Consolidated Balance Sheets (Unaudited) Parenthetical - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Oct. 01, 2017
Current assets
Accounts receivable, allowance for doubtful accounts	$ 96,000	$ 31,400	$ 33,900
Property, plant and equipment, accumulated depreciation	452,000	422,100	417,000
Other assets
Other intangibles, accumulated amortization	$ 924,700	$ 904,900	$ 898,300
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)	82,979,119	85,244,923	85,139,302