Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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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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The difference between the carrying value and the sale price of an investment. A gain would be recognized when the sale price of the investment is greater than the carrying value of the investment. This element refers to the Gain included in earnings and not to the cash proceeds of the sale.

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For investments which are quantified by principal amount, the principle balance held at close of period.

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Balance held at close of period in number of shares.

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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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Dividends received on equity and other investments during the current period.

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Cash received on stock transaction after deduction of issuance costs.

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The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

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Price of a single share of a number of saleable stocks of a company.

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Represents the equity in unrealized gains or losses from investments in unconsolidated affiliates.

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Equity Method Investment, Fully Diluted Ownership Percentage

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Realized Gain From Transaction

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Significant Transactions - MediaAlpha (Details) - USD ($) $ / shares in Units, $ in Millions			12 Months Ended
	Oct. 30, 2020	Feb. 26, 2019	Dec. 31, 2019	Dec. 31, 2020
Other Significant Noncash Transactions [Line Items]
Realized gain from transaction			$ 67.5
Unrealized investment gain			$ 180.0
MediaAlpha
Other Significant Noncash Transactions [Line Items]
Proceeds from dividends received	$ 55.0
Ownership interest (as a percent)	35.00%
Fully diluted ownership interest (as a percent)	32.30%
Investment owned (in shares)	20,532,202
Share price (in USD per share)				$ 39.07
Investment owned, balance				$ 802.2
MediaAlpha \| IPO
Other Significant Noncash Transactions [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	3,609,894
Sale of stock, consideration received in transaction	$ 63.8
MediaAlpha
Other Significant Noncash Transactions [Line Items]
Proceeds from dividends received		$ 89.3
Realized gain from transaction		$ 67.5
Ownership interest (as a percent)		48.30%
Fully diluted ownership interest (as a percent)		42.00%
Assets, fair value		$ 114.7
Unrealized investment gain		114.7
Total realized and unrealized gain on sale of minority stake		$ 182.2