Net Loss Per Share (Computation Of Basic And Diluted Net Loss Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator
Net loss	$ (81,499)	$ (87,435)
Basic
Weighted average shares used in computing basic net loss	222,289	194,790
Basic net loss per share	$ (0.37)	$ (0.45)
Diluted
Weighted average shares used in computing basic net loss per share	222,289	194,790
Weighted average shares used in computing diluted net loss per share	222,289	194,790
Diluted net loss per share	$ (0.37)	$ (0.45)