Consolidated Statements of Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010	Mar. 31, 2009
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 822,664	$ 788,665	$ 822,664	$ 788,665	$ 754,494	$ 718,165
Net Income (Loss) Attributable to Parent	44,171	39,000	136,115	51,265	128,467
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax			(7,279)	(1,024)	554
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax			70	192	423
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax			(14,352)	23,029	27,814
Comprehensive Income (Loss), Net of Tax, Attributable to Parent			114,554	73,462	157,258
Treasury Stock, Shares, Acquired			1,851,510	925,848
Payments for Repurchase of Common Stock			(56,751)	(29,965)	(310)
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures			13,075	21,061	20,580
Tax Benefit from Stock Options Exercised			1,514	2,525	2,467
Dividends, Common Stock, Cash			(38,560)	(33,228)	(144,017)
Noncontrolling Interest, Change in Redemption Value			167	316	351
Common Stock [Member]
Shares, Issued	57,733,000	59,122,000	57,733,000	59,122,000	59,227,000	58,452,000
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	244,091	241,343	244,091	241,343	237,165	232,282
Net Income (Loss) Attributable to Parent			0	0	0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax			0	0
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax			0	0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax			0	0	0
Treasury Stock, Shares, Acquired			(1,887,000)	(952,000)	(24,000)
Payments for Repurchase of Common Stock			0	0	0
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures			498,000	847,000	799,000
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures			1,234	1,653	2,416
Stock Issued During Period, Value, Stock Options Exercised			0
Tax Benefit from Stock Options Exercised			1,514	2,525	2,467
Dividends, Common Stock, Cash			0
Noncontrolling Interest, Change in Redemption Value			0	0	0
Treasury Stock [Member]
Shares, Issued	12,307,000	10,918,000	12,307,000	10,918,000	10,813,000	11,588,000
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(350,718)	(305,808)	(350,718)	(305,808)	(295,251)	(313,105)
Net Income (Loss) Attributable to Parent			0	0	0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax			0	0
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax			0	0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax			0	0	0
Treasury Stock, Shares, Acquired			1,887,000	952,000	24,000
Payments for Repurchase of Common Stock			(56,751)	(29,965)	(310)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures			(498,000)	(847,000)	(799,000)
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures			11,841	19,408	18,164
Stock Issued During Period, Value, Stock Options Exercised			0
Tax Benefit from Stock Options Exercised			0
Dividends, Common Stock, Cash			0	0	0
Noncontrolling Interest, Change in Redemption Value			0	0	0
Retained Earnings [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	914,401	816,846	914,401	816,846	798,809	814,359
Net Income (Loss) Attributable to Parent			136,115	51,265	128,467
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax			0	0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax			0	0	0
Payments for Repurchase of Common Stock			0	0	0
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures			0	0	0
Tax Benefit from Stock Options Exercised			0	0	0
Dividends, Common Stock, Cash			(38,560)	(33,228)	(144,017)
Noncontrolling Interest, Change in Redemption Value			0
Accumulated Other Comprehensive Income (Loss) [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	13,627	35,188	13,627	35,188	12,991	(15,800)
Net Income (Loss) Attributable to Parent			0	0	0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax			(7,279)	(1,024)	554
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax			70	192	423
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax			(14,352)	23,029	27,814
Payments for Repurchase of Common Stock			0	0	0
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures			0	0	0
Tax Benefit from Stock Options Exercised			0	0	0
Dividends, Common Stock, Cash			0	0	0
Noncontrolling Interest, Change in Redemption Value			0	0	0
Noncontrolling Interest [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,263	1,096	1,263	1,096	780	429
Net Income (Loss) Attributable to Parent			0	0	0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax			0	0
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax			0	0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax			0	0	0
Payments for Repurchase of Common Stock			0	0	0
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures			0	0	0
Tax Benefit from Stock Options Exercised			0	0	0
Dividends, Common Stock, Cash			0	0	0
Noncontrolling Interest, Change in Redemption Value			$ 167	$ 316	$ 351