Investment in Unconsolidated Ventures - Summarized Balance Sheet Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Venture Assets	$ 287,479	$ 309,067
Venture Borrowings	126,059	134,103
Venture Equity	145,521	154,738
Investment in venture	79,564	82,453
242, LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	27,110	26,687
Venture Borrowings	3,182	0
Venture Equity	21,428	24,877
Investment in venture	10,048	11,766
CL Ashton Woods, LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	4,426	7,654
Venture Borrowings	0	0
Venture Equity	3,685	6,084
Investment in venture	2,107	3,615
CL Realty, LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	7,913	7,872
Venture Borrowings	0	0
Venture Equity	7,798	7,662
Investment in venture	3,899	3,831
CREA FMF Nashville LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	56,117	57,820
Venture Borrowings	37,192	50,845
Venture Equity	17,297	4,291
Investment in venture	4,984	3,820
Elan 99, LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	49,671	34,192
Venture Borrowings	32,461	14,587
Venture Equity	13,628	15,838
Investment in venture	12,265	14,255
FOR/SR Forsyth LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	9,584	6,500
Venture Borrowings	0	0
Venture Equity	9,016	6,500
Investment in venture	8,115	5,850
FMF Littleton LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	70,704	52,376
Venture Borrowings	42,083	22,347
Venture Equity	23,838	24,370
Investment in venture	6,138	6,270
FMF Peakview LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	0	48,869
Venture Borrowings	0	30,485
Venture Equity	0	16,828
Investment in venture	0	3,447
HM Stonewall Estates, Ltd
Schedule of Equity Method Investments [Line Items]
Venture Assets	814	2,842
Venture Borrowings	0	0
Venture Equity	814	2,842
Investment in venture	814	1,294
LM Land Holdings, LP
Schedule of Equity Method Investments [Line Items]
Venture Assets	29,350	31,984
Venture Borrowings	4,481	7,728
Venture Equity	23,762	22,751
Investment in venture	10,770	9,664
MRECV DT Holdings LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	4,039	4,215
Venture Borrowings	0	0
Venture Equity	4,039	4,215
Investment in venture	3,635	3,807
MRECV Edelweiss LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	2,816	2,237
Venture Borrowings	0	0
Venture Equity	2,816	2,237
Investment in venture	2,764	2,029
MREC VH Juniper Ridge LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	4,403	3,006
Venture Borrowings	0	0
Venture Equity	4,403	3,006
Investment in venture	3,882	2,730
MRECV Meadow Crossing II LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	2,366	728
Venture Borrowings	0	0
Venture Equity	2,366	728
Investment in venture	2,129	655
Miramonte Boulder Pass, LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	12,783	12,627
Venture Borrowings	6,660	5,869
Venture Equity	5,380	5,474
Investment in venture	5,387	5,349
Temco Associates, LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	5,357	5,284
Venture Borrowings	0	0
Venture Equity	5,225	5,113
Investment in venture	2,612	2,557
Other ventures
Schedule of Equity Method Investments [Line Items]
Venture Assets	26	4,174
Venture Borrowings	0	2,242
Venture Equity	26	1,922
Investment in venture	$ 15	$ 1,514