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Stockholders' Equity and Stock-Based Compensation - Textual (Details) (USD $)
 0 Months Ended 1 Months Ended 12 Months Ended 0 Months Ended 12 Months Ended 0 Months Ended 2 Months Ended
Feb. 22, 2010
Nov. 30, 2008
Dec. 27, 2008
Nov. 30, 2008
Dec. 27, 2014
Dec. 28, 2013
Dec. 29, 2012
Nov. 21, 2011
Jun. 30, 2012
Dec. 31, 2011
Jan. 01, 2011
May 24, 2013
Feb. 24, 2015
Nov. 29, 2010
May 29, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                              
Shares of common stock         47,000,000us-gaap_CommonStockSharesAuthorized 47,000,000us-gaap_CommonStockSharesAuthorized                  
Common stock, par value per share (in dollars per share)         $ 0.001us-gaap_CommonStockParOrStatedValuePerShare $ 0.001us-gaap_CommonStockParOrStatedValuePerShare                  
Shares of preferred stock         3,000,000us-gaap_PreferredStockSharesAuthorized 3,000,000us-gaap_PreferredStockSharesAuthorized                  
Preferred stock, par value per share (in dollars per share)         $ 0.001us-gaap_PreferredStockParOrStatedValuePerShare $ 0.001us-gaap_PreferredStockParOrStatedValuePerShare                  
Total cost of repurchase         $ 5,344,000us-gaap_StockRepurchasedAndRetiredDuringPeriodValue $ 5,000,000us-gaap_StockRepurchasedAndRetiredDuringPeriodValue $ 8,504,000us-gaap_StockRepurchasedAndRetiredDuringPeriodValue                
Common stock repurchased and retired, shares         362,633us-gaap_StockRepurchasedAndRetiredDuringPeriodShares 332,771us-gaap_StockRepurchasedAndRetiredDuringPeriodShares 587,766us-gaap_StockRepurchasedAndRetiredDuringPeriodShares                
Weighted average price (in dollars per share)         $ 14.74us-gaap_TreasuryStockAcquiredAverageCostPerShare $ 15.03us-gaap_TreasuryStockAcquiredAverageCostPerShare $ 14.47us-gaap_TreasuryStockAcquiredAverageCostPerShare                
Shares purchased under the ESPP         122,112us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans 126,068us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans 113,512us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans                
Estimated forfeiture rate         10.70%nano_ShareBasedCompensationArrangementByShareBasedPaymentAwardForfeitureRate 11.90%nano_ShareBasedCompensationArrangementByShareBasedPaymentAwardForfeitureRate 7.60%nano_ShareBasedCompensationArrangementByShareBasedPaymentAwardForfeitureRate                
Excess tax benefit         0us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities (53,000)us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities 910,000us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities                
Initial vesting percentage 25.00%nano_ShareBasedCompensationArrangementByShareBasedPaymentAwardInitialVestingPercentage 33.33%nano_ShareBasedCompensationArrangementByShareBasedPaymentAwardInitialVestingPercentage                          
Option term   7 years                          
Vesting rate, percentage     33.33%nano_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingPercentage 2.78%nano_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingPercentage                      
Period of vesting 4 years 3 years                          
Weighted average fair value per share of stock options (in dollars per share)         $ 8.13us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue $ 8.58us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue $ 10.00us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue                
Closing stock price (in dollars per share)         $ 16.59nano_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsShareClosingPrice                    
Intrinsic value of options exercised         3,000,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue 2,900,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue 4,900,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue                
Fair value of options vested         3,200,000us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1 3,700,000us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1 3,600,000us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1                
Employee Stock Purchase Plan [Member]                              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                              
Maximum percentage of salary withholdings         10.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockMember		                    
Purchase price of common stock, percent         85.00%us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockMember		                    
Shares remaining for issuance under the ESPP         400,000nano_ShareBasedCompensationArrangementByShareBasedPaymentAwardRemainingNumberOfAuthorizedShares
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockMember		                    
Weighted average price of shares issued (in dollars per share)         $ 13.76nano_StockIssuedDuringPeriodWeightedAveragePriceEmployeeStockPurchasePlans
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockMember		 $ 12.36nano_StockIssuedDuringPeriodWeightedAveragePriceEmployeeStockPurchasePlans
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockMember		 $ 14.16nano_StockIssuedDuringPeriodWeightedAveragePriceEmployeeStockPurchasePlans
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockMember		                
Restricted Stock Units (RSUs) [Member]                              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                              
Vesting rate, percentage               33.33%nano_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingPercentage
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember		              
RSUs granted (in shares)         473,600us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember		 348,328us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember		                  
RSUs cancelled (in shares)         98,473us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember		                    
Unrecognized compensation costs         5,700,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember		                    
Weighted average remaining amortization period for unrecognized compensation costs         1 year 10 months 16 days                    
Shares per unit granted         1.7nano_ShareBasedCompensationArrangementByShareBasedPaymentAwardShareConversionRatio
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember		                    
Restricted Stock Units (RSUs) [Member] | Minimum [Member]                              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                              
Period of vesting         1 year                    
Restricted Stock Units (RSUs) [Member] | Maximum [Member]                              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                              
Period of vesting         3 years                    
Stock Options [Member]                              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                              
Unrecognized compensation costs         2,500,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember		                    
Weighted average remaining amortization period for unrecognized compensation costs         2 years 2 months 15 days                    
November 29, 2010 Program [Member]                              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                              
Maximum amount of common stock approved to repurchase, Value                           10,000,000.0us-gaap_StockRepurchaseProgramAuthorizedAmount1
/ us-gaap_PlanNameAxis
= nano_NovemberTwentyNineTwoThousandTenProgramMember		  
Total cost of repurchase             4,900,000us-gaap_StockRepurchasedAndRetiredDuringPeriodValue
/ us-gaap_PlanNameAxis
= nano_NovemberTwentyNineTwoThousandTenProgramMember		     4,300,000us-gaap_StockRepurchasedAndRetiredDuringPeriodValue
/ us-gaap_PlanNameAxis
= nano_NovemberTwentyNineTwoThousandTenProgramMember		 800,000us-gaap_StockRepurchasedAndRetiredDuringPeriodValue
/ us-gaap_PlanNameAxis
= nano_NovemberTwentyNineTwoThousandTenProgramMember		        
Common stock repurchased and retired, shares                 667,406us-gaap_StockRepurchasedAndRetiredDuringPeriodShares
/ us-gaap_PlanNameAxis
= nano_NovemberTwentyNineTwoThousandTenProgramMember		            
Weighted average repurchase price of common stock (in dollars per share)                 $ 14.97nano_WeightedAverageRepurchasePriceOfCommonStock
/ us-gaap_PlanNameAxis
= nano_NovemberTwentyNineTwoThousandTenProgramMember		            
May 29, 2012 Program [Member]                              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                              
Maximum amount of common stock approved to repurchase, Value                             20,000,000.0us-gaap_StockRepurchaseProgramAuthorizedAmount1
/ us-gaap_PlanNameAxis
= nano_MayTwentyNineTwoThousandTwelveProgramMember
Common stock repurchased and retired, shares             250,400us-gaap_StockRepurchasedAndRetiredDuringPeriodShares
/ us-gaap_PlanNameAxis
= nano_MayTwentyNineTwoThousandTwelveProgramMember		                
Weighted average repurchase price of common stock (in dollars per share)             $ 14.15nano_WeightedAverageRepurchasePriceOfCommonStock
/ us-gaap_PlanNameAxis
= nano_MayTwentyNineTwoThousandTwelveProgramMember		                
2005 Equity Incentive Plan [Member]                              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                              
Ratio of restricted stock units against available for grant pool 2nano_RatioofRestrictedStockUnitsAgainstAvailableforGrantPool
/ us-gaap_PlanNameAxis
= nano_TwoThousandFiveEquityIncentivePlanMember		                     1.7nano_RatioofRestrictedStockUnitsAgainstAvailableforGrantPool
/ us-gaap_PlanNameAxis
= nano_TwoThousandFiveEquityIncentivePlanMember		      
Number of shares of common stock authorized         7,292,594us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
/ us-gaap_PlanNameAxis
= nano_TwoThousandFiveEquityIncentivePlanMember		             2,600,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
/ us-gaap_PlanNameAxis
= nano_TwoThousandFiveEquityIncentivePlanMember		      
RSUs granted (in shares)         805,120us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_PlanNameAxis
= nano_TwoThousandFiveEquityIncentivePlanMember		                    
RSUs cancelled (in shares)         167,404us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_PlanNameAxis
= nano_TwoThousandFiveEquityIncentivePlanMember		                    
Subsequent Event [Member]                              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                              
Total cost of repurchase                         $ 1,700,000us-gaap_StockRepurchasedAndRetiredDuringPeriodValue
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember		    
Common stock repurchased and retired, shares                         111,050us-gaap_StockRepurchasedAndRetiredDuringPeriodShares
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember		    
Weighted average price (in dollars per share)                         $ 15.49us-gaap_TreasuryStockAcquiredAverageCostPerShare
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember		    
Remaining shares available for future repurchase (in shares)                         4,400,000us-gaap_StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember