CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	3 Months Ended
	Apr. 30, 2015	Apr. 30, 2014
Operating activities:
Net income	$ 19.1	$ 28.3
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion	37.8	36.1
Stock-based compensation expense	50.2	33.6
Deferred income taxes	(5.3)	21.1
Restructuring charges, net	0	2.3
Other operating activities	(3.5)	8.3
Changes in operating assets and liabilities, net of business combinations
Accounts receivable	143.1	117.2
Prepaid expenses and other current assets	(22.4)	(1.6)
Accounts payable and accrued liabilities	(110.8)	(44.8)
Deferred revenue	(3.4)	52.5
Accrued income taxes	(18.3)	(34.3)
Net cash provided by operating activities	86.5	218.7
Investing activities:
Purchases of marketable securities	(485.2)	(306.4)
Sales of marketable securities	97.5	59.2
Maturities of marketable securities	192.4	163.1
Capital expenditures	(12.5)	(14.5)
Acquisitions, net of cash acquired	(34.5)	(322.3)
Other investing activities	(10.6)	(0.8)
Net cash used in investing activities	(252.9)	(421.7)
Financing activities:
Proceeds from issuance of common stock, net of issuance costs	34.1	62.2
Repurchase and retirement of common shares	(95.4)	(102.5)
Net cash used in financing activities	(61.3)	(40.3)
Effect of exchange rate changes on cash and cash equivalents	(0.2)	(0.1)
Net decrease in cash and cash equivalents	(227.9)	(243.4)
Cash and cash equivalents at beginning of fiscal year	1,410.6	1,853.0
Cash and cash equivalents at end of period	$ 1,182.7	$ 1,609.6