Stockholders' Equity - Narrative (Details) $ / shares in Units, $ in Millions		3 Months Ended	12 Months Ended
	Jan. 21, 2019 shares	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) vote $ / shares shares	Dec. 31, 2018 shares	Dec. 31, 2017 shares	Oct. 22, 2018 shares
Class of Stock [Line Items]
Shares repurchased in association with tax withholdings on the vesting of RSUs (in shares)			40,356	30,119	32,457
Payments for repurchase of capped call options | $		$ 36.5
Proceeds received from capped call options expirations | $			$ 38.9
Class A common stock
Class of Stock [Line Items]
Conversion of common stock (in shares)			1
Common stock number of votes | vote			1
Additional amount authorized to be repurchased						250,000,000
Class A common stock | Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Treasury stock acquired, average cost (in dollars per share) | $ / shares			$ 80.39
Adjustments related to tax withholding for share-based compensation | $			$ 3.2
Class A common stock | The 2016 Stock Repurchase Authorization
Class of Stock [Line Items]
Remaining authorized repurchase amount | $			$ 233.6
Class B common stock
Class of Stock [Line Items]
Percentage of Class B common to total common stock subject to automatic conversion			1.00%
Common stock number of votes | vote			10
Number of shares that were agreed to be converted (in shares)	1,000,000
Percent of shares required to be converted by the end of every two years	15.00%
Stock conversion, term	2 years
Percent of shares required to be converted by December 31, 2020	15.00%
Percent of shares required to be converted by December 31, 2022	30.00%
Percent of shares required to be converted by December 31, 2024	45.00%
Number of shares issued in transaction			600,000