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Stock-Based Compensation - Additional Information (Detail) (USD $)
3 Months Ended 12 Months Ended 0 Months Ended
Mar. 28, 2015
Mar. 29, 2014
Dec. 27, 2014
Dec. 26, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Authorized number of common stock shares for grant 2,000,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized      
Date of plan approval May 20, 2009      
Maximum grant period from date of plan approval 10 years      
Shares available for grant under the plan 1,683,562us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant      
Compensation cost related to restricted stock $ 300,000us-gaap_RestrictedStockExpense $ 500,000us-gaap_RestrictedStockExpense    
Cash received from option exercises under the plan   262,000us-gaap_ProceedsFromStockOptionsExercised    
Cash received or excess tax benefit 0us-gaap_ProceedsAndExcessTaxBenefitFromSharebasedCompensation      
Maximum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Compensation cost related to stock options 100,000us-gaap_StockOptionPlanExpense
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
100,000us-gaap_StockOptionPlanExpense
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
   
Restricted Stock [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized compensation cost related to non-vested stock options 2,300,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
     
Unrecognized compensation cost related to non-vested stock options, weighted-average period 1 year 8 months 12 days      
Tax benefit generated from compensation cost and credited to additional paid-in capital 100,000us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
     
Stock Options [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized compensation cost related to non-vested stock options, weighted-average period 1 year      
Tax benefit generated from compensation cost and credited to additional paid-in capital   100,000us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
   
Capitalized compensation cost     0us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
 
Stock options granted 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
   
Percentage of forfeiture assumption in calculation of compensation cost     5.40%dorm_PercentageOfForfeitureAssumptionInCalculationOfCompensationCost
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
 
Intrinsic value of stock options exercised 1,200,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
     
Cash received from option exercises under the plan   300,000us-gaap_ProceedsFromStockOptionsExercised
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
   
Stock Options [Member] | Scenario, Forecast [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Capitalized compensation cost       0us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember
Percentage of forfeiture assumption in calculation of compensation cost       5.40%dorm_PercentageOfForfeitureAssumptionInCalculationOfCompensationCost
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember
Stock Options [Member] | Maximum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized compensation cost related to non-vested stock options $ 100,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember