Financial Instruments and Fair Value Measurements Additional information (Details) (USD $)	24 Months Ended						6 Months Ended
	Dec. 31, 2008 acre	Jun. 30, 2014	Apr. 30, 2014	Dec. 31, 2013	Jun. 30, 2014 Carrying Value Level 3	Dec. 31, 2013 Carrying Value Level 3	Jun. 30, 2014 Minimum	Jun. 30, 2014 Maximum	Dec. 31, 2007 Defeased Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long term debt		$ 54,253,000		$ 44,217,000					$ 29,300,000
Area of timber land sold (in acres)	132,055
Maturity of notes receivables	15 years
Aggregate amount of notes receivables	183,300,000
Monetized notes receivables	183,300,000
Monetized note receivable, percentage	90.00%
Proceeds from monetized note	163,000,000
Retained interest promissory note receivable	14,300,000		20,000,000
Notes, maturity period	15 years
Note maturity year							2022	2024
Retained Interest, Fair Value Disclosure					$ 9,782,000	$ 9,639,000
Retained interest, effective interest rate							3.70%	12.60%