Commitments, Contingencies and Uncertainties (Future Minimum Payments For Operating Leases) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	$ 1,700	$ 2,400	$ 1,700
2019	923
2020	820
2021	700
2022	544
2023	$ 526
Newman Land Lease
Operating Leased Assets [Line Items]
Lease Expiration Date	Jun. 30, 2033
Lessee, Operating Lease, Renewal Term	25 years
Other Property
Operating Leased Assets [Line Items]
Lessee Leasing Arrangements, Operating Leases, Term of Contract	P5Y