Discontinued Operations Discontinued Operations Assets and Liabilities Table (Details) - Oppenheimer Multi Family Housing And Healthcare Finance [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disposal Group, Including Discontinued Operation, Interest Income	$ 0	$ 8	$ 943
Disposal Group, Including Discontinued Operation, Principal Transactions	0	0	(9,022)
Disposal Group, including discontinued operations, Gain on Sale of Assets	0	0	16,475
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	0	2,165	16,917
Disposal Group, Including Discontinued Operation, Revenue	0	2,173	25,313
Disposal Group, Including Discontinued Operation, Compensation and Related Expenses	0	18	4,311
Disposal Group, Including Discontinued Operation, Communications and Technology	0	27	221
Disposal Group, Including Discontinued Operation, Occupancy and Equipment	0	0	415
Disposal Group, Including Discontinued Operation, Interest Expense	0	12	408
Disposal Group, Including Discontinued Operation, Other Expense	0	45	2,619
Disposal Group, Including Discontinued Operation, Operating Expense	0	102	7,974
Disposal Group, Including Discontinued Operation, Gross Profit (Loss)	0	2,071	17,339
Income (Loss) from Discontinued Operations, before tax, Attributable to Noncontrolling Interest	0	338	2,830
Disposal Group, Including Discontinued Operation, Communications and Technology	0	5,721	(14,097)
Cash Provided by (Used in) Investing Activities, Discontinued Operations	0	0	45,448
Cash Provided by (Used in) Financing Activities, Discontinued Operations	(372)	(20,035)	(35,421)
Net Cash Provided by (Used in) Discontinued Operations	$ (372)	$ (14,314)	$ (4,070)