Shareholders' Equity (Deficit): Dividends and Repurchase of Common Stock (Details) - USD ($)			12 Months Ended
	May. 13, 2015	Apr. 15, 2015	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Repurchase of Common Stock
Aggregate purchase price of shares repurchased (in dollars)			$ 74,853,700	$ 11,564,800	$ 1,854,900
Dividends
Cash dividends declared and paid (in dollars per share)			$ 0.27	$ 0.23	$ 0.19
Aggregate quarterly cash dividends declared and paid			$ 1,200,000	$ 1,200,000	$ 960,000
Special cash dividend approved by Board of Directors (in dollars per share)				$ 5.00
Total special dividend in cash				$ 25,800,000
Common Stock
Repurchase of Common Stock
Number of shares repurchased			881,518	166,030	28,422
Aggregate purchase price of shares repurchased (in dollars)			$ 2,010,600	$ 4,453,400	$ 1,854,900
Common Stock | Tender Offer
Repurchase of Common Stock
Shares authorized for repurchase		875,000
Purchase Of Stock Price Per Share		$ 84.72
Number of shares repurchased	875,000
Aggregate purchase price of shares repurchased (in dollars)	$ 74,300,000
Common Stock | Common Stock Repurchase Program
Repurchase of Common Stock
Aggregate purchase price per share of shares repurchased (in dollars per share)			$ 90.85	$ 69.65	$ 65.26
Number of shares repurchased			6,518	166,030	28,422
Aggregate purchase price of shares repurchased (in dollars)			$ 600,000	$ 11,600,000	$ 1,900,000
Number of additional shares that can be repurchased			160,182