Variable Interest Entities - Total Risk of Loss Related to Contract Land Deposits (Textual) (Detail) - lot	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure [Abstract]
Finished lots committed to purchase under specific performance obligations	10	10

Finished lots committed to purchase under specific performance obligations.

No definition available.

Name:	nvr_FinishedLotsCommittedToPurchase
Namespace Prefix:	nvr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant