Commitments and Contingencies (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Legal Proceedings
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 2,729
Operating Leases, Future Minimum Payments, Due in Two Years	2,744
Operating Leases, Future Minimum Payments, Due in Three Years	2,771
Operating Leases, Future Minimum Payments, Due in Four Years	2,767
Operating Leases, Future Minimum Payments, Due in Five Years	2,761
Operating Leases, Future Minimum Payments, Due Thereafter	68,516
Loss Contingency Accrual	8,700	$ 32,100
Operating Leases, Future Minimum Payments Due	82,288
Cleven Litigation Case [Member]
Legal Proceedings
Loss Contingency, Estimate of Possible Loss	54,600
Brown Litigation Case [Member]
Legal Proceedings
Loss Contingency, Estimate of Possible Loss	$ 8,400