Consolidated Statements of Changes in Shareholders' Equity (USD $)	Total	Series B 6.75% Convertible Perpetual Preferred Stock [Member]	Series B Preferred Stock [Member]	Common Stock	Common Stock [Member]	Retained Earnings [Member]	Retained Earnings [Member] Series B Preferred Stock [Member]	Retained Earnings [Member] Common Stock	Accumulated Other Comprehensive Income (Loss) [Member]	Non-controlling Interests [Member]	Parent [Member] Series B Preferred Stock [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, 2012	$ 1,205,990,000	$ 213,023,000			$ 196,135,000	$ 854,654,000			$ (80,361,000)	$ 22,539,000
Balance at beginning of year, shares at Mar. 31, 2012					23,257,175
Balance at beginning of year, shares at Mar. 31, 2012		219,999
Changes in preferred and common stock
Issuance of common stock	3,949,000				3,949,000
Repurchase of stock	(1,432,000)				(1,432,000)
Issuance of stock, shares		0			256,230
Repurchase of stock, shares		0			(169,432)
Accrual of stock-based compensation	6,171,000				6,171,000
Withholding of shares from stock-based compensation for grantee income taxes	(2,819,000)				(2,819,000)
Dividend equivalents on RSUs	575,000				575,000
Changes in retained earnings
Net income	140,919,000					132,750,000				8,169,000
Cash dividends declared
Series B 6.75% convertible perpetual preferred stock ($67.50 per share)	(14,850,000)					(14,850,000)
Common stock	(46,272,000)					(46,272,000)
Repurchase of stock, retained earnings	0			(7,198,000)				(7,198,000)
Dividend equivalents on RSUs	(575,000)					(575,000)
Other comprehensive income (loss)
Foreign currency translation, net of income taxes	(3,370,000)								(3,705,000)	335,000
Hedges, net of income taxes												87,000	87,000	(364,000)	(364,000)
Pension and other postretirement benefit plans, net of income taxes	8,803,000								8,803,000
Other changes in noncontrolling interests
Dividends paid to noncontrolling shareholders	(1,957,000)									(1,957,000)
Balance at end of year at Mar. 31, 2013	1,287,657,000	213,023,000			202,579,000	918,509,000			(75,540,000)	29,086,000
Balance at end of year, shares at Mar. 31, 2013					23,343,973
Balance at end of year, shares at Mar. 31, 2013		219,999
Changes in preferred and common stock
Issuance of common stock	457,000				457,000
Repurchase of stock	(2,049,000)				(2,049,000)
Issuance of stock, shares		0			110,825
Repurchase of stock, shares		0			(238,486)
Accrual of stock-based compensation	6,278,000				6,278,000
Withholding of shares from stock-based compensation for grantee income taxes	(1,410,000)				(1,410,000)
Dividend equivalents on RSUs	591,000				591,000
Changes in retained earnings
Net income	155,155,000					149,009,000				6,146,000
Cash dividends declared
Series B 6.75% convertible perpetual preferred stock ($67.50 per share)	(14,850,000)					(14,850,000)
Common stock	(46,888,000)					(46,888,000)
Repurchase of stock, retained earnings	0			(12,096,000)				(12,096,000)
Dividend equivalents on RSUs	(591,000)					(591,000)
Other comprehensive income (loss)
Foreign currency translation, net of income taxes	6,480,000								7,079,000	(599,000)
Hedges, net of income taxes												1,624,000	1,624,000	483,000	483,000
Pension and other postretirement benefit plans, net of income taxes	32,022,000								32,022,000
Other changes in noncontrolling interests
Dividends paid to noncontrolling shareholders	(1,971,000)									(1,971,000)
Balance at end of year at Mar. 31, 2014	1,410,892,000	213,023,000			206,446,000	993,093,000			(34,332,000)	32,662,000
Balance at end of year, shares at Mar. 31, 2014					23,216,312
Balance at end of year, shares at Mar. 31, 2014		219,999
Changes in preferred and common stock
Issuance of common stock	187,000				187,000
Repurchase of stock			(1,461,000)	(6,439,000)	(6,439,000)						(1,461,000)
Issuance of stock, shares		0			96,947
Repurchase of stock, shares		(1,509)			(719,993)
Accrual of stock-based compensation	6,230,000				6,230,000
Withholding of shares from stock-based compensation for grantee income taxes	(1,076,000)				(1,076,000)
Dividend equivalents on RSUs	654,000				654,000
Changes in retained earnings
Net income	120,461,000					114,608,000				5,853,000
Cash dividends declared
Series B 6.75% convertible perpetual preferred stock ($67.50 per share)	(14,824,000)					(14,824,000)
Common stock	(47,244,000)					(47,244,000)
Repurchase of stock, retained earnings	36,000		(36,000)	(24,788,000)			(36,000)	(24,788,000)
Dividend equivalents on RSUs	(654,000)					(654,000)
Other comprehensive income (loss)
Foreign currency translation, net of income taxes	(22,625,000)								(22,662,000)	37,000
Hedges, net of income taxes												(2,603,000)	(2,603,000)	(1,374,000)	(1,374,000)
Pension and other postretirement benefit plans, net of income taxes	(14,023,000)								(14,023,000)
Other changes in noncontrolling interests
Dividends paid to noncontrolling shareholders	(4,183,000)									(4,183,000)
Balance at end of year at Mar. 31, 2015	$ 1,397,094,000	$ 211,562,000			$ 206,002,000	$ 1,020,155,000			$ (74,994,000)	$ 34,369,000
Balance at end of year, shares at Mar. 31, 2015	22,593,266				22,593,266
Balance at end of year, shares at Mar. 31, 2015		218,490