Workday (WDAY) 10-Q 5 Dec 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
In Millions, unless otherwise specified	Oct. 31, 2014	Nov. 30, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	31-Oct-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'WDAY	'
Entity Registrant Name	'Workday, Inc.	'
Entity Central Index Key	'0001327811	'
Current Fiscal Year End Date	'--01-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	187

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Oct. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$192,142	$581,326	[1]
Marketable securities	1,642,517	1,305,253	[1]
Accounts receivable, net	118,943	92,184	[1]
Deferred costs	19,024	16,446	[1]
Prepaid expenses and other current assets	37,120	28,449	[1]
Total current assets	2,009,746	2,023,658	[1]
Property and equipment, net	116,640	77,664	[1]
Deferred costs, noncurrent	18,342	20,797	[1]
Goodwill and acquisition-related intangible assets, net	35,079	8,488	[1]
Other assets	52,511	45,658	[1]
Total assets	2,232,318	2,176,265	[1]
Current liabilities:	'	'
Accounts payable	9,610	6,212	[1]
Accrued expenses and other current liabilities	34,508	17,999	[1]
Accrued compensation	47,510	55,620	[1]
Capital leases	4,681	9,377	[1]
Unearned revenue	441,324	332,682	[1]
Total current liabilities	537,633	421,890	[1]
Convertible senior notes, net	484,855	468,412	[1]
Capital leases, noncurrent	0	3,589	[1]
Unearned revenue, noncurrent	66,807	80,883	[1]
Other liabilities	13,807	14,274	[1]
Total liabilities	1,103,102	989,048	[1]
Stockholders’ equity:	'	'
Common stock	185	181	[1]
Additional paid-in capital	1,891,872	1,761,156	[1]
Accumulated other comprehensive income (loss)	64	269	[1]
Accumulated deficit	-762,905	-574,389	[1]
Total stockholders’ equity	1,129,216	1,187,217	[1]
Total liabilities and stockholders’ equity	$2,232,318	$2,176,265	[1]
[1]	Amounts as of January 31, 2014 were derived from the January 31, 2014 audited financial statements.

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended				9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Oct. 31, 2014		Oct. 31, 2013		Oct. 31, 2014		Oct. 31, 2013
Revenues:	'		'		'		'
Subscription services	$164,403		$93,925		$431,462		$243,454
Professional services	50,667		33,947		130,125		83,618
Total revenues	215,070		127,872		561,587		327,072
Costs and expenses:	'		'		'		'
Costs of subscription services	27,426	[1]	18,076	[1]	73,258	[1]	49,333	[1]
Costs of professional services	44,363	[1]	30,515	[1]	121,590	[1]	76,711	[1]
Product development	85,270	[1]	49,349	[1]	227,905	[1]	126,799	[1]
Sales and marketing	80,681	[1]	54,051	[1]	227,371	[1]	136,565	[1]
General and administrative	28,796	[1]	16,280	[1]	76,781	[1]	42,970	[1]
Total costs and expenses	266,536		168,271		726,905		432,378
Operating loss	-51,466		-40,399		-165,318		-105,306
Other expense, net	-8,047		-6,893		-21,999		-10,628
Loss before provision for income taxes	-59,513		-47,292		-187,317		-115,934
Provision for income taxes	399		242		1,199		593
Net loss	($59,912)		($47,534)		($188,516)		($116,527)
Net loss per share, basic and diluted	($0.33)		($0.27)		($1.03)		($0.68)
Weighted-average shares used to compute net loss per share, basic and diluted	184,310		174,385		182,770		171,269
[1]	Costs and expenses include share-based compensation as follows: Costs of subscription services $1,959 $783 $4,622 $1,446 Costs of professional services $4,214 $1,559 $9,931 $2,835 Product development $19,191 $7,032 $46,796 $12,404 Sales and marketing $8,678 $4,583 $22,807 $7,431 General and administrative $12,966 $5,726 $32,508 $12,766

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Operations (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Costs of subscription services	'	'	'	'
Allocated share-based compensation expense	$1,959	$783	$4,622	$1,446
Costs of professional services	'	'	'	'
Allocated share-based compensation expense	4,214	1,559	9,931	2,835
Product development	'	'	'	'
Allocated share-based compensation expense	19,191	7,032	46,796	12,404
Sales and marketing	'	'	'	'
Allocated share-based compensation expense	8,678	4,583	22,807	7,431
General and administrative	'	'	'	'
Allocated share-based compensation expense	$12,966	$5,726	$32,508	$12,766

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Comprehensive Loss (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net loss	($59,912)	($47,534)	($188,516)	($116,527)
Other comprehensive income (loss), net of tax:	'	'	'	'
Changes in foreign currency translation adjustment	-201	32	-177	-54
Net change in unrealized gains (losses) on available-for-sale investments	302	41	-28	170
Other comprehensive income (loss), net of tax	101	73	-205	116
Comprehensive loss	($59,811)	($47,461)	($188,721)	($116,411)

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014		Oct. 31, 2013
Cash flows from operating activities	'	'	'		'
Net loss	($59,912)	($47,534)	($188,516)		($116,527)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:	'	'	'		'
Depreciation and amortization	15,682	9,361	42,679		23,981
Share-based compensation expenses	47,008	19,683	116,664		36,882
Amortization of deferred costs	5,740	3,211	14,113		8,449
Amortization of debt discount and issuance costs	6,083	5,764	18,005		8,554
Other	1,808	86	2,654		256
Changes in operating assets and liabilities, net of business combinations:	'	'	'		'
Accounts receivable	-18,598	-19,997	-27,052		-19,674
Deferred costs	-4,340	-5,346	-14,236		-12,449
Prepaid expenses and other assets	1,586	-2,652	-8,512		-12,794
Accounts payable	4,056	1,891	1,603		5,563
Accrued expense and other liabilities	15,271	16,458	1,760		22,720
Unearned revenue	26,658	26,151	94,566		66,509
Net cash provided by operating activities	41,042	7,076	53,728		11,470
Cash flows from investing activities	'	'	'		'
Purchases of marketable securities	-454,219	-499,787	-1,490,404		-1,229,488
Maturities of marketable securities	368,984	256,240	1,136,456		833,107
Sales of available-for-sale securities	0	0	8,138		0
Business combinations, net of cash acquired	0	0	-26,317		0
Purchases of property and equipment	-27,699	-16,757	-65,981		-48,384
Purchase of cost method investment	0	0	-10,000		0
Other	0	0	1,000		90
Net cash (used in) investing activities	-112,934	-260,304	-447,108		-444,675
Cash flows from financing activities	'	'	'		'
Proceeds from borrowings on convertible senior notes, net of issuance costs	0	0	0		584,291
Proceeds from issuance of warrants	0	0	0		92,708
Purchase of convertible senior notes hedges	0	0	0		-143,729
Proceeds from issuance of common stock from employee equity plans	2,615	2,637	20,780		9,312
Principal payments on capital lease obligations	-1,123	-2,817	-8,285		-9,505
Shares repurchased for tax withholdings on vesting of restricted stock	0	-637	-8,291		-637
Other	91	41	151		121
Net cash provided by (used in) financing activities	1,583	-776	4,355		532,561
Effect of exchange rate changes	-183	32	-159		-54
Net increase (decrease) in cash and cash equivalents	-70,492	-253,972	-389,184		99,302
Cash and cash equivalents at the beginning of period	262,634	437,432	581,326	[1]	84,158
Cash and cash equivalents at the end of period	192,142	183,460	192,142		183,460
Supplemental cash flow data	'	'	'		'
Cash paid for interest	56	264	3,614		991
Non-cash investing and financing activities:	'	'	'		'
Property and equipment acquired under capital leases	0	0	0		115
Vesting of early exercise stock options	472	398	1,416		1,974
Purchases of property and equipment, accrued but not paid	$9,052	$1,360	$9,052		$1,360
[1]	Amounts as of January 31, 2014 were derived from the January 31, 2014 audited financial statements.

Overview_and_Basis_of_Presenta

Overview and Basis of Presentation	9 Months Ended
	Oct. 31, 2014
Accounting Policies [Abstract]	'
Overview and Basis of Presentation	'
	Overview and Basis of Presentation
	Company and Background
	Workday provides financial management, human capital management, and analytics applications designed for the world's largest companies, educational institutions, and government agencies. We offer innovative and adaptable technology focused on the consumer Internet experience and cloud delivery model. Our applications are designed for global enterprises to manage complex and dynamic operating environments. We provide our customers highly adaptable, accessible and reliable applications to manage critical business functions that enable them to optimize their financial and human capital resources. We are incorporated in Delaware.
	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (GAAP) and applicable rules and regulations of the Securities and Exchange Commission (SEC) regarding interim financial reporting. The condensed consolidated financial statements include the results of Workday, Inc. and its wholly-owned subsidiaries. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. In the opinion of our management, the information contained herein reflects all adjustments necessary for a fair presentation of Workday’s results of operations, financial position and cash flows. All such adjustments are of a normal, recurring nature. The results of operations for the three and nine months ended October 31, 2014 shown in this report are not necessarily indicative of results to be expected for the full year ending January 31, 2015. The unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements in our Annual Report on Form 10-K for the year ended January 31, 2014, filed on March 31, 2014. There have been no changes to our significant accounting policies described in the annual report that have had a material impact on our condensed consolidated financial statements and related notes.
	Subsequent to the filing of our Annual Report on Form 10-K, we added a policy related to business combinations. For business combinations, we use our best estimates and assumptions to accurately assign fair value to the tangible and intangible assets acquired and liabilities assumed as of the acquisition date. Our estimates are inherently uncertain and subject to refinement. During the measurement period, which may be up to one year from the acquisition date, we may record adjustments to the fair value of these tangible and intangible assets acquired and liabilities assumed, with the corresponding offset to goodwill. In addition, uncertain tax positions and tax-related valuation allowances are initially established in connection with a business combination as of the acquisition date. We continue to collect information and reevaluate these estimates and assumptions quarterly and record any adjustments to our preliminary estimates to goodwill provided that we are within the measurement period. Upon the conclusion of the measurement period or final determination of the fair value of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to our condensed consolidated statements of operations.
	Use of Estimates
	The preparation of condensed consolidated financial statements in conformity with GAAP requires us to make certain estimates, judgments and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. These estimates include, but are not limited to, the determination of the relative selling prices for our services, the recoverability of deferred costs, certain assumptions used in the valuation of equity awards and the fair value of assets acquired and liabilities assumed through business combinations. Actual results could differ from those estimates and such differences could be material to our consolidated financial position and results of operations.
	Segment Information
	We operate in one operating segment, cloud applications. Operating segments are defined as components of an enterprise about which separate financial information is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and assessing performance. Our chief operating decision maker allocates resources and assesses performance based upon discrete financial information at the consolidated level. Since we operate in one operating segment, all required financial segment information can be found in the condensed consolidated financial statements.
	Recent Accounting Pronouncements
	On May 28, 2014, the FASB issued ASU 2014-9 regarding ASC Topic 606, Revenue from Contracts with Customers. The standard provides principles for recognizing revenue for the transfer of promised goods or services to customers with the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance will be effective for our fiscal year beginning February 1, 2017. Early adoption is not permitted. We are currently evaluating the accounting, transition and disclosure requirements of the standard and cannot currently estimate the financial statement impact of adoption.

Marketable_Securities

Marketable Securities	9 Months Ended
	Oct. 31, 2014
Investments, Debt and Equity Securities [Abstract]	'
Marketable Securities	'
	Marketable Securities
	At October 31, 2014, marketable securities consisted of the following (in thousands):
		Amortized		Unrealized		Unrealized			Aggregate
		Cost		Gains		Losses			Fair Value
	U.S. agency obligations	$	1,352,592	$	317	$	(51	)	$	1,352,858
	U.S. treasury securities	189,796		84		(4		)	189,876
	U.S. corporate securities	99,826		3		(46		)	99,783
	Commercial paper	80,991		—		—			80,991
	Money market funds	42,106		—		—			42,106
		$	1,765,311	$	404	$	(101	)	$	1,765,614
	Included in cash and cash equivalents	$	123,097	$	—	$	—		$	123,097
	Included in marketable securities	$	1,642,214	$	404	$	(101	)	$	1,642,517
	At January 31, 2014, marketable securities consisted of the following (in thousands):
		Amortized		Unrealized		Unrealized			Aggregate
		Cost		Gains		Losses			Fair Value
	U.S. agency obligations	$	1,125,170	$	334	$	(50	)	$	1,125,454
	U.S. treasury securities	536,747		88		(47		)	536,788
	Commercial paper	62,997		—		—			62,997
	U.S. corporate securities	11,771		6		—			11,777
	Money market funds	90,159		—		—			90,159
		$	1,826,844	$	428	$	(97	)	$	1,827,175
	Included in cash and cash equivalents	$	521,956	$	3	$	(37	)	$	521,922
	Included in marketable securities	$	1,304,888	$	425	$	(60	)	$	1,305,253
	We do not believe the unrealized losses represent other-than-temporary impairments based on our evaluation of available evidence, which includes our intent to hold these investments to maturity as of October 31, 2014. No marketable securities held as of October 31, 2014 have been in a continuous unrealized loss position for more than 12 months. We classify our marketable securities as available-for-sale at the time of purchase and reevaluate such classification as of each balance sheet date. We may sell these securities at any time for use in current operations or for other purposes, such as consideration for acquisitions, even if they have not yet reached maturity. As a result, we classify our investments, including securities with maturities beyond twelve months as Current assets in the accompanying condensed consolidated balance sheets. Marketable securities on the condensed consolidated balance sheets consist of securities with original maturities at the time of purchase of greater than three months and the remainder of the securities is reflected in cash and cash equivalents. During the three months ended October 31, 2014, we did not have any sales of available-for-sale securities. During the nine months ended October 31 2014, we sold $8.1 million of our available-for-sale securities and the realized gain from the sale is immaterial.

Deferred_Costs

Deferred Costs	9 Months Ended
	Oct. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]	'
Deferred Costs	'
	Deferred Costs
	Deferred costs consisted of the following (in thousands):
		October 31,		January 31,
		2014		2014
	Current:
	Deferred professional service costs	$	4,297	$	3,555
	Deferred sales commissions	14,727		12,891
	Total	$	19,024	$	16,446
	Noncurrent:
	Deferred professional service costs	$	1,485	$	4,357
	Deferred sales commissions	16,857		16,440
	Total	$	18,342	$	20,797

Property_and_Equipment_Net

Property and Equipment, Net	9 Months Ended
	Oct. 31, 2014
Property, Plant and Equipment [Abstract]	'
Property and Equipment, Net	'
	Property and Equipment, Net
	Property and equipment consisted of the following (in thousands):
		October 31,			January 31,
		2014			2014
	Computers, equipment and software	$	117,767		$	75,867
	Computers, equipment and software acquired under capital leases	35,873			38,912
	Furniture and fixtures	11,036			7,782
	Leasehold improvements	38,614			15,885
		203,290			138,446
	Less accumulated depreciation and amortization	(86,650		)	(60,782		)
	Property and equipment, net	$	116,640		$	77,664
	Depreciation expense totaled $12.7 million and $7.9 million for the three months ended October 31, 2014 and 2013, respectively, and $32.9 million and $20.5 million for the nine months ended October 31, 2014 and 2013, respectively.
	These amounts include depreciation of assets recorded under capital leases of $2.3 million and $3.0 million for the three months ended October 31, 2014 and 2013, respectively, and $7.1 million and $9.4 million for the nine months ended October 31, 2014 and 2013, respectively.

Business_Combinations

Business Combinations	9 Months Ended
	Oct. 31, 2014
Business Combinations [Abstract]	'
Business Combinations	'
	Business Combinations
	Identified, Inc.
	On February 20, 2014, we acquired Identified, Inc., for the purpose of enhancing search capabilities and accelerating the delivery of predictive analytics and machine learning throughout our suite of applications. We have included the financial results of the acquired company in the consolidated financial statements from the date of acquisition. The consideration paid for this acquisition was $26.4 million, not including cash acquired.
	The following table summarizes the estimated fair values of assets acquired and liabilities assumed as of the date of acquisition (in thousands):
	Cash	$	74
	Prepaid expenses and other current assets	150
	Identified intangible assets acquired:
	Developed technology	3,600
	Goodwill	23,824
	Total assets acquired	27,648
	Accrued expenses and other current liabilities	(1,257		)
	Deferred tax liabilities	—
	Total liabilities assumed	(1,257		)
	Net assets acquired	$	26,391
	The excess of purchase consideration over the fair value of net tangible and identifiable intangible assets acquired was recorded as goodwill. The fair values assigned to tangible and identifiable intangible assets acquired and liabilities assumed are based on management’s estimates and assumptions. The preliminary estimated fair values of assets acquired and liabilities assumed, including current and noncurrent income taxes payable and deferred taxes, and identifiable intangible assets may be subject to change as additional information is received and certain tax returns are finalized. We expect to finalize the allocation of purchase consideration as soon as practicable and no later than one year from the acquisition date.
	Developed technology represents the estimated fair value of the acquired existing technology and is being amortized over its estimated remaining useful life of three years. Goodwill amounts are not amortized, but rather tested for impairment at least annually during the last three months of the fiscal year. The goodwill balance is not deductible for U.S. income tax purposes.

Goodwill_and_Acquisitionrelate

Goodwill and Acquisition-related Intangible Assets, Net	9 Months Ended
	Oct. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Acquisition-related Intangible Assets, Net	'
	Goodwill and Acquisition-related Intangible Assets, net
	Goodwill and acquisition-related intangible assets consisted of the following (in thousands):
		October 31,			January 31,
		2014			2014
	Acquired purchased technology	$	4,200		$	600
	Customer relationship assets	338			338
		4,538			938
	Less accumulated amortization	(1,771		)	(938		)
	Intangible assets, net	2,767			—
	Goodwill	32,312			8,488
	Goodwill and acquisition-related intangible assets, net	$	35,079		$	8,488

Other_Assets

Other Assets	9 Months Ended
	Oct. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]	'
Other Assets	'
	Other Assets
	Other assets consisted of the following (in thousands):
		October 31,		January 31,
		2014		2014
	Issuance costs of convertible senior notes	$	9,064	$	10,625
	Acquired land leasehold interest, net	9,912		9,991
	Technology patents, net	4,172		4,865
	Cost method investment	10,000		—
	Other	19,363		20,177
	Total	$	52,511	$	45,658
	Amortization expense on our land leasehold interest and technology patents, both of which were acquired in the three months ended January 31, 2014, was $0.3 million and $0.8 million, respectively, for the three months and nine months ended October 31, 2014. In July 2014, we purchased 1.4 million shares of series D preferred stock in a private company for $10.0 million. The investment is recorded at cost as we do not have significant influence over the company’s operational or financial policies.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Oct. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	We measure our financial assets and liabilities at fair value at each reporting period using a fair value hierarchy that requires that we maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s classification within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Three levels of inputs may be used to measure fair value:
	Level 1 — Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets.
	Level 2 — Include other inputs that are directly or indirectly observable in the marketplace.
	Level 3 — Unobservable inputs that are supported by little or no market activity.
	Financial assets
	We value our marketable securities using quoted prices for identical instruments in active markets when available. If we are unable to value our marketable securities using quoted prices for identical instruments in active markets, we value our investments using broker reports that utilize quoted market prices for identical or comparable instruments. We validate, on a sample basis, the derived prices provided by the brokers by comparing their assessment of the fair values of our investments against the fair values of the portfolio balances of another third-party professional’s pricing service. To date, all of our marketable securities can be valued using one of these two methodologies.
	Based on our valuation of our marketable securities, we concluded that they are classified in either Level 1 or Level 2 and we have no financial assets or liabilities measured using Level 3 inputs. The following tables present information about our assets that are measured at fair value on a recurring basis using the above input categories (in thousands):
		Fair Value Measurements as of
		31-Oct-14
	Description	Level 1		Level 2		Total
	U.S. agency obligations	$	—	$	1,352,858	$	1,352,858
	U.S. treasury securities	189,876		—		189,876
	U.S. corporate securities	—		99,783		99,783
	Commercial paper	—		80,991		80,991
	Money market funds	42,106		—		42,106
		$	231,982	$	1,533,632	$	1,765,614
	Included in cash and cash equivalents					$	123,097
	Included in marketable securities					$	1,642,517
		Fair Value Measurements as of
		January 31, 2014
	Description	Level 1		Level 2		Total
	U.S. agency obligations	$	—	$	1,125,454	$	1,125,454
	U.S. treasury securities	536,788		—		536,788
	Commercial paper	—		62,997		62,997
	U.S. corporate securities	—		11,777		11,777
	Money market funds	90,159		—		90,159
		$	626,947	$	1,200,228	$	1,827,175
	Included in cash and cash equivalents					$	521,922
	Included in marketable securities					$	1,305,253
	Financial liabilities
	The carrying amounts and estimated fair values of financial instruments not recorded at fair value are as follows (in thousands):
		October 31, 2014				January 31, 2014
		Carrying		Estimated		Carrying		Estimated
		Amount		Fair Value		Amount		Fair Value
	0.75% Convertible senior notes	$	291,721	$	460,688	$	281,359	$	434,875
	1.50% Convertible senior notes	193,134		341,719		187,053		319,219
	The difference between the principal amount of the notes, $350.0 million for the 0.75% convertible senior notes and $250.0 million for the 1.50% convertible senior notes, and the carrying value represents the unamortized debt discount (see Note 9). The estimated fair value of the convertible senior notes, which we have classified as Level 2 financial instruments, was determined based on the quoted bid price of the convertible senior notes in an over-the-counter market on October 31, 2014 and January 31, 2014.
	Based on the closing price of our common stock of $95.48 on October 31, 2014, the if-converted value of the 0.75% convertible senior notes and the if-converted value of the 1.50% convertible senior notes were more than their respective principal amounts.
	Derivative Financial Instruments
	In order to manage certain exposures to currency fluctuations, we initiated a limited hedging program in fiscal 2015 by entering into foreign currency forward contracts to hedge a portion of our net outstanding monetary assets and liabilities. These forward contracts are not designated as hedging instruments under applicable accounting guidance, and therefore all changes in the fair value of the forward contracts are reported in Other expense, net in our condensed consolidated statements of operations. These forward contracts are intended to offset the foreign currency gains or losses associated with the underlying monetary assets and liabilities. We do not enter into any derivatives for trading or speculative purposes.
	As of October 31, 2014 we had no outstanding forward contracts.
	During the nine months ended October 31, 2014, we recognized a gain of less than $0.1 million on non-designated derivative instruments within Other expense, net, in our condensed consolidated statements of operations.
	Our foreign currency contracts are classified within Level 2 because the valuation inputs are based on quoted prices and market observable data of similar instruments in active markets, such as currency spot and forward rates.

Convertible_Senior_Notes

Convertible Senior Notes	9 Months Ended
	Oct. 31, 2014
Debt Disclosure [Abstract]	'
Convertible Senior Notes	'
	Convertible Senior Notes
	Convertible Senior Notes
	In June 2013, we issued 0.75% convertible senior notes due July 15, 2018 (2018 Notes) with a principal amount of $350.0 million. The 2018 Notes are unsecured, unsubordinated obligations, and interest is payable in cash in arrears at a fixed rate of 0.75% on January 15 and July 15 of each year, beginning on January 15, 2014. The 2018 Notes mature on July 15, 2018 unless repurchased or converted in accordance with their terms prior to such date. We cannot redeem the 2018 Notes prior to maturity.
	Concurrently, we issued 1.50% convertible senior notes due July 15, 2020 (2020 Notes) with a principal amount of $250.0 million (together with the 2018 Notes, referred to as Notes). The 2020 Notes are unsecured, unsubordinated obligations of Workday, and interest is payable in cash in arrears at a fixed rate of 1.5% on January 15 and July 15 of each year, beginning on January 15, 2014. The 2020 Notes mature on July 15, 2020 unless repurchased or converted in accordance with their terms prior to such date. We cannot redeem the 2020 Notes prior to maturity.
	The terms of the Notes are governed by Indentures by and between us and Wells Fargo Bank, National Association, as Trustee (the Indentures). Upon conversion, holders of the Notes will receive cash, shares of Class A Common Stock or a combination of cash and shares of Class A Common Stock, at our election.
	For the 2018 Notes, the initial conversion rate is 12.0075 shares of Class A Common Stock per $1,000 principal amount, which is equal to an initial conversion price of approximately $83.28 per share of Class A Common Stock, subject to adjustment. Prior to the close of business on March 14, 2018, the conversion is subject to the satisfaction of certain conditions as described below. For the 2020 Notes, the initial conversion rate is 12.2340 shares of Class A Common Stock per $1,000 principal amount, which is equal to an initial conversion price of approximately $81.74 per share of Class A Common Stock, subject to adjustment. Prior to the close of business on March 13, 2020, the conversion is subject to the satisfaction of certain conditions, as described below.
	Holders of the Notes who convert their Notes in connection with certain corporate events that constitute a make-whole fundamental change (as defined in the Indentures) are, under certain circumstances, entitled to an increase in the conversion rate. Additionally, in the event of a corporate event that constitutes a fundamental change (as defined in the Indentures), holders of the Notes may require us to repurchase all or a portion of their Notes at a price equal to 100% of the principal amount of the Notes, plus any accrued and unpaid interest.
	Holders of the 2018 Notes and 2020 Notes may convert all or a portion of their Notes prior to the close of business on March 14, 2018 for the 2018 Notes and March 13, 2020 for the 2020 Notes, in multiples of $1,000 principal amount, only under the following circumstances, none of which have occurred to date:
	•	if the last reported sale price of Class A Common Stock for at least twenty trading days during a period of thirty consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price of the respective Notes on each applicable trading day;
	•	during the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of the respective Notes for each day of that five day consecutive trading day period was less than 98% of the product of the last reported sale price of Class A Common Stock and the conversion rate of the respective Notes on such trading day; or
	•	upon the occurrence of specified corporate events, as noted in the Indentures.
	In accounting for the issuance of the Notes, we separated each of the Notes into liability and equity components. The carrying amounts of the liability components were calculated by measuring the fair value of similar liabilities that do not have associated convertible features. The carrying amount of the equity components representing the conversion option was determined by deducting the fair value of the liability components from the par value of the respective Notes. These differences represent debt discounts that are amortized to interest expense over the respective terms of the Notes. The equity components are not remeasured as long as they continue to meet the conditions for equity classification.
	We allocated the total issuance costs incurred to the 2018 Notes and 2020 Notes on a prorated basis using the aggregate principal balances. In accounting for the issuance costs related to the 2018 Notes and 2020 Notes, we allocated the total amount of issuance costs incurred to liability and equity components. Issuance costs attributable to the liability components are being amortized to interest expense over the respective terms of the Notes, and the issuance costs attributable to the equity components were netted against the respective equity components in additional paid-in capital. For the 2018 Notes, we recorded liability issuance costs of $7.2 million and equity issuance costs of $2.0 million. Amortization expense for the liability issuance costs was $0.4 million and $0.3 million, respectively, for the three months ended October 31, 2014 and 2013 and $1.1 million and $0.5 million, respectively, for the nine months ended October 31, 2014 and 2013. For the 2020 Notes, we recorded liability issuance costs of $4.7 million and equity issuance costs of $1.8 million. Amortization expense for the liability issuance costs was $0.2 million and $0.2 million, respectively, for the three months ended October 31, 2014 and 2013 and $0.5 million and $0.3 million, respectively, for the nine months ended October 31, 2014 and 2013.
	The Notes consisted of the following (in thousands):
		October 31, 2014						January 31, 2014
		2018 Notes			2020 Notes			2018 Notes			2020 Notes
	Principal amounts:
	Principal	$	350,000		$	250,000		$	350,000		$	250,000
	Unamortized debt discount(1)	(58,279		)	(56,866		)	(68,641		)	(62,947		)
	Net carrying amount	$	291,721		$	193,134		$	281,359		$	187,053
	Carrying amount of the equity component(2)	$	74,892		$	66,007		$	74,892		$	66,007
	-1	Included in the condensed consolidated balance sheets within Convertible senior notes, net and amortized over the remaining lives of the Notes on the straight-line basis as it approximates the effective interest rate method.
	-2	Included in the condensed consolidated balance sheets within Additional paid-in capital, net of $2.0 million and $1.8 million for the 2018 Notes and 2020 Notes, respectively, in equity issuance costs.
	As of October 31, 2014, the remaining life of the 2018 Notes and 2020 Notes is approximately 44 months and 68 months, respectively.
	The effective interest rates of the liability components of the 2018 Notes and 2020 Notes are 5.75% and 6.25%, respectively. These interest rates were based on the interest rates of similar liabilities at the time of issuance that did not have associated convertible features. The following table sets forth total interest expense recognized related to the 2018 Notes and 2020 Notes (in thousands):
		Three Months ended												Nine Months ended
		October 31,												October 31,
		2014						2013						2014				2013
		2018			2020			2018			2020			2018		2020		2018		2020
		Notes			Notes			Notes			Notes			Notes		Notes		Notes		Notes
	Contractual interest expense	$	656		$	938		$	656		$	938		$	1,969	$	2,813	$	977	$	1,396
	Interest cost related to amortization of debt issuance costs	353			168			352			169			1,057		505		524		251
	Interest cost related to amortization of the debt discount	3,503			2,059			3,308			1,935			10,362		6,081		4,909		2,870
	Notes Hedges
	In connection with the issuance of the 2018 Notes and 2020 Notes, we entered into convertible note hedge transactions with respect to our Class A common stock (Purchased Options). The Purchased Options cover, subject to anti-dilution adjustments substantially identical to those in the Notes, approximately 7.3 million shares of our Class A common stock and are exercisable upon conversion of the Notes. The Purchased Options have initial exercise prices that correspond to the initial conversion prices of the 2018 Notes and 2020 Notes, respectively, subject to anti-dilution adjustments substantially similar to those in the Notes. The Purchased Options will expire in 2018 for the 2018 Notes and in 2020 for the 2020 Notes, if not earlier exercised. The Purchased Options are intended to offset potential economic dilution to our Class A Common Stock upon any conversion of the Notes. The Purchased Options are separate transactions and are not part of the terms of the Notes.
	We paid an aggregate amount of $143.7 million for the Purchased Options, which is included in additional paid-in capital in the consolidated balance sheets.
	Warrants
	In connection with the issuance of the Notes, we also entered into warrant transactions to sell warrants (the Warrants) to acquire, subject to anti-dilution adjustments, up to approximately 4.2 million shares in July 2018 and 3.1 million shares in July 2020 of our Class A common stock at an exercise price of $107.96 per share. If the Warrants are not exercised on their exercise dates, they will expire. If the market value per share of our Class A common stock exceeds the applicable exercise price of the Warrants, the Warrants will have a dilutive effect on our earnings per share assuming that we are profitable. The Warrants are separate transactions, and are not part of the terms of the Notes or the Purchased Options.
	We received aggregate proceeds of $92.7 million from the sale of the Warrants, which is recorded in additional paid-in capital in the consolidated balance sheets.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Oct. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	Leases
	We lease office space under noncancelable operating leases in the U.S. and other countries with various expiration dates. In addition, we leased a 6-acre parcel of vacant land under a 95-year lease adjacent to our existing Pleasanton, California leased facility in January 2014. Certain of our office leases are with an affiliate of our Chairman, David Duffield, who is also a significant stockholder (see Note 15).
	The facility lease agreements generally provide for rental payments on a graduated basis and for options to renew, which could increase future minimum lease payments if exercised. We recognize rent expense on a straight-line basis over the period in which we benefit from the lease and have accrued for rent expense incurred but not paid. Rent expense totaled $5.7 million and $3.6 million for the three months ended October 31, 2014 and 2013, respectively, and $14.9 million and $7.4 million for the nine months ended October 31, 2014 and 2013, respectively.
	We leased certain equipment and related software from various third parties. The equipment lease terms contain a bargain purchase option and are therefore classified as capital leases.
	Legal Matters
	We are a party to various legal proceedings and claims which arise in the ordinary course of business. In our opinion, there was not at least a reasonable possibility that we had incurred a material loss, or a material loss in excess of a recorded accrual, with respect to such loss contingencies.

Common_Stock_and_Stockholders_

Common Stock and Stockholders' Equity	9 Months Ended
	Oct. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Common Stock and Stockholders' Equity	'
	Common Stock and Stockholders’ Equity
	Common Stock
	As of October 31, 2014, there were 102.9 million shares of Class A common stock and 84.1 million shares of Class B common stock outstanding. The rights of the holders of Class A common stock and Class B common stock are identical, except with respect to voting, transferability and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to ten votes per share. Each share of Class B common stock can be converted into a share of Class A common stock at any time at the option of the holder.
	Employee Equity Plans
	Our 2012 Equity Incentive Plan (EIP) serves as the successor to our 2005 Stock Plan. Pursuant to the terms of the EIP, the share reserve increased by 9.2 million shares on March 31, 2014. As of October 31, 2014, we had approximately 49.7 million shares of Class A common stock available for future grants under the EIP.
	We also have a 2012 Employee Stock Purchase Plan (ESPP). Under the ESPP, eligible employees are granted options to purchase shares at the lower of 85% of the fair market value of the stock at the time of grant or 85% of the fair market value at the time of exercise. Options to purchase shares are granted twice yearly on or about June 1 and December 1 and exercisable on or about the succeeding November 30 and May 31, respectively, of each year. We commenced our first purchase period under the ESPP on June 1, 2013. On May 31, 2014, 194,231 shares of Class A common shares were purchased under the ESPP at a weighted-average price of $66.61 per share, resulting in cash proceeds of $12.9 million. Pursuant to the terms of the ESPP, the share reserve increased by 1.8 million shares on March 31, 2014. As of October 31, 2014, 3.4 million shares of Class A common stock were available for issuance under the ESPP.
	Stock Options
	The EIP provides for the issuance of stock option awards to employees. Stock option awards generally vest over five years. A summary of information related to stock option activity during the nine months ended October 31, 2014 is as follows (in millions, except share and per share data):
		Outstanding		Weighted-		Aggregate
		Stock		Average		Intrinsic
		Options		Exercise		Value
				Price
	Balance as of January 31, 2014	20,706,207		$	3.93	$	1,773
	Stock option grants	—		—
	Stock options exercised	(2,706,189	)	2.9
	Stock options canceled	(250,830	)	9.65
	Balance as of October 31, 2014	17,749,188		$	4.01	$	1,624
	Vested and expected to vest as of October 31, 2014	17,355,265		$	3.92	$	1,589
	Exercisable as of October 31, 2014	13,378,551		$	2.95	$	1,238
	Common Stock Subject to Repurchase
	The equity plans allow for the early exercise of stock options for certain individuals as determined by the board of directors. We have the right to purchase at the original exercise price any unvested (but issued) common shares during the repurchase period following termination of services of an employee. The consideration received for an exercise of an option is considered to be a deposit of the exercise price and the related dollar amount is recorded as a liability. The shares and liabilities are reclassified into equity as the awards vest. As of October 31, 2014 and January 31, 2014, we had $4.9 million and $6.4 million, respectively, recorded in liabilities related to early exercises of stock options.
	Restricted Stock Awards
	The EIP provides for the issuance of restricted stock awards to employees. Restricted stock awards generally vest over five years. During the three months and nine months ended October 31, 2014, 67,000 and 201,000 shares of restricted stock awards vested and 831,500 restricted awards of Class B common stock are outstanding with weighted average grant date fair value of $12.88, all of which are subject to forfeiture as of October 31, 2014. As of October 31, 2014, there was a total of $10.4 million in unrecognized compensation cost related to restricted stock awards, which is expected to be recognized over a weighted-average period of approximately 3.1 years.
	Restricted Stock Units
	The EIP provides for the issuance of restricted stock units to employees. Restricted stock units generally vest over four years. A summary of information related to restricted stock units activity during the nine months ended October 31, 2014 is as follows:
		Number of Shares		Weighted-Average
				Grant Date Fair Value
	Balance as of January 31, 2014	3,966,728		$	70.72
	Restricted stock units granted	3,441,394		81.51
	Restricted stock units vested	(820,842	)	70.18
	Restricted stock units forfeited	(150,437	)	74.7
	Balance as of October 31, 2014	6,436,843		$	76.47
	As of October 31, 2014, there was a total of $430.7 million in unrecognized compensation cost related to restricted stock units, which is expected to be recognized over a weighted-average period of approximately 3.2 years.
	Performance-based Restricted Stock Awards
	We granted 11,550 and 99,000 shares of performance-based restricted stock units (PRSUs) during the three and nine months ended October 31, 2014, with a weighted average grant date fair value per share of $86.17 and $84.13, respectively. The PRSU awards, which were granted to all employees, include performance conditions related to company-wide goals and service conditions. These PRSU awards will vest if the performance conditions are achieved for the fiscal year ended January 31, 2015 and if the individual employee continues to provide service through the vesting date of March 15, 2015.
	As of October 31, 2014, there was a total of $4.9 million in unrecognized compensation cost related to all performance-based restricted stock units, which is expected to be recognized over a weighted-average period of approximately 0.4 years.

Other_Expense_net

Other Expense, net	9 Months Ended
	Oct. 31, 2014
Other Income and Expenses [Abstract]	'
Other Expense, net	'
	Other Expense, net
	Other expense, net consisted of the following (in thousands):
		Three Months Ended						Nine Months Ended
		October 31,						October 31,
		2014			2013			2014			2013
	Interest income	$	737		$	576		$	2,101		$	1,377
	Interest expense (1)	(7,778		)	(7,663		)	(23,251		)	(11,964		)
	Other income (expense)	(1,006		)	194			(849		)	(41		)
	Other expense, net	$	(8,047	)	$	(6,893	)	$	(21,999	)	$	(10,628	)
	-1	Interest expense includes the contractual interest expense related to the 2018 Notes and 2020 Notes, non-cash interest related to amortization of the debt discount and amortization of debt issuance costs (See Note 9).

Income_Taxes

Income Taxes	9 Months Ended
	Oct. 31, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	The effective tax rate for the three months and nine months ended October 31, 2014 and 2013 was less than one percent, primarily as a result of the estimated and actual tax loss for the fiscal year 2015 and 2014, respectively. Our tax expense relates to state minimum taxes and income taxes associated with our non-U.S. operations.
	There were no material changes to the unrecognized tax benefits for the three months and nine months ended October 31, 2014. We intend to review the measurement of the uncertain tax positions attributable to prior years as a result of additional analysis that will be performed once the information necessary to perform the analysis is available. As a result of the additional analysis, it is reasonably possible that the total amount of unrecognized tax benefits related to prior years could be reduced significantly in the next 12 months. An estimate of the range of the reduction cannot be made as the information necessary to complete the analysis is not available. Due to a valuation allowance, the recognition of any unrecognized tax benefits will not impact the effective tax rate. Due to our history of tax losses, all years remain open to tax audit. However, subsequent to October 31, 2014, the Internal Revenue Service concluded its audit of our calendar 2011 and one month period ended January 31, 2012 federal tax returns and issued a final determination letter. The audit adjustments were immaterial.

Net_Loss_Per_Share

Net Loss Per Share	9 Months Ended
	Oct. 31, 2014
Earnings Per Share [Abstract]	'
Net Loss Per Share	'
	Net Loss Per Share
	Basic net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by giving effect to all potential shares of common stock, our outstanding stock options, outstanding warrants, stock related to unvested early exercised stock options and stock related to unvested restricted stock awards to the extent dilutive. Basic and diluted net loss per share was the same for each period presented as the inclusion of all potential common shares outstanding would have been anti-dilutive.
	The net loss per share attributable to common stockholders is allocated based on the contractual participation rights of the Class A common shares and Class B common shares as if the loss for the year had been distributed. As the liquidation and dividend rights are identical, the net loss attributable to common stockholders is allocated on a proportionate basis.
	We consider shares issued upon the early exercise of options subject to repurchase and unvested restricted stock awards to be participating securities because holders of such shares have non-forfeitable dividend rights in the event of our declaration of a dividend for common shares. In future periods to the extent we are profitable, we will subtract earnings allocated to these participating securities from net income to determine net income attributable to common stockholders.
	The following table presents the calculation of basic and diluted net loss attributable to common stockholders per share (in thousands, except per share data):
		Three Months Ended October 31,													Nine Months Ended October 31,
		2014							2013						2014						2013
		Class A				Class B			Class A			Class B			Class A			Class B			Class A			Class B
	Net loss per share, basic and diluted:
	Numerator:
	Allocation of distributed net loss	$	(32,981	)		$	(26,931	)	$	(19,998	)	$	(27,536	)	$	(100,214	)	$	(88,302	)	$	(39,899	)	$	(76,628	)
	Denominator:
	Weighted-average common shares outstanding	101,462				82,848			73,365			101,020			97,159			85,611			58,642			112,627
	Basic and diluted net loss per share	$	(0.33	)		$	(0.33	)	$	(0.27	)	$	(0.27	)	$	(1.03	)	$	(1.03	)	$	(0.68	)	$	(0.68	)
	The anti-dilutive securities excluded from the weighted-average shares used to calculate the diluted net loss per common share were as follows (in thousands):
		As of October 31,
		2014			2013
	Outstanding common stock options	17,754			22,263
	Shares subject to repurchase	1,299			1,936
	Unvested restricted stock awards, units, and PRSUs	7,378			5,055
	Shares related to the convertible senior notes	7,261			7,261
	Shares subject to warrants related to the issuance of convertible senior notes	7,261			7,261
		40,953			43,776

RelatedParty_Transactions

Related-Party Transactions	9 Months Ended
	Oct. 31, 2014
Related Party Transactions [Abstract]	'
Related-Party Transactions	'
	Related-Party Transactions
	We currently lease certain office space from an affiliate of our Chairman, Mr. Duffield, adjacent to our corporate headquarters in Pleasanton, California under various lease agreements. The term of the agreements is 10 years and the total rent due under the agreements is $3.0 million for the fiscal year ended January 31, 2015, and $50.2 million in total. Rent expense under these agreements for the three months ended October 31, 2014 and 2013 was $1.1 million and $0.4 million, respectively, and for the nine months ended October 31, 2014 and 2013 were $2.6 million and $0.9 million, respectively.
	In June 2010, we entered into a capital lease agreement with an affiliate of Mr. Duffield. The lease agreement provides for an equipment lease financing facility to be drawn upon for purchases of certain equipment for use in our business operations. The capital lease under this agreement was paid in full during the three months ended July 31, 2014. The amounts paid in the three months ended October 31, 2013 was $0.4 million. The amounts paid in the nine months ended October 31, 2014 and 2013 were $0.1 million and $1.9 million, respectively.

Geographic_Information

Geographic Information	9 Months Ended
	Oct. 31, 2014
Segment Reporting [Abstract]	'
Geographic Information	'
	Geographic Information
	Revenue by geography is generally based on the address of the customer as defined in our master subscription agreement. The following tables set forth revenue by geographic area (in thousands):
		Three Months Ended				Nine Months Ended
		October 31,				October 31,
		2014		2013		2014		2013
	United States	$	179,823	$	107,802	$	468,640	$	275,836
	International	35,247		20,070		92,947		51,236
	Total	$	215,070	$	127,872	$	561,587	$	327,072
	No single country other than the United States had revenues greater than 10% of total revenues for the three and nine months ended October 31, 2014 or 2013. No customer individually accounted for more than 10% of our accounts receivable, net as of October 31, 2014 or January 31, 2014.

Overview_and_Basis_of_Presenta1

Overview and Basis of Presentation (Policies)	9 Months Ended
	Oct. 31, 2014
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (GAAP) and applicable rules and regulations of the Securities and Exchange Commission (SEC) regarding interim financial reporting. The condensed consolidated financial statements include the results of Workday, Inc. and its wholly-owned subsidiaries. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. In the opinion of our management, the information contained herein reflects all adjustments necessary for a fair presentation of Workday’s results of operations, financial position and cash flows. All such adjustments are of a normal, recurring nature. The results of operations for the three and nine months ended October 31, 2014 shown in this report are not necessarily indicative of results to be expected for the full year ending January 31, 2015. The unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements in our Annual Report on Form 10-K for the year ended January 31, 2014, filed on March 31, 2014. There have been no changes to our significant accounting policies described in the annual report that have had a material impact on our condensed consolidated financial statements and related notes.
	Subsequent to the filing of our Annual Report on Form 10-K, we added a policy related to business combinations. For business combinations, we use our best estimates and assumptions to accurately assign fair value to the tangible and intangible assets acquired and liabilities assumed as of the acquisition date. Our estimates are inherently uncertain and subject to refinement. During the measurement period, which may be up to one year from the acquisition date, we may record adjustments to the fair value of these tangible and intangible assets acquired and liabilities assumed, with the corresponding offset to goodwill. In addition, uncertain tax positions and tax-related valuation allowances are initially established in connection with a business combination as of the acquisition date. We continue to collect information and reevaluate these estimates and assumptions quarterly and record any adjustments to our preliminary estimates to goodwill provided that we are within the measurement period. Upon the conclusion of the measurement period or final determination of the fair value of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to our condensed consolidated statements of operations.
Use of Estimates	'
	Use of Estimates
	The preparation of condensed consolidated financial statements in conformity with GAAP requires us to make certain estimates, judgments and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. These estimates include, but are not limited to, the determination of the relative selling prices for our services, the recoverability of deferred costs, certain assumptions used in the valuation of equity awards and the fair value of assets acquired and liabilities assumed through business combinations. Actual results could differ from those estimates and such differences could be material to our consolidated financial position and results of operations.
Segment Information	'
	Segment Information
	We operate in one operating segment, cloud applications. Operating segments are defined as components of an enterprise about which separate financial information is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and assessing performance. Our chief operating decision maker allocates resources and assesses performance based upon discrete financial information at the consolidated level. Since we operate in one operating segment, all required financial segment information can be found in the condensed consolidated financial statements.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	On May 28, 2014, the FASB issued ASU 2014-9 regarding ASC Topic 606, Revenue from Contracts with Customers. The standard provides principles for recognizing revenue for the transfer of promised goods or services to customers with the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance will be effective for our fiscal year beginning February 1, 2017. Early adoption is not permitted. We are currently evaluating the accounting, transition and disclosure requirements of the standard and cannot currently estimate the financial statement impact of adoption.
Marketable Securities	'
	We classify our marketable securities as available-for-sale at the time of purchase and reevaluate such classification as of each balance sheet date. We may sell these securities at any time for use in current operations or for other purposes, such as consideration for acquisitions, even if they have not yet reached maturity. As a result, we classify our investments, including securities with maturities beyond twelve months as Current assets in the accompanying condensed consolidated balance sheets. Marketable securities on the condensed consolidated balance sheets consist of securities with original maturities at the time of purchase of greater than three months and the remainder of the securities is reflected in cash and cash equivalents.
Fair Value Measurements	'
	We measure our financial assets and liabilities at fair value at each reporting period using a fair value hierarchy that requires that we maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s classification within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Three levels of inputs may be used to measure fair value:
	Level 1 — Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets.
	Level 2 — Include other inputs that are directly or indirectly observable in the marketplace.
	Level 3 — Unobservable inputs that are supported by little or no market activity.
Fair Value of Financial Instruments	'
	We value our marketable securities using quoted prices for identical instruments in active markets when available. If we are unable to value our marketable securities using quoted prices for identical instruments in active markets, we value our investments using broker reports that utilize quoted market prices for identical or comparable instruments. We validate, on a sample basis, the derived prices provided by the brokers by comparing their assessment of the fair values of our investments against the fair values of the portfolio balances of another third-party professional’s pricing service. To date, all of our marketable securities can be valued using one of these two methodologies.
Income Tax Uncertainties	'
	We intend to review the measurement of the uncertain tax positions attributable to prior years as a result of additional analysis that will be performed once the information necessary to perform the analysis is available. As a result of the additional analysis, it is reasonably possible that the total amount of unrecognized tax benefits related to prior years could be reduced significantly in the next 12 months. An estimate of the range of the reduction cannot be made as the information necessary to complete the analysis is not available. Due to a valuation allowance, the recognition of any unrecognized tax benefits will not impact the effective tax rate. Due to our history of tax losses, all years remain open to tax audit. However, subsequent to October 31, 2014, the Internal Revenue Service concluded its audit of our calendar 2011 and one month period ended January 31, 2012 federal tax returns and issued a final determination letter. The audit adjustments were immaterial.
Net Loss Per Share	'
	Basic net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by giving effect to all potential shares of common stock, our outstanding stock options, outstanding warrants, stock related to unvested early exercised stock options and stock related to unvested restricted stock awards to the extent dilutive. Basic and diluted net loss per share was the same for each period presented as the inclusion of all potential common shares outstanding would have been anti-dilutive.
	The net loss per share attributable to common stockholders is allocated based on the contractual participation rights of the Class A common shares and Class B common shares as if the loss for the year had been distributed. As the liquidation and dividend rights are identical, the net loss attributable to common stockholders is allocated on a proportionate basis.
	We consider shares issued upon the early exercise of options subject to repurchase and unvested restricted stock awards to be participating securities because holders of such shares have non-forfeitable dividend rights in the event of our declaration of a dividend for common shares. In future periods to the extent we are profitable, we will subtract earnings allocated to these participating securities from net income to determine net income attributable to common stockholders.

Marketable_Securities_Tables

Marketable Securities (Tables)	9 Months Ended
	Oct. 31, 2014
Investments, Debt and Equity Securities [Abstract]	'
Summary of Marketable Securities	'
	At October 31, 2014, marketable securities consisted of the following (in thousands):
		Amortized		Unrealized		Unrealized			Aggregate
		Cost		Gains		Losses			Fair Value
	U.S. agency obligations	$	1,352,592	$	317	$	(51	)	$	1,352,858
	U.S. treasury securities	189,796		84		(4		)	189,876
	U.S. corporate securities	99,826		3		(46		)	99,783
	Commercial paper	80,991		—		—			80,991
	Money market funds	42,106		—		—			42,106
		$	1,765,311	$	404	$	(101	)	$	1,765,614
	Included in cash and cash equivalents	$	123,097	$	—	$	—		$	123,097
	Included in marketable securities	$	1,642,214	$	404	$	(101	)	$	1,642,517
	At January 31, 2014, marketable securities consisted of the following (in thousands):
		Amortized		Unrealized		Unrealized			Aggregate
		Cost		Gains		Losses			Fair Value
	U.S. agency obligations	$	1,125,170	$	334	$	(50	)	$	1,125,454
	U.S. treasury securities	536,747		88		(47		)	536,788
	Commercial paper	62,997		—		—			62,997
	U.S. corporate securities	11,771		6		—			11,777
	Money market funds	90,159		—		—			90,159
		$	1,826,844	$	428	$	(97	)	$	1,827,175
	Included in cash and cash equivalents	$	521,956	$	3	$	(37	)	$	521,922
	Included in marketable securities	$	1,304,888	$	425	$	(60	)	$	1,305,253

Deferred_Costs_Tables

Deferred Costs (Tables)	9 Months Ended
	Oct. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]	'
Summary of Deferred Costs	'
	Deferred costs consisted of the following (in thousands):
		October 31,		January 31,
		2014		2014
	Current:
	Deferred professional service costs	$	4,297	$	3,555
	Deferred sales commissions	14,727		12,891
	Total	$	19,024	$	16,446
	Noncurrent:
	Deferred professional service costs	$	1,485	$	4,357
	Deferred sales commissions	16,857		16,440
	Total	$	18,342	$	20,797

Property_and_Equipment_Net_Tab

Property and Equipment, Net (Tables)	9 Months Ended
	Oct. 31, 2014
Property, Plant and Equipment [Abstract]	'
Summary of Property and Equipment	'
	Property and equipment consisted of the following (in thousands):
		October 31,			January 31,
		2014			2014
	Computers, equipment and software	$	117,767		$	75,867
	Computers, equipment and software acquired under capital leases	35,873			38,912
	Furniture and fixtures	11,036			7,782
	Leasehold improvements	38,614			15,885
		203,290			138,446
	Less accumulated depreciation and amortization	(86,650		)	(60,782		)
	Property and equipment, net	$	116,640		$	77,664

Business_Combinations_Tables

Business Combinations (Tables)	9 Months Ended
	Oct. 31, 2014
Business Combinations [Abstract]	'
Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed	'
	The following table summarizes the estimated fair values of assets acquired and liabilities assumed as of the date of acquisition (in thousands):
	Cash	$	74
	Prepaid expenses and other current assets	150
	Identified intangible assets acquired:
	Developed technology	3,600
	Goodwill	23,824
	Total assets acquired	27,648
	Accrued expenses and other current liabilities	(1,257		)
	Deferred tax liabilities	—
	Total liabilities assumed	(1,257		)
	Net assets acquired	$	26,391

Goodwill_and_Acquisitionrelate1

Goodwill and Acquisition-related Intangible Assets, Net (Tables)	9 Months Ended
	Oct. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Schedule of Goodwill and Acquisition-related Intangible Assets	'
	Goodwill and acquisition-related intangible assets consisted of the following (in thousands):
		October 31,			January 31,
		2014			2014
	Acquired purchased technology	$	4,200		$	600
	Customer relationship assets	338			338
		4,538			938
	Less accumulated amortization	(1,771		)	(938		)
	Intangible assets, net	2,767			—
	Goodwill	32,312			8,488
	Goodwill and acquisition-related intangible assets, net	$	35,079		$	8,488

Other_Assets_Tables

Other Assets (Tables)	9 Months Ended
	Oct. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]	'
Schedule of Other Assets	'
	Other assets consisted of the following (in thousands):
		October 31,		January 31,
		2014		2014
	Issuance costs of convertible senior notes	$	9,064	$	10,625
	Acquired land leasehold interest, net	9,912		9,991
	Technology patents, net	4,172		4,865
	Cost method investment	10,000		—
	Other	19,363		20,177
	Total	$	52,511	$	45,658

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Oct. 31, 2014
Fair Value Disclosures [Abstract]	'
Information about Assets that are Measured at Fair Value on a Recurring Basis	'
	The following tables present information about our assets that are measured at fair value on a recurring basis using the above input categories (in thousands):
		Fair Value Measurements as of
		31-Oct-14
	Description	Level 1		Level 2		Total
	U.S. agency obligations	$	—	$	1,352,858	$	1,352,858
	U.S. treasury securities	189,876		—		189,876
	U.S. corporate securities	—		99,783		99,783
	Commercial paper	—		80,991		80,991
	Money market funds	42,106		—		42,106
		$	231,982	$	1,533,632	$	1,765,614
	Included in cash and cash equivalents					$	123,097
	Included in marketable securities					$	1,642,517
		Fair Value Measurements as of
		January 31, 2014
	Description	Level 1		Level 2		Total
	U.S. agency obligations	$	—	$	1,125,454	$	1,125,454
	U.S. treasury securities	536,788		—		536,788
	Commercial paper	—		62,997		62,997
	U.S. corporate securities	—		11,777		11,777
	Money market funds	90,159		—		90,159
		$	626,947	$	1,200,228	$	1,827,175
	Included in cash and cash equivalents					$	521,922
	Included in marketable securities					$	1,305,253
Summary of Carrying Amounts and Estimated Fair Values of Financial Instruments	'
	The carrying amounts and estimated fair values of financial instruments not recorded at fair value are as follows (in thousands):
		October 31, 2014				January 31, 2014
		Carrying		Estimated		Carrying		Estimated
		Amount		Fair Value		Amount		Fair Value
	0.75% Convertible senior notes	$	291,721	$	460,688	$	281,359	$	434,875
	1.50% Convertible senior notes	193,134		341,719		187,053		319,219

Convertible_Senior_Notes_Table

Convertible Senior Notes (Tables)	9 Months Ended
	Oct. 31, 2014
Debt Disclosure [Abstract]	'
Schedule of Senior Notes	'
	The Notes consisted of the following (in thousands):
		October 31, 2014						January 31, 2014
		2018 Notes			2020 Notes			2018 Notes			2020 Notes
	Principal amounts:
	Principal	$	350,000		$	250,000		$	350,000		$	250,000
	Unamortized debt discount(1)	(58,279		)	(56,866		)	(68,641		)	(62,947		)
	Net carrying amount	$	291,721		$	193,134		$	281,359		$	187,053
	Carrying amount of the equity component(2)	$	74,892		$	66,007		$	74,892		$	66,007
	-1	Included in the condensed consolidated balance sheets within Convertible senior notes, net and amortized over the remaining lives of the Notes on the straight-line basis as it approximates the effective interest rate method.
	-2	Included in the condensed consolidated balance sheets within Additional paid-in capital, net of $2.0 million and $1.8 million for the 2018 Notes and 2020 Notes, respectively, in equity issuance costs.
Schedule of Interest Expense Recognized Related to Convertible Senior Notes	'
	The following table sets forth total interest expense recognized related to the 2018 Notes and 2020 Notes (in thousands):
		Three Months ended												Nine Months ended
		October 31,												October 31,
		2014						2013						2014				2013
		2018			2020			2018			2020			2018		2020		2018		2020
		Notes			Notes			Notes			Notes			Notes		Notes		Notes		Notes
	Contractual interest expense	$	656		$	938		$	656		$	938		$	1,969	$	2,813	$	977	$	1,396
	Interest cost related to amortization of debt issuance costs	353			168			352			169			1,057		505		524		251
	Interest cost related to amortization of the debt discount	3,503			2,059			3,308			1,935			10,362		6,081		4,909		2,870

Common_Stock_and_Stockholders_1

Common Stock and Stockholders' Equity (Tables)	9 Months Ended
	Oct. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Summary of Combined Activity Under 2005 Stock Plan and EIP	'
	A summary of information related to stock option activity during the nine months ended October 31, 2014 is as follows (in millions, except share and per share data):
		Outstanding		Weighted-		Aggregate
		Stock		Average		Intrinsic
		Options		Exercise		Value
				Price
	Balance as of January 31, 2014	20,706,207		$	3.93	$	1,773
	Stock option grants	—		—
	Stock options exercised	(2,706,189	)	2.9
	Stock options canceled	(250,830	)	9.65
	Balance as of October 31, 2014	17,749,188		$	4.01	$	1,624
	Vested and expected to vest as of October 31, 2014	17,355,265		$	3.92	$	1,589
	Exercisable as of October 31, 2014	13,378,551		$	2.95	$	1,238
Summary of Information Related to Restricted Stock Units Activity	'
	A summary of information related to restricted stock units activity during the nine months ended October 31, 2014 is as follows:
		Number of Shares		Weighted-Average
				Grant Date Fair Value
	Balance as of January 31, 2014	3,966,728		$	70.72
	Restricted stock units granted	3,441,394		81.51
	Restricted stock units vested	(820,842	)	70.18
	Restricted stock units forfeited	(150,437	)	74.7
	Balance as of October 31, 2014	6,436,843		$	76.47

Other_Expense_Net_Tables

Other Expense, Net (Tables)	9 Months Ended
	Oct. 31, 2014
Other Income and Expenses [Abstract]	'
Other Expense, Net	'
	Other expense, net consisted of the following (in thousands):
		Three Months Ended						Nine Months Ended
		October 31,						October 31,
		2014			2013			2014			2013
	Interest income	$	737		$	576		$	2,101		$	1,377
	Interest expense (1)	(7,778		)	(7,663		)	(23,251		)	(11,964		)
	Other income (expense)	(1,006		)	194			(849		)	(41		)
	Other expense, net	$	(8,047	)	$	(6,893	)	$	(21,999	)	$	(10,628	)
	-1	Interest expense includes the contractual interest expense related to the 2018 Notes and 2020 Notes, non-cash interest related to amortization of the debt discount and amortization of debt issuance costs (See Note 9).

Net_Loss_Per_Share_Tables

Net Loss Per Share (Tables)	9 Months Ended
	Oct. 31, 2014
Earnings Per Share [Abstract]	'
Summary of Calculation of Basic and Diluted Net Income Per Share	'
	The following table presents the calculation of basic and diluted net loss attributable to common stockholders per share (in thousands, except per share data):
		Three Months Ended October 31,													Nine Months Ended October 31,
		2014							2013						2014						2013
		Class A				Class B			Class A			Class B			Class A			Class B			Class A			Class B
	Net loss per share, basic and diluted:
	Numerator:
	Allocation of distributed net loss	$	(32,981	)		$	(26,931	)	$	(19,998	)	$	(27,536	)	$	(100,214	)	$	(88,302	)	$	(39,899	)	$	(76,628	)
	Denominator:
	Weighted-average common shares outstanding	101,462				82,848			73,365			101,020			97,159			85,611			58,642			112,627
	Basic and diluted net loss per share	$	(0.33	)		$	(0.33	)	$	(0.27	)	$	(0.27	)	$	(1.03	)	$	(1.03	)	$	(0.68	)	$	(0.68	)
Summary of Diluted Net Loss Per Common Share	'
	The anti-dilutive securities excluded from the weighted-average shares used to calculate the diluted net loss per common share were as follows (in thousands):
		As of October 31,
		2014			2013
	Outstanding common stock options	17,754			22,263
	Shares subject to repurchase	1,299			1,936
	Unvested restricted stock awards, units, and PRSUs	7,378			5,055
	Shares related to the convertible senior notes	7,261			7,261
	Shares subject to warrants related to the issuance of convertible senior notes	7,261			7,261
		40,953			43,776

Geographic_Information_Tables

Geographic Information (Tables)	9 Months Ended
	Oct. 31, 2014
Segment Reporting [Abstract]	'
Summary of Revenues by Geographic Area	'
	The following tables set forth revenue by geographic area (in thousands):
		Three Months Ended				Nine Months Ended
		October 31,				October 31,
		2014		2013		2014		2013
	United States	$	179,823	$	107,802	$	468,640	$	275,836
	International	35,247		20,070		92,947		51,236
	Total	$	215,070	$	127,872	$	561,587	$	327,072

Overview_and_Basis_of_Presenta2

Overview and Basis of Presentation - Additional Information (Detail)	9 Months Ended
	Oct. 31, 2014
	Segment
Accounting Policies [Abstract]	'
Number of operating segments	1

Marketable_Securities_Summary_

Marketable Securities - Summary of Marketable Securities (Detail) (USD $)	Oct. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	$1,765,311	$1,826,844
Unrealized Gains	404	428
Unrealized Losses	-101	-97
Aggregate Fair Value	1,765,614	1,827,175
U.S. agency obligations	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	1,352,592	1,125,170
Unrealized Gains	317	334
Unrealized Losses	-51	-50
Aggregate Fair Value	1,352,858	1,125,454
U.S. treasury securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	189,796	536,747
Unrealized Gains	84	88
Unrealized Losses	-4	-47
Aggregate Fair Value	189,876	536,788
U.S. corporate securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	99,826	11,771
Unrealized Gains	3	6
Unrealized Losses	-46	0
Aggregate Fair Value	99,783	11,777
Commercial paper	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	80,991	62,997
Unrealized Gains	0	0
Unrealized Losses	0	0
Aggregate Fair Value	80,991	62,997
Money market funds	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	42,106	90,159
Unrealized Gains	0	0
Unrealized Losses	0	0
Aggregate Fair Value	42,106	90,159
Included in cash and cash equivalents	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	123,097	521,956
Unrealized Gains	0	3
Unrealized Losses	0	-37
Aggregate Fair Value	123,097	521,922
Included in marketable securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	1,642,214	1,304,888
Unrealized Gains	404	425
Unrealized Losses	-101	-60
Aggregate Fair Value	$1,642,517	$1,305,253

Marketable_Securities_Addition

Marketable Securities - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Sales of available-for-sale securities	$0	$0	$8,138,000	$0
Included in marketable securities	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Marketable securities continuous unrealized loss position for more than 12 months	$0	'	$0	'

Deferred_Costs_Summary_of_Defe

Deferred Costs - Summary of Deferred Costs (Detail) (USD $)	Oct. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Current:	'	'
Deferred professional service costs	$4,297	$3,555
Deferred sales commissions	14,727	12,891
Total	19,024	16,446	[1]
Noncurrent:	'	'
Deferred professional service costs	1,485	4,357
Deferred sales commissions	16,857	16,440
Total	$18,342	$20,797	[1]
[1]	Amounts as of January 31, 2014 were derived from the January 31, 2014 audited financial statements.

Property_and_Equipment_Net_Sum

Property and Equipment, Net - Summary of Property and Equipment (Detail) (USD $)	Oct. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Property, Plant and Equipment [Abstract]	'	'
Computers, equipment and software	$117,767	$75,867
Computers, equipment and software acquired under capital leases	35,873	38,912
Furniture and fixtures	11,036	7,782
Leasehold improvements	38,614	15,885
Property and equipment, gross	203,290	138,446
Less accumulated depreciation and amortization	-86,650	-60,782
Property and equipment, net	$116,640	$77,664	[1]
[1]	Amounts as of January 31, 2014 were derived from the January 31, 2014 audited financial statements.

Property_and_Equipment_Net_Add

Property and Equipment, Net - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Property, Plant and Equipment [Abstract]	'	'	'	'
Depreciation expense	$12.70	$7.90	$32.90	$20.50
Depreciation on assets recorded under capital leases	$2.30	$3	$7.10	$9.40

Business_Combinations_Addition

Business Combinations - Additional Information (Detail) (USD $)	0 Months Ended
In Thousands, unless otherwise specified	Feb. 20, 2014
Business Acquisition [Line Items]	'
Consideration paid for acquisition, not including cash acquired	26,391
Developed Technology Rights	'
Business Acquisition [Line Items]	'
Estimated remaining useful life	'3 years

Business_Combinations_Summary_

Business Combinations - Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed (Detail) (USD $)	Oct. 31, 2014	Feb. 20, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Identified intangible assets acquired:	'	'	'
Goodwill	$32,312	'	$8,488
Net assets acquired	'	26,391	'
Identified Inc.	'	'	'
Business Acquisition [Line Items]	'	'	'
Cash	'	74	'
Prepaid expenses and other current assets	'	150	'
Identified intangible assets acquired:	'	'	'
Goodwill	'	23,824	'
Total assets acquired	'	27,648	'
Accrued expenses and other current liabilities	'	-1,257	'
Deferred tax liabilities	'	0	'
Total liabilities assumed	'	-1,257	'
Net assets acquired	'	26,391	'
Developed Technology Rights | Identified Inc.	'	'	'
Identified intangible assets acquired:	'	'	'
Developed technology	'	$3,600	'

Goodwill_and_Acquisitionrelate2

Goodwill and Acquisition-related Intangible Assets, Net - Schedule of Goodwill and Acquisition-related Intangible Assets (Detail) (USD $)	Oct. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible assets, gross	$4,538	$938
Less accumulated amortization	-1,771	-938
Intangible assets, net	2,767	0
Goodwill	32,312	8,488
Goodwill and acquisition-related intangible assets, net	35,079	8,488	[1]
Acquired purchased technology	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible assets, gross	4,200	600
Customer relationship assets	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible assets, gross	$338	$338
[1]	Amounts as of January 31, 2014 were derived from the January 31, 2014 audited financial statements.

Other_Assets_Schedule_of_Other

Other Assets - Schedule of Other Assets (Detail) (USD $)	Oct. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]	'	'
Other assets	$52,511	$45,658	[1]
Issuance costs of convertible senior notes	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Other assets	9,064	10,625
Acquired land leasehold interest, net	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Other assets	9,912	9,991
Technology patents, net	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Other assets	4,172	4,865
Cost method investment	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Other assets	10,000	0
Other	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Other assets	$19,363	$20,177
[1]	Amounts as of January 31, 2014 were derived from the January 31, 2014 audited financial statements.

Other_Assets_Additional_Inform

Other Assets - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2014	Jul. 31, 2014
			Series D Preferred Stock
Finite-Lived Intangible Assets [Line Items]	'	'	'
Amortization expense	$0.30	$0.80	'
Number of shares purchased in private company	'	'	1.4
Amount of shares purchased in private company	'	'	$10

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	9 Months Ended
	Oct. 31, 2014	Oct. 31, 2014	Jan. 31, 2014	Jun. 30, 2013	Oct. 31, 2014	Jan. 31, 2014	Jun. 30, 2013
		2018 Notes	2018 Notes	2018 Notes	2020 Notes	2020 Notes	2020 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'	'	'	'
Convertible Senior Notes, principal amount	'	$350,000,000	$350,000,000	$350,000,000	$250,000,000	$250,000,000	$250,000,000
Contractual interest rate	'	0.75%	0.75%	0.75%	1.50%	1.50%	1.50%
Closing price of company's common stock	$95.48	'	'	'	'	'	'
Net gain on non-designated derivative instruments (less than $0.1 million)	$100,000	'	'	'	'	'	'

Fair_Value_Measurements_Inform

Fair Value Measurements - Information about Assets that are Measured at Fair Value on a Recurring Basis (Detail) (USD $)	Oct. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	$1,765,614	$1,827,175
U.S. agency obligations	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	1,352,858	1,125,454
U.S. treasury securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	189,876	536,788
U.S. corporate securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	99,783	11,777
Commercial paper	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	80,991	62,997
Money market funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	42,106	90,159
Included in cash and cash equivalents	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	123,097	521,922
Included in marketable securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	1,642,517	1,305,253
Fair Value, measurements, recurring | Level 1	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	231,982	626,947
Fair Value, measurements, recurring | Level 1 | U.S. agency obligations	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	0	0
Fair Value, measurements, recurring | Level 1 | U.S. treasury securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	189,876	536,788
Fair Value, measurements, recurring | Level 1 | U.S. corporate securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	0	0
Fair Value, measurements, recurring | Level 1 | Commercial paper	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	0	0
Fair Value, measurements, recurring | Level 1 | Money market funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	42,106	90,159
Fair Value, measurements, recurring | Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	1,533,632	1,200,228
Fair Value, measurements, recurring | Level 2 | U.S. agency obligations	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	1,352,858	1,125,454
Fair Value, measurements, recurring | Level 2 | U.S. treasury securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	0	0
Fair Value, measurements, recurring | Level 2 | U.S. corporate securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	99,783	11,777
Fair Value, measurements, recurring | Level 2 | Commercial paper	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	80,991	62,997
Fair Value, measurements, recurring | Level 2 | Money market funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets fair value disclosure	$0	$0

Fair_Value_Measurements_Summar

Fair Value Measurements - Summary of Carrying Amounts and Estimated Fair Values of Financial Instruments (Detail) (USD $)	Oct. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Amount	$484,855	$468,412	[1]
2018 Notes	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Amount	291,721	281,359
Estimated Fair Value	460,688	434,875
2020 Notes	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Amount	193,134	187,053
Estimated Fair Value	$341,719	$319,219
[1]	Amounts as of January 31, 2014 were derived from the January 31, 2014 audited financial statements.

Fair_Value_Measurements_Summar1

Fair Value Measurements - Summary of Carrying Amounts and Estimated Fair Values of Financial Instruments (Parenthetical) (Detail)	Oct. 31, 2014	Jan. 31, 2014	Jun. 30, 2013
2018 Notes	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'
Contractual interest rate	0.75%	0.75%	0.75%
2020 Notes	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'
Contractual interest rate	1.50%	1.50%	1.50%

Convertible_Senior_Notes_Addit

Convertible Senior Notes - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013	Jan. 31, 2014	Jun. 30, 2013
Debt Instrument [Line Items]	'	'	'	'	'	'
Proceeds from sale of warrants	$0	$0	$0	$92,708,000	'	'
2018 Notes	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Convertible Senior Notes, principal amount	350,000,000	'	350,000,000	'	350,000,000	350,000,000
Contractual interest rate	0.75%	'	0.75%	'	0.75%	0.75%
Liability issuance costs	'	'	7,200,000	'	'	'
Equity issuance costs	'	'	2,000,000	'	'	'
Amortization expense for liability issuance costs	353,000	352,000	1,057,000	524,000	'	'
Remaining life of the Notes	'	'	'44 months	'	'	'
Effective interest rates of the liability components	5.75%	'	5.75%	'	'	'
2020 Notes	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Convertible Senior Notes, principal amount	250,000,000	'	250,000,000	'	250,000,000	250,000,000
Contractual interest rate	1.50%	'	1.50%	'	1.50%	1.50%
Liability issuance costs	'	'	4,700,000	'	'	'
Equity issuance costs	'	'	1,800,000	'	'	'
Amortization expense for liability issuance costs	168,000	169,000	505,000	251,000	'	'
Remaining life of the Notes	'	'	'68 months	'	'	'
Effective interest rates of the liability components	6.25%	'	6.25%	'	'	'
Warrants expires in July 2018	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Shares covered by each purchased option/warrant	4.2	'	4.2	'	'	'
Warrants expires in July 2020	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Shares covered by each purchased option/warrant	3.1	'	3.1	'	'	'
Shares related to the convertible senior notes	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Repurchase of notes percentage	'	'	100.00%	'	'	'
Exercise price of warrants, per share	$107.96	'	$107.96	'	'	'
Proceeds from sale of warrants	'	'	92,700,000	'	'	'
Shares related to the convertible senior notes | Employee Stock Option	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Shares covered by each purchased option/warrant	7.3	'	7.3	'	'	'
Aggregate amount for Purchased Options	143,700,000	'	143,700,000	'	'	'
Class A | 2018 Notes	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Initial conversion rate	'	'	12.0075	'	'	'
Principal amount converted in to Class A Common Stock	'	'	1,000	'	'	'
Initial conversion price	$83.28	'	$83.28	'	'	'
Class A | 2020 Notes	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Initial conversion rate	'	'	12.234	'	'	'
Principal amount converted in to Class A Common Stock	'	'	$1,000	'	'	'
Initial conversion price	$81.74	'	$81.74	'	'	'
Debt Conversion, Option One | Shares related to the convertible senior notes	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Threshold trading days	'	'	20	'	'	'
Threshold consecutive trading days	'	'	'30 days	'	'	'
Threshold percentage of conversion price	'	'	130.00%	'	'	'
Debt Conversion, Option Two | Shares related to the convertible senior notes	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Threshold trading days	'	'	5	'	'	'
Threshold consecutive trading days	'	'	'5 days	'	'	'
Debt Conversion, Option Two | Shares related to the convertible senior notes | Maximum	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Threshold percentage of conversion price	'	'	98.00%	'	'	'

Convertible_Senior_Notes_Sched

Convertible Senior Notes - Schedule of Senior Notes (Detail) (USD $)	Oct. 31, 2014		Jan. 31, 2014		Jun. 30, 2013
Convertible Debt [Abstract]	'		'		'
Net carrying amount	$484,855,000		$468,412,000	[1]	'
2018 Notes	'		'		'
Convertible Debt [Abstract]	'		'		'
Principal	350,000,000		350,000,000		350,000,000
Unamortized debt discount	-58,279,000	[2]	-68,641,000	[2]	'
Net carrying amount	291,721,000		281,359,000		'
Carrying amount of the equity component	74,892,000	[3]	74,892,000	[3]	'
2020 Notes	'		'		'
Convertible Debt [Abstract]	'		'		'
Principal	250,000,000		250,000,000		250,000,000
Unamortized debt discount	-56,866,000	[2]	-62,947,000	[2]	'
Net carrying amount	193,134,000		187,053,000		'
Carrying amount of the equity component	$66,007,000	[3]	$66,007,000	[3]	'
[1]	Amounts as of January 31, 2014 were derived from the January 31, 2014 audited financial statements.
[2]	Included in the condensed consolidated balance sheets within Convertible senior notes, net and amortized over the remaining lives of the Notes on the straight-line basis as it approximates the effective interest rate method.
[3]	Included in the condensed consolidated balance sheets within Additional paid-in capital, net of $2.0 million and $1.8 million for the 2018 Notes and 2020 Notes, respectively, in equity issuance costs.

Convertible_Senior_Notes_Sched1

Convertible Senior Notes - Schedule of Senior Notes (Parenthetical) (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Oct. 31, 2014
2018 Notes	'
Debt Instrument [Line Items]	'
Equity issuance costs	$2
2020 Notes	'
Debt Instrument [Line Items]	'
Equity issuance costs	$1.80

Convertible_Senior_Notes_Sched2

Convertible Senior Notes - Schedule of Interest Expense Recognized Related to Convertible Senior Notes (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Debt Instrument [Line Items]	'	'	'	'
Interest cost related to amortization of the debt discount	$6,083	$5,764	$18,005	$8,554
2018 Notes	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Contractual interest expense	656	656	1,969	977
Interest cost related to amortization of debt issuance costs	353	352	1,057	524
Interest cost related to amortization of the debt discount	3,503	3,308	10,362	4,909
2020 Notes	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Contractual interest expense	938	938	2,813	1,396
Interest cost related to amortization of debt issuance costs	168	169	505	251
Interest cost related to amortization of the debt discount	$2,059	$1,935	$6,081	$2,870

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2014	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
	acre
Commitments and Contingencies Disclosure [Abstract]	'	'	'	'	'
Parcel of vacant land	6	'	'	'	'
Lease term period	'95 years	'	'	'	'
Rent expense	'	$5.70	$3.60	$14.90	$7.40

Common_Stock_and_Stockholders_2

Common Stock and Stockholders' Equity - Additional Information (Detail) (USD $)

Oct. 31, 2014

Jan. 31, 2014

31-May-14

Mar. 31, 2014

Oct. 31, 2014

Oct. 31, 2014

Oct. 31, 2014

Oct. 31, 2014

Oct. 31, 2014

Jan. 31, 2014

Oct. 31, 2014

Oct. 31, 2014

Oct. 31, 2014

Mar. 31, 2014

Oct. 31, 2014

Oct. 31, 2014

Oct. 31, 2014

In Millions, except Share data, unless otherwise specified

Employee Stock Purchase Plan

Employee Stock Purchase Plan

Employee Stock Purchase Plan

Employee Stock Option

Restricted Stock Award

Restricted Stock Award

Restricted Stock Units

Restricted Stock Units

Performance-based Restricted Stock Units (PRSUs)

Performance-based Restricted Stock Units (PRSUs)

Class A

Class A

Class A

Class B

Class B

vote

2012 Equity Incentive Plan

2012 Equity Incentive Plan

vote

Restricted Stock Award

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, outstanding

'

'

'

'

'

'

'

'

'

'

'

'

102,900,000

'

'

84,100,000

'

Common stock, votes per share

'

'

'

'

'

'

'

'

'

'

'

'

1

'

'

10

'

Share reserve increased

'

'

'

1,800,000

'

'

'

'

'

'

'

'

'

9,200,000

'

'

'

Common stock available for future grants

'

'

'

'

3,400,000

'

'

'

'

'

'

'

'

'

49,700,000

'

'

Employee Stock Purchase Plan Purchase Price Of Shares As Percentage Of Fair Market Value Of Common Stock, At The Time Of Exercise

'

'

'

'

85.00%

'

'

'

'

'

'

'

'

'

'

'

'

Employee Stock Purchase Plan Purchase Price Of Shares As Percentage Of Fair Market Value Of Common Stock, At The Time Of Grant

'

'

'

'

85.00%

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares purchased by employees

'

'

194,231

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted-average purchase price (in dollars per share)

'

'

$66.61

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash proceeds

'

'

$12.90

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted stock awards vesting period

'

'

'

'

'

'5 years

'

'5 years

'4 years

'

'

'

'

'

'

'

'

Liabilities related to early exercises of stock options

4.9

6.4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted stock awards vested

'

'

'

'

'

'

67,000

201,000

820,842

'

'

'

'

'

'

'

'

Restricted stock awards outstanding

'

'

'

'

'

'

'

'

6,436,843

3,966,728

'

'

'

'

'

'

831,500

Restricted stock weighted-average grant date fair value (in dollars per share)

'

'

'

'

'

'

'

'

$76.47

$70.72

'

'

'

'

'

'

$12.88

Unrecognized compensation cost

'

'

'

'

'

'

$10.40

$10.40

$430.70

'

$4.90

$4.90

'

'

'

'

'

Weighted-average period to be recognized

'

'

'

'

'

'

'

'3 years 1 month 18 days

'3 years 2 months 18 days

'

'

'4 months 15 days

'

'

'

'

'

Number of shares granted

'

'

'

'

'

'

'

'

3,441,394

'

11,550

99,000

'

'

'

'

'

Weighted average grant date fair value (in dollars per share)

'

'

'

'

'

'

'

'

$81.51

'

$86.17

$84.13

'

'

'

'

'

Common_Stock_and_Stockholders_3

Common Stock and Stockholders' Equity - Summary of Combined Activity Under 2005 Stock Plan and EIP (Detail) (USD $)	9 Months Ended
In Millions, except Share data, unless otherwise specified	Oct. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'
Beginning Balance, Outstanding Stock Options	20,706,207
Stock option grants, Outstanding Stock Options	0
Stock options exercised, Outstanding Stock Options	-2,706,189
Stock options canceled, Outstanding Stock Options	-250,830
Ending Balance, Outstanding Stock Options	17,749,188
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]	'
Beginning Balance, Weighted-Average Exercise Price (in dollars per share)	$3.93
Stock option grants, Weighted-Average Exercise Price (in dollars per share)	$0
Stock options exercised, Weighted-Average Exercise Price (in dollars per share)	$2.90
Stock options canceled, Weighted-Average Exercise Price (in dollars per share)	$9.65
Ending Balance, Weighted-Average Exercise Price (in dollars per share)	$4.01
Beginning Balance, Aggregate Intrinsic Value	$1,773
Ending Balance, Aggregate Intrinsic Value	1,624
Vested and expected to vest, Outstanding Stock Options	17,355,265
Vested and expected to vest, Weighted-Average Exercise Price (in dollars per share)	$3.92
Vested and expected to vest, Aggregate Intrinsic Value	1,589
Exercisable, Outstanding Stock Options	13,378,551
Exercisable, Weighted-Average Exercise Price (in dollars per share)	$2.95
Exercisable, Aggregate Intrinsic Value	$1,238

Common_Stock_and_Stockholders_4

Common Stock and Stockholders' Equity - Summary of Information Related to Restricted Stock Units Activity (Detail) (Restricted Stock Units (RSUs), USD $)	9 Months Ended
	Oct. 31, 2014
Restricted Stock Units (RSUs)	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]	'
Beginning Balance, Number of Shares	3,966,728
Restricted stock units granted, Number of Shares	3,441,394
Restricted stock units vested, Number of Shares	-820,842
Restricted stock units forfeited, Number of Shares	-150,437
Ending Balance, Number of Shares	6,436,843
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]	'
Beginning Balance, Weighted-Average Grant Date Fair Value (in dollars per share)	$70.72
Restricted stock units granted, Weighted-Average Grant Date Fair Value (in dollars per share)	$81.51
Restricted stock units vested, Weighted-Average Grant Date Fair Value (in dollars per share)	$70.18
Restricted stock units forfeited, Weighted-Average Grant Date Fair Value (in dollars per share)	$74.70
Ending Balance, Weighted-Average Grant Date Fair Value (in dollars per share)	$76.47

Other_Expense_Net_Other_Expens

Other Expense, Net - Other Expense, Net (Detail) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014		Oct. 31, 2013		Oct. 31, 2014		Oct. 31, 2013
Other Income and Expenses [Abstract]	'		'		'		'
Interest income	$737		$576		$2,101		$1,377
Interest expense	-7,778	[1]	-7,663	[1]	-23,251	[1]	-11,964	[1]
Other income (expense)	-1,006		194		-849		-41
Other expense, net	($8,047)		($6,893)		($21,999)		($10,628)
[1]	Interest expense includes the contractual interest expense related to the 2018 Notes and 2020 Notes, non-cash interest related to amortization of the debt discount and amortization of debt issuance costs (See Note 9).

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Income Tax Contingency [Line Items]	'	'	'	'
Effective tax rate (less than 1%)	1.00%	1.00%	1.00%	1.00%

Net_Loss_Per_Share_Summary_of_

Net Loss Per Share - Summary of Calculation of Basic and Diluted Net Income Per Share (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Denominator:	'	'	'	'
Weighted-average common shares outstanding	184,310	174,385	182,770	171,269
Basic and diluted net loss per share	($0.33)	($0.27)	($1.03)	($0.68)
Class A	'	'	'	'
Numerator:	'	'	'	'
Allocation of distributed net loss	($32,981)	($19,998)	($100,214)	($39,899)
Denominator:	'	'	'	'
Weighted-average common shares outstanding	101,462	73,365	97,159	58,642
Basic and diluted net loss per share	($0.33)	($0.27)	($1.03)	($0.68)
Class B	'	'	'	'
Numerator:	'	'	'	'
Allocation of distributed net loss	($26,931)	($27,536)	($88,302)	($76,628)
Denominator:	'	'	'	'
Weighted-average common shares outstanding	82,848	101,020	85,611	112,627
Basic and diluted net loss per share	($0.33)	($0.27)	($1.03)	($0.68)

Net_Loss_Per_Share_Summary_of_1

Net Loss Per Share - Summary of Diluted Net Loss Per Common Share (Detail)	9 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total anti-dilutive securities	40,953	43,776
Outstanding common stock options	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total anti-dilutive securities	17,754	22,263
Shares subject to repurchase	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total anti-dilutive securities	1,299	1,936
Unvested restricted stock awards, units, and PRSUs	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total anti-dilutive securities	7,378	5,055
Shares related to the convertible senior notes	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total anti-dilutive securities	7,261	7,261
Shares subject to warrants related to the issuance of convertible senior notes	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total anti-dilutive securities	7,261	7,261

RelatedParty_Transactions_Addi

Related-Party Transactions - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 31, 2014	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Related Party Transaction [Line Items]	'	'	'	'	'
Term of agreements	'95 years	'	'	'	'
Amounts paid under lease agreement	'	$1,123,000	$2,817,000	$8,285,000	$9,505,000
Management	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'
Term of agreements	'	'	'	'10 years	'
Total rent due under agreements, 2015	'	3,000,000	'	3,000,000	'
Total rent due under agreements	'	50,200,000	'	50,200,000	'
Rent expense	'	1,100,000	400,000	2,600,000	900,000
Amounts paid under lease agreement	'	'	$400,000	$100,000	$1,900,000

Geographic_Information_Summary

Geographic Information - Summary of Revenues by Geographic Area (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Revenue from External Customer [Line Items]	'	'	'	'
Revenue	$215,070	$127,872	$561,587	$327,072
United States	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'
Revenue	179,823	107,802	468,640	275,836
International	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'
Revenue	$35,247	$20,070	$92,947	$51,236