Consolidated Balance Sheets (Unaudited) Parenthetical - USD ($) $ in Thousands	Sep. 29, 2019	Dec. 30, 2018	Sep. 30, 2018
Current assets
Accounts receivable, allowance for doubtful accounts	$ 18,200	$ 9,100	$ 96,000
Property, plant and equipment, accumulated depreciation	496,700	462,700	452,000
Other assets
Other intangibles, accumulated amortization	$ 771,700	$ 721,700	$ 924,700
Shareholders' equity
Preference stock, par value (in dollars per share)	$ 2.5	$ 2.5	$ 2.5
Preference stock, authorized shares (in shares)	5,000,000	5,000,000	5,000,000
Preference stock, issued (in shares)	0	0	0
Common stock, par value (in dollars per share)	$ 0.5	$ 0.5	$ 0.5
Common stock, authorized shares (in shares)	600,000,000	600,000,000	600,000,000
Common stock, issued (in shares)	209,694,630	209,694,630	209,694,630
Treasury stock, at cost; shares (in shares)	83,442,005	83,565,598	82,979,119