Variable Interest Entities - Total Risk of Loss Related to Contract Land Deposits (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure [Abstract]
Contract land deposits	$ 439,833	$ 441,423
Loss reserve on contract land deposits	(52,205)	(27,572)
Contract land deposits, net	387,628	413,851
Contingent obligations in the form of letters of credit	8,249	5,606
Total risk of loss	$ 395,877	$ 419,457

The gross amount as of the balance sheet date of deposits paid to secure the right to purchase finished lots.

No definition available.

Name:	nvr_ContractLandDeposits
Namespace Prefix:	nvr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Letters of credit related to contract land deposits.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The reserve account established to account for expected but unspecified losses related to contract land deposits.

+ References

No definition available.

+ Details

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

- Definition

Carrying value of amounts transferred to third parties for security purposes that are expected to be returned or applied towards payment in the future.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12069-110248

+ Details

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

- References

No definition available.

+ Details

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