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Revenue (Details)
6 Months Ended
Jun. 30, 2019
USD ($)
Revenue, Performance Obligation [Abstract]  
Number of Types of Performance Obligations 2
Contract with Customer, Refund Liability $ 0
Stand Ready Performance Obligations [Member]  
Revenue, Performance Obligation [Abstract]  
Revenue, Performance Obligation, Description of Good or Service those that require us to stand ready to provide goods and services to a customer to use as and when requested (“Stand Ready Performance Obligations”)
Other Performance Obligations [Member]  
Revenue, Performance Obligation [Abstract]  
Revenue, Performance Obligation, Description of Good or Service those that do not require us to stand ready (“Other Performance Obligations”)