Capital Stock	3 Months Ended
Mar. 31, 2018
Equity [Abstract]
Capital Stock	Capital Stock The Company had 34,067,912 shares of Class A common stock and 22,631,503 shares of Class B common stock outstanding as of March 31, 2018. The Company had 33,560,202 shares of Class A common stock and 22,905,357 shares of Class B common stock outstanding as of December 31, 2017. During the three months ended March 31, 2018, the Company did not repurchase any shares of its Class A common stock. All other stock repurchases during the three months ended March 31, 2018 and 2017 were redemptions of vested restricted shares tendered in lieu of cash for payment of income tax withholding amounts by participants in the Company's equity compensation plans.

Capital Stock

3 Months Ended

Mar. 31, 2018

The Company had 34,067,912 shares of Class A common stock and 22,631,503 shares of Class B common stock outstanding as of March 31, 2018. The Company had 33,560,202 shares of Class A common stock and 22,905,357 shares of Class B common stock outstanding as of December 31, 2017.

During the three months ended March 31, 2018, the Company did not repurchase any shares of its Class A common stock. All other stock repurchases during the three months ended March 31, 2018 and 2017 were redemptions of vested restricted shares tendered in lieu of cash for payment of income tax withholding amounts by participants in the Company's equity compensation plans.