XML 60 R48.htm IDEA: XBRL DOCUMENT
v3.20.2

Stock Repurchase and Dividends - Narrative (Details) - USD ($) | Jun. 28, 2020 | Jan. 27, 2020 | Nov. 05, 2018 | Sep. 30, 2018
--- | --- | --- | --- | ---
Stock Repurchase And Dividends [Abstract] |  |  |  |
Maximum repurchase amount under stock repurchase program |  | $ 200,000,000 | $ 200,000,000 |
Remaining authorized amount under share repurchase program | $ 222,800,000 |  |  | $ 25,000,000

X
- Definition Stock Repurchase And Dividends [Abstract] + References No definition available. + Details
Name: | ttek_StockRepurchaseAndDividendsAbstract
Namespace Prefix: | ttek_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of stock repurchase plan authorized. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount remaining of a stock repurchase plan authorized. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant