Summary of Significant Accounting Policies (Details 3) (USD $)	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Lot Option Purchase Disclosures
Consolidated inventory not owned	$ 51,400,000	$ 88,289,000
Noncontrolling interest	34,223,000	61,806,000	0
Primary variable interest | Lot option purchase contracts
Lot Option Purchase Disclosures
Consolidated inventory not owned	51,400,000	88,300,000
Cash deposits	17,200,000	26,500,000
Noncontrolling interest	34,200,000	61,800,000
Not primary variable interest | Lot option purchase contracts
Lot Option Purchase Disclosures
Cash deposits and/or letters of credit	22,300,000	11,600,000
Aggregate purchase price	$ 208,500,000	$ 130,700,000