Real Estate Inventory and Land Deposits - Schedule of Inventory (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Real Estate [Abstract]
Real estate developed and under development	$ 2,169,321		$ 2,167,771
Real estate held for development or held for sale	202,390		173,448
Operating communities	803,562		672,499
Capitalized interest	111,412	$ 111,063	105,148	$ 106,985	$ 106,470	$ 94,880
Total owned inventory	3,286,685		3,118,866
Real estate not owned under option agreements	612		7,921
Total real estate inventory	$ 3,287,297		$ 3,126,787