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Investments in Unconsolidated Affiliates (Details)	Dec. 31, 2018	Jan. 24, 2018	Dec. 31, 2017
DavidShield & PassportCard
Investments in and Advances to Affiliates [Line Items]
Ownership interest (as a percent)	50.00%
Kudu
Investments in and Advances to Affiliates [Line Items]
Ownership interest (as a percent)	49.50%		0.00%
YOUSURE Tarifvergleich GmbH “durchblicker”
Investments in and Advances to Affiliates [Line Items]
Ownership interest (as a percent)	45.00%		45.00%
Compare.com
Investments in and Advances to Affiliates [Line Items]
Ownership interest (as a percent)	18.40%		22.10%
Tuckerman Capital Fund III, L.P.
Investments in and Advances to Affiliates [Line Items]
Ownership interest (as a percent)	18.50%		21.30%
DavidShield
Investments in and Advances to Affiliates [Line Items]
Ownership interest (as a percent)	50.00%	50.00%
PassportCard
Investments in and Advances to Affiliates [Line Items]
Ownership interest (as a percent)	25.00%	50.00%	50.00%
White Mountains | DavidShield
Investments in and Advances to Affiliates [Line Items]
Ownership interest (as a percent)	25.00%

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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