Acquisitions (Schedule Of Allocation Of Purchase Price) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Business Acquisition [Line Items]
Contractual non-compliance liability	$ (1,600)
Contingent consideration	(8,000)	0
Simena [Member]
Business Acquisition [Line Items]
Current assets	2,300
Identifiable intangible assets	4,470
Goodwill	14,013
Total assets acquired	20,783
Current liabilities	(338)
Deferred revenue	(759)
Contractual non-compliance liability	(1,600)
Contingent consideration	(8,000)
Total consideration	10,086
Replay [Member]
Business Acquisition [Line Items]
Current assets	2,310
Fixed assets	85
Identifiable intangible assets	4,950
Goodwill	15,313
Total assets acquired	22,658
Current liabilities	(74)
Deferred revenue	(715)
Deferred income tax liabilities	(1,632)
Cash and cash equivalents	547
Psytechnics [Member]
Business Acquisition [Line Items]
Current assets	1,099
Fixed assets	50
Identifiable intangible assets	4,350
Goodwill	13,179
Total assets acquired	18,678
Current liabilities	(1,198)
Deferred revenue	(466)
Cash and cash equivalents	$ 69