Acquistions (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Deferred Taxes	$ 2,700
Deferred tax assets, net	5,165	5,507	[1]
Total current assets	139,178	147,059	[1]
Goodwill	29,748	29,748	[1]
Total assets	282,151	297,273	[1]
Other accrued liabilities	11,931	16,195	[1]
Total current liabilities	93,515	76,479	[1]
Other long-term liabilities	8,420	9,061	[1]
Total long-term liabilities	26,420	54,061	[1]
Total liabilities	119,935	130,540	[1]
Accumulated deficit	(139,720)	(136,212)	[1]
Total shareholders’ equity	162,216	166,733	[1]
Total liabilities and shareholders' equity	282,151	297,273	[1]
Continuous Computing [Member]
Business Acquisition [Line Items]
Total purchase price	119,731
Cash and cash equivalents	2,214
Accounts receivable	13,434
Inventories	4,036
Prepaid expenses and other current assets	3,316
Fixed assets	2,469
Other assets	614
Accounts payable	(5,368)
Accrued expenses	(6,891)
Deferred revenue	(1,825)
Other long-term liabilities	(1,226)
Net assets acquired	10,773
Fair value of identifiable intangible assets acquired	89,240
Net deferred tax liability	(9,870)
Goodwill	29,588
Scenario, Previously Reported [Member]
Business Acquisition [Line Items]
Deferred tax assets, net		5,875
Total current assets		147,427
Goodwill		26,599
Total assets		294,492
Other accrued liabilities		16,106
Total current liabilities		76,390
Other long-term liabilities		9,065
Total long-term liabilities		54,065
Total liabilities		130,455
Accumulated deficit		(138,908)
Total shareholders’ equity		164,037
Total liabilities and shareholders' equity		294,492
Purchase Price Allocation Adjustments [Member] | Continuous Computing [Member]
Business Acquisition [Line Items]
Deferred tax assets, net		(368)
Total current assets		(368)
Goodwill		3,149
Total assets		2,781
Other accrued liabilities		89
Total current liabilities		89
Other long-term liabilities		(4)
Total long-term liabilities		(4)
Total liabilities		85
Accumulated deficit		2,696
Total shareholders’ equity		2,696
Total liabilities and shareholders' equity		$ 2,781

[1] (A)As adjusted to reflect the impact of additional tax-related adjustments to the Company's purchase accounting for Continuous Computing in accordance with ASC 805-10 "Business Combinations". See Note 2 — Acquisitions for additional information.