Cash paid to purchase debt and equity securities, classified as operating activities, during the period; includes trading securities and any other investments classified as operating.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3536-108585

Name:	us-gaap_PaymentsForPurchaseOfSecuritiesOperatingActivities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Note 6 - CMBS Structured Pass Through Certificates (Details Textual) - Multifamily [Member] - USD ($) $ in Millions	Mar. 18, 2022	Feb. 03, 2022	Sep. 29, 2021	Jun. 11, 2021	May 04, 2021	Apr. 28, 2021
CMBS I/O Strip, Four [Member]
Payments for Purchase of Securities, Operating Activities					$ 15	$ 50
CMBS IO Strip Seven [Member]
Payments for Purchase of Securities, Operating Activities	$ 50	$ 40	$ 35	$ 80