Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 497.0	$ 31.0	$ 817.0	$ 64.0
Other comprehensive income (loss)
Other comprehensive income (loss), net of tax	8.0	0.0	2.0	(22.0)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	505.0	31.0	819.0	42.0
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest		(2.0)
Comprehensive income (loss) attributed to LP	506.0	33.0	819.0	44.0
Foreign currency translation adjustments
Other comprehensive income (loss)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	7.0	2.0	0.0	(21.0)
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	$ 2.0	$ 2.0