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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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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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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Investments in Affiliates Accounted for Using the Equity Method (Investment in Lending Tree) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Carrying amount	$ 121,880		$ 121,880		$ 114,655
Share of earnings (losses)	$ 10,350	$ 1,600	$ 7,858	$ 3,323
LendingTree
Schedule of Equity Method Investments [Line Items]
Percentage ownership	25.89%		25.89%
Market value	$ 689,289		$ 689,289
Carrying amount	116,554		116,554		114,655
Share of earnings (losses)	7,700	$ 1,600	5,300	$ 3,300
Other
Schedule of Equity Method Investments [Line Items]
Carrying amount	$ 5,326		$ 5,326		$ 0