Investments and other assets - Narrative (Details) - USD ($)	3 Months Ended
Mar. 31, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Investment balance	$ 36,646,000	$ 27,650,000
Gain on other equity investments	$ 0
CareerBuilder
Schedule of Equity Method Investments [Line Items]
Equity method investment retained after disposal, ownership interest (as a percent)	17.00%
Equity method investment retained after disposal, fully diluted ownership interest (as a percent)	10.00%
After-tax gain on sale of equity method investment	$ 12,100,000
Investment balance	$ 17,400,000	$ 7,900,000

Discontinued Operation, Equity Method Investment Retained after Disposal, Ownership Interest after Disposal, Diluted

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- Definition

Percent, after disposal, of ownership interest of a discontinued operation in which an equity method investment is retained.

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- Definition

Amount of gain (loss) on sale or disposal of an equity method investment.

+ References

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Amount of unrealized and realized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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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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No definition available.

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