Stock-Based Compensation - Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands		6 Months Ended		12 Months Ended
	Dec. 02, 2013	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Employee stock options
Number of Shares subject to outstanding options
Balance at the beginning of the period (in shares)		7,174,319
Options granted (in shares)		1,433,699	1,700,583
Options forfeited (in shares)		(115,261)
Options exercised (in shares)		(261,786)
Balance at the end of the period (in shares)		8,230,971		7,174,319
Exercisable options (in shares)		4,587,110
Weighted Average Exercise Price (Per Share)
Balance at the beginning of the period (in dollars per share)		$ 24.03
Options granted (in dollars per share)		32.10
Options forfeited (in dollars per share)		31.28
Options exercised (in dollars per share)		18.13
Balance at the end of the period (in dollars per share)		25.52		$ 24.03
Exercisable (in dollars per share)		$ 20.28
Weighted-average remaining contractual life		7 years 3 months 29 days		7 years 3 months 25 days
Weighted-average remaining contractual life of awards exercisable		6 years 1 month 6 days
Aggregate intrinsic value of options outstanding		$ 65,362
Aggregate intrinsic value of options exercisable		$ 58,544
Closing price of common stock (in dollars per share)		$ 32.39
Weighted average fair value of options granted (in dollars per share)		$ 16.44	$ 20.74
The 2010 Plan
Number of Shares subject to outstanding options
Options granted (in shares)	0