Goodwill And Intangible Assets Goodwill And Intangible Assets (Fair Value Measurement) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019 Rate	Dec. 31, 2018 Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Period of cash flow before terminal value	4	4	5
Weighted Average Discount Rate	15.00%
Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market Multiple		850.00%	850.00%
Weighted Average Discount Rate		15.00%	13.00%
Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market Multiple		600.00%	700.00%
Weighted Average Discount Rate		12.50%	12.00%