Revenues From Contracts With Customers (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue From Contract With Customer [Abstract]
Receivables related to contract with customers	$ 148,600,000	$ 151,300,000
Impairment related to receivables	0
Deferred Revenue	$ 12,100,000	$ 11,300,000