Revenue (Details 2) $ in Thousands	Jun. 30, 2019 USD ($)
Period 1 [Member]
Revenue, Remaining Performance Obligation, Amount	$ 188,220
Period 2 [Member]
Revenue, Remaining Performance Obligation, Amount	269,397
Period 3 [Member]
Revenue, Remaining Performance Obligation, Amount	222,702
Period 4 [Member]
Revenue, Remaining Performance Obligation, Amount	225,308
Period 5 [Member]
Revenue, Remaining Performance Obligation, Amount	226,892
Thereafter [Member]
Revenue, Remaining Performance Obligation, Amount	$ 2,008,649