CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $) In Millions, unless otherwise specified	Apr. 30, 2013	Jan. 31, 2013
Current assets [Abstract]:
Cash and cash equivalents	$ 1,655.8	$ 1,612.2
Marketable securities	432.1	342.1
Accounts receivable, net	285.8	495.1
Deferred income taxes	56.0	42.2
Prepaid expenses and other current assets	81.4	60.8
Total current assets	2,511.1	2,552.4
Marketable securities	392.0	411.1
Computer equipment, software, furniture and leasehold improvements, net	129.0	114.9
Purchased technologies, net	69.2	76.0
Goodwill	895.7	871.5
Deferred income taxes, net	134.3	122.8
Other assets	158.4	159.7
Assets, Total	4,289.7	4,308.4
Current liabilities [Abstract]:
Accounts payable	86.1	94.2
Accrued compensation	123.2	189.6
Accrued income taxes	35.4	13.9
Deferred revenue	663.7	647.0
Other accrued liabilities	71.4	99.0
Total current liabilities	979.8	1,043.7
Deferred revenue	187.7	187.6
Long term income taxes payable	193.3	194.2
Long-term Debt	745.8	745.6
Other liabilities	98.6	94.1
Commitments and contingencies
Stockholders' equity [Abstract]:
Preferred stock	0	0
Common stock and additional paid-in capital	1,499.5	1,449.8
Accumulated other comprehensive income	(2.0)	(5.7)
Retained earnings	587.0	599.1
Total stockholders' equity	2,084.5	2,043.2
Liabilities and Equity, Total	$ 4,289.7	$ 4,308.4