Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Series B 6.75% Convertible Perpetual Preferred Stock [Member]	Common Stock - Class A [Member]	Forward Foreign Currency Exchange Contracts [Member]	Interest Rate Swap Agreements [Member]	Preferred Stock [Member]	Preferred Stock [Member] Series B 6.75% Convertible Perpetual Preferred Stock [Member]	Common Stock [Member]	Common Stock [Member] Common Stock - Class A [Member]	Retained Earnings [Member]	Retained Earnings [Member] Series B 6.75% Convertible Perpetual Preferred Stock [Member]	Retained Earnings [Member] Common Stock - Class A [Member]	AOCI Attributable to Parent [Member]	AOCI Attributable to Parent [Member] Forward Foreign Currency Exchange Contracts [Member]	AOCI Attributable to Parent [Member] Interest Rate Swap Agreements [Member]	Noncontrolling Interest [Member]
Balance at beginning of year at Mar. 31, 2013	$ 1,287,657					$ 213,023		$ 202,579		$ 918,509			$ (75,540)			$ 29,086
Balance at beginning of year, shares at Mar. 31, 2013		219,999
Balance at beginning of year, shares at Mar. 31, 2013			23,343,973
Changes in preferred and common stock
Issuance of common stock	457							457
Repurchase of stock			$ (2,049)						$ (2,049)
Issuance of stock, shares		0	110,825
Repurchase of stock, shares		0	(238,486)
Accrual of stock-based compensation	6,278							6,278
Withholding of shares from stock-based compensation for grantee income taxes	(1,410)							(1,410)
Dividend equivalents on RSUs	591							591
Changes in retained earnings
Net income	155,155									149,009						6,146
Cash dividends declared
Series B 6.75% convertible perpetual preferred stock ($67.50 per share)	(14,850)									(14,850)
Common stock	(46,888)									(46,888)
Repurchase of stock, retained earnings	0		$ (12,096)									$ (12,096)
Dividend equivalents on RSUs	(591)									(591)
Other comprehensive income (loss)
Foreign currency translation, net of income taxes	6,480												7,079			(599)
Hedges, net of income taxes				$ 1,624	$ 483									$ 1,624	$ 483
Pension and other postretirement benefit plans, net of income taxes	32,022												32,022
Other changes in noncontrolling interests
Dividends paid to noncontrolling shareholders	(1,971)															(1,971)
Balance at end of year at Mar. 31, 2014	1,410,892					213,023		206,446		993,093			(34,332)			32,662
Balance at end of year, shares at Mar. 31, 2014		219,999
Balance at end of year, shares at Mar. 31, 2014			23,216,312
Changes in preferred and common stock
Issuance of common stock	187							187
Repurchase of stock	(1,461)		$ (6,439)				$ (1,461)		$ (6,439)
Issuance of stock, shares		0	96,947
Repurchase of stock, shares		(1,509)	(719,993)
Accrual of stock-based compensation	6,230							6,230
Withholding of shares from stock-based compensation for grantee income taxes	(1,076)							(1,076)
Dividend equivalents on RSUs	654							654
Changes in retained earnings
Net income	120,461									114,608						5,853
Cash dividends declared
Series B 6.75% convertible perpetual preferred stock ($67.50 per share)	(14,824)									(14,824)
Common stock	(47,244)									(47,244)
Repurchase of stock, retained earnings	36	$ (36)	$ (24,788)								$ (36)	$ (24,788)
Dividend equivalents on RSUs	(654)									(654)
Other comprehensive income (loss)
Foreign currency translation, net of income taxes	(22,625)												(22,662)			37
Hedges, net of income taxes				(2,603)	(1,374)									(2,603)	(1,374)
Pension and other postretirement benefit plans, net of income taxes	(14,023)												(14,023)
Other changes in noncontrolling interests
Dividends paid to noncontrolling shareholders	(4,183)															(4,183)
Balance at end of year at Mar. 31, 2015	1,397,094					211,562		206,002		1,020,155			(74,994)			34,369
Balance at end of year, shares at Mar. 31, 2015		218,490
Balance at end of year, shares at Mar. 31, 2015			22,593,266
Changes in preferred and common stock
Issuance of stock, shares		0	124,469
Repurchase of stock, shares		0	0
Accrual of stock-based compensation	5,206							5,206
Withholding of shares from stock-based compensation for grantee income taxes	(2,940)							(2,940)
Dividend equivalents on RSUs	678							678
Changes in retained earnings
Net income	118,148									109,016						9,132
Cash dividends declared
Series B 6.75% convertible perpetual preferred stock ($67.50 per share)	(14,748)									(14,748)
Common stock	(47,681)									(47,681)
Repurchase of stock, retained earnings	0
Dividend equivalents on RSUs	(678)									(678)
Other comprehensive income (loss)
Foreign currency translation, net of income taxes	3,934												4,146			(212)
Hedges, net of income taxes				$ 2,509	$ (5,015)									$ 2,509	$ (5,015)
Pension and other postretirement benefit plans, net of income taxes	1,004												1,004
Other changes in noncontrolling interests
Dividends paid to noncontrolling shareholders	(4,449)															(4,449)
Balance at end of year at Mar. 31, 2016	$ 1,453,062					$ 211,562		$ 208,946		$ 1,066,064			$ (72,350)			$ 38,840
Balance at end of year, shares at Mar. 31, 2016		218,490
Balance at end of year, shares at Mar. 31, 2016	22,717,735		22,717,735