Common Stock and Treasury Stock (Details) - shares shares in Thousands |
9 Months Ended | 12 Months Ended |
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Sep. 30, 2018 |
Dec. 31, 2017 |
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Class A Common Stock [Member] | ||
Common Stock [Line Items] | ||
Balance, shares | 6,694 | 6,638 |
Conversion of shares | 17 | |
Issuance of restricted stock | 4 | 19 |
Forfeiture of restricted stock | (1) | (1) |
Exercise of stock options | 21 | |
Balance, shares | 6,697 | 6,694 |
Class B Common Stock [Member] | ||
Common Stock [Line Items] | ||
Balance, shares | 898 | 878 |
Conversion of shares | (17) | |
Issuance of restricted stock | 0 | 29 |
Forfeiture of restricted stock | 0 | 0 |
Exercise of stock options | 8 | |
Balance, shares | 898 | 898 |
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- References No definition available.
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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. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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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. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Number of shares related to Restricted Stock Award forfeited during the period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Number of shares issued during the period related to Restricted Stock Awards, net of any shares forfeited. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Number of share options (or share units) exercised during the current period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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