Treasury Stock	12 Months Ended
Dec. 31, 2020
Equity [Abstract]
Treasury Stock	(14) Treasury Stock The Board of Directors has authorized the Company’s repurchase of up to an aggregate of $800.0 million of its class A common stock from time to time on the open market through April 29, 2023 under the Share Repurchase Program, although the program may be suspended or discontinued by the Company at any time. The timing and amount of any shares repurchased will be determined by the Company’s management based on its evaluation of market conditions and other factors. The Share Repurchase Program may be funded using the Company’s working capital, as well as proceeds from any other funding arrangements that the Company may enter into in the future. During 2020, the Company repurchased an aggregate of 444,769 shares of its class A common stock at an average price per share of $139.12 and an aggregate cost of $61.9 million pursuant to the Share Repurchase Program. During 2019, the Company repurchased an aggregate of 521,843 shares of its class A common stock at an average price per share of $139.35 and an aggregate cost of $72.7 million pursuant to the Share Repurchase Program. During 2018, the Company repurchased an aggregate of 880,667 shares of its class A common stock at an average price per share of $126.02 and an aggregate cost of $111.0 million pursuant to the Share Repurchase Program. As of December 31, 2020, the Company had repurchased an aggregate of 5,674,226 shares of its class A common stock at an average price per share of $104.13 and an aggregate cost of $590.9 million pursuant to the Share Repurchase Program. As of December 31, 2020, $209.1 million of the Company’s class A common stock remained available for repurchase pursuant to the Share Repurchase Program. The average price per share and aggregate cost amounts disclosed above include broker commissions. On August 11, 2020, the Company announced that it commenced an offer to purchase up to $250.0 million in value of shares of its issued and outstanding class A common stock, or such lesser number of shares as are properly tendered and not properly withdrawn, at a price not greater than $140.00 nor less than $122.00 per share (the “Offer”). The Offer expired at 5:00 p.m., New York City time, on September 10, 2020. During the year ended December 31, 2020, the Company repurchased an aggregate of 432,313 shares of its class A common stock through the Offer at a price of $140.00 per share for an aggregate cost of $61.3 million, inclusive of $0.8 million in certain fees and expenses related to the Offer.

Treasury Stock

12 Months Ended

Dec. 31, 2020

(14) Treasury Stock

The Board of Directors has authorized the Company’s repurchase of up to an aggregate of $800.0 million of its class A common stock from time to time on the open market through April 29, 2023 under the Share Repurchase Program, although the program may be suspended or discontinued by the Company at any time. The timing and amount of any shares repurchased will be determined by the Company’s management based on its evaluation of market conditions and other factors. The Share Repurchase Program may be funded using the Company’s working capital, as well as proceeds from any other funding arrangements that the Company may enter into in the future. During 2020, the Company repurchased an aggregate of 444,769 shares of its class A common stock at an average price per share of $139.12 and an aggregate cost of $61.9 million pursuant to the Share Repurchase Program. During 2019, the Company repurchased an aggregate of 521,843 shares of its class A common stock at an average price per share of $139.35 and an aggregate cost of $72.7 million pursuant to the Share Repurchase Program. During 2018, the Company repurchased an aggregate of 880,667 shares of its class A common stock at an average price per share of $126.02 and an aggregate cost of $111.0 million pursuant to the Share Repurchase Program. As of December 31, 2020, the Company had repurchased an aggregate of 5,674,226 shares of its class A common stock at an average price per share of $104.13 and an aggregate cost of $590.9 million pursuant to the Share Repurchase Program. As of December 31, 2020, $209.1 million of the Company’s class A common stock remained available for repurchase pursuant to the Share Repurchase Program. The average price per share and aggregate cost amounts disclosed above include broker commissions.

On August 11, 2020, the Company announced that it commenced an offer to purchase up to $250.0 million in value of shares of its issued and outstanding class A common stock, or such lesser number of shares as are properly tendered and not properly withdrawn, at a price not greater than $140.00 nor less than $122.00 per share (the “Offer”). The Offer expired at 5:00 p.m., New York City time, on September 10, 2020. During the year ended December 31, 2020, the Company repurchased an aggregate of 432,313 shares of its class A common stock through the Offer at a price of $140.00 per share for an aggregate cost of $61.3 million, inclusive of $0.8 million in certain fees and expenses related to the Offer.