Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 26, 2019	Dec. 25, 2018
Consolidated Balance Sheets
Receivables, allowance for doubtful accounts (in dollars)	$ 30	$ 34
Property and equipment, accumulated depreciation (in dollars)	623,515	602,451
Intangible assets, accumulated amortization (in dollars)	$ 13,664	$ 13,416
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	71,827,836	71,617,510
Common stock, shares outstanding	71,827,836	71,617,510