CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 7.9	$ 14.4	$ (25.8)	$ 39.8
Reclassification of amounts recognized in the condensed consolidated statements of operations:
Amortization of adjustments to pension and other postretirement benefit liabilities (Note 6)	1.6	1.3	4.7	4.4
SERP settlement loss (Note 6)	0.0	0.1	0.0	0.1
Amounts recognized in the condensed consolidated statements of operations	1.6	1.4	4.7	4.5
Unrealized foreign currency translation gain (loss)	7.9	(6.9)	7.5	(8.6)
Net gain from pension and other postretirement benefit plans	0.0	0.0	0.0	4.9
Income (loss) from other comprehensive income items	9.5	(5.5)	12.2	0.8
Provision for income taxes	0.8	0.3	1.4	2.1
Other comprehensive income (loss)	8.7	(5.8)	10.8	(1.3)
Comprehensive income (loss)	$ 16.6	$ 8.6	$ (15.0)	$ 38.5