Balance Sheet Of Partnership Co-Investments (Narrative) (Details) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
	Jan. 31, 2018 USD ($) Property	Jan. 31, 2017 USD ($) Property	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Oct. 31, 2018 USD ($)
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Pretax income (loss)			$ 2,861	$ 626	$ 11,235	$ 12,176
Fund II
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Operating term for Fund					10 years
Pope Resources and ORMLLC combined ownership percentage					20.00%
Number of tree farms sold | Property		1
Proceeds from sale of tree farms		$ 26,500
Fund II | Productive Land
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Pretax income (loss)						$ 2,500
Fund III
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Operating term for Fund					10 years
Pope Resources and ORMLLC combined ownership percentage					5.00%
Fund IV
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Operating term for Fund					15 years
Pope Resources and ORMLLC combined ownership percentage					15.00%
Total purchase price	$ 17,000
Payment for deposit							$ 5,700
Purchase price allocated to timber and roads	100,700
Purchase price allocated to underlying land	$ 13,300
Southwestern Oregon and South Puget Sound Washington | Fund IV
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of acquisitions | Property	2
Southwestern Oregon | Fund IV
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of acquisitions | Property	1
Total purchase price	$ 33,600
South Puget Sound, Washington | Fund IV
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of acquisitions | Property	1
Total purchase price	$ 80,400
Subsequent Event | South Puget Sound, Washington
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Total purchase price								$ 4,800
Subsequent Event | South Puget Sound, Washington | Fund IV
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Total purchase price								$ 32,200