Related-Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018	Jan. 31, 2019
Refined Coal [Member]
Related-Party Transactions (Details) [Line Items]
Payments for Commissions	$ 0.3	$ 0.2	$ 0.3	$ 0.3
Accrued Liabilities for Commissions, Expense and Taxes	1.0		1.0		$ 1.6
One Earth Energy And Nu Gen Energy [Member]
Related-Party Transactions (Details) [Line Items]
Costs and Expenses, Related Party	43.5	$ 45.2	90.2	$ 91.4
Accounts Payable, Related Parties, Current	$ 1.7		$ 1.7		$ 1.9

No definition available.

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- Definition

Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

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- Definition

The carrying amount for commissions, taxes and other expenses that were incurred but unpaid as of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
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Costs of sales and operating expenses for the period incurred from transactions with related parties.

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The amount of cash paid for commissions during the current period.

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