Supplemental Balance Sheet Disclosures (Narrative) (Details) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Jan. 31, 2019 USD ($) a	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Payment for deposit		$ 5	$ 0
Fund Two and Three
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Operating term for Fund		10 years
Fund IV
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Operating term for Fund		15 years
South Central WA
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Total purchase price	$ 20,300
Purchase price allocated to timber and roads	17,500
Purchase price allocated to underlying land	$ 2,800
South Central WA | Fund IV
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Acres of land acquired | a	7,100
Total purchase price	$ 3,000
Payment for deposit				$ 1,000
Fund II | Pope Resources And Olympic Resource Management LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest		20.00%
Fund III | Pope Resources And Olympic Resource Management LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest		5.00%
Fund IV | Pope Resources And Olympic Resource Management LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest		15.00%