Common Stock and Treasury Stock - Information Relating to the Number of Shares of Our Common Stock Issued (Details) - shares shares in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Class A Common Stock
Common Stock [Line Items]
Balance, shares	6,771	6,771	6,732
Conversion of shares			13
Issuance of restricted stock			29
Forfeiture of restricted stock (in shares)	(2)	(2)	(3)
Balance, shares	6,769	6,769	6,771
Class B Common Stock
Common Stock [Line Items]
Balance, shares	954	954	923
Conversion of shares			(13)
Issuance of restricted stock			44
Forfeiture of restricted stock (in shares)		0	0
Balance, shares	954	954	954

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- Definition

The number of new shares issued in the conversion of stock in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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- Definition

Number of shares of stock issued as of the balance sheet date, including shares that had been issued and were previously outstanding but which are now held in the treasury.

+ References

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Number of shares related to Restricted Stock Award forfeited during the period.

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Number of shares issued during the period related to Restricted Stock Awards, net of any shares forfeited.

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