Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Forward Foreign Currency Exchange Contracts [Member]	Interest Rate Swap Agreements [Member]	Common Stock [Member]	Retained Earnings [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, 2017	$ 1,326,578			$ 321,207	$ 1,034,841	$ (69,559)			$ 40,089
Balance at beginning of year, shares at Mar. 31, 2017	25,274,506
Changes in preferred and common stock
Repurchase of stock	$ (5,142)			(5,142)
Issuance of stock, shares	59,843
Repurchase of stock, shares	(403,624)
Accrual of stock-based compensation	$ 7,610			7,610
Withholding of shares from stock-based compensation for grantee income taxes	(2,828)			(2,828)
Dividend equivalents on RSUs	712			712
Changes in retained earnings
Net income	116,168				105,662				10,506
Cash dividends declared
Common stock	(54,762)				(54,762)
Stock Repurchased And Retired During Period Value Retained Earnings	16,468				16,468
Dividend equivalents on RSUs	(712)				712
Adoption of FASB Accounting Standards Update	0				12,373	(12,373)
Other comprehensive income (loss)
Foreign currency translation, net of income taxes	14,162					14,534			(372)
Hedges, net of income taxes		$ 223	$ 4,498				$ 223	$ 4,498
Pension and other postretirement benefit plans, net of income taxes	2,613					2,613
Adoption of FASB Accounting Standards Update	0				12,373	(12,373)
Other changes in noncontrolling interests
Dividends paid to noncontrolling shareholders	(7,350)								(7,350)
Balance at end of year at Mar. 31, 2018	$ 1,385,302			321,559	1,080,934	(60,064)			42,873
Balance at end of year, shares at Mar. 31, 2018	24,930,725
Changes in preferred and common stock
Repurchase of stock	$ (397)			(397)
Issuance of stock, shares	89,998
Repurchase of stock, shares	(30,777)
Accrual of stock-based compensation	$ 8,152			8,152
Withholding of shares from stock-based compensation for grantee income taxes	(3,697)			(3,697)
Dividend equivalents on RSUs	983			983
Changes in retained earnings
Net income	110,134				104,121				6,013
Cash dividends declared
Common stock	(74,914)				(74,914)
Stock Repurchased And Retired During Period Value Retained Earnings	1,046				1,046
Dividend equivalents on RSUs	(983)				(983)
Adoption of FASB Accounting Standards Update	(1,934)				(1,934)
Other comprehensive income (loss)
Foreign currency translation, net of income taxes	(16,316)					(16,159)			(157)
Hedges, net of income taxes		(341)	(7,462)				(341)	(7,462)
Pension and other postretirement benefit plans, net of income taxes	(11,665)					(11,665)
Adoption of FASB Accounting Standards Update	(1,934)				(1,934)
Other changes in noncontrolling interests
Dividends paid to noncontrolling shareholders	(5,938)								(5,938)
Balance at end of year at Mar. 31, 2019	$ 1,379,878			326,600	1,106,178	(95,691)			42,791
Balance at end of year, shares at Mar. 31, 2019	24,989,946
Changes in preferred and common stock
Repurchase of stock	$ (8,562)			(8,562)
Issuance of stock, shares	88,709
Repurchase of stock, shares	(656,820)
Accrual of stock-based compensation	$ 5,631			5,631
Withholding of shares from stock-based compensation for grantee income taxes	(3,183)			(3,183)
Dividend equivalents on RSUs	1,016			1,016
Changes in retained earnings
Net income	78,003				71,680				6,323
Cash dividends declared
Common stock	(75,187)				(75,187)
Repurchase of stock, retained earnings	(24,895)				(24,895)
Dividend equivalents on RSUs	(1,016)				(1,016)
Other comprehensive income (loss)
Foreign currency translation, net of income taxes	(3,066)					(2,822)			(244)
Hedges, net of income taxes		$ (11,850)	$ (26,468)				$ (11,850)	$ (26,468)
Pension and other postretirement benefit plans, net of income taxes	(14,766)					(14,766)
Other changes in noncontrolling interests
Dividends paid to noncontrolling shareholders	(6,251)								(6,251)
Balance at end of year at Mar. 31, 2020	$ 1,289,284			$ 321,502	$ 1,076,760	$ (151,597)			$ 42,619
Balance at end of year, shares at Mar. 31, 2020	0
Balance at end of year, shares at Mar. 31, 2020	24,421,835