SPECIAL PURPOSE ENTITIES (Details) $ in Millions	3 Months Ended	6 Months Ended
Jul. 31, 2018 USD ($) item	Jul. 31, 2018 USD ($) item project
GPS
Variable Interest Entity
Number of natural gas-fired power plants \| project		2
Number of joint ventures \| item	2	2
VIE
Variable Interest Entity
Development costs incurred \| $	$ 0.4	$ 0.7

Development costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 18
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62014-109447

Name:	us-gaap_CostsIncurredDevelopmentCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration