Discontinued Operations - Results of Operations (Details) - USD ($) $ in Millions		3 Months Ended
	Jan. 21, 2020	Mar. 31, 2020	Mar. 31, 2019
Operating expenses:
Income (loss) from discontinued operations, net of tax		$ 208.6	$ 5.3
Income from discontinued operations, net of tax		208.6	5.3
Discontinued Operations, Disposed of by Sale | Fairbanks Morse
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales		7.6	57.9
Cost of sales		7.6	44.3
Gross profit		0.0	13.6
Operating expenses:
Selling, general, and administrative expenses		1.5	6.3
Other		(0.1)	0.0
Total operating expenses		1.4	6.3
Income (loss) from discontinued operations before income tax		(1.4)	7.3
Income tax benefit (expense)		0.3	(2.0)
Income (loss) from discontinued operations, net of tax		(1.1)	5.3
Gain from sale of discontinued operations, net of tax	$ 209.7	209.7	0.0
Income from discontinued operations, net of tax		$ 208.6	$ 5.3