| Earnings Per Share - Narrative (Details) shares in Thousands | 9 Months Ended | |
|---|---|---|
| Oct. 11, 2016 | Sep. 30, 2017  shares | |
| Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] | ||
| Number of shares out-of-the-money (in shares) | 356 | |
| Convertible Class B Stock | ||
| Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] | ||
| Common stock conversion | 0.15 | |
| Date of payment of dividend to shareholders | Oct. 11, 2016 | 
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- Definition Common Stock, Conversion Ratio No definition available. 
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- Definition Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format. No definition available. 
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- Definition 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. No definition available. 
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- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
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