CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 30, 2018
Accounts receivable, allowances	$ 13,302	$ 13,249
Accumulated depreciation and amortization	$ 940,034	$ 911,845
Common stock, par value (in usd per share)	$ 0.1	$ 0.1
Class A Common Stock
Authorized shares (in shares)	300,000,000	300,000,000
Issued shares (in shares)	174,077,502	173,158,414
Treasury shares (in shares)	8,870,801	8,870,801
Class B Common Stock
Authorized shares (in shares)	803,408	803,408
Issued shares (in shares)	803,408	803,408

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount of allowance for credit loss on accounts receivable, classified as current.

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