Stockholders' Deficit - Share Repurchases (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Class of Stock [Line Items]
Stock repurchased during period, value		$ 42,717	$ 26,527	$ 90,073
2019 Repurchase Program
Class of Stock [Line Items]
Stock repurchased during period (in shares)	0		459,899
Stock repurchased during period, value	$ 0		$ 26,500
Cumulative amount of shares repurchased (in shares)	1,697,597		1,697,597
Cumulative payments for repurchase of common stock	$ 129,800		$ 129,800
Remaining dollar value of shares that may be repurchased	$ 70,200		$ 70,200