Document And Entity Information - shares	9 Months Ended
	Dec. 31, 2015	Feb. 04, 2016
Document And Entity Information [Abstract]
Entity Registrant Name	Synutra International, Inc.
Entity Filer Category	Accelerated Filer
Entity Central Index Key	0001293593
Amendment Flag	false
Document Type	10-Q
Document Fiscal Period Focus	Q3
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2016
Current Fiscal Year End Date	--03-31
Entity Common Stock, Shares Outstanding		56,836,797