Share-Based Compensation - RSU and RSA activity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
RSUs
RSU and RSA activity ( including Performance RSUs and RSAs)
Outstanding at beginning of year	4,993,918
Granted (in shares)	7,850,175
Released (in shares)	(2,682,186)
Forfeited (in shares)	(1,808,058)
Outstanding at end of year	8,353,849	4,993,918
Additional disclosures
Total estimated fair value of RSUs vested	$ 49.3	$ 52.8
Performance-Contingent Awards - RSAs
RSU and RSA activity ( including Performance RSUs and RSAs)
Outstanding at beginning of year	414,000
Released (in shares)	(414,000)
Outstanding at end of year		414,000