Property and equipment (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Total	$ 42,143	$ 36,298
Less accumulated depreciation and amortization	(31,487)	(28,868)
Property, Plant and Equipment, Net	10,656	7,430
Equipment [Member]
Total	23,798	21,833
Less accumulated depreciation and amortization	(1,600)	(1,500)
Software [Member]
Total	7,583	6,216
Furniture and Office Equipment [Member]
Total	3,400	2,658
Leasehold Improvements [Member]
Total	$ 7,362	$ 5,591

The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement.

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Gross amount of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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- Definition

Amount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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