Consolidated Statements Of Cash Flows - USD ($) $ in Thousands		9 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income		$ 76,056	$ 65,554
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation		26,107	27,221
Net provision for losses (recoveries) on advances and guaranteed loans to suppliers		414	(1,026)
Foreign currency remeasurement loss (gain), net		12,493	21,492
Fair value gain upon acquisition of partner's interest in joint venture		0	(3,390)
Restructuring and impairment costs	[1]	3,860	2,389
Other, net		7,290	18,004
Changes in operating assets and liabilities, net		56,533	(120,045)
Net cash provided by operating activities		182,753	10,199
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property, plant and equipment		(28,544)	(38,504)
Purchase of partner's interest in joint venture, net of cash held by the business		0	(5,964)
Proceeds from sale of property, plant and equipment		665	1,380
Other Investing Activities		0	(398)
Net cash used by investing activities		(27,879)	(43,486)
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance (repayment) of short-term debt, net		(11,299)	4,168
Dividends paid to noncontrolling interests		(1,260)	(1,260)
Dividends paid on convertible perpetual preferred stock		(11,061)	(11,061)
Dividends paid on common stock		(36,181)	(35,349)
Other		(2,256)	(3,736)
Net cash used by financing activities		(62,057)	(47,238)
Effect of exchange rate changes on cash		(757)	(633)
Net increase (decrease) in cash and cash equivalents		92,060	(81,158)
Cash and cash equivalents at beginning of year		319,447	248,783
Cash and cash equivalents at end of period		411,507	$ 167,625
Series B 6.75% Convertible Perpetual Preferred Stock [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Non-cash reclassification of preferred stock converted		$ 107,600
Preferred stock, shares converted to common stock		111,072

[1] Restructuring and impairment costs are excluded from segment operating income, but are included in consolidated operating income in the consolidated statements of income and comprehensive income.