Business Segments (Tables)

12 Months Ended

Dec. 31, 2017

Segment Reporting [Abstract]

Business Segments (in thousands)

	Year ended			Three months ended			Year ended			Year ended
	December 31,			December 31,			September 30,			September 30,
	2017			2016			2016			2015
Revenues:
Asset management	$	29,873			7,321			28,739			27,570
Mining royalty lands		7,241			1,880			7,533			6,094
Land development and construction		1,230			311			1,185			982
RiverFront on the Anacostia		4,847			—			—			—
	$	43,191			9,512			37,457			34,646
Operating profit:
Before corporate expenses:
Asset management	$	13,799			3,509			13,374			13,288
Mining royalty lands		6,732			1,750			7,029			5,478
Land development and construction		(1,528	)		(400	)		(940	)		(2,197	)
RiverFront on the Anacostia		(2,018	)
Corporate expenses:
Allocated to asset management		(1,917	)		(485	)		(1,591	)		(1,248	)
Allocated to mining royalty		(167	)		(42	)		(231	)		(1,322	)
Allocated to land development and construction		(1,231	)		(328	)		(1,258	)		(737	)
Allocated to RiverFront on the Anacostia		(65	)
Unallocated to discontinued operations		—			—			—			(1,081	)
		(3,380	)		(855	)		(3,080	)		(4,388	)
	$	13,605			4,004			16,383			12,181
Interest expense:
Asset management	$	1,340			306			1,561			2,014
RiverFront on the Anacostia		2,983			—			—			—
	$	4,323			306			1,561			2,014
Depreciation, depletion and amortization:
Asset management	$	8,110			2,005			7,689			6,963
Mining royalty lands		110			35			104			133
Land development and construction		337			55			258			282
RiverFront on the Anacostia		4,975			—			—			—
	$	13,532			2,095			8,051			7,378
Capital expenditures:
Asset management	$	6,913			1,199			20,747			2,408
Mining royalty lands		—			2			205			—
Land development and construction		8,840			4,206			6,602			4,085
RiverFront on the Anacostia		857			—			—			—
	$	16,610			5,407			27,554			6,493
Identifiable net assets at end of period:
Asset management	$	179,654			169,736			170,562			151,023
Mining royalty lands		38,656			39,259			39,570			39,300
Land development and construction		46,684			57,126			54,157			60,682
RiverFront on the Anacostia		144,386			—			—			—
Cash items		4,524			—			—			419
Unallocated corporate assets		4,830			439			500			1,054
	$	418,734			266,560			264,789			252,478