Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Statement of Stockholders' Equity [Abstract]
Common Stock, Dividends, Per Share, Cash Paid	$ 0.8675	$ 0.79	$ 0.74
Contribution of shares to retirement plans	7,837	8,516	10,272
Acquisition of shares from stockholders	22,500	21,276	21,356
Sale of shares to stockholders	7,686	8,463	8,835
Retirement of shares	13,476	13,225	12,480