Percentage of non-vested options cancelled.

No definition available.

Name:	tess_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonvestedOptionsCancelledPercentageOfShares
Namespace Prefix:	tess_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cost to be recognized for option under share-based payment arrangement.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardDateAxis=tess_AwardDateFy2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardDateAxis=tess_AwardDateFy2020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardDateAxis=tess_AwardDateFy2019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=tess_StockOptionsVestingBasedOnPerformanceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Stock-Based Compensation - Stock Option Valuation Assumptions (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended	9 Months Ended	12 Months Ended
	Oct. 01, 2020	May 15, 2020	Dec. 30, 2020	Dec. 27, 2020	Mar. 29, 2020	Mar. 31, 2019
Valuation assumptions
Resulting Black Scholes Value (in dollars per share)				$ 2.00
Options Granted (in shares)				225,000
Grant Fiscal Year 2021
Valuation assumptions
Expected Stock Price Volatility (as a percent)				46.68%
Risk-Free Interest Rate (as a percent)				1.16%
Expected Dividend Yield (as a percent)				0.00%
Average Expected Term				4 years
Resulting Black Scholes Value (in dollars per share)				$ 2.00
Options Granted (in shares)				225,000
Grant Fiscal Year 2020
Valuation assumptions
Expected Stock Price Volatility (as a percent)					35.88%
Risk-Free Interest Rate (as a percent)					2.00%
Expected Dividend Yield (as a percent)					5.82%
Average Expected Term					4 years
Resulting Black Scholes Value (in dollars per share)					$ 2.53
Options Granted (in shares)					405,000
Grant Fiscal Year 2019
Valuation assumptions
Expected Stock Price Volatility (as a percent)						35.59%
Risk-Free Interest Rate (as a percent)						3.11%
Expected Dividend Yield (as a percent)						4.99%
Average Expected Term						4 years
Resulting Black Scholes Value (in dollars per share)						$ 3.38
Options Granted (in shares)						66,500
Stock Options
Valuation assumptions
Unrecognized compensation costs (in dollars)				$ 0.8
Unrecognized compensation costs, period for recognition				3 years
Stock Options Vesting Based On Performance \| Grant Fiscal Year 2021
Valuation assumptions
Options Granted (in shares)		65,000
Options cancelled (as a percent)	50.00%
Stock Options Vesting Based On Performance \| Grant Fiscal Year 2021 \| Forecast
Valuation assumptions
Options cancelled (as a percent)			50.00%