Stock Plans 8 (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Restricted Stock Awards (RSAs) [Member]
Summary of RSA and RSU activity under the Plans
Shares, Outstanding beginning balance	5.0	5.7	5.8
Weighted average grant date fair value, Outstanding beginning balance (in dollars per share)	$ 24.98	$ 22.41	$ 20.56
Shares, Granted	2.7	3.5	3.8
Weighted average grant date fair value, Granted (in dollars per share)	$ 27.06	$ 26.21	$ 24.54
Shares, Released	(2.6)	(3.6)	(3.0)
Weighted average grant date fair value, Released (in dollars per share)	$ 24.49	$ 22.22	$ 21.57
Shares, Forfeitures	(0.8)	(0.6)	(0.9)
Weighted average grant date fair value, Forfeitures (in dollars per share)	$ 26.14	$ 24.69	$ 22.33
Shares, Outstanding ending balance	4.3	5.0	5.7
Weighted average grant date fair value, Outstanding ending balance (in dollars per share)	$ 26.38	$ 24.98	$ 22.41
Restricted Stock Units (RSUs) [Member]
Summary of RSA and RSU activity under the Plans
Shares, Outstanding beginning balance	1.4	1.2	1.0
Weighted average grant date fair value, Outstanding beginning balance (in dollars per share)	$ 23.28	$ 21.91	$ 20.03
Shares, Granted	0.7	0.9	0.7
Weighted average grant date fair value, Granted (in dollars per share)	$ 25.45	$ 23.72	$ 24.06
Shares, Released	(0.6)	(0.6)	(0.3)
Weighted average grant date fair value, Released (in dollars per share)	$ 23.01	$ 21.03	$ 20.70
Shares, Forfeitures	(0.1)	(0.1)	(0.2)
Weighted average grant date fair value, Forfeitures (in dollars per share)	$ 24.41	$ 23.38	$ 21.61
Shares, Outstanding ending balance	1.4	1.4	1.2
Weighted average grant date fair value, Outstanding ending balance (in dollars per share)	$ 24.47	$ 23.28	$ 21.91