Real Estate Inventory and Land Deposits - Additional Information (Detail) $ in Millions	Sep. 30, 2016 USD ($) Lot	Dec. 31, 2015 USD ($) Lot
Real Estate [Abstract]
Right to purchase lots of land option (in lot) \| Lot	8,581	8,888
Aggregate purchase price	$ 720.5	$ 710.6
Non-refundable option deposits	$ 35.1	$ 34.1

The carrying amount as of the balance sheet date of land not owned but under a contract in which the entity has an option to purchase the land.

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 210.5-02.6(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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