Net Income (Loss) Per Share - Potentially Dilutive Securities Excluded from the Computation of Diluted Net Income Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net income per unit (in shares)	5,040	7,352	5,725
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net income per unit (in shares)	0	2,228	31
Shares of Class B and Class C common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net income per unit (in shares)	0	191,426	216,569