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.

+ References+ Details

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

+ References+ Details

- Definition

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.

+ References+ Details

- 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.

+ References+ Details

Fixed Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013 country	Sep. 30, 2012	Sep. 30, 2013 country	Sep. 30, 2012	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Total fixed assets	$ 38,544		$ 38,544		$ 33,067
Less: Accumulated depreciation and amortization	(26,251)		(26,251)		(22,422)
Fixed assets, net	12,293		12,293		10,645
Number of countries outside the US that own greater than 10% of fixed assets	0		0
Depreciation expense	1,269	1,384	3,829	3,657
Computer and office equipment and software [Member]
Property, Plant and Equipment [Line Items]
Total fixed assets	30,006		30,006		26,710
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Total fixed assets	2,180		2,180		2,036
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total fixed assets	$ 6,358		$ 6,358		$ 4,321