Stock-based Compensation (Assumptions Used in the Black-Scholes Model) (Details) - Common Stock Options [Member]	Dec. 31, 2020 $ / shares USD ($)
Measurement Input, Expected Dividend Rate [Member]
Fair value input, equity securities	0
Minimum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Fair value input, equity securities	0.13
Minimum [Member] | Measurement Input, Price Volatility [Member]
Fair value input, equity securities | $ / shares	90.43
Maximum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Fair value input, equity securities	1.48
Maximum [Member] | Measurement Input, Price Volatility [Member]
Fair value input, equity securities	94.0