CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Millions, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net Of Taxes [Member]	Accumulated Other Comprehensive Income (Loss), Unrealized Gain (Loss) On Securities Available For Sale, Net Of Taxes [Member]	Loss On Cash Flow Hedge, Net Of Taxes [Member]	Treasury Stock, At Cost [Member]
Beginning Balance at Mar. 31, 2010	$ 1,387.7	$ 2.5	$ 965.4	$ 2,389.3	$ 10.4	$ (5.0)		$ (1,974.9)
Beginning Balance, shares at Mar. 31, 2010		249.1
Comprehensive income:
Net earnings	456.2			456.2
Other comprehensive income, net of total tax (benefit) provision of $2.0, $(2.8) and $(3.5) for 2011, 2012 and 2013 respectively	26.6				24.1	2.5
Treasury stock purchases	(464.1)							(464.1)
Shares issued/forfeited for share-based compensation	130.1		(14.4)	(0.3)				144.8
Share-based compensation expense	109.2		109.2
Excess tax benefit of share-based compensation expense	17.2		17.2
Ending Balance at Mar. 31, 2011	1,662.9	2.5	1,077.4	2,845.2	34.5	(2.5)		(2,294.2)
Ending Balance, shares at Mar. 31, 2011		249.1
Comprehensive income:
Net earnings	401.0			401.0
Other comprehensive income, net of total tax (benefit) provision of $2.0, $(2.8) and $(3.5) for 2011, 2012 and 2013 respectively	(0.1)				(0.5)	0.4
Treasury stock purchases	(818.7)							(818.7)
Shares issued/forfeited for share-based compensation	54.1		(44.5)	(0.9)				99.5
Share-based compensation expense	133.2		133.2
Excess tax benefit of share-based compensation expense	13.4		13.4
Ending Balance at Mar. 31, 2012	1,445.8	2.5	1,179.5	3,245.3	34.0	(2.1)		(3,013.4)
Ending Balance, shares at Mar. 31, 2012		249.1
Comprehensive income:
Net earnings	331.0			331.0
Other comprehensive income, net of total tax (benefit) provision of $2.0, $(2.8) and $(3.5) for 2011, 2012 and 2013 respectively	0.1				(0.3)	0.7	(0.3)
Treasury stock purchases	(1,195.2)		(225.0)					(970.2)
Shares issued/forfeited for share-based compensation	81.0		(49.5)					130.5
Share-based compensation expense	152.9		152.9
Excess tax benefit of share-based compensation expense	2.9		2.9
Ending Balance at Mar. 31, 2013	$ 818.5	$ 2.5	$ 1,060.8	$ 3,576.3	$ 33.7	$ (1.4)	$ (0.3)	$ (3,853.1)
Ending Balance, shares at Mar. 31, 2013		249.1