Common Stock and Earnings (Loss) Per Share (Common and Preferred Stock) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) votes $ / shares shares	Dec. 26, 2015 USD ($) $ / shares shares	Dec. 27, 2014 USD ($) $ / shares shares
Class of Stock [Line Items]
Common stock, shares authorized	80,000,000	80,000,000
Common stock, par value | $ / shares	$ 3.00	$ 3.00
Votes Per Share of Class B Common Stock | votes	20
Common stock, shares issued	15,248,338	15,155,274
Common Stock, shares issued equity offering	0	0	2,500,000
Price Per Share From Equity Offering | $ / shares			$ 10.65
Proceeds from equity offering, net of issuance costs | $	$ 0	$ 0	$ 24,559
Common Class A [Member]
Class of Stock [Line Items]
Common stock, shares authorized	80,000,000
Common stock, par value | $ / shares	$ 3
Common Class B [Member]
Class of Stock [Line Items]
Common stock, shares authorized	16,000,000
Common stock, par value | $ / shares	$ 3
Common Class C [Member]
Class of Stock [Line Items]
Common stock, shares authorized	200,000,000
Common stock, par value | $ / shares	$ 3
Common stock, shares issued	0
Preferred Stock [Member]
Class of Stock [Line Items]
Common stock, shares authorized	16,000,000
Common stock, shares issued	0