Investment in Unconsolidated Ventures - Summarized Income Statement Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Schedule of Equity Method Investments [Line Items]
Revenues	$ 23,114	$ 6,621	$ 45,750	$ 11,464
Earnings (loss)	6,327	404	18,548	101
Equity in earnings of unconsolidated ventures	2,747	188	9,109	235
242, LLC
Schedule of Equity Method Investments [Line Items]
Revenues	0	0	13,073	0
Earnings (loss)	(83)	(164)	8,382	(464)
Equity in earnings of unconsolidated ventures	(41)	(82)	4,277	(232)
CL Ashton Woods, LLC
Schedule of Equity Method Investments [Line Items]
Revenues	846	993	2,628	1,689
Earnings (loss)	348	151	1,098	518
Equity in earnings of unconsolidated ventures	473	324	1,432	763
CL Realty, LLC
Schedule of Equity Method Investments [Line Items]
Revenues	0	113	199	246
Earnings (loss)	(64)	17	2,401	64
Equity in earnings of unconsolidated ventures	(32)	8	1,200	31
CREA FMF Nashville LLC
Schedule of Equity Method Investments [Line Items]
Revenues	1,465	1,081	2,870	1,982
Earnings (loss)	(150)	(498)	(320)	(1,069)
Equity in earnings of unconsolidated ventures	(43)	(149)	(97)	(320)
Elan 99, LLC
Schedule of Equity Method Investments [Line Items]
Revenues	1,026	147	1,928	167
Earnings (loss)	(601)	(934)	(1,254)	(1,344)
Equity in earnings of unconsolidated ventures	(541)	(841)	(1,129)	(1,210)
FMF Littleton LLC
Schedule of Equity Method Investments [Line Items]
Revenues	1,596	526	3,011	847
Earnings (loss)	(15)	(178)	(180)	(348)
Equity in earnings of unconsolidated ventures	(4)	(44)	(45)	(86)
FMF Peakview LLC
Schedule of Equity Method Investments [Line Items]
Revenues	0	0	0	939
Earnings (loss)	0	0	0	(248)
Equity in earnings of unconsolidated ventures	0	0	0	(50)
FOR/SR Forsyth LLC
Schedule of Equity Method Investments [Line Items]
Revenues	0	0	0	0
Earnings (loss)	(36)	(17)	(68)	(17)
Equity in earnings of unconsolidated ventures	(33)	(15)	(61)	(15)
HM Stonewall Estates, Ltd
Schedule of Equity Method Investments [Line Items]
Revenues	0	580	496	1,126
Earnings (loss)	0	294	243	514
Equity in earnings of unconsolidated ventures	0	124	103	227
LM Land Holdings, LP
Schedule of Equity Method Investments [Line Items]
Revenues	15,880	2,026	16,933	3,026
Earnings (loss)	5,589	1,415	6,217	2,055
Equity in earnings of unconsolidated ventures	1,774	501	1,989	645
MRECV DT Holdings LLC
Schedule of Equity Method Investments [Line Items]
Revenues	287	119	588	217
Earnings (loss)	287	117	586	215
Equity in earnings of unconsolidated ventures	259	105	528	193
MRECV Edelweiss LLC/MRECV Lender VIII LLC
Schedule of Equity Method Investments [Line Items]
Revenues	238	94	423	181
Earnings (loss)	237	87	422	174
Equity in earnings of unconsolidated ventures	214	78	380	156
MREC VH Juniper Ridge LLC
Schedule of Equity Method Investments [Line Items]
Revenues	597	202	610	205
Earnings (loss)	597	203	610	206
Equity in earnings of unconsolidated ventures	537	183	549	186
MRECV Meadow Crossing II LLC
Schedule of Equity Method Investments [Line Items]
Revenues	237	29	359	29
Earnings (loss)	236	16	358	(18)
Equity in earnings of unconsolidated ventures	212	14	322	(17)
Miramonte Boulder Pass, LLC
Schedule of Equity Method Investments [Line Items]
Revenues	894	663	2,536	663
Earnings (loss)	(40)	(34)	4	(159)
Equity in earnings of unconsolidated ventures	(38)	(17)	(363)	(79)
Temco Associates, LLC
Schedule of Equity Method Investments [Line Items]
Revenues	48	48	96	147
Earnings (loss)	22	12	49	79
Equity in earnings of unconsolidated ventures	10	6	24	40
Other ventures
Schedule of Equity Method Investments [Line Items]
Revenues	0	0	0	0
Earnings (loss)	0	(83)	0	(57)
Equity in earnings of unconsolidated ventures	$ 0	$ (7)	$ 0	$ 3