Revenue from Contracts with Customers (Capitalized Contract Cost) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jan. 01, 2019
Revenue from Contract with Customer [Abstract]
Contract costs capitalized during the period		$ 19,270
Costs amortized during the period	$ 13,600	(25,496)
Change in capitalized contract cost, other		119
Balance of costs to obtain a contract	$ 15,204	$ 15,204	$ 21,311