Acquisition of RSI Communities - Summary of Preliminary Amounts for Acquired Assets and Liabilities Recorded at Fair Value (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Assets Acquired
Goodwill	$ 118,877,000	$ 66,902,000
RSI Communities
Assets Acquired
Real estate inventories	436,578
Goodwill	51,975
Other	6,532
Total Assets	495,085
Liabilities Assumed
Accounts payable	9,315
Accrued expenses	8,244
Notes payable	2,305
Total liabilities	19,864
Net assets acquired	$ 475,221