Income Taxes Reconciliation of deferred taxes (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Valuation Allowance [Line Items]
Accrued liabilities	$ 18.0	$ 22.0
Pension and post-retirement benefits	7.0	8.0
Share-based compensation	5.0	5.0
Benefit of capital loss and NOL carryovers	28.0	16.0
Other	8.0	13.0
Inventory	7.0	8.0
Market value write down of ARS	3.0	3.0
Deferred Tax Liabilities, Leasing Arrangements	6.0
Valuation Allowance, Amount	(11.0)	(12.0)
Deferred Tax Assets, Net	71.0	63.0
Property, plant and equipment	(121.0)	(111.0)
Timber and timberlands	10.0	10.0
Installment sale gain deferral	6.0
Total Deferred Tax Liabilities	(143.0)	(121.0)
Deferred Tax Liabilities, Net	(72.0)	(58.0)
Long-term deferred tax asset	(1.0)	(4.0)
Long-term deferred tax liability	$ (73.0)	$ (62.0)