Stock-Based Compensation (Details 3) (Stock options, USD $) In Thousands, except Per Share data, unless otherwise specified					12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010	Mar. 31, 2013 Range of exercise price, $ 12.65 - $ 25.00	Mar. 31, 2013 Range of exercise price, $ 25.01 - $ 35.00	Mar. 31, 2013 Range of exercise price, $ 35.01 - $ 94.00	Mar. 31, 2013 Range of exercise price, $ 94.01 - $ 100.00	Mar. 31, 2013 Range of exercise price, $ 100.01 - $ 134.97	Mar. 31, 2013 Total	Mar. 31, 2012 Total	Mar. 31, 2011 Total
Stock options outstanding, and stock options exercisable
Lower range					$ 12.65	$ 25.01	$ 35.01	$ 94.01	$ 100.01
Upper range					$ 25.00	$ 35.00	$ 94.00	$ 100.00	$ 134.97
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options					971	2,649	84	462	1,195	5,361
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 53.13	$ 57.78	$ 59.82	$ 57.75	$ 23.03	$ 31.86	$ 61.02	$ 95.14	$ 107.98
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term					6 years 292 days	4 years 256 days	0 years 109 days	1 year 109 days	1 year 36 days	2 years 192 days
Options exercisable (in shares)	3,254				81	1,432	84	462	1,195	3,254	3,334	2,860
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price					$ 17.32	$ 31.59	$ 61.02	$ 95.14	$ 107.98	$ 69.07	$ 73.60	$ 77.20
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value										$ 3,555