Condensed Consolidated Statement of Changes in Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended	6 Months Ended
Jul. 18, 2015	Jul. 12, 2014	Jul. 18, 2015	Jul. 12, 2014
Statement Of Stockholders Equity [Abstract]
Dividends paid, per common share	$ 0.1450	$ 0.1200	$ 0.2775	$ 0.2325

Aggregate dividends paid during the period for each share of common stock outstanding.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration