Stockholders' Equity - Schedule of Stock Option and Restricted Stock Activity (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2020	Dec. 31, 2019
Number of shares available for issuance under the Plans
Beginning balance (in shares)	66.2
Additional shares authorized (in shares)	21.7
Options and RSUs canceled (in shares)	5.9
Shares repurchased for tax withholdings on release of restricted stock (unaudited) (in shares)	2.2
Restricted stock granted (in shares)	(20.8)
Ending balance (in shares)	75.2	66.2
Options Outstanding, Number of shares outstanding under the Plans
Beginning balance (in shares)	2.0
Options exercised (in shares)	(0.3)
Options canceled (in shares)	(0.2)
Options granted (in shares)	0.0
Ending balance (in shares)	1.5	2.0
Vested during period (in shares)	1.0
Unvested at end of period (in shares)			0.5
Options Outstanding, Weighted- average exercise price per share
Beginning balance (in dollars per share)	$ 12.28
Options exercised (in dollars per share)	4.77
Options canceled (in dollars per share)	17.40
Options granted (in dollars per share)	0
Ending balance (in dollars per share)	13.37	$ 12.28
Vested during period (in dollars per share)	$ 16.47
Unvested at end of period (in dollars per shares)			$ 5.55
Options Outstanding, Weighted- average remaining contractual term (In years)
Weighted-average contractual term	6 years 2 months 12 days	6 years 6 months
Vested during period	5 years 6 months
Options outstanding, aggregate intrinsic value			$ 12,700	$ 16,400
Vested during period, aggregate intrinsic value			6,300
Unvested during period, aggregate intrinsic value			$ 6,400
Restricted Stock
Restricted Stock Outstanding, Number of Plan shares outstanding
Beginning balance (in shares)	30.7
RSUs released (in shares)	(6.1)
RSUs canceled (in shares)	(5.8)
Restricted stock granted (in shares)	20.8
Ending balance (in shares)	39.6	30.7
Vested during period (in shares)	0.0
Unvested at end of period (in shares)	39.6	30.7	39.6	30.7
Restricted Stock Outstanding, Weighted- average grant date fair value per share
Beginning balance (in dollars per share)	$ 20.48
RSUs released (in dollars per share)	20.01
RSUs canceled (in dollars per share)	20.25
Shares repurchased for tax withholdings on release of restricted stock (in dollars per share)	20.00
Restricted stock granted (in dollars per share)	18.64
Ending balance (in dollars per share)	19.62	$ 20.48
Vested during period (in dollars per share)	0
Unvested at end of period (in dollars per share)	$ 19.62	$ 20.48	$ 19.62	$ 20.48