Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

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Period Type:	instant

- Definition

Represents the number of derivative agreements entered into by the entity during the reporting period.

+ References

No definition available.

+ Details

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Namespace Prefix:	ttek_
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Period Type:	duration

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

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- Definition

Estimated period for the anticipated transfer of gain (loss), net, from accumulated other comprehensive income into earnings, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Derivative Financial Instruments - General Information (Details) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 29, 2013 item	Jul. 02, 2017 USD ($)	Sep. 29, 2013 item
Interest rate swap agreements \| Designated as cash flow hedges \| Derivatives designated as hedging instruments
Derivative Financial Instruments
Number of derivative agreements \| item	2		3
Period of reclassification from accumulated other comprehensive income (loss) to interest expense		12 months
Interest rate swap agreement bearing fixed rate 1.36%
Derivative Financial Instruments
Notional Amount		$ 41,320
Fixed Rate (as a percent)		1.36%
Interest rate swap agreement bearing fixed rate 1.34%
Derivative Financial Instruments
Notional Amount		$ 41,320
Fixed Rate (as a percent)		1.34%
Interest rate swap agreement bearing fixed rate 1.35%
Derivative Financial Instruments
Notional Amount		$ 41,320
Fixed Rate (as a percent)		1.35%
Interest rate swap agreement bearing fixed rate 1.23%
Derivative Financial Instruments
Notional Amount		$ 20,660
Fixed Rate (as a percent)		1.23%
Interest rate swap agreement bearing fixed rate 1.24%
Derivative Financial Instruments
Notional Amount		$ 20,660
Fixed Rate (as a percent)		1.24%