Business Combinations (Estimated Fair Values of Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Thousands	Jan. 31, 2017	Nov. 30, 2016	Oct. 31, 2016	Sep. 30, 2016	Aug. 31, 2016	Feb. 29, 2016	Jan. 31, 2016	Feb. 28, 2015	Jan. 31, 2015
Business Acquisition [Line Items]
Goodwill	$ 7,263,846						$ 3,849,937		$ 3,782,660
BeyondCore [Member]
Business Acquisition [Line Items]
Cash and cash equivalents				$ 2,046
Other current and noncurrent tangible assets				462
Intangible assets				15,600
Goodwill				90,794
Deferred revenue, current and noncurrent				(818)
Other liabilities, current and noncurrent				(923)
Deferred tax liability				(563)
Net assets acquired				$ 106,598
Krux, Inc. [Member]
Business Acquisition [Line Items]
Cash and cash equivalents		$ 17,883
Other current and noncurrent tangible assets		12,418
Intangible assets		86,000
Goodwill		642,489
Deferred revenue, current and noncurrent		(7,037)
Other liabilities, current and noncurrent		(9,308)
Deferred tax liability		(679)
Net assets acquired		$ 741,766
SteelBrick, Inc. [Member]
Business Acquisition [Line Items]
Cash and cash equivalents						$ 59,296
Other current and noncurrent tangible assets						3,012
Customer contract asset, noncurrent						6,954
Intangible assets						49,160
Goodwill						217,986
Deferred revenue, current and noncurrent						(8,479)
Other liabilities, current and noncurrent						(2,665)
Deferred tax liability						(10,479)
Net assets acquired						$ 314,785
Demandware [Member]
Business Acquisition [Line Items]
Cash and cash equivalents			$ 139,259
Marketable securities			37,230
Accounts receivable			56,982
Other current assets			13,545
Customer contract asset, noncurrent			327,830
Intangible assets			633,277
Property and equipment			29,463
Other noncurrent assets			4,579
Goodwill			1,985,269
Deferred revenue, current and noncurrent			(22,647)
Accounts payable, accrued expenses and other liabilities			(51,870)
Other liabilities, noncurrent			(12,935)
Deferred tax liability			(210,302)
Net assets acquired			$ 2,929,680
Quip [Member]
Business Acquisition [Line Items]
Cash and cash equivalents					$ 27,985
Other current and noncurrent tangible assets					556
Intangible assets					31,200
Goodwill					357,610
Other liabilities, current and noncurrent					(2,491)
Deferred tax liability					(2,840)
Net assets acquired					$ 412,020
50 Fremont Street [Member]
Business Acquisition [Line Items]
Building								$ 435,390
Land								183,888
Intangible assets								7,590
Loan assumed on 50 Fremont fair market value adjustment								1,249
Net assets acquired								$ 637,600