Investments - Dun And Bradstreet (Details) - USD ($)		1 Months Ended
Feb. 08, 2019	Apr. 30, 2019
Dun And Bradstreet Corporation \| Dun And Bradstreet Corporation
Business Acquisition [Line Items]
Additional amount syndicated of Dun & Bradstreet Investment		$ 2,600,000
Ownership (as a percent)		24.30%
Dun And Bradstreet Corporation
Business Acquisition [Line Items]
Common equity financed from Consortium and Black Knight, Inc.	$ 2,100,000,000
Financed by preferred equity from preferred equity sources	1,100,000,000
Debt financing from various lenders	4,000,000,000.0
Dun And Bradstreet Corporation \| Cannae \| Commitment To Purchase Common Equity of Dun And Bradstreet
Business Acquisition [Line Items]
Commitment to purchase	$ 900,000,000.0
Percentage of outstanding common equity	24.50%
Syndication fee income	$ 9,100,000
Dun And Bradstreet Corporation \| Cannae \| Equity Commitment to Purchase, Retained And Funded
Business Acquisition [Line Items]
Commitment to purchase	$ 505,600,000

Business Combination, Consideration Transferred, Common Equity From Consortium

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Business Combination, Consideration Transferred, From Debt Financing, Various Lenders

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Business Combination, Consideration Transferred, Preferred Equity From Preferred Equity Sources

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Other Commitment, Percentage Of Outstanding Common Equity

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

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The cash inflow associated with the sale of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

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