Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Income Statement [Abstract]
Lease pool depreciation	$ 14,370	$ 25,753	$ 29,462

Depreciation of property, plant and equipment directly related to goods produced and sold and services rendered by an entity during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

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