Income Taxes (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012 item	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012 item	Dec. 31, 2011
Provision for income taxes from continuing operations
U.S. state current income tax expense									$ 593,000	$ 158,000
Foreign current income tax expense									317,000	3,164,000
Foreign deferred income tax expense									64,000	380,000
Total	195,000	(59,000)	5,000	833,000	1,655,000	421,000	1,024,000	602,000	974,000	3,702,000
Reconciliation of provision for income taxes to the expected income tax expense at the U.S. federal statutory income tax rate
U.S. federal income tax rate (as a percent)									35.00%
Computed expected tax based on federal statutory rate									5,112,000	9,936,000
Expired capital loss carryforward										17,701,000
Change in valuation allowance									(4,611,000)	(22,316,000)
Inclusion of income attributable to noncontrolling interest in an 80%-owned subsidiary									94,000	220,000
Change in tax credit carryforwards									(501,000)	(4,955,000)
Other									(94,000)	(586,000)
U.S. state and foreign income tax									974,000	3,702,000
Total	195,000	(59,000)	5,000	833,000	1,655,000	421,000	1,024,000	602,000	974,000	3,702,000
Ownership percentage of subsidiaries for whom the company has noncontrolling interest	80.00%								80.00%
Deferred tax assets (liabilities):
Basis difference in Acquisition Partnership investments	17,509,000				19,533,000				17,509,000	19,533,000
Intangibles, principally due to differences in amortization	264,000				283,000				264,000	283,000
Basis difference in property and equipment	143,000				128,000				143,000	128,000
Foreign non-repatriated earnings	1,215,000				(4,151,000)				1,215,000	(4,151,000)
Federal net operating loss carryforwards	2,725,000				11,749,000				2,725,000	11,749,000
Tax credit carryforwards	5,456,000				4,955,000				5,456,000	4,955,000
Other	640,000				67,000				640,000	67,000
Total deferred tax assets, net	27,952,000				32,564,000				27,952,000	32,564,000
Valuation allowance	(27,952,000)				(32,564,000)				(27,952,000)	(32,564,000)
Net deferred tax assets	0								0
Income Taxes
Net operating loss carryforwards for federal income tax purposes	7,800,000								7,800,000
Number of states in which the entity files tax returns	39								39
Number of consolidated subsidiaries currently subject to income tax examination	1								1
Number of states in which consolidated subsidiaries currently examined	1								1
Foreign
Income Taxes
Deferred foreign tax liabilities	$ 0				$ 100,000				$ 0	$ 100,000