Stockholders' Equity - Option activity (Details) - Employee Stock Option - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	6 Months Ended	12 Months Ended
	Jul. 31, 2016	Jun. 30, 2016	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Shares Subject to Outstanding Options, Shares
Outstanding at the beginning of the period (in shares)			12,115,288
Options granted (in shares)			2,540,313
Options exercised (in shares)			(622,944)
Options cancelled (in shares)			(1,269,197)
Outstanding at the end of the period (in shares)			12,763,460	12,115,288
Shares Subject to Outstanding Options, Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)			$ 88.31
Options granted (in dollars per share)			84.92
Options exercised (in dollars per share)			66.44
Options cancelled (in dollars per share)			91.44
Outstanding at the end of the period (in dollars per share)			$ 88.39	$ 88.31
Termination period	10 years	7 years
Vesting period	4 years	3 years
Stock option, other disclosures
Options exercisable and vested (in shares)			8,024,951	6,732,942	6,896,492
Intrinsic value of options exercised			$ 12.7	$ 87.5	$ 113.8
Intrinsic value of options outstanding			13.5
Intrinsic value of vested options			$ 13.4
Tranche One
Shares Subject to Outstanding Options, Weighted Average Exercise Price
Vesting period	1 year	1 year
Vesting Percentage	25.00%	33.00%
Tranche Two
Shares Subject to Outstanding Options, Weighted Average Exercise Price
Vesting period	36 months	24 months