Impairments of Long-Lived Assets Impairments of Long-Lived Assets (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of Long-Lived Assets Held-for-use	$ 0.0	$ 8.0	$ 0.0	$ 15.0
Fiber production [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of Long-Lived Assets Held-for-use	$ 0.0	9.0
East River
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of Long-Lived Assets Held-for-use		$ 4.0