Revenue Recognition (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Total revenues	$ 183,506	$ 157,312	$ 352,134	$ 286,475
Residential Real Estate [Member]
Disaggregation of Revenue [Line Items]
Total revenues	175,054	146,180	336,642	267,444
Residential Real Estate [Member] | Transferred at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	172,490	143,878	331,723	264,244
Residential Real Estate [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Total revenues	2,564	2,302	4,919	3,200
Real Estate, Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues	8,452	11,132	15,492	19,031
Real Estate, Other [Member] | Transferred at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	8,452	11,132	15,492	19,031
1531 Operative Builders [Member] | Residential Real Estate [Member]
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
1531 Operative Builders [Member] | Real Estate, Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues	8,452	10,692	15,492	18,591
Individual Counterparty [Member] | Residential Real Estate [Member]
Disaggregation of Revenue [Line Items]
Total revenues	175,054	146,180	336,642	267,444
Individual Counterparty [Member] | Real Estate, Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues	0	440	0	440
Central | Residential Real Estate [Member]
Disaggregation of Revenue [Line Items]
Total revenues	79,168	68,892	163,593	141,338
Central | Real Estate, Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues	8,452	10,692	15,482	14,691
Southeast [Domain] | Residential Real Estate [Member]
Disaggregation of Revenue [Line Items]
Total revenues	95,886	77,288	173,049	126,106
Southeast [Domain] | Real Estate, Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues	0	440	10	4,340
Land development
Disaggregation of Revenue [Line Items]
Total revenues	8,452	10,692	15,482	14,691
Land development | Residential Real Estate [Member]
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Builder operations
Disaggregation of Revenue [Line Items]
Total revenues	175,054	146,620
Builder operations | Real Estate, Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues		400	0	4,300
Builder operations | Land and Lots [Member]
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Builder operations | Central
Disaggregation of Revenue [Line Items]
Total revenues	79,168	68,892
Builder operations | Southeast [Domain]
Disaggregation of Revenue [Line Items]
Total revenues	$ 95,886	$ 77,728	$ 173,059	$ 130,446