CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Operating activities:
Net loss	$ (129.6)	$ (167.7)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, amortization and accretion	28.4	37.4
Stock-based compensation expense	66.8	51.6
Deferred income taxes	(0.4)	6.2
Restructuring (benefits) charges and other facility exit costs, net	(0.3)	52.3
Other operating activities	7.3	8.3
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	220.9	397.4
Prepaid expenses and other current assets	6.2	(14.9)
Accounts payable and accrued liabilities	(133.1)	(80.7)
Deferred revenue	13.3	4.1
Accrued income taxes	(34.3)	(129.6)
Net cash provided by operating activities	45.2	164.4
Investing activities:
Purchases of marketable securities	(119.4)	(577.5)
Sales of marketable securities	100.0	107.6
Maturities of marketable securities	282.6	322.6
Capital expenditures	(8.6)	(22.3)
Acquisitions, net of cash acquired	0.0	(59.6)
Other investing activities	3.9	(1.0)
Net cash provided by (used in) investing activities	258.5	(230.2)
Financing activities:
Proceeds from issuance of common stock, net of issuance costs	50.1	51.2
Taxes paid related to net share settlement of equity awards	(33.0)	(18.3)
Repurchases of common stock	(195.9)	(100.1)
Net cash used in financing activities	(178.8)	(67.2)
Effect of exchange rate changes on cash and cash equivalents	2.2	3.4
Net increase (decrease) in cash and cash equivalents	127.1	(129.6)
Cash and cash equivalents at beginning of period	1,213.1	1,353.0
Cash and cash equivalents at end of period	$ 1,340.2	$ 1,223.4