Income Taxes (Deferred Tax Liabilities (Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Abstract]
Capitalized software	$ 7,432	$ 7,933
Depreciation and amortization	15,404	16,910
Intangible Assets	9,920
Unrealized gain on derivative instruments	709	105
Undistributed earnings of foreign subsidiaries	8,437	9,024
Gross deferred tax liabilities	41,902	33,972
Operating loss carryforwards	(86,285)	(61,148)
Intangible assets		(10,800)
Vacation and other accruals	(5,895)	(6,432)
Inventory valuation and warranty provisions	(11,773)	(10,724)
Doubtful accounts and sales provisions	(1,229)	(1,084)
Unrealized exchange loss	(1,664)	(33)
Deferred revenue	(3,987)	(1,991)
Accrued rent expenses	(219)	(132)
GSA Accrual		(4,831)
10% minority stock investment	(932)	(915)
Stock-based compensation	(5,471)	(4,640)
Research and development tax credit carryforward	(2,421)	(4,562)
Foreign tax credit carryforward		(1,006)
Other	(561)	(518)
Gross deferred tax assets	(120,437)	(108,816)
Valuation allowance	91,649	79,864
Net deferred tax liability (asset)	$ 13,114	$ 5,020