Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 33.0	$ 26.0
Other comprehensive income (loss)
Other comprehensive income (loss), net of tax	(22.0)	2.0
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	11.0	28.0
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	0.0	0.0
Comprehensive income (loss) attributed to LP	11.0	29.0
Foreign currency translation adjustments
Other comprehensive income (loss)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(23.0)	2.0
Unrealized gain (loss) on investments
Other comprehensive income (loss)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0.0	(1.0)
Amortization of pension and post-retirement prior service costs and net loss
Other comprehensive income (loss)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ 1.0	$ 1.0