Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 27, 2020	Dec. 29, 2019
Current assets
Restricted cash	$ 73,168	$ 0
Accounts receivable, allowance for doubtful accounts	$ 28,100	$ 17,200
Shareholders’ equity
Preference stock, par value (in dollars per share)	$ 2.50	$ 2.50
Preference stock, shares authorized (in shares)	5,000,000	5,000,000
Preference stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.50	$ 0.50
Common stock, shares authorized (in shares)	600,000,000	600,000,000
Common stock, shares issued (in shares)	220,286,736	220,286,736
Treasury stock, at cost, shares (in shares)	82,979,403	83,424,129