Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal.

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+ Details

Discontinued Operations - Additional Information (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	Jan. 21, 2020	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Tax expense, discontinued operations				$ 67.8
Increase in income tax expense		$ 3.2
Discontinued Operations, Disposed of by Sale \| Fairbanks Morse
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Proceeds from sale of investment projects	$ 450.0
The pre-tax gain on the disposition	274.3
Gain (loss) from sale of discontinued operations, net of taxes	$ 206.5	$ (3.2)	$ 0.0	$ 206.5	$ 0.0