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Stock Buy Back Plans | 12 Months Ended
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Dec. 31, 2017
Equity [Abstract] |
Stock Buy Back Plans | NOTE 15. Stock Buy Back Plans On February 2, 2016, our Board of Directors authorized the purchase of up to $100 million of our Class A Common Stock. This authorization expired on December 31, 2016. We purchased 2,672,227 shares under this authorization during the year ended December 31, 2016, completing the authorization. There was no purchase authorized in 2017.

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- Definition The entire disclosure for treasury stock, including, but not limited to, average cost per share, description of share repurchase program, shares repurchased, shares held for each class of treasury stock. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -URI http://asc.fasb.org/subtopic&trid=2208821 + Details
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