CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Operating Activities
Net (loss) income	$ (330.5)	$ 81.8	$ 228.8
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, amortization, and accretion	145.8	145.9	128.9
Stock-based compensation expense	197.2	165.6	132.2
Deferred income taxes	235.9	(18.8)	(49.4)
Excess tax benefits from stock-based compensation	0.0	(0.5)	(9.1)
Restructuring charges, net	0.0	3.1	12.8
Other operating activities	(25.0)	16.2	(16.1)
Changes in operating assets and liabilities, net of business combinations:
Accounts receivable	(195.5)	(17.3)	72.3
Prepaid expenses and other current assets	(2.8)	6.8	(20.3)
Accounts payable and accrued liabilities	24.9	130.8	(19.6)
Deferred revenue	360.5	245.2	66.0
Accrued income taxes	3.5	(50.7)	37.0
Net cash provided by operating activities	414.0	708.1	563.5
Investing Activities
Purchases of marketable securities	(2,250.1)	(1,355.1)	(1,214.2)
Sales of marketable securities	329.4	190.0	537.0
Maturities of marketable securities	1,376.6	969.0	742.1
Acquisitions, net of cash acquired	(148.5)	(630.0)	(176.1)
Capital expenditures	(72.4)	(75.5)	(64.2)
Other investing activities	(44.5)	(4.0)	(18.6)
Net cash used in investing activities	(809.5)	(905.6)	(194.0)
Financing Activities
Proceeds from issuance of common stock	110.8	175.4	312.8
Taxes paid related to net share settlement of equity awards	(51.6)	(40.0)	(24.6)
Repurchase and retirement of common shares	(458.0)	(372.4)	(423.8)
Proceeds from debt, net of discount	748.3	0.0	0.0
Excess tax benefits from stock-based compensation	0.0	0.5	9.1
Other financing activities	(6.3)	(3.4)	0.0
Net cash provided by (used in) financing activities	343.2	(239.9)	(126.5)
Effect of exchange rate changes on cash and cash equivalents	(5.3)	(5.0)	(2.2)
Net (decrease) increase in cash and cash equivalents	(57.6)	(442.4)	240.8
Cash and cash equivalents at beginning of fiscal year	1,410.6	1,853.0	1,612.2
Cash and cash equivalents at end of fiscal year	1,353.0	1,410.6	1,853.0
Supplemental cash flow information:
Cash paid during the year for interest	34.7	20.4	20.5
Net cash paid during the year for income taxes	$ 59.1	$ 63.4	$ 75.7