Investment In Unconsolidated Ventures - Summarized Income Statement Information (Detail) - USD ($) $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2015	[1]	Sep. 30, 2015	[1]	Jun. 30, 2015	[1]	Mar. 31, 2015	[1]	Dec. 31, 2014	[1]	Sep. 30, 2014	[1]	Jun. 30, 2014	[1]	Mar. 31, 2014	[1]	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]
Revenues																		$ 125,729	$ 42,443	$ 51,983
Earnings (Loss)																		59,320	25,288	16,662
Our share of earnings (loss)		$ 4,470		$ 2,909		$ 5,584		$ 3,045		$ 4,720		$ 2,016		$ 958		$ 991		16,008	8,685	8,737
242, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Revenues	[2]																	20,995	5,612	6,269
Earnings (Loss)	[2]																	9,588	2,951	1,512
Our share of earnings (loss)	[2]																	4,919	1,514	805
CJUF III, RH Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Revenues	[3]																	0	2,168	120
Earnings (Loss)	[3]																	0	(956)	(652)
Our share of earnings (loss)	[3]																	0	(956)	(652)
CL Ashton Woods [Member]
Schedule of Equity Method Investments [Line Items]
Revenues	[4]																	9,820	5,431	9,018
Earnings (Loss)	[4]																	3,881	1,748	2,660
Our share of earnings (loss)	[4]																	5,000	2,471	4,169
CL Realty [Member]
Schedule of Equity Method Investments [Line Items]
Revenues																		856	1,573	1,603
Earnings (Loss)																		424	1,068	1,028
Our share of earnings (loss)																		212	534	514
CREA FMF [Member]
Schedule of Equity Method Investments [Line Items]
Revenues	[2]																	1,227	0	0
Earnings (Loss)	[2]																	(1,696)	(163)	0
Our share of earnings (loss)	[2]																	(1,696)	(163)	0
Elan 99 LLC [Member]
Schedule of Equity Method Investments [Line Items]
Revenues																		0	0	0
Earnings (Loss)																		(49)	(87)	0
Our share of earnings (loss)																		(44)	(78)	0
FMF Littleton [Member]
Schedule of Equity Method Investments [Line Items]
Revenues																		120	0	0
Earnings (Loss)																		(367)	(239)	0
Our share of earnings (loss)																		(92)	(60)	0
FMF Peakview [Member]
Schedule of Equity Method Investments [Line Items]
Revenues																		2,057	4	1
Earnings (Loss)																		(1,116)	(410)	(252)
Our share of earnings (loss)																		(223)	(83)	(50)
FOR/SR Forsyth LLC [Member]
Schedule of Equity Method Investments [Line Items]
Revenues																		0	0	0
Earnings (Loss)																		0	0	0
Our share of earnings (loss)																		0	0	0
HM Stonewall Estates [Member]
Schedule of Equity Method Investments [Line Items]
Revenues	[4]																	3,990	1,728	2,922
Earnings (Loss)	[4]																	1,881	613	1,082
Our share of earnings (loss)	[4]																	952	248	452
LM Land Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Revenues	[4]																	10,956	21,980	25,426
Earnings (Loss)	[4]																	8,251	15,520	11,012
Our share of earnings (loss)	[4]																	3,342	4,827	3,418
MRECV DT Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Revenues																		0	0	0
Earnings (Loss)																		167	0	0
Our share of earnings (loss)																		0	0	0
MRECV Edelweiss LLC [Member]
Schedule of Equity Method Investments [Line Items]
Revenues																		0	0	0
Earnings (Loss)																		151	0	0
Our share of earnings (loss)																		137	0	0
MRECV Juniper Ridge LLC [Member]
Schedule of Equity Method Investments [Line Items]
Revenues																		0	0	0
Earnings (Loss)																		106	0	0
Our share of earnings (loss)																		0	0	0
Miramonte Boulder Pass, LLC [Member] [Domain]
Schedule of Equity Method Investments [Line Items]
Revenues																		0	0	0
Earnings (Loss)																		(250)	0	0
Our share of earnings (loss)																		(125)	0	0
PSW Communities [Member]
Schedule of Equity Method Investments [Line Items]
Revenues																		29,986	0	0
Earnings (Loss)																		2,688	(86)	0
Our share of earnings (loss)																		1,169	(76)	0
Temco [Member]
Schedule of Equity Method Investments [Line Items]
Revenues																		9,485	2,155	630
Earnings (Loss)																		2,358	494	96
Our share of earnings (loss)																		1,179	247	48
Other Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Revenues																		36,237	1,792	5,994
Earnings (Loss)																		33,303	4,835	176
Our share of earnings (loss)																		$ 1,278	$ 260	$ 33

[1] Non-cash impairment charges for unproved leasehold interests and proved oil and gas properties included in our quarterly financial results are as follows: First Quarter Second Quarter Third Quarter FourthQuarter (In thousands)2015$7 $45,938 $81,240 $37,6462014755 584 735 30,591

[2] Includes unamortized deferred gains on real estate contributed by us to ventures. We recognize deferred gains as income as real estate is sold to third parties. Deferred gains of $1,496,000 are reflected as a reduction to our investment in unconsolidated ventures at year-end 2015.

[3] In 2014, we acquired full ownership in the Eleven venture for $21,500,000. The acquisition-date fair value was $55,275,000, including debt of $23,936,000. Our investment in the Eleven venture prior to acquiring our partner’s interest was $2,229,000.

[4] Includes unrecognized basis difference of $34,000 which is reflected as a reduction of our investment in unconsolidated ventures at year-end 2015. This difference between estimated fair value of the equity investment and our capital account within the respective ventures at closing will be accreted as income or expense over the life of the investment and included in our share of earnings (loss) from the respective ventures.