Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Series B 6.75% Convertible Perpetual Preferred Stock [Member]	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Non-controlling Interests [Member]	Forward Foreign Currency Exchange Contracts [Member]	Forward Foreign Currency Exchange Contracts [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Interest Rate Swap Agreements [Member]	Interest Rate Swap Agreements [Member] Accumulated Other Comprehensive Income (Loss) [Member]
Balance at beginning of year at Mar. 31, 2010	$ 1,128,375	$ 213,023	$ 195,001	$ 767,213	$ (52,667)	$ 5,805
Balance at beginning of year, shares at Mar. 31, 2010			24,325,000
Balance at beginning of year, shares at Mar. 31, 2010		220,000
Changes in preferred and common stock
Issuance of common stock	0		0
Repurchase of common stock	(8,995)		(8,995)
Issuance of stock, shares		0	28,000
Repurchase of stock, shares		0	(1,113,000)
Accrual of stock-based compensation	5,893		5,893
Withholding of shares from stock-based compensation for grantee income taxes	(724)		(724)
Dividend equivalents on RSUs	(433)		(433)
Changes in retained earnings
Net income	164,550			156,565		7,985
Cash dividends declared
Series B 6.75% convertible perpetual preferred stock ($67.50 per share)	(14,850)			(14,850)
Common stock	(45,043)			(45,043)
Repurchase of common stock	(37,701)			(37,701)
Dividend equivalents on RSUs	(433)			(433)
Other comprehensive income (loss)
Foreign currency translation adjustments, net of income taxes	7,297				7,188	109
Foreign currency hedge adjustments, net of income taxes							2,961	2,961	0
Pension and other postretirement benefit plan adjustments, net of income taxes	(2,258)				(2,258)
Other changes in noncontrolling interests
Dividends paid to noncontrolling shareholders	(100)					(100)
Balance at end of year at Mar. 31, 2011	1,199,405	213,023	191,608	825,751	(44,776)	13,799
Balance at end of year, shares at Mar. 31, 2011			23,241,000
Balance at end of year, shares at Mar. 31, 2011		220,000
Changes in preferred and common stock
Issuance of common stock	259		259
Repurchase of common stock	(661)		(661)
Issuance of stock, shares		0	97,000
Repurchase of stock, shares		0	(80,000)
Accrual of stock-based compensation	5,987		5,987
Withholding of shares from stock-based compensation for grantee income taxes	(1,584)		(1,584)
Dividend equivalents on RSUs	(526)		(526)
Changes in retained earnings
Net income	100,819			92,057		8,762
Cash dividends declared
Series B 6.75% convertible perpetual preferred stock ($67.50 per share)	(14,850)			(14,850)
Common stock	(44,951)			(44,951)
Repurchase of common stock	(2,827)			(2,827)
Dividend equivalents on RSUs	(526)			(526)
Other comprehensive income (loss)
Foreign currency translation adjustments, net of income taxes	(8,158)				(8,239)	81
Foreign currency hedge adjustments, net of income taxes							(3,424)	(3,424)	(727)	(727)
Pension and other postretirement benefit plan adjustments, net of income taxes	(23,195)				(23,195)
Other changes in noncontrolling interests
Dividends paid to noncontrolling shareholders	(103)					(103)
Balance at end of year at Mar. 31, 2012	1,205,990	213,023	196,135	854,654	(80,361)	22,539
Balance at end of year, shares at Mar. 31, 2012			23,257,000
Balance at end of year, shares at Mar. 31, 2012		219,999
Changes in preferred and common stock
Issuance of common stock	3,949		3,949
Repurchase of common stock	(1,432)		(1,432)
Issuance of stock, shares		0	256,000
Repurchase of stock, shares		0	(169,000)
Accrual of stock-based compensation	6,171		6,171
Withholding of shares from stock-based compensation for grantee income taxes	(2,819)		(2,819)
Dividend equivalents on RSUs	(575)		(575)
Changes in retained earnings
Net income	140,919			132,750		8,169
Cash dividends declared
Series B 6.75% convertible perpetual preferred stock ($67.50 per share)	(14,850)			(14,850)
Common stock	(46,272)			(46,272)
Repurchase of common stock	(7,198)			(7,198)
Dividend equivalents on RSUs	(575)			(575)
Other comprehensive income (loss)
Foreign currency translation adjustments, net of income taxes	(3,370)				(3,705)	335
Foreign currency hedge adjustments, net of income taxes							87	87	(364)	(364)
Pension and other postretirement benefit plan adjustments, net of income taxes	8,803				8,803
Other changes in noncontrolling interests
Dividends paid to noncontrolling shareholders	(1,957)					(1,957)
Balance at end of year at Mar. 31, 2013	$ 1,287,657	$ 213,023	$ 202,579	$ 918,509	$ (75,540)	$ 29,086
Balance at end of year, shares at Mar. 31, 2013	23,343,973		23,344,000
Balance at end of year, shares at Mar. 31, 2013		219,999