Variable Interest Entities ("VIE") (Details) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Lot Option Purchase Disclosures
Consolidated inventory not owned	$ 33,944,000	$ 39,490,000
Noncontrolling interest	16,629,000	21,824,000
Primary variable interest | Lot option purchase contracts
Lot Option Purchase Disclosures
Consolidated inventory not owned	33,900,000	39,500,000
Cash deposits	17,300,000	17,700,000
Noncontrolling interest	16,600,000	21,800,000
Not primary variable interest | Lot option purchase contracts
Lot Option Purchase Disclosures
Cash deposits and/or letters of credit	25,000,000	22,200,000
Aggregate purchase price	$ 406,500,000	$ 310,100,000