Business Combinations (Schedule Of Components And The Allocations Of The Purchase Prices) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Oct. 31, 2011		Jan. 31, 2011
Business Acquisition [Line Items]
Fair value of contingent consideration	$ 34,623		$ 3,686
Weighted-average estimated useful life of acquired finite-lived identifiable intangible assets (in years)	7.5
Vovici [Member]
Business Acquisition [Line Items]
Cash and cash equivalents	55,708
Fair value of contingent consideration	9,900
Fair value of stock options	60
Bank debt, prepaid at closing	435
Total purchase price	66,103
Accounts receivable	1,106
Other current assets	4,396
Other assets	912
Current and other liabilities	(1,794)
Deferred revenue	(2,264)
Deferred income taxes - long-term	(2,300)
Net tangible assets (liabilities)	56
Total identifiable intangible assets	28,400	[1]
Goodwill	37,647
Weighted-average estimated useful life of acquired finite-lived identifiable intangible assets (in years)	8.1
Vovici [Member] | Trademarks And Trade Names [Member]
Business Acquisition [Line Items]
Total identifiable intangible assets	1,700
Weighted-average estimated useful life of acquired finite-lived identifiable intangible assets (in years)	5.0
Vovici [Member] | Developed Technology [Member]
Business Acquisition [Line Items]
Total identifiable intangible assets	11,300
Weighted-average estimated useful life of acquired finite-lived identifiable intangible assets (in years)	6.0
Vovici [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Total identifiable intangible assets	15,400
Weighted-average estimated useful life of acquired finite-lived identifiable intangible assets (in years)	10.0
GMT [Member]
Business Acquisition [Line Items]
Cash and cash equivalents	24,596
Fair value of contingent consideration	12,000
Total purchase price	36,596
Accounts receivable	512
Other current assets	1,717
Other assets	482
Current and other liabilities	(1,634)
Deferred revenue	(1,234)
Net tangible assets (liabilities)	(157)
Total identifiable intangible assets	15,100	[1]
Goodwill	21,653
Weighted-average estimated useful life of acquired finite-lived identifiable intangible assets (in years)	7.3
GMT [Member] | Trademarks And Trade Names [Member]
Business Acquisition [Line Items]
Total identifiable intangible assets	400
Weighted-average estimated useful life of acquired finite-lived identifiable intangible assets (in years)	3
GMT [Member] | Developed Technology [Member]
Business Acquisition [Line Items]
Total identifiable intangible assets	7,500
Weighted-average estimated useful life of acquired finite-lived identifiable intangible assets (in years)	5
GMT [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Total identifiable intangible assets	7,200
Weighted-average estimated useful life of acquired finite-lived identifiable intangible assets (in years)	10
Other Acquisitions [Member]
Business Acquisition [Line Items]
Cash and cash equivalents	21,965
Fair value of contingent consideration	11,804
Other purchase price adjustments	317
Total purchase price	34,086
Accounts receivable	493
Other current assets	12,445
Other assets	5,508
Current and other liabilities	(15,653)
Deferred revenue	(845)
Bank debt	(3,330)
Net tangible assets (liabilities)	(1,382)
Total identifiable intangible assets	15,914	[1]
Goodwill	19,554
Weighted-average estimated useful life of acquired finite-lived identifiable intangible assets (in years)	6.7
Other Acquisitions [Member] | Trademarks And Trade Names [Member]
Business Acquisition [Line Items]
Total identifiable intangible assets	1,000
Weighted-average estimated useful life of acquired finite-lived identifiable intangible assets (in years)	5
Other Acquisitions [Member] | Developed Technology [Member]
Business Acquisition [Line Items]
Total identifiable intangible assets	6,943
Weighted-average estimated useful life of acquired finite-lived identifiable intangible assets (in years)	6
Other Acquisitions [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Total identifiable intangible assets	6,550
Other Acquisitions [Member] | Other Identifiable Intangible Assets [Member]
Business Acquisition [Line Items]
Total identifiable intangible assets	$ 1,421

[1] The weighted-average estimated useful life of all finite-lived identifiable intangible assets is 7.5 years.