Revenue (Contract Liabilities, Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Revenue from Contract with Customer [Abstract]
Increase in contract liabilities from cash payments received	$ 72.3
Contract liability	$ 282.3
Minimum [Member]
Disaggregation of Revenue [Line Items]
Revenue performance period	12 months
Maximum [Member]
Disaggregation of Revenue [Line Items]
Revenue performance period	36 months