Borrowing Facilities (Borrowings Under the Facility) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Borrowing Facilities [Abstract]
Total available under the financing arrangement	$ 55,000	$ 55,000
Amount borrowed by affiliated partnerships and limited liability companies under the venture, acquisition, and warehouse facilities	(1,849)	(850)
Total remaining available under the working capital, acquisition and warehouse facilities	$ 53,151	$ 54,150

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant