diluted (in dollars per share)	$ (2.85)	$ (1.50)	$ (2.46)	$ (1.57)	$ 0.65	$ 1.26	$ 1.61	$ 1.55	$ (8.38)	$ 5.06	$ 5.65
Common Class A [Member]
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Common Stock, Shares Authorized	200,000,000				200,000,000				200,000,000	200,000,000
Class B [Member]
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Common Stock, Shares Authorized	0				0				0	0