Property and Equipment, Net (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 136,662	$ 128,877
Accumulated depreciation	(84,121)	(81,430)
Net property and equipment	52,541	47,447
Depreciation expense	13,322	12,783	9,700
Computers, internal use software, furniture & fixtures and automobiles [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	96,248	93,462
Land and Building [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	27,010	26,652
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 13,404	$ 8,763

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, at the balance sheet date, of long-lived physical assets used in the normal conduct of business and not intended for resale. This can include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

+ References+ Details

- Definition

Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

+ References+ Details