Workday (WDAY) 10-Q 2 Sep 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
In Millions, unless otherwise specified	Jul. 31, 2014	Aug. 15, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	31-Jul-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
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	'	186

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Jul. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$262,634	$581,326	[1]
Marketable securities	1,559,748	1,305,253	[1]
Accounts receivable, net	100,534	92,184	[1]
Deferred costs	20,064	16,446	[1]
Prepaid expenses and other current assets	37,830	28,449	[1]
Total current assets	1,980,810	2,023,658	[1]
Property and equipment, net	105,855	77,664	[1]
Deferred costs, noncurrent	18,702	20,797	[1]
Goodwill and acquisition-related intangible assets, net	35,379	8,488	[1]
Other assets	54,152	45,658	[1]
Total assets	2,194,898	2,176,265	[1]
Current liabilities:	'	'
Accounts payable	6,561	6,212	[1]
Accrued expenses and other current liabilities	30,180	17,999	[1]
Accrued compensation	38,565	55,620	[1]
Capital leases	5,133	9,377	[1]
Unearned revenue	409,026	332,682	[1]
Total current liabilities	489,465	421,890	[1]
Convertible senior notes, net	479,293	468,412	[1]
Capital leases, noncurrent	671	3,589	[1]
Unearned revenue, noncurrent	72,447	80,883	[1]
Other liabilities	14,181	14,274	[1]
Total liabilities	1,056,057	989,048	[1]
Stockholders' equity:	'	'
Common stock	183	181	[1]
Additional paid-in capital	1,841,688	1,761,156	[1]
Accumulated other comprehensive income (loss)	-37	269	[1]
Accumulated deficit	-702,993	-574,389	[1]
Total stockholders' equity	1,138,841	1,187,217	[1]
Total liabilities and stockholders' equity	$2,194,898	$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				6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jul. 31, 2014		Jul. 31, 2013		Jul. 31, 2014		Jul. 31, 2013
Revenues:	'		'		'		'
Subscription services	$143,652		$81,111		$267,059		$149,529
Professional services	43,128		26,444		79,458		49,671
Total revenues	186,780		107,555		346,517		199,200
Costs and expenses:	'		'		'		'
Costs of subscription services	24,373	[1]	16,327	[1]	45,832	[1]	31,257	[1]
Costs of professional services	41,267	[1]	24,427	[1]	77,227	[1]	46,196	[1]
Product development	77,464	[1]	41,168	[1]	142,635	[1]	77,450	[1]
Sales and marketing	78,523	[1]	44,150	[1]	146,690	[1]	82,514	[1]
General and administrative	26,922	[1]	13,766	[1]	47,985	[1]	26,690	[1]
Total costs and expenses	248,549	[1]	139,838	[1]	460,369	[1]	264,107	[1]
Operating loss	-61,769		-32,283		-113,852		-64,907
Other expense, net	-6,953		-3,479		-13,952		-3,735
Loss before provision for income taxes	-68,722		-35,762		-127,804		-68,642
Provision for income taxes	493		216		800		351
Net loss	($69,215)		($35,978)		($128,604)		($68,993)
Net loss per share, basic and diluted	($0.38)		($0.21)		($0.70)		($0.40)
Weighted-average shares used to compute net loss per share, basic and diluted	184,319		173,375		183,733		170,617
[1]	Costs and expenses include share-based compensation as follows: Costs of subscription services $ 1,608 $ 401 $ 2,663 $ 663 Costs of professional services 3,519 801 5,717 1,276 Product development 16,737 3,465 27,605 5,372 Sales and marketing 7,377 1,805 14,129 2,848 General and administrative 11,541 3,311 19,542 7,040

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Operations (Parenthetical) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Costs of subscription services [Member]	'	'	'	'
Allocated share-based compensation expense	$1,608	$401	$2,663	$663
Costs of professional services [Member]	'	'	'	'
Allocated share-based compensation expense	3,519	801	5,717	1,276
Product development [Member]	'	'	'	'
Allocated share-based compensation expense	16,737	3,465	27,605	5,372
Selling and Marketing Expense [Member]	'	'	'	'
Allocated share-based compensation expense	7,377	1,805	14,129	2,848
General and Administrative Expense [Member]	'	'	'	'
Allocated share-based compensation expense	$11,541	$3,311	$19,542	$7,040

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Comprehensive Loss (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]	'	'	'	'
Net loss	($69,215)	($35,978)	($128,604)	($68,993)
Other comprehensive income (loss), net of tax:	'	'	'	'
Changes in foreign currency translation adjustment	-15	0	24	-86
Net change in unrealized gains (losses) on available-for-sale investments	-503	46	-330	129
Other comprehensive income (loss), net of tax	-518	46	-306	43
Comprehensive loss	($69,733)	($35,932)	($128,910)	($68,950)

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014		Jul. 31, 2013
Cash flows from operating activities	'	'	'		'
Net loss	($69,215)	($35,978)	($128,604)		($68,993)
Adjustments to reconcile net loss to net cash provided (used in) by operating activities:	'	'	'		'
Depreciation and amortization	14,474	8,051	26,997		14,620
Share-based compensation expenses	40,782	9,783	69,656		17,199
Amortization of deferred costs	4,421	2,756	8,373		5,238
Amortization of debt discount and issuance costs	6,002	2,790	11,922		2,790
Other	242	196	846		170
Changes in operating assets and liabilities, net of business combinations:	'	'	'		'
Accounts receivable	-1,441	-6,808	-8,454		323
Deferred costs	-6,433	-3,867	-9,896		-7,103
Prepaid expenses and other assets	-2,748	-6,579	-10,098		-10,142
Accounts payable	-23	1,251	-2,453		3,672
Accrued expense and other liabilities	-14,602	-9,191	-13,511		6,262
Unearned revenue	19,530	24,680	67,908		40,358
Net cash provided by (used in) operating activities	-9,011	-12,916	12,686		4,394
Cash flows from investing activities	'	'	'		'
Purchases of marketable securities	-365,779	-441,860	-1,036,185		-729,701
Maturities of marketable securities	414,242	170,159	767,472		576,867
Sales of available-for-sale securities	8,138	0	8,138		0
Business combinations, net of cash acquired	0	0	-26,317		0
Purchases of property and equipment	-28,409	-29,732	-38,282		-31,627
Purchase of cost method investment	-10,000	0	-10,000		0
Other	0	0	1,000		90
Net cash provided by (used in) investing activities	18,192	-301,433	-334,174		-184,371
Cash flows from financing activities	'	'	'		'
Proceeds from borrowings on convertible senior notes, net of issuance costs	0	584,291	0		584,291
Proceeds from issuance of warrants	0	92,708	0		92,708
Purchase of convertible senior notes hedges	0	-143,729	0		-143,729
Proceeds from issuance of common stock from employee equity plans	15,169	2,110	18,165		6,675
Principal payments on capital lease obligations	-4,418	-2,935	-7,162		-6,688
Shares repurchased for tax withholdings on vesting of restricted stock	-3,284	0	-8,291		0
Other	0	72	60		80
Net cash provided by financing activities	7,467	532,517	2,772		533,337
Effect of exchange rate changes	-15	0	24		-86
Net increase (decrease) in cash and cash equivalents	16,633	218,168	-318,692		353,274
Cash and cash equivalents at the beginning of period	246,001	219,264	581,326	[1]	84,158
Cash and cash equivalents at the end of period	262,634	437,432	262,634		437,432
Supplemental cash flow data	'	'	'		'
Cash paid for interest	3,369	303	3,558		727
Non-cash investing and financing activities:	'	'	'		'
Property and equipment acquired under capital leases	0	0	0		115
Vesting of early exercise stock options	471	1,045	944		1,576
Purchases of property and equipment, accrued but not paid	$12,171	$413	$12,171		$413
[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	6 Months Ended
	Jul. 31, 2014
Accounting Policies [Abstract]	'
Overview and Basis of Presentation	'
	Note 1. Overview and Basis of Presentation
	Company and Background
	Workday provides enterprise cloud applications for human capital management (HCM), payroll, financial management and analytics. 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 six months ended July 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 2014-09 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	6 Months Ended
	Jul. 31, 2014
Cash And Cash Equivalents [Abstract]	'
Marketable Securities	'
	Note 2. Marketable Securities
	At July 31, 2014, marketable securities consisted of the following (in thousands):
		Amortized		Unrealized		Unrealized			Aggregate
		Cost		Gains		Losses			Fair Value
	U.S. agency obligations	$	1,393,276	$	177	$	(286	)	$	1,393,167
	U.S. treasury securities		178,654		122		—			178,776
	Commercial paper		107,825		—		—			107,825
	U.S. corporate securities		41,987		18		(30	)		41,975
	Money market funds		42,526		—		—			42,526
		$	1,764,268	$	317	$	(316	)	$	1,764,269
	Included in cash and cash equivalents	$	204,524	$	—	$	(3	)	$	204,521
	Included in marketable securities	$	1,559,744	$	317	$	(313	)	$	1,559,748
	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 July 31, 2014. No marketable securities held as of July 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 and six months ended July 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	6 Months Ended
	Jul. 31, 2014
Text Block [Abstract]	'
Deferred Costs	'
	Note 3. Deferred Costs
	Deferred costs consisted of the following (in thousands):
		July 31,		January 31,
		2014		2014
	Current:
	Deferred professional service costs	$	5,487	$	3,555
	Deferred sales commissions		14,577		12,891
	Total	$	20,064	$	16,446
	Noncurrent:
	Deferred professional service costs	$	1,716	$	4,357
	Deferred sales commissions		16,986		16,440
	Total	$	18,702	$	20,797

Property_and_Equipment_Net

Property and Equipment, Net	6 Months Ended
	Jul. 31, 2014
Property Plant And Equipment [Abstract]	'
Property and Equipment, Net	'
	Note 4. Property and Equipment, Net
	Property and equipment consisted of the following (in thousands):
		July 31,			January 31,
		2014			2014
	Computers, equipment and software	$	104,627		$	75,867
	Computers, equipment and software acquired under capital leases		35,899			38,912
	Furniture and fixtures		10,528			7,782
	Leasehold improvements		29,259			15,885
			180,313			138,446
	Less accumulated depreciation and amortization		(74,458	)		(60,782	)
	Property and equipment, net	$	105,855		$	77,664
	Depreciation expense totaled $10.8 million and $7.0 million for the three months ended July 31, 2014 and 2013, respectively, and $20.2 million and $12.6 million for the six months ended July 31, 2014 and 2013, respectively.
	These amounts include depreciation of assets recorded under capital leases of $2.3 million and $3.2 million for the three months ended July 31, 2014 and 2013, respectively and $4.8 million and $6.4 million for the six months ended July 31, 2014 and 2013, respectively.

Business_Combinations

Business Combinations	6 Months Ended
	Jul. 31, 2014
Business Combinations [Abstract]	'
Business Combinations	'
	Note 5. 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	6 Months Ended
	Jul. 31, 2014
Goodwill And Intangible Assets Disclosure [Abstract]	'
Goodwill and Acquisition-related Intangible Assets, Net	'
	Note 6. Goodwill and Acquisition-related Intangible Assets, net
	Goodwill and acquisition-related intangible assets consisted of the following (in thousands):
		July 31,			January 31,
		2014			2014
	Acquired purchased technology	$	4,200		$	600
	Customer relationship assets		338			338
			4,538			938
	Less accumulated amortization		(1,471	)		(938	)
	Intangible assets, net		3,067			—
	Goodwill		32,312			8,488
	Goodwill and acquisition-related intangible assets, net	$	35,379		$	8,488

Other_Assets

Other Assets	6 Months Ended
	Jul. 31, 2014
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]	'
Other Assets	'
	Note 7. Other Assets
	Other assets consisted of the following (in thousands):
		July 31,		January 31,
		2014		2014
	Issuance costs of convertible senior notes	$	9,584	$	10,625
	Acquired land leasehold interest, net		9,939		9,991
	Technology patents, net		4,403		4,865
	Cost method investment		10,000		—
	Other		20,226		20,177
	Total	$	54,152	$	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 $0.5 million, respectively for the three months and six months ended July 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	6 Months Ended
	Jul. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Note 8. 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
		July 31, 2014
	Description	Level 1		Level 2		Total
	U.S. agency obligations	$	—	$	1,393,167	$	1,393,167
	U.S. treasury securities		178,776		—		178,776
	Commercial paper		—		107,825		107,825
	U.S. corporate securities		—		41,975		41,975
	Money market funds		42,526		—		42,526
		$	221,302	$	1,542,967	$	1,764,269
	Included in cash and cash equivalents					$	204,521
	Included in marketable securities					$	1,559,748
		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):
		July 31, 2014				January 31, 2014
		Carrying		Estimated		Carrying		Estimated
		Amount		Fair Value		Amount		Fair Value
	0.75% Convertible senior notes	$	288,218	$	430,938	$	281,359	$	434,875
	1.50% Convertible senior notes		191,075		316,100		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 July 31, 2014 and January 31, 2014.
	Based on the closing price of our common stock of $83.84 on July 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 July 2014 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 July 31, 2014 we had outstanding forward contracts with a total notional value of $2.7 million and all contracts have terms of less than sixty days to maturity. The fair value amounts of the derivative assets and the derivative liabilities, each of which is less than $0.1 million as of July 31, 2014, are included in Prepaid expenses and other current assets and in Accrued and other current liabilities, respectively, on our condensed consolidated balance sheet. We are not a party to a master netting agreement with the respective counterparties of the foreign exchange contracts and thus we are not permitted to net settle transactions of the same currency with a single net amount payable by one party to the other. We do not believe we are subject to significant counterparty concentration risk given the short-term nature, volume, and size of the derivative contracts outstanding.
	During the three months ended July 31, 2014, we recognized a net 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	6 Months Ended
	Jul. 31, 2014
Debt Disclosure [Abstract]	'
Convertible Senior Notes	'
	Note 9. 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 1.50% 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 were 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 $0.7 million, respectively, for the three and six months ended July 31, 2014. 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 $0.3 million, respectively, for the three and six months ended July 31, 2014.
	The Notes consisted of the following (in thousands):
			July 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)			(61,782	)		(58,925	)		(68,641	)		(62,947	)
	Net carrying amount		$	288,218		$	191,075		$	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 July 31, 2014, the remaining life of the 2018 Notes and 2020 Notes is approximately 47 months and 71 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												Six Months ended
			July 31,												July 31,
			2014						2013						2014				2013
			2018			2020			2018			2020			2018		2020		2018		2020
			Notes			Notes			Notes			Notes			Notes		Notes		Notes		Notes
	Contractual interest expense		$	657		$	937		$	321		$	458		$	1,313	$	1,875	$	321	$	458
	Interest cost related to amortization of debt issuance costs			352			169			172			82			704		337		172		82
	Interest cost related to amortization of the debt discount			3,454			2,027			1,601			935			6,859		4,022		1,601		935
	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	6 Months Ended
	Jul. 31, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Note 10. 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 $4.9 million and $2.0 million for the three months ended July 31, 2014 and 2013, respectively, and $9.2 million and $3.8 million for the six months ended July 31, 2014 and 2013, respectively.
	We leased certain equipment and related software from an affiliate of Mr. Duffield (see Note 15) and 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	6 Months Ended
	Jul. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Common Stock and Stockholders' Equity	'
	Note 11. Common Stock and Stockholders’ Equity
	Common Stock
	As of July 31, 2014, there were 98.9 million shares of Class A common stock and 86.9 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 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 board of directors adopted the 2012 Equity Incentive Plan, which serves as the successor to our 2005 Stock Plan (EIP). Pursuant to the terms of the EIP, the share reserve increased by 9.2 million shares on March 31, 2014. As of July 31, 2014, we had approximately 50.2 million shares of Class A common stock available for future grants under the EIP.
	Our board of directors has also adopted the 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 generally granted twice yearly on June 1 and December 1 and exercisable on 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 July 31, 2014, 3.4 million shares of Class A common stock were available for issuance under the ESPP.
	Stock Options
	A summary of information related to stock option activity during the six months ended July 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		(1,943,940	)		2.69
	Stock options canceled		(185,355	)		8.68
	Balance as of July 31, 2014		18,576,912		$	4.01	$	1,483
	Vested and expected to vest as of July 31, 2014		18,078,824		$	3.91	$	1,445
	Exercisable as of July 31, 2014		13,477,441		$	2.85	$	1,092
	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 July 31, 2014 and January 31, 2014, we had $5.4 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 six months ended July 31, 2014, 67,000 and 134,000 shares of restricted stock awards vested and 898,500 restricted awards of Class B common stock are outstanding with weighted average grant date fair value of $12.87, all of which are subject to forfeiture as of July 31, 2024. As of July 31, 2014, there was a total of $11.2 million in unrecognized compensation cost related to restricted stock awards, which is expected to be recognized over a weighted-average period of approximately 3.3 years.
	Restricted Stock Units
	A summary of information related to restricted stock units activity during the six months ended July 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		2,865,139			80.91
	Restricted stock units vested		(309,370	)		64.96
	Restricted stock units forfeited		(97,502	)		74.54
	Balance as of July 31, 2014		6,424,995		$	75.49
	As of July 31, 2014, there was a total of $421.7 million in unrecognized compensation cost related to restricted stock units, which is expected to be recognized over a weighted-average period of approximately 3.3 years.
	Performance-based Restricted Stock Awards
	On June 15, 2014, we granted 87,450 performance-based restricted stock units (PRSUs) with a weighted average grant date fair value per share of $83.86. The PRSU awards, which were granted to all employees, include both performance conditions and service conditions. The PRSU awards will be vested if the performance targets are achieved for the fiscal year ended January 31, 2015 and the employees continue to provide service through the vesting date of March 15, 2015. As of July 31, 2014, there was a total of $6.1 million in unrecognized compensation cost related to the PRSU awards, which is expected to be recognized over a weighted-average period of approximately 0.6 years.

Other_Expense_net

Other Expense, net	6 Months Ended
	Jul. 31, 2014
Other Income And Expenses [Abstract]	'
Other Expense, net	'
	Note 12. Other Expense, net
	Other expense, net consisted of the following (in thousands):
			Three Months Ended						Six Months Ended
			July 31,						July 31,
			2014			2013			2014			2013
	Interest income		$	669		$	450		$	1,364		$	801
	Interest expense (1)			(7,765	)		(3,879	)		(15,473	)		(4,301	)
	Other income (expense)			143			(50	)		157			(235	)
	Other expense, net		$	(6,953	)	$	(3,479	)	$	(13,952	)	$	(3,735	)
	(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	6 Months Ended
	Jul. 31, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Note 13. Income Taxes
	The effective tax rate for the three months and six months ended July 31, 2014 and 2013 was less than one percent, primarily as a result of the estimated tax loss for the fiscal year 2014 and 2013, respectively. Our tax expense relates to state minimum taxes and foreign income taxes associated with our non-U.S. operations.
	There were no material changes to the unrecognized tax benefits in the three months and six months ended July 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, any reduction in the uncertain tax positions will not impact the effective tax rate. Due to our history of tax losses, all years remain open to tax audit. We are under examination by the Internal Revenue Service (IRS) for our 2011 tax year.

Net_Loss_Per_Share

Net Loss Per Share	6 Months Ended
	Jul. 31, 2014
Earnings Per Share [Abstract]	'
Net Loss Per Share	'
	Note 14. 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 has 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 July 31,												Six Months Ended July 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	$	(36,528	)	$	(32,687	)	$	(13,607	)	$	(22,371	)	$	(66,916	)	$	(61,688	)	$	(21,058	)	$	(47,935	)
	Denominator:
	Weighted-average common shares outstanding		97,275			87,044			65,571			107,804			95,602			88,131			52,075			118,542
	Basic and diluted net loss per share	$	(0.38	)	$	(0.38	)	$	(0.21	)	$	(0.21	)	$	(0.70	)	$	(0.70	)	$	(0.40	)	$	(0.40	)
	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 July 31,
		2014			2013
	Shares subject to outstanding common stock options		18,577			23,659
	Shares subject to repurchase		1,435			2,067
	Shares subject to unvested restricted stock awards, units, and PRSUs		7,411			2,280
	Convertible senior notes		7,261			7,261
	Warrants related to the issuance of convertible senior notes		7,261			7,261
			41,945			42,528

RelatedParty_Transactions

Related-Party Transactions	6 Months Ended
	Jul. 31, 2014
Related Party Transactions [Abstract]	'
Related-Party Transactions	'
	Note 15. Related-Party Transactions
	We currently lease certain office space from an affiliate of 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 $51.6 million in total. Rent expense under these agreements for the three months ended July 31, 2014 and 2013 was $0.8 million and $0.3 million, respectively and for the six months ended July 31, 2014 and 2013 were $1.5 million and $0.5 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 July 31, 2013 was $0.6 million. The amounts paid in the six months ended July 31, 2014 and 2013 were $0.1 million and $1.5 million, respectively.

Geographic_Information

Geographic Information	6 Months Ended
	Jul. 31, 2014
Segment Reporting [Abstract]	'
Geographic Information	'
	Note 16. 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				Six Months Ended
		July 31,				July 31,
		2014		2013		2014		2013
	United States	$	156,288	$	91,335	$	288,817	$	168,033
	International		30,492		16,220		57,700		31,167
	Total	$	186,780	$	107,555	$	346,517	$	199,200
	No single country other than the United States had revenues greater than 10% of total revenues for the three and six months ended July 31, 2014 or 2013. No customer individually accounted for more than 10% of our accounts receivable, net as of July 31, 2014. We had two customers that individually accounted for more than 10% of our accounts receivable, net as of July 31, 2013.

Overview_and_Basis_of_Presenta1

Overview and Basis of Presentation (Policies)	6 Months Ended
	Jul. 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 six months ended July 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 2014-09 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, any reduction in the uncertain tax positions will not impact the effective tax rate. Due to our history of tax losses, all years remain open to tax audit. We are under examination by the Internal Revenue Service (IRS) for our 2011 tax year.
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 has 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)	6 Months Ended
	Jul. 31, 2014
Cash And Cash Equivalents [Abstract]	'
Summary of Marketable Securities	'
	At July 31, 2014, marketable securities consisted of the following (in thousands):
		Amortized		Unrealized		Unrealized			Aggregate
		Cost		Gains		Losses			Fair Value
	U.S. agency obligations	$	1,393,276	$	177	$	(286	)	$	1,393,167
	U.S. treasury securities		178,654		122		—			178,776
	Commercial paper		107,825		—		—			107,825
	U.S. corporate securities		41,987		18		(30	)		41,975
	Money market funds		42,526		—		—			42,526
		$	1,764,268	$	317	$	(316	)	$	1,764,269
	Included in cash and cash equivalents	$	204,524	$	—	$	(3	)	$	204,521
	Included in marketable securities	$	1,559,744	$	317	$	(313	)	$	1,559,748
	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)	6 Months Ended
	Jul. 31, 2014
Text Block [Abstract]	'
Summary of Deferred Costs	'
	Deferred costs consisted of the following (in thousands):
		July 31,		January 31,
		2014		2014
	Current:
	Deferred professional service costs	$	5,487	$	3,555
	Deferred sales commissions		14,577		12,891
	Total	$	20,064	$	16,446
	Noncurrent:
	Deferred professional service costs	$	1,716	$	4,357
	Deferred sales commissions		16,986		16,440
	Total	$	18,702	$	20,797

Property_and_Equipment_Net_Tab

Property and Equipment, Net (Tables)	6 Months Ended
	Jul. 31, 2014
Property Plant And Equipment [Abstract]	'
Summary of Property and Equipment	'
	Property and equipment consisted of the following (in thousands):
		July 31,			January 31,
		2014			2014
	Computers, equipment and software	$	104,627		$	75,867
	Computers, equipment and software acquired under capital leases		35,899			38,912
	Furniture and fixtures		10,528			7,782
	Leasehold improvements		29,259			15,885
			180,313			138,446
	Less accumulated depreciation and amortization		(74,458	)		(60,782	)
	Property and equipment, net	$	105,855		$	77,664

Business_Combinations_Tables

Business Combinations (Tables)	6 Months Ended
	Jul. 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)	6 Months Ended
	Jul. 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):
		July 31,			January 31,
		2014			2014
	Acquired purchased technology	$	4,200		$	600
	Customer relationship assets		338			338
			4,538			938
	Less accumulated amortization		(1,471	)		(938	)
	Intangible assets, net		3,067			—
	Goodwill		32,312			8,488
	Goodwill and acquisition-related intangible assets, net	$	35,379		$	8,488

Other_Assets_Tables

Other Assets (Tables)	6 Months Ended
	Jul. 31, 2014
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]	'
Schedule of Other Assets	'
	Other assets consisted of the following (in thousands):
		July 31,		January 31,
		2014		2014
	Issuance costs of convertible senior notes	$	9,584	$	10,625
	Acquired land leasehold interest, net		9,939		9,991
	Technology patents, net		4,403		4,865
	Cost method investment		10,000		—
	Other		20,226		20,177
	Total	$	54,152	$	45,658

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jul. 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
		July 31, 2014
	Description	Level 1		Level 2		Total
	U.S. agency obligations	$	—	$	1,393,167	$	1,393,167
	U.S. treasury securities		178,776		—		178,776
	Commercial paper		—		107,825		107,825
	U.S. corporate securities		—		41,975		41,975
	Money market funds		42,526		—		42,526
		$	221,302	$	1,542,967	$	1,764,269
	Included in cash and cash equivalents					$	204,521
	Included in marketable securities					$	1,559,748
		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):
		July 31, 2014				January 31, 2014
		Carrying		Estimated		Carrying		Estimated
		Amount		Fair Value		Amount		Fair Value
	0.75% Convertible senior notes	$	288,218	$	430,938	$	281,359	$	434,875
	1.50% Convertible senior notes		191,075		316,100		187,053		319,219

Convertible_Senior_Notes_Table

Convertible Senior Notes (Tables)	6 Months Ended
	Jul. 31, 2014
Debt Disclosure [Abstract]	'
Schedule of Senior Notes	'
	The Notes consisted of the following (in thousands):
			July 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)			(61,782	)		(58,925	)		(68,641	)		(62,947	)
	Net carrying amount		$	288,218		$	191,075		$	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												Six Months ended
			July 31,												July 31,
			2014						2013						2014				2013
			2018			2020			2018			2020			2018		2020		2018		2020
			Notes			Notes			Notes			Notes			Notes		Notes		Notes		Notes
	Contractual interest expense		$	657		$	937		$	321		$	458		$	1,313	$	1,875	$	321	$	458
	Interest cost related to amortization of debt issuance costs			352			169			172			82			704		337		172		82
	Interest cost related to amortization of the debt discount			3,454			2,027			1,601			935			6,859		4,022		1,601		935

Common_Stock_and_Stockholders_1

Common Stock and Stockholders' Equity (Tables)	6 Months Ended
	Jul. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Summary of Combined Activity Under 2005 Stock Plan and EIP	'
	A summary of information related to stock option activity during the six months ended July 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		(1,943,940	)		2.69
	Stock options canceled		(185,355	)		8.68
	Balance as of July 31, 2014		18,576,912		$	4.01	$	1,483
	Vested and expected to vest as of July 31, 2014		18,078,824		$	3.91	$	1,445
	Exercisable as of July 31, 2014		13,477,441		$	2.85	$	1,092
Summary of Information Related to Restricted Stock Units Activity	'
	A summary of information related to restricted stock units activity during the six months ended July 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		2,865,139			80.91
	Restricted stock units vested		(309,370	)		64.96
	Restricted stock units forfeited		(97,502	)		74.54
	Balance as of July 31, 2014		6,424,995		$	75.49

Other_Expense_net_Tables

Other Expense, net (Tables)	6 Months Ended
	Jul. 31, 2014
Other Income And Expenses [Abstract]	'
Other Expense, Net	'
	Other expense, net consisted of the following (in thousands):
			Three Months Ended						Six Months Ended
			July 31,						July 31,
			2014			2013			2014			2013
	Interest income		$	669		$	450		$	1,364		$	801
	Interest expense (1)			(7,765	)		(3,879	)		(15,473	)		(4,301	)
	Other income (expense)			143			(50	)		157			(235	)
	Other expense, net		$	(6,953	)	$	(3,479	)	$	(13,952	)	$	(3,735	)
	(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)	6 Months Ended
	Jul. 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 July 31,												Six Months Ended July 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	$	(36,528	)	$	(32,687	)	$	(13,607	)	$	(22,371	)	$	(66,916	)	$	(61,688	)	$	(21,058	)	$	(47,935	)
	Denominator:
	Weighted-average common shares outstanding		97,275			87,044			65,571			107,804			95,602			88,131			52,075			118,542
	Basic and diluted net loss per share	$	(0.38	)	$	(0.38	)	$	(0.21	)	$	(0.21	)	$	(0.70	)	$	(0.70	)	$	(0.40	)	$	(0.40	)
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 July 31,
		2014			2013
	Shares subject to outstanding common stock options		18,577			23,659
	Shares subject to repurchase		1,435			2,067
	Shares subject to unvested restricted stock awards, units, and PRSUs		7,411			2,280
	Convertible senior notes		7,261			7,261
	Warrants related to the issuance of convertible senior notes		7,261			7,261
			41,945			42,528

Geographic_Information_Tables

Geographic Information (Tables)	6 Months Ended
	Jul. 31, 2014
Segment Reporting [Abstract]	'
Summary of Revenues by Geographic Area	'
	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				Six Months Ended
		July 31,				July 31,
		2014		2013		2014		2013
	United States	$	156,288	$	91,335	$	288,817	$	168,033
	International		30,492		16,220		57,700		31,167
	Total	$	186,780	$	107,555	$	346,517	$	199,200

Overview_and_Basis_of_Presenta2

Overview and Basis of Presentation - Additional Information (Detail)	6 Months Ended
	Jul. 31, 2014
	Segment
Accounting Policies [Abstract]	'
Number of operating segments	1

Marketable_Securities_Summary_

Marketable Securities - Summary of Marketable Securities (Detail) (USD $)	Jul. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	$1,764,268	$1,826,844
Unrealized Gains	317	428
Unrealized Losses	-316	-97
Aggregate Fair Value	1,764,269	1,827,175
US Government Agencies Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	1,393,276	1,125,170
Unrealized Gains	177	334
Unrealized Losses	-286	-50
Aggregate Fair Value	1,393,167	1,125,454
US Treasury Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	178,654	536,747
Unrealized Gains	122	88
Unrealized Losses	0	-47
Aggregate Fair Value	178,776	536,788
Commercial Paper [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	107,825	62,997
Unrealized Gains	0	0
Unrealized Losses	0	0
Aggregate Fair Value	107,825	62,997
Domestic Corporate Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	41,987	11,771
Unrealized Gains	18	6
Unrealized Losses	-30	0
Aggregate Fair Value	41,975	11,777
Money Market Funds [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	42,526	90,159
Unrealized Gains	0	0
Unrealized Losses	0	0
Aggregate Fair Value	42,526	90,159
Cash and Cash Equivalents [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	204,524	521,956
Unrealized Gains	0	3
Unrealized Losses	-3	-37
Aggregate Fair Value	204,521	521,922
Included in marketable securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	1,559,744	1,304,888
Unrealized Gains	317	425
Unrealized Losses	-313	-60
Aggregate Fair Value	$1,559,748	$1,305,253

Marketable_Securities_Addition

Marketable Securities - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Sales of available-for-sale securities	$8,138,000	$0	$8,138,000	$0
Included in marketable securities [Member]	'	'	'	'
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 $)	Jul. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Current:	'	'
Deferred professional service costs	$5,487	$3,555
Deferred sales commissions	14,577	12,891
Total	20,064	16,446	[1]
Noncurrent:	'	'
Deferred professional service costs	1,716	4,357
Deferred sales commissions	16,986	16,440
Total	$18,702	$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 $)	Jul. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Property Plant And Equipment [Abstract]	'	'
Computers, equipment and software	$104,627	$75,867
Computers, equipment and software acquired under capital leases	35,899	38,912
Furniture and fixtures	10,528	7,782
Leasehold improvements	29,259	15,885
Property and equipment, gross	180,313	138,446
Less accumulated depreciation and amortization	-74,458	-60,782
Property and equipment, net	$105,855	$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		6 Months Ended
In Millions, unless otherwise specified	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Property Plant And Equipment [Abstract]	'	'	'	'
Depreciation expense	$10.80	$7	$20.20	$12.60
Depreciation on assets recorded under capital leases	$2.30	$3.20	$4.80	$6.40

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 [Member]	'
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 $)	Jul. 31, 2014	Feb. 20, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Business Acquisition [Line Items]	'	'	'
Cash	'	$74	'
Prepaid expenses and other current assets	'	150	'
Identified intangible assets acquired:	'	'	'
Goodwill	32,312	23,824	8,488
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 [Member]	'	'	'
Identified intangible assets acquired:	'	'	'
Identified intangible assets acquired	'	$3,600	'

Goodwill_and_Acquisitionrelate2

Goodwill and Acquisition-related Intangible Assets, Net - Schedule of Goodwill and Acquisition-related Intangible Assets (Detail) (USD $)	Jul. 31, 2014	Feb. 20, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]	'	'	'
Intangible assets, gross	$4,538	'	$938
Less accumulated amortization	-1,471	'	-938
Intangible assets, net	3,067	'	0
Goodwill	32,312	23,824	8,488
Goodwill and acquisition-related intangible assets, net	35,379	'	8,488	[1]
Acquired purchased technology [Member]	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'
Intangible assets, gross	4,200	'	600
Customer Relationships [Member]	'	'	'
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 $)	Jul. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]	'	'
Other assets	$54,152	$45,658	[1]
Issuance costs of convertible senior notes [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Other assets	9,584	10,625
Acquired land leasehold interest, net [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Other assets	9,939	9,991
Patented Technology [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Other assets	4,403	4,865
Cost-method Investments [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Other assets	10,000	0
Other Noncurrent Assets [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Other assets	$20,226	$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		6 Months Ended
In Millions, unless otherwise specified	Jul. 31, 2014	Jan. 31, 2014	Jul. 31, 2014
Acquired land leasehold interest, net [Member]	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'
Amortization expense	$0.50	$0.30	$0.50
Patented Technology [Member]	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'
Amortization expense	0.5	0.3	0.5
Series D Preferred Stock [Member]	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'
Number of shares purchased in private company	1.4	'	1.4
Amount of shares purchased in private company	$10	'	$10

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	3 Months Ended
	Jul. 31, 2014	Jul. 31, 2014	Jul. 31, 2014	Jul. 31, 2014	Jan. 31, 2014	Jun. 30, 2013	Jul. 31, 2014	Jan. 31, 2014	Jun. 30, 2013
		Foreign Exchange Contract [Member]	Fair Value, Inputs, Level 3 [Member]	2018 Notes [Member]	2018 Notes [Member]	2018 Notes [Member]	2020 Notes [Member]	2020 Notes [Member]	2020 Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'	'	'	'	'	'
Financial assets	'	'	$0	'	'	'	'	'	'
Financial liabilities	'	'	0	'	'	'	'	'	'
Convertible Senior Notes, principal amount	'	'	'	350,000,000	350,000,000	350,000,000	250,000,000	250,000,000	'
Closing price of company's common stock	$83.84	'	'	'	'	'	'	'	'
Contractual interest rate	'	'	'	0.75%	0.75%	0.75%	1.50%	1.50%	1.50%
Notional value of forward contracts	'	2,700,000	'	'	'	'	'	'	'
Fair value of derivative assets and derivative liabilities	'	100,000	'	'	'	'	'	'	'
Net gain on non-designated derivative instruments	$100,000	'	'	'	'	'	'	'	'

Fair_Value_Measurements_Inform

Fair Value Measurements - Information about Assets that are Measured at Fair Value on a Recurring Basis (Detail) (USD $)	Jul. 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	$1,764,269	$1,827,175
US Government Agencies Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	1,393,167	1,125,454
US Treasury Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	178,776	536,788
Commercial Paper [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	107,825	62,997
US Government Corporations and Agencies Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	41,975	11,777
Money Market Funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	42,526	90,159
Cash and Cash Equivalents [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	204,521	521,922
Included in marketable securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	1,559,748	1,305,253
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	221,302	626,947
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Government Agencies Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	178,776	536,788
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial Paper [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Government Corporations and Agencies Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	42,526	90,159
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	1,542,967	1,200,228
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	1,393,167	1,125,454
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Treasury Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	107,825	62,997
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Government Corporations and Agencies Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets Fair Value Disclosure	41,975	11,777
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]	'	'
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 $)	Jul. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Convertible senior notes, Carrying Amount	$479,293	$468,412	[1]
2018 Notes [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Convertible senior notes, Carrying Amount	288,218	281,359
Convertible senior notes, Estimated Fair Value	430,938	434,875
2020 Notes [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Convertible senior notes, Carrying Amount	191,075	187,053
Convertible senior notes, Estimated Fair Value	$316,100	$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)	Jul. 31, 2014	Jan. 31, 2014	Jun. 30, 2013
2018 Notes [Member]	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'
Contractual interest rate	0.75%	0.75%	0.75%
2020 Notes [Member]	'	'	'
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		6 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013	Jan. 31, 2014	Jun. 30, 2013
Debt Instrument [Line Items]	'	'	'	'	'	'
Proceeds from sale of warrants	$0	$92,708,000	$0	$92,708,000	'	'
2018 Notes [Member]	'	'	'	'	'	'
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%
Convertible Senior Notes, maturity date	'	'	15-Jul-18	'	'	'
First required date for interest payment	'	'	15-Jan-14	'	'	'
Latest date for conversion	'	'	14-Mar-18	'	'	'
Liability issuance costs	'	'	7,200,000	'	'	'
Equity issuance costs	'	'	2,000,000	'	'	'
Amortization expense for liability issuance costs	352,000	172,000	704,000	172,000	'	'
Remaining life of the Notes	'	'	'47 months	'	'	'
Effective interest rates of the liability components	5.75%	'	5.75%	'	'	'
2018 Notes [Member] | Employee Stock Option [Member]	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Purchased options expiration year	'	'	'2018	'	'	'
2018 and 2020 Senior Notes [Member]	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Convertible Senior Notes, principal amount	'	'	'	'	'	250,000,000
2020 Notes [Member]	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Convertible Senior Notes, principal amount	250,000,000	'	250,000,000	'	250,000,000	'
Contractual interest rate	1.50%	'	1.50%	'	1.50%	1.50%
Convertible Senior Notes, maturity date	'	'	15-Jul-20	'	'	'
First required date for interest payment	'	'	15-Jan-14	'	'	'
Latest date for conversion	'	'	13-Mar-20	'	'	'
Liability issuance costs	'	'	4,700,000	'	'	'
Equity issuance costs	'	'	1,800,000	'	'	'
Amortization expense for liability issuance costs	169,000	82,000	337,000	82,000	'	'
Remaining life of the Notes	'	'	'71 months	'	'	'
Effective interest rates of the liability components	6.25%	'	6.25%	'	'	'
2020 Notes [Member] | Employee Stock Option [Member]	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Purchased options expiration year	'	'	'2020	'	'	'
Convertible Senior Notes [Member]	'	'	'	'	'	'
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	'	'	'
Convertible Senior Notes [Member] | Scenario One [Member]	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Threshold trading days	'	'	20	'	'	'
Threshold consecutive trading days	'	'	'30 days	'	'	'
Threshold percentage of conversion price	'	'	130.00%	'	'	'
Convertible Senior Notes [Member] | Scenario two [Member]	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Threshold trading days	'	'	5	'	'	'
Threshold consecutive trading days	'	'	'5 days	'	'	'
Convertible Senior Notes [Member] | Scenario two [Member] | Maximum [Member]	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Threshold percentage of conversion price	'	'	98.00%	'	'	'
Convertible Senior Notes [Member] | Employee Stock Option [Member]	'	'	'	'	'	'
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	'	'	'
Warrants expires in July 2018 [Member]	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Shares covered by each purchased option/warrant	4.2	'	4.2	'	'	'
Warrants expiration period	'	'	'2018-07	'	'	'
Warrants expires in July 2020 [Member]	'	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'	'
Shares covered by each purchased option/warrant	3.1	'	3.1	'	'	'
Warrants expiration period	'	'	'2020-07	'	'	'
Common Class A [Member] | 2018 Notes [Member]	'	'	'	'	'	'
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	'	'	'
Common Class A [Member] | 2020 Notes [Member]	'	'	'	'	'	'
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	'	'	'

Convertible_Senior_Notes_Sched

Convertible Senior Notes - Schedule of Senior Notes (Detail) (USD $)	Jul. 31, 2014	Jan. 31, 2014		Jun. 30, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'		'
Net carrying amount	$479,293	$468,412	[1]	'
2018 Notes [Member]	'	'		'
Debt Instrument [Line Items]	'	'		'
Principal	350,000	350,000		350,000
Unamortized debt discount	-61,782	-68,641		'
Net carrying amount	288,218	281,359		'
Carrying amount of the equity component	74,892	74,892		'
2020 Notes [Member]	'	'		'
Debt Instrument [Line Items]	'	'		'
Principal	250,000	250,000		'
Unamortized debt discount	-58,925	-62,947		'
Net carrying amount	191,075	187,053		'
Carrying amount of the equity component	$66,007	$66,007		'
[1]	Amounts as of January 31, 2014 were derived from the January 31, 2014 audited financial statements.

Convertible_Senior_Notes_Sched1

Convertible Senior Notes - Schedule of Senior Notes (Parenthetical) (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jul. 31, 2014
2018 Notes [Member]	'
Debt Instrument [Line Items]	'
Equity issuance costs	$2
2020 Notes [Member]	'
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		6 Months Ended
In Thousands, unless otherwise specified	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Debt Instrument [Line Items]	'	'	'	'
Interest cost related to amortization of the debt discount	$6,002	$2,790	$11,922	$2,790
2018 Notes [Member]	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Contractual interest expense	657	321	1,313	321
Interest cost related to amortization of debt issuance costs	352	172	704	172
Interest cost related to amortization of the debt discount	3,454	1,601	6,859	1,601
2020 Notes [Member]	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Contractual interest expense	937	458	1,875	458
Interest cost related to amortization of debt issuance costs	169	82	337	82
Interest cost related to amortization of the debt discount	$2,027	$935	$4,022	$935

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2014	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
	acre
Commitments And Contingencies Disclosure [Abstract]	'	'	'	'	'
Lease term period	'95 years	'	'	'	'
Parcel of vacant land	6	'	'	'	'
Rent expense	'	$4.90	$2	$9.20	$3.80

Common_Stock_and_Stockholders_2

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

Jul. 31, 2014

Jan. 31, 2014

31-May-14

Mar. 31, 2014

Jul. 31, 2014

Jul. 31, 2014

Jan. 31, 2014

Jul. 31, 2014

Jul. 31, 2014

Jun. 15, 2014

Jul. 31, 2014

Jul. 31, 2014

Mar. 31, 2014

Jul. 31, 2014

Jul. 31, 2014

Jul. 31, 2014

In Millions, except Share data, unless otherwise specified

Employee Stock Purchase Plan [Member]

Employee Stock Purchase Plan [Member]

Employee Stock Purchase Plan [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Performance-based Restricted Stock Units (PRSUs) [Member]

Performance-based Restricted Stock Units (PRSUs) [Member]

Common Class A [Member]

Common Class A [Member]

Common Class A [Member]

Common Class B [Member]

Common Class B [Member]

vote_per_share

2012 Equity Incentive Plan [Member]

2012 Equity Incentive Plan [Member]

vote_per_share

Restricted Stock [Member]

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

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, outstanding

'

'

'

'

'

'

'

'

'

'

'

98,900,000

'

'

86,900,000

'

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

'

'

'

'

'

'

'

'

50,200,000

'

'

Percentage of fair market value of stock at which employees are granted shares

'

'

'

'

85.00%

'

'

'

'

'

'

'

'

'

'

'

Number of shares purchased by employees

'

'

194,231

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted-average purchase price

'

'

$66.61

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash proceeds

'

'

$12.90

'

'

'

'

'

'

'

'

'

'

'

'

'

Liabilities related to early exercises of stock options

5.4

6.4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted stock awards vested

'

'

'

'

'

'

'

67,000

134,000

'

'

'

'

'

'

'

Restricted stock awards vesting period

'

'

'

'

'

'

'

'

'5 years

'

'

'

'

'

'

'

Restricted stock awards outstanding

'

'

'

'

'

6,424,995

3,966,728

'

'

'

'

'

'

'

'

898,500

Restricted stock weighted-average grant date fair value

'

'

'

'

'

$75.49

$70.72

'

'

'

'

'

'

'

'

$12.87

Restricted common stock forfeiture date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

31-Jul-24

Unrecognized compensation cost

'

'

'

'

'

$421.70

'

$11.20

$11.20

'

$6.10

'

'

'

'

'

Weighted-average period to be recognized

'

'

'

'

'

'3 years 3 months 18 days

'

'

'3 years 3 months 18 days

'

'7 months 6 days

'

'

'

'

'

Number of shares granted

'

'

'

'

'

2,865,139

'

'

'

87,450

'

'

'

'

'

'

Weighted average grant date fair value

'

'

'

'

'

$80.91

'

'

'

$83.86

'

'

'

'

'

'

Restricted stock units vesting date

'

'

'

'

'

'

'

'

'

'

15-Mar-15

'

'

'

'

'

Common_Stock_and_Stockholders_3

Common Stock and Stockholders' Equity - Summary of Combined Activity Under 2005 Stock Plan and EIP (Detail) (USD $)	6 Months Ended
In Millions, except Share data, unless otherwise specified	Jul. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Beginning Balance, Outstanding Stock Options	20,706,207
Stock option grants, Outstanding Stock Options	0
Stock options exercised, Outstanding Stock Options	-1,943,940
Stock options canceled, Outstanding Stock Options	-185,355
Ending Balance, Outstanding Stock Options	18,576,912
Vested and expected to vest, Outstanding Stock Options	18,078,824
Exercisable, Outstanding Stock Options	13,477,441
Beginning Balance, Weighted-Average Exercise Price	$3.93
Stock option grants, Weighted-Average Exercise Price	$0
Stock options exercised, Weighted-Average Exercise Price	$2.69
Stock options canceled, Weighted-Average Exercise Price	$8.68
Ending Balance, Weighted-Average Exercise Price	$4.01
Vested and expected to vest, Weighted-Average Exercise Price	$3.91
Exercisable, Weighted-Average Exercise Price	$2.85
Beginning Balance, Aggregate Intrinsic Value	$1,773
Ending Balance, Aggregate Intrinsic Value	1,483
Vested and expected to vest, Aggregate Intrinsic Value	1,445
Exercisable, Aggregate Intrinsic Value	$1,092

Common_Stock_and_Stockholders_4

Common Stock and Stockholders' Equity - Summary of Information Related to Restricted Stock Units Activity (Detail) (Restricted Stock Units (RSUs) [Member], USD $)	6 Months Ended
	Jul. 31, 2014
Restricted Stock Units (RSUs) [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Beginning Balance, Number of Shares	3,966,728
Restricted stock units granted, Number of Shares	2,865,139
Restricted stock units vested, Number of Shares	-309,370
Restricted stock units forfeited, Number of Shares	-97,502
Ending Balance, Number of Shares	6,424,995
Beginning Balance, Weighted-Average Grant Date Fair Value	$70.72
Restricted stock units granted, Weighted-Average Grant Date Fair Value	$80.91
Restricted stock units vested, Weighted-Average Grant Date Fair Value	$64.96
Restricted stock units forfeited, Weighted-Average Grant Date Fair Value	$74.54
Ending Balance, Weighted-Average Grant Date Fair Value	$75.49

Other_Expense_Net_Other_Expens

Other Expense, Net - Other Expense, Net (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Other Income And Expenses [Abstract]	'	'	'	'
Interest income	$669	$450	$1,364	$801
Interest expense	-7,765	-3,879	-15,473	-4,301
Other income (expense)	143	-50	157	-235
Other expense, net	($6,953)	($3,479)	($13,952)	($3,735)

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Income Tax Contingency [Line Items]	'	'	'	'
Unrecognized tax benefits	0	'	0	'
Maximum [Member]	'	'	'	'
Income Tax Contingency [Line Items]	'	'	'	'
Effective tax rate	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		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Denominator:	'	'	'	'
Weighted-average common shares outstanding	184,319	173,375	183,733	170,617
Basic and diluted net loss per share	($0.38)	($0.21)	($0.70)	($0.40)
Common Class A [Member]	'	'	'	'
Numerator:	'	'	'	'
Allocation of distributed net loss	($36,528)	($13,607)	($66,916)	($21,058)
Denominator:	'	'	'	'
Weighted-average common shares outstanding	97,275	65,571	95,602	52,075
Basic and diluted net loss per share	($0.38)	($0.21)	($0.70)	($0.40)
Common Class B [Member]	'	'	'	'
Numerator:	'	'	'	'
Allocation of distributed net loss	($32,687)	($22,371)	($61,688)	($47,935)
Denominator:	'	'	'	'
Weighted-average common shares outstanding	87,044	107,804	88,131	118,542
Basic and diluted net loss per share	($0.38)	($0.21)	($0.70)	($0.40)

Net_Loss_Per_Share_Summary_of_1

Net Loss Per Share - Summary of Diluted Net Loss Per Common Share (Detail)	6 Months Ended
In Thousands, unless otherwise specified	Jul. 31, 2014	Jul. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total anti-dilutive securities	41,945	42,528
Equity Option [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total anti-dilutive securities	18,577	23,659
Warrant [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total anti-dilutive securities	1,435	2,067
Shares Subject to Unvested Restricted Stock Awards, Units, and PRSUs [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total anti-dilutive securities	7,411	2,280
Convertible Senior Notes [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total anti-dilutive securities	7,261	7,261
Warrants Related to the Issuance of Convertible Senior Notes [Member]	'	'
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		6 Months Ended
	Jan. 31, 2014	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Related Party Transaction [Line Items]	'	'	'	'	'
Term of agreements	'95 years	'	'	'	'
Amounts paid under lease agreement	'	$4,418,000	$2,935,000	$7,162,000	$6,688,000
Management [Member]	'	'	'	'	'
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	'	51,600,000	'	51,600,000	'
Rent expense	'	800,000	300,000	1,500,000	500,000
Amounts paid under lease agreement	'	'	$600,000	$100,000	$1,500,000

Geographic_Information_Summary

Geographic Information - Summary of Revenues by Geographic Area (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Revenue from External Customer [Line Items]	'	'	'	'
Revenue	$186,780	$107,555	$346,517	$199,200
UNITED STATES	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'
Revenue	156,288	91,335	288,817	168,033
UNKNOWN COUNTRY	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'
Revenue	$30,492	$16,220	$57,700	$31,167

Geographic_Information_Additio

Geographic Information - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Revenue from External Customer [Line Items]	'	'	'	'
Number of customers accounted for more than 10 percent of accounts receivable	'	'	0	2
Entity wide accounts receivable major customer percentage	10.00%	10.00%	10.00%	10.00%
Sales Revenue, Services, Net [Member] | Customer Concentration Risk [Member] | UNITED STATES | Minimum [Member]	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'
Entity wide revenue major customer percentage threshold	10.00%	10.00%	10.00%	10.00%