v2.4.0.8

Employee Benefit Plan (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 29, 2013 | Dec. 30, 2012 | Jan. 01, 2012
Employee Benefit Plan [Abstract] |  |  |
Employee Benefit Plan, Contributions by Employer | $ 0.3 | $ 0.3 | $ 0.2

X
- Details
Name: | nile_EmployeeBenefitPlanAbstract
Namespace Prefix: | nile_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition The increase in the fair value of plan assets from contributions made by the employer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration