Financial instruments at fair value (Details) - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Level 1
Forward contracts
Investment product
Level 2
Forward contracts	$ (196)	$ (327)
Investment product
Level 3
Forward contracts
Investment product	$ 391
Total
Forward contracts	(196)	$ (327)
Investment product	$ 391

The net of the gross additions and gross reductions to the investment in and advance to the affiliate.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 6

-Subparagraph (SX 210.12-14.1(b))

-URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611322-123010

Name:	us-gaap_InvestmentsInAndAdvancesToAffiliatesAtFairValuePeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration