Segment Information - Segment Revenues and Earnings (Detail) - USD ($) $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2015		Sep. 30, 2015	[1]	Jun. 30, 2015	[1]	Mar. 31, 2015	[1]	Dec. 31, 2014		Sep. 30, 2014	[1]	Jun. 30, 2014	[1]	Mar. 31, 2014	[1]	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenues		$ 114,018	[1]	$ 43,168		$ 57,430		$ 47,805		$ 80,316	[1]	$ 58,840		$ 83,013		$ 84,605		$ 262,421	$ 306,774	$ 331,045
Depreciation, depletion and amortization																		45,085	41,715	29,980
Equity in earnings of unconsolidated ventures		4,470	[1]	$ 2,909		$ 5,584		$ 3,045		4,720	[1]	$ 2,016		$ 958		$ 991		16,008	8,685	8,737
Income (loss) before taxes																		(180,412)	25,240	36,529
Total assets		980,513								1,258,199								980,513	1,258,199	1,172,152
Investment in unconsolidated ventures		82,453								65,005								82,453	65,005	41,147
Capital expenditures	[2]																	64,407	138,798	107,897
Operating Segments [Member] | Real Estate [Member]
Segment Reporting Information [Line Items]
Revenues																		202,830	213,112	248,011
Depreciation, depletion and amortization																		7,605	3,741	3,117
Equity in earnings of unconsolidated ventures																		15,582	8,068	8,089
Income (loss) before taxes																		67,678	96,906	68,454
Total assets		691,406								654,774								691,406	654,774	582,802
Investment in unconsolidated ventures		82,453								65,005								82,453	65,005	41,147
Capital expenditures	[2]																	13,644	28,980	7,265
Operating Segments [Member] | Oil and Gas [Member]
Segment Reporting Information [Line Items]
Revenues																		52,939	84,300	72,313
Depreciation, depletion and amortization																		28,774	29,442	19,552
Equity in earnings of unconsolidated ventures																		275	586	592
Income (loss) before taxes																		(184,396)	(22,686)	18,859
Total assets		144,436								342,703								144,436	342,703	312,553
Investment in unconsolidated ventures		0								0								0	0	0
Capital expenditures	[2]																	49,776	103,385	97,696
Operating Segments [Member] | Other Natural Resources [Member]
Segment Reporting Information [Line Items]
Revenues																		6,652	9,362	10,721
Depreciation, depletion and amortization																		540	497	651
Equity in earnings of unconsolidated ventures																		151	31	56
Income (loss) before taxes																		(608)	5,499	6,507
Total assets		19,106								22,531								19,106	22,531	23,478
Investment in unconsolidated ventures		0								0								0	0	0
Capital expenditures	[2]																	745	5,817	2,720
Items Not Allocated To Segments [Member]
Segment Reporting Information [Line Items]
Revenues																		0	0	0
Depreciation, depletion and amortization																		8,166	8,035	6,660
Equity in earnings of unconsolidated ventures																		0	0	0
Income (loss) before taxes	[3]																	(63,086)	(54,479)	(57,291)
Total assets		125,565								238,191								125,565	238,191	253,319
Investment in unconsolidated ventures		$ 0								$ 0								0	0	0
Capital expenditures	[2]																	$ 242	$ 616	$ 216

[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] Consists of expenditures for oil and gas properties and equipment, commercial and income producing properties, property, plant and equipment and reforestation of timber.

[3] Items not allocated to segments consist of: For the Year 2015 2014 2013 (In thousands)General and administrative expense$(24,802) $(21,229) $(20,597)Share-based and long-term incentive compensation expense(4,474) (3,417) (16,809)Interest expense(34,066) (30,286) (20,004)Other corporate non-operating income256 453 119 $(63,086) $(54,479) $(57,291)