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Equity-Method Eligible Investments - Significant Equity Method Eligible Investments (Details)	Mar. 31, 2021	Dec. 31, 2020	May 07, 2020	May 06, 2020
PassportCard/DavidShield
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	53.80%	53.80%	53.80%	50.00%
New Market Solutions, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	46.70%	46.70%
durchblicker
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	45.00%	45.00%
MediaAlpha
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	28.50%	35.00%
Elementum Holdings L.P.
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	29.70%	28.90%
Compare.com
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	18.40%	18.40%
Minimum | Tuckerman Capital Funds
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	16.10%	14.90%
Minimum | Enlightenment Capital Funds
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	9.10%	9.70%
Minimum | Kudu Investments
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	3.20%	3.20%
Maximum | Tuckerman Capital Funds
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	30.00%	62.00%
Maximum | Enlightenment Capital Funds
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	66.30%	66.70%
Maximum | Kudu Investments
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	35.60%	35.00%

X

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

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+ References

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