Revenue from Contracts with Customers (Capitalized Contract Cost) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Contract costs capitalized during the period		$ 29,381
Costs amortized during the period	$ 9,200	(34,729)
Change in capitalized contract cost, other		(312)
Balance of costs to obtain a contract	$ 15,651	$ 15,651	$ 21,311