Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 30, 2017
Allowance on trade accounts receivable	$ 6,496	$ 6,131
Allowance on other receivables	6,796	6,012
Accumulated depreciation and amortization on operating property	$ 224,042	$ 218,700
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized shares	160,000,000	160,000,000
Common stock, issued shares	67,836,164	67,740,380
Treasury stock, shares	25,768,669	25,749,493