Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Jan. 31, 2013
Commitment And Contingencies [Line Items]
Surety bonds, issued and outstanding	$ 60.5
Letters of credit, issued and outstanding	17.1
Letter of credit facilities	50	80
HomeAmerican [Member]
Commitment And Contingencies [Line Items]
Letters of credit, issued and outstanding	7.9
Estimated cost related to bonds	19.0
Estimated cost related to letters of credit	2.4
Letter of Credit [Member]
Commitment And Contingencies [Line Items]
Letter of credit facilities	65
Option Contracts [Member]
Commitment And Contingencies [Line Items]
Letters of credit, issued and outstanding	4.2
Cash deposits	$ 7.8
Right to acquire lots under options contracts, number of lots	2,284