Fair Value Disclosures (Schedule Of Assets And Liabilities Measured With Level 3 Inputs) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Schedule of additional information about assets and liabilities measured at fair value on a recurring basis level 3 inputs
Level 3 inputs, Beginning balance		$ 2,522	$ 2,756
Net trading		(78)
Gains and losses	[1]	(603)	(33)
Accretion of income	[1]	78	106
Purchases		609
Sales and returns of capital		(2,973)	(50)
Reclassification of RTLs		5,278
Level 3 inputs, Ending balance		4,833	2,779
Change in unrealized gains /(losses)	[2]	$ (385)	$ (33)

[1] Gains and losses and accretion of income on other investments, at fair value are recorded as a component of principal transactions and other income in the consolidated statements of operations.

[2] Represents the change in unrealized gains and losses for the period included in earnings for assets held at the end of the reporting period.