Investment in Unconsolidated Ventures - Summarized Balance Sheet Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Venture Assets	$ 272,280	$ 279,674
Venture Borrowings	125,021	128,288
Venture Equity	133,922	141,802
Investment in venture	74,674	77,611
242, LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	23,014	26,503
Venture Borrowings	0	1,107
Venture Equity	22,822	23,136
Investment in venture	10,863	10,934
CL Ashton Woods, LP
Schedule of Equity Method Investments [Line Items]
Venture Assets	1,350	2,653
Venture Borrowings	0	0
Venture Equity	1,296	2,198
Investment in venture	939	1,107
CL Realty, LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	7,989	8,048
Venture Borrowings	0	0
Venture Equity	7,900	7,899
Investment in venture	3,950	3,950
CREA FMF Nashville LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	54,121	56,081
Venture Borrowings	35,844	37,446
Venture Equity	17,321	17,091
Investment in venture	4,850	4,923
Elan 99, LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	49,191	49,652
Venture Borrowings	36,356	36,238
Venture Equity	11,845	13,100
Investment in venture	10,659	11,790
FMF Littleton LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	70,541	70,282
Venture Borrowings	46,158	44,446
Venture Equity	23,618	23,798
Investment in venture	6,083	6,128
FMF Peakview LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	0	0
Venture Borrowings	0	0
Venture Equity	0	0
Investment in venture	0	0
FOR/SR Forsyth LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	11,195	10,672
Venture Borrowings	1,545	1,568
Venture Equity	9,627	8,990
Investment in venture	8,664	8,091
HM Stonewall Estates, Ltd
Schedule of Equity Method Investments [Line Items]
Venture Assets	0	852
Venture Borrowings	0	0
Venture Equity	0	852
Investment in venture	0	477
LM Land Holdings, LP
Schedule of Equity Method Investments [Line Items]
Venture Assets	24,211	25,538
Venture Borrowings	2,470	3,477
Venture Equity	13,162	20,945
Investment in venture	6,424	9,685
MRECV DT Holdings LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	3,855	4,155
Venture Borrowings	0	0
Venture Equity	3,855	4,144
Investment in venture	3,470	3,729
MRECV Edelweiss LLC/MRECV Lender VIII LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	7,283	3,484
Venture Borrowings	0	0
Venture Equity	7,283	3,484
Investment in venture	6,555	3,358
MREC VH Juniper Ridge LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	3,371	4,156
Venture Borrowings	0	0
Venture Equity	3,371	4,156
Investment in venture	3,034	3,741
MRECV Meadow Crossing II LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	2,850	2,492
Venture Borrowings	0	0
Venture Equity	2,850	2,491
Investment in venture	2,565	2,242
Miramonte Boulder Pass, LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	8,903	10,738
Venture Borrowings	2,648	4,006
Venture Equity	4,670	5,265
Investment in venture	4,467	5,330
Temco Associates, LLC
Schedule of Equity Method Investments [Line Items]
Venture Assets	4,406	4,368
Venture Borrowings	0	0
Venture Equity	4,302	4,253
Investment in venture	2,151	2,126
Other ventures
Schedule of Equity Method Investments [Line Items]
Venture Assets	0	0
Venture Borrowings	0	0
Venture Equity	0	0
Investment in venture	$ 0	$ 0