Revenue Recognition (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue	$ 91,603	$ 70,959	$ 169,691	$ 137,361
Contract acquisition costs	36,100		36,100		$ 32,000
Remaining performance obligation	221,000		221,000
Recognition of deferred revenue			60,500
Accounts for doubtful accounts	4,428		4,428		3,100
Sales reserve	$ 2,900		$ 2,900		$ 1,100