Related-Party Transactions - Additional Information (Detail) - USD ($) |
3 Months Ended | 9 Months Ended | ||
---|---|---|---|---|
Sep. 30, 2015 |
Sep. 30, 2014 |
Sep. 30, 2015 |
Sep. 30, 2014 |
|
Affiliates [Member] | ||||
Related Party Transaction [Line Items] | ||||
Real estate inventory acquisitions from affiliates | $ 0 | $ 9,500,000 | $ 16,800,000 | $ 40,500,000 |