XML 51 R39.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Stockholders' Equity and Stock Compensation Plans (Details) - USD ($) $ / shares in Units, $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Apr. 01, 2018 | Apr. 02, 2017 | Apr. 01, 2018 | Apr. 02, 2017
Stockholders' Equity and Stock Compensation Plans |  |  |  |
Stock-based compensation expense | $ 4.7 | $ 3.4 | $ 8.7 | $ 6.6
Non-employee directors and executive officers |  |  |  |
Stockholders' Equity and Stock Compensation Plans |  |  |  |
Options granted (in shares) |  |  | 170,222 |
Exercise price of stock options granted (in dollars per share) |  |  | $ 47.95 |
Weighted-average fair value of stock options granted (in dollars per share) |  |  | $ 14.79 |
Stock options | Executive officers |  |  |  |
Stockholders' Equity and Stock Compensation Plans |  |  |  |
Vesting period |  |  | 4 years |
Stock options | Non-employee director |  |  |  |
Stockholders' Equity and Stock Compensation Plans |  |  |  |
Vesting period |  |  | 1 year |
Performance-based restricted stock |  |  |  |
Stockholders' Equity and Stock Compensation Plans |  |  |  |
Percentage of shares that ultimately vest depending on growth in diluted earnings per share |  |  | 50.00% |
Percentage of shares that ultimately vest depending on the shareholder return relative to peer group of companies over vesting period |  |  | 50.00% |
Performance-based restricted stock | Non-employee directors and executive officers |  |  |  |
Stockholders' Equity and Stock Compensation Plans |  |  |  |
Vesting period |  |  | 3 years |
Granted (in shares) |  |  | 98,599 |
Granted, fair value (in dollars per share) |  |  | $ 56.10 |
Restricted stock units | Non-employee directors, executive officers and employees |  |  |  |
Stockholders' Equity and Stock Compensation Plans |  |  |  |
Granted (in shares) |  |  | 189,651 |
Granted, fair value (in dollars per share) |  |  | $ 48.01 |
Restricted stock units | Non-employee director |  |  |  |
Stockholders' Equity and Stock Compensation Plans |  |  |  |
Vesting period |  |  | 1 year |
Restricted stock units | Executive officers and employees |  |  |  |
Stockholders' Equity and Stock Compensation Plans |  |  |  |
Vesting period |  |  | 4 years |

X
- Definition The weighted average price at which grantees could acquire the shares reserved for issuance on stock options awarded under the plan during the period. + References No definition available. + Details
Name: | ttek_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePriceDuringThePeriod
Namespace Prefix: | ttek_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage of performance-based shares that ultimately vests, depending upon the fiscal year growth in the diluted earnings per share. + References No definition available. + Details
Name: | ttek_ShareBasedCompensationArrangementPercentageOfAwardedSharesThatUltimatelyVests1
Namespace Prefix: | ttek_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage of performance-based shares that ultimately vests, depending upon the fiscal year shareholder return relative to peer group of companies over the vesting period of the reporting entity. + References No definition available. + Details
Name: | ttek_ShareBasedCompensationArrangementPercentageOfAwardedSharesThatUltimatelyVests2
Namespace Prefix: | ttek_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5047-113901 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(2) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- 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
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Net number of share options (or share units) granted during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- 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 Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_TitleOfIndividualAxis=ttek_DirectorAndExecutiveOfficerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_TitleOfIndividualAxis=us-gaap_ExecutiveOfficerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TitleOfIndividualAxis=us-gaap_DirectorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=ttek_RestrictedStockPerformanceBasedAwardMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TitleOfIndividualAxis=ttek_DirectorExecutiveOfficerAndEmployeesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TitleOfIndividualAxis=ttek_ExecutiveOfficerAndEmployeesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |