Goodwill and Other Intangible Assets (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Goodwill [Line Items]
Goodwill and other intangible assets	$ 25.0	$ 25.0
Productive Land [Member]
Goodwill [Line Items]
Timber and Timberlands	32.0	34.0
Amortization of Intangible Assets	(2.0)
Developed Technology Rights [Member]
Goodwill [Line Items]
Amortization of Intangible Assets	(1.0)
Finite-Lived Intangible Assets, Net	17.0	19.0
Other Intangible Assets [Member]
Goodwill [Line Items]
Amortization of Intangible Assets	0.0
Finite-Lived Intangible Assets, Net	$ 2.0	$ 3.0