Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629

Name:	us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

LONG-TERM DEBT LONG-TERM DEBT - 2017 CREDIT AGREEMENT ISSUANCE COSTS (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jul. 31, 2018	Jan. 31, 2018	Jul. 31, 2017	Jul. 31, 2018	Jul. 31, 2017
Debt Instrument
Loss on early retirement of debt	$ 0		$ (1,934)	$ 0	$ (1,934)
Amortization of Debt Issuance Costs				206	$ 6,482
2017 Credit Agreement
Debt Instrument
Amortization of Debt Issuance Costs				6,800
2017 Term Loan
Debt Instrument
Loss on early retirement of debt		$ 200
Amortization of Debt Issuance Costs				4,100
2017 Revolving Credit Facility
Debt Instrument
Amortization of Debt Issuance Costs				$ 2,700