Equity - Stock Repurchase Activities (Details) $ / shares in Units, shares in Millions									3 Months Ended		12 Months Ended
	Dec. 26, 2018 $ / shares	Oct. 24, 2018 $ / shares	Sep. 25, 2018 $ / shares	Jul. 26, 2018 $ / shares	Jun. 22, 2018 $ / shares	May 02, 2018 $ / shares	Mar. 22, 2018 $ / shares	Jan. 30, 2018 $ / shares	Dec. 31, 2018 USD ($) shares	Mar. 31, 2018 USD ($) shares	Dec. 31, 2018 USD ($) Dividend $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares	Feb. 28, 2018 USD ($)	Jan. 31, 2018 USD ($)
Dividends
Per Share (in dollars per share) | $ / shares	$ 0.18		$ 0.18		$ 0.18		$ 0.18				$ 0.72	$ 0.40	$ 0.40
Amount											$ 249,300,000	$ 150,400,000	$ 152,500,000
Stock Repurchase Program
Number of quarterly cash dividends declared | Dividend											4
Cash dividends declared per share of common stock (in dollars per share) | $ / shares		$ 0.18		$ 0.18		$ 0.18		$ 0.18
Cash dividends paid per share of common stock (in dollars per share) | $ / shares	$ 0.18		$ 0.18		$ 0.18		$ 0.18				$ 0.72	$ 0.40	$ 0.40
Payment to repurchase stock											$ 756,600,000	$ 725,800,000	$ 324,600,000
Stock Repurchase Program 2018
Stock Repurchase Program
Shares (in shares) | shares											29.3
Average price per share (in dollars per share) | $ / shares											$ 25.62
Amount											$ 750,000,000
Tax Withholding Amount											6,600,000
Total of Dividends and Stock Repurchase Program, Amount											1,005,900,000
Stock repurchase program, authorized amount															$ 2,000,000,000
Stock repurchase program, authorized funds remaining									$ 1,300,000,000		$ 1,300,000,000
Accelerated Share Repurchase Program
Stock Repurchase Program
Shares (in shares) | shares									6.0	23.3	29.3	26.1
Average price per share (in dollars per share) | $ / shares											$ 25.62	$ 27.61
Amount												$ 719,700,000
Tax Withholding Amount												6,100,000
Total of Dividends and Stock Repurchase Program, Amount												$ 876,200,000
Stock repurchase program, authorized amount														$ 750,000,000	$ 750,000,000
Payment to repurchase stock										$ 750,000,000
Stock Repurchase Program 2014
Stock Repurchase Program
Shares (in shares) | shares													13.5
Average price per share (in dollars per share) | $ / shares													$ 23.25
Amount													$ 312,900,000
Tax Withholding Amount													11,700,000
Total of Dividends and Stock Repurchase Program, Amount													$ 477,100,000