Debt - Additional Information (Detail) (USD $)	3 Months Ended
Mar. 31, 2015
Debt Disclosure [Abstract]
Senior notes principal amount	$ 600,000,000us-gaap_DebtInstrumentFaceAmount
Senior notes effective interest rate	3.97%
Senior notes maturity	Sep. 15, 2022
Senior notes interest rate	3.95%
Frequency of senior notes payment	semi-annually in arrears on March 15 and September 15
Repurchase agreement maximum loan borrowing capacity	25,000,000
Expiration date of repurchase agreement	Jul. 29, 2015
Debt outstanding under repurchase agreement	0us-gaap_WarehouseAgreementBorrowings
Borrowing base	$ 0

Debt instrument borrowing base limitation amount.

No definition available.

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Namespace Prefix:	nvr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Expiration date of repurchase agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	nvr_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Details

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Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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-Topic 835

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-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

+ Details

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

- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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-Topic 942

-SubTopic 470

-Section 50

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-Subparagraph (c)

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+ Details

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

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

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-Subparagraph (SX 210.5-02.22(a)(1))

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+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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-Name Regulation S-X (SX)

-Number 210

-Section 02

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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-Subparagraph (SX 210.5-02.22(a)(2))

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+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any 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

Carrying value as of the balance sheet date of the outstanding short-term borrowings under a revolving line of credit used by mortgage bankers to finance the origination or purchase of loans.

+ References

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-Topic 942

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-Paragraph 1

-Subparagraph (SX 210.9-03.16)

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+ Details

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Balance Type:	credit
Period Type:	instant