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Revenue Recognition (Narrative) (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Revenue Recognition [Line Items]          
Contract liabilities $ 21,553   $ 21,553   $ 28,909
Remaining performance obligations expected to be satisfied beyond one year 127,300   $ 127,300    
Contract termination notice days with no penality     30 days    
Revenue by managed services 223,056 $ 184,713 $ 425,918 $ 362,781  
Managed Services [Member] | Revenue [Member] | Product Concentration Risk [Member]          
Revenue Recognition [Line Items]          
Revenue by managed services $ 60,600 $ 31,900 $ 117,400 $ 63,300  
Percentage of revenue by managed services 31.00% 19.00% 31.00% 19.00%  
Effect of Adoption of Topic 606 [Member]          
Revenue Recognition [Line Items]          
Contract liabilities $ 21,600   $ 21,600   $ 27,200
Amount of contract liability, revenue recognized $ 5,300   $ 23,000