Leases (Schedule of lease assets and liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating right of use asset	$ 4,551	$ 0
Finance right of use assets	18,886
Total right of use assets	23,437
Current operating lease liability	2,369	0
Current finance lease liability	4,041
Operating lease liability	1,952	$ 0
Finance lease liability	6,354
Total lease liability	$ 14,716