Loss per Common Share (Summary Of Anti-Dilutive Shares) (Details) - shares shares in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computation of diluted loss per share	63,829	56,201
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computation of diluted loss per share	22,730	24,425
Warrants Outstanding [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computation of diluted loss per share	10,346	9,819
Convertible Debt Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computation of diluted loss per share	30,753	21,957