REVENUES FROM CONTRACTS WITH CUSTOMERS - Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Disaggregation of Revenues
Revenues earned under fixed-price (as percent)			74.00%	90.00%
Consolidated Revenues	$ 63,059	$ 136,670	$ 112,603	$ 278,036
United States
Disaggregation of Revenues
Consolidated Revenues	37,650	108,939	77,416	233,093
United Kingdom
Disaggregation of Revenues
Consolidated Revenues	19,618	19,690	25,282	34,158
Republic of Ireland
Disaggregation of Revenues
Consolidated Revenues	5,748	7,415	9,751	10,159
Other
Disaggregation of Revenues
Consolidated Revenues	$ 43	$ 626	$ 154	$ 626

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045

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