Goodwill and Other Intangible Assets (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill additions	$ 14.0
Goodwill and other intangible assets	30.0	$ 16.0
Productive Land [Member]
Goodwill [Line Items]
Timber and Timberlands	39.0	41.0
Additions to Timberlands	0.0
Amortization of Intangible Assets	(2.0)
Developed Technology Rights [Member]
Goodwill [Line Items]
Amortization of Intangible Assets	(1.0)
Additions to finite-lived Intangible Assets	12.0
Finite-Lived Intangible Assets, Net	21.0	10.0
Other Intangible Assets [Member]
Goodwill [Line Items]
Amortization of Intangible Assets	0.0
Additions to finite-lived Intangible Assets	3.0
Finite-Lived Intangible Assets, Net	$ 3.0	$ 0.0