RESTRUCTURING, IMPAIRMENT AND OTHER CHARGES: Gains, losses and other items (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring and Related Activities [Abstract]
Restructuring plan charges and adjustments	$ 489	$ 2,834	$ 491	$ 2,831
Other	0	(1)	0	(1)
Gains, losses and other items, net	$ 489	$ 2,833	$ 491	$ 2,830

Amount of general expenses not normally included in Other Operating Costs and Expenses.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.6)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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