CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Statement of Stockholders' Equity [Abstract]
Cash dividends per share (in dollars per share)	$ 1.50	$ 1.50	$ 1.375
Number of shares acquired	441,949	1,435,488	2,711,149
Stock plan exercises; shares acquired (in shares)	16,777	112,995	97,974
Stock options exercised; shares issued (in shares)	109,893	169,493	194,627
Stock awards; shares issued (in shares)	15,700	10,329	22,010