v3.20.2

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020 USD ($) customer	Sep. 28, 2019	Sep. 26, 2020 USD ($) customer	Sep. 28, 2019 customer	Dec. 28, 2019 USD ($) customer
Summary of Significant Accounting Policies, Narrative [Line Items]
Document Period End Date			Sep. 26, 2020
Financial reporting and operating period, quarter	91 days	91 days
Number of customer that accounted for more than 10% of accounts and notes receivable \| customer	1		1		1
Carrying Value and Estimated Fair Value Of Long Term Debt [Abstract]
Long-term debt \| $	$ 3,023,480		$ 3,023,480		$ 3,035,366
Term loans, Estimated fair value \| $	$ 3,227,605		$ 3,227,605		$ 3,149,505
Minimum
Summary of Significant Accounting Policies, Narrative [Line Items]
Financial reporting and operating period, year	364 days
Customer Concentration Risk [Member] \| Revenue Benchmark [Member]
Summary of Significant Accounting Policies, Narrative [Line Items]
Concentration risk, number of customers \| customer			0	0
Manufacture and/or Distributer [Member] \| Customer Concentration Risk [Member] \| Revenue Benchmark [Member]
Summary of Significant Accounting Policies, Narrative [Line Items]
Concentration risk, customer	No	No	No	No
Majority-Owned Subsidiaries [Member] \| Customer Concentration Risk [Member]
Summary of Significant Accounting Policies, Narrative [Line Items]
Percentage of receivable from one master licensee account	11.00%		11.00%		15.00%
Third Party [Member] \| Customer Concentration Risk [Member]
Summary of Significant Accounting Policies, Narrative [Line Items]
Percentage of receivable from one master licensee account	18.00%		18.00%

The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD.

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Carrying Value and Estimated Fair Value Of Long Term Debt [Abstract]

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Concentration Risk, Number of Customers

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Financial Reporting and Operating Period, Quarter

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Financial Reporting and Operating Period, Year

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Number Of Individual Customers Accounting For More Than Ten Percent Of Accounts Receivable

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The percentage of total accounts receivable, net for one master licensee that exceeds the benchmark for the concentration of credit risk.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Description of risks that arise due to the volume of business transacted with a particular customer. At a minimum, the description informs financial statement users of the general nature of the risk, but excludes "Information about Major Customers" that may be disclosed elsewhere (for instance, segment disclosures).

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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DUNKIN' BRANDS GROUP, INC. 10-Q