XML 49 R30.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Note C - New Accounting Pronouncements Not yet Adopted (Details Textual) | 12 Months Ended
--- | ---
Mar. 26, 2017 USD ($)
Advertising Fund Contributions From Franchises and Other Third Parties | $ 2,572,000

X
- Definition The contributions to the advertising fund received from franchises and other third parties during the period. + References No definition available. + Details
Name: | nath_AdvertisingFundContributionsFromFranchisesAndOtherThirdParties
Namespace Prefix: | nath_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration