CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Oct. 31, 2011	Oct. 31, 2010
Operating activities:
Net income	$ 213.3	$ 150.4
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	85.2	79.6
Stock-based compensation expense	78.8	62.3
Excess tax benefits from stock-based compensation	(33.0)
Restructuring (benefits) charges, net	(1.3)	9.0
Changes in operating assets and liabilities, net of business combinations	55.3	63.6
Net cash provided by operating activities	398.3	364.9
Investing activities:
Purchases of marketable securities	(456.0)	(425.8)
Sales of marketable securities	110.8	85.9
Maturities of marketable securities	307.0	201.3
Capital expenditures, including developed technologies	(88.8)	(18.1)
Business combinations, net of cash acquired	(142.6)	(8.5)
Other investing activities	(23.5)	(4.0)
Net cash used in investing activities	(293.1)	(169.2)
Financing activities:
Proceeds from issuance of common stock, net of issuance costs	156.3	76.4
Repurchases of common stock	(263.7)	(204.1)
Excess tax benefits from stock-based compensation	33.0
Net cash used in financing activities	(74.4)	(127.7)
Effect of exchange rate changes on cash and cash equivalents	(2.6)	(2.4)
Net increase in cash and cash equivalents	28.2	65.6
Cash and cash equivalents at beginning of fiscal year	1,075.1	838.7
Cash and cash equivalents at end of period	$ 1,103.3	$ 904.3