Property, Plant And Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Mar. 31, 2015
Property, Plant and Equipment [Line Items]
Total cost	$ 166,109		$ 166,109		$ 167,866
Total accumulated depreciation	77,708		77,708		75,172
Construction in progress	186,616		186,616		94,391
Property, plant and equipment, net	275,017		275,017		187,085
Depreciation expense	2,400	$ 3,300	7,247	$ 10,953
Land [Member]
Property, Plant and Equipment [Line Items]
Total cost	1,669		1,669		1,447
Capital Lease Of Building [Member]
Property, Plant and Equipment [Line Items]
Total cost	5,441		5,441		5,753
Total accumulated depreciation	1,063		1,063		992
Buildings And Renovations [Member]
Property, Plant and Equipment [Line Items]
Total cost	79,588		79,588		80,013
Total accumulated depreciation	19,748		19,748		17,790
Plant And Machinery [Member]
Property, Plant and Equipment [Line Items]
Total cost	63,998		63,998		65,790
Total accumulated depreciation	44,668		44,668		44,193
Office Equipment And Furnishings [Member]
Property, Plant and Equipment [Line Items]
Total cost	11,846		11,846		11,146
Total accumulated depreciation	9,525		9,525		9,599
Motor Vehicles [Member]
Property, Plant and Equipment [Line Items]
Total cost	2,454		2,454		2,577
Total accumulated depreciation	1,885		1,885		1,834
Others [Member]
Property, Plant and Equipment [Line Items]
Total cost	1,113		1,113		1,140
Total accumulated depreciation	$ 819		$ 819		$ 764