Commitments, Contingencies and Other Regulatory Matters (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2003	Dec. 31, 2019
Loss Contingencies [Line Items]
Unfunded contingent investment commitments		$ 43
Certificates of deposit scheduled to mature in less than one year.		$ 14
Axajo Complaint [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Awarded, Value	$ 1

Amount of damages awarded to the plaintiff in the legal matter.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14557-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14435-108349

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration