CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Oct. 31, 2018	Oct. 31, 2017
Operating activities:
Net loss	$ (145.5)	$ (393.4)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation, amortization and accretion	69.8	81.5
Stock-based compensation expense	175.5	199.5
Deferred income taxes	16.5	7.3
Restructuring and other exit costs, net	34.5	0.2
Other operating activities	14.8	18.1
Changes in operating assets and liabilities
Accounts receivable	129.4	143.3
Prepaid expenses and other current assets	8.3	(6.5)
Accounts payable and accrued liabilities	(181.0)	(69.3)
Deferred revenue	(73.8)	(21.8)
Accrued income taxes	17.1	(37.3)
Net cash provided by (used in) operating activities	65.6	(78.4)
Investing activities:
Purchases of marketable securities	(135.3)	(419.6)
Sales of marketable securities	61.3	199.2
Maturities of marketable securities	194.9	530.1
Capital expenditures	(49.4)	(39.3)
Acquisitions, net of cash acquired	(34.1)	0.0
Other investing activities	2.3	(11.5)
Net cash provided by investing activities	39.7	258.9
Financing activities:
Proceeds from issuance of common stock, net of issuance costs	90.1	93.2
Taxes paid related to net share settlement of equity awards	(120.7)	(120.6)
Repurchases of common stock	(261.3)	(437.9)
Proceeds from debt, net of discount	0.0	496.9
Repayment of debt	0.0	(400.0)
Other financing activities	0.0	(5.8)
Net cash used in financing activities	(291.9)	(374.2)
Effect of exchange rate changes on cash and cash equivalents	(15.7)	5.8
Net decrease in cash and cash equivalents	(202.3)	(187.9)
Cash and cash equivalents at beginning of period	1,078.0	1,213.1
Cash and cash equivalents at end of period	875.7	1,025.2
Non-cash investing activities:
Fair value of common stock issued as consideration for business combination (See Note 8)	$ 44.8	$ 0.0