Revenue from Contracts with Customers (Capitalized Contract Cost) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Contract costs capitalized during the period	$ 11,833
Costs amortized during the period	(13,298)
Change in capitalized contract cost, other	(95)
Balance of costs to obtain a contract	$ 22,803	$ 24,363