CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions		12 Months Ended
		Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Operating Activities
Net (loss) income		$ (582.1)	$ (330.5)	$ 81.8
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, amortization, and accretion		139.2	145.8	145.9
Stock-based compensation expense		221.8	197.2	165.6
Deferred income taxes		(38.8)	235.9	(18.8)
Restructuring charges and other facility exit costs, net		80.5	0.0	3.1
Other operating activities		(7.7)	(25.0)	16.2
Changes in operating assets and liabilities, net of business combinations:
Accounts receivable		201.5	(195.5)	(17.3)
Prepaid expenses and other current assets		(13.5)	(2.8)	6.8
Accounts payable and accrued liabilities		2.7	24.9	130.8
Deferred revenue		267.0	360.5	245.2
Accrued income taxes		(100.9)	3.5	(50.7)
Net cash provided by operating activities (1)	[1]	169.7	414.0	708.6
Investing Activities
Purchases of marketable securities		(1,867.9)	(2,250.1)	(1,355.1)
Sales of marketable securities		1,257.7	329.4	190.0
Maturities of marketable securities		1,057.2	1,376.6	969.0
Acquisitions, net of cash acquired		(85.2)	(148.5)	(630.0)
Capital expenditures		(76.0)	(72.4)	(75.5)
Other investing activities		(13.8)	(44.5)	(4.0)
Net cash provided by (used in) investing activities		272.0	(809.5)	(905.6)
Financing Activities
Proceeds from issuance of common stock		119.6	110.8	175.4
Taxes paid related to net share settlement of equity awards		(76.2)	(51.6)	(40.0)
Repurchase and retirement of common shares		(621.7)	(458.0)	(372.4)
Proceeds from debt, net of discount		0.0	748.3	0.0
Other financing activities		0.0	(6.3)	(3.4)
Net cash provided by (used in) financing activities (1)	[1]	(578.3)	343.2	(240.4)
Effect of exchange rate changes on cash and cash equivalents		(3.3)	(5.3)	(5.0)
Net decrease in cash and cash equivalents		(139.9)	(57.6)	(442.4)
Cash and cash equivalents at beginning of fiscal year		1,353.0	1,410.6	1,853.0
Cash and cash equivalents at end of fiscal year		1,213.1	1,353.0	1,410.6
Supplemental cash flow information:
Cash paid during the year for interest		47.6	34.7	20.4
Net cash paid during the year for income taxes		$ 77.7	$ 59.1	$ 63.4

[1] During the three months ended July 31, 2016, the Company early adopted Accounting Standards Update No. 2016-09, “Improvements to Employee Share-Based Payment Accounting (Topic 718)” (“ASU 2016-09”), which addresses among other items, updates to the presentation and treatment of excess tax benefits related to stock based compensation. The Company has adopted changes to the consolidated statements of cash flows on a retrospective basis. The impact for the fiscal year ended January 31, 2015 to net cash provided by operating activities and net cash used in financing activities was $0.5 million. There was no impact to the fiscal year ended January 31, 2016.