Dividend Payment (Details Textual) (USD $) In Millions, except Per Share data, unless otherwise specified	0 Months Ended	3 Months Ended
Mar. 20, 2015	Mar. 21, 2015	Mar. 22, 2014
Dividend Payment Terms [Line Items]
Common Stock, Dividends, Per Share, Declared (in dollars per share)	$ 0.10	$ 0.10	$ 0.09
Dividends, Common Stock, Cash (in dollars)	$ 1.4us-gaap_DividendsCommonStockCash

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: 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

Name:	us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration