Debt Covenant, Liquidity Availability

No definition available.

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Balance Type:	debit
Period Type:	instant

- Definition

Line of Credit Facility, Available Increase in Borrowing Capacity

+ References

No definition available.

+ Details

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Namespace Prefix:	nvee_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The Minimum level of fixed charge coverage ratio under the line of credit facility.

+ References

No definition available.

+ Details

Name:	nvee_LineOfCreditFacilityCovenantMinimumFixedChargeCoverageRatio
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Balance Type:	na
Period Type:	instant

- Definition

Line of Credit Facility, Covenant, Net Leverage Ratio

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Amount of amortization expense attributable to debt issuance costs.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
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+ Details

Name:	us-gaap_AmortizationOfFinancingCosts
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

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+ Details

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

- Definition

The effective interest rate during the reporting period.

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+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

+ References

No definition available.

+ Details

Name:	us-gaap_OtherCommitment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

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-Publisher FASB
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+ Details

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Balance Type:	debit
Period Type:	duration

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
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Balance Type:
Period Type:

- Details

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- Details

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Notes Payable and Other Obligations - Narrative (Details)		3 Months Ended
	Aug. 13, 2021 USD ($)	Apr. 02, 2022 USD ($)	Apr. 03, 2021 USD ($)	Jan. 01, 2022 USD ($)	Dec. 07, 2016 USD ($)
Debt Instrument [Line Items]
Debt covenant, liquidity availability		$ 30,000,000
Amortization of debt issuance costs		185,000	$ 227,000
Other obligations		$ 28,456,000		$ 34,226,000
Weighted average interest rate		2.40%
Senior Credit Facility
Debt Instrument [Line Items]
Long-term debt, gross		$ 98,750,000		98,750,000
Senior Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity					$ 150,000,000
Senior Credit Facility \| Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity					$ 215,000,000
Long-term debt, gross		$ 98,750,000		$ 98,750,000
Second A&R Credit Agreement
Debt Instrument [Line Items]
Minimum fixed charge coverage ratio		3.25
Second A&R Credit Agreement \| Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 400,000,000
Aggregate credit agreement	138,750,000
Available increase in borrowing capacity	$ 200,000,000
Interest rate during period		1.20%
Covenant, net leverage ratio		4.00
Minimum fixed charge coverage ratio		1.10
AR Credit Agreement
Debt Instrument [Line Items]
Debt issuance costs		$ 3,702,000
Amortization of debt issuance costs		$ 185,000	$ 227,000