Other Assets and Liabilities - Other Current Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Prepaid Expense and Other Assets, Current [Abstract]
Biodiesel tax credit (see Note 4)	$ 97.5	$ 0.0
Income and other tax receivables	61.9	24.3
Short-term derivative assets (see Note 12)	30.2	61.9
Prepaid expenses	21.9	15.8
Environmental Credits Obligation surplus (see Note 13)	16.8	10.3
RINs assets	14.5	13.0
Investment commodities	12.1	15.6
Note receivable - current portion (see Note 8)	6.2	0.0
Other	7.6	7.8
Total	$ 268.7	$ 148.7