Summary of Significant Accounting Policies (Narrative) (Details) $ in Thousands, a in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) a
Principle Accounting Policies [Line Items]
Timber And Timberlands Acres Owned | a	1.4
Operating Leases, Future Minimum Payments Due	$ 15,193
Allowance for doubtful accounts on accounts receivables	$ 500
Timber and Timberlands [Member] | Minimum [Member]
Principle Accounting Policies [Line Items]
Timber Volume Estimate, Review Period	5 years
Property, Plant and Equipment, Useful Life	5 years
Timber and Timberlands [Member] | Maximum [Member]
Principle Accounting Policies [Line Items]
Timber Volume Estimate, Review Period	10 years
Property, Plant and Equipment, Useful Life	20 years