Properties and Equipment Property and equipment, net (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 97,249	$ 101,209
Accumulated depreciation	(75,159)	(75,914)
Property and equipment, net	22,090	25,295	31,019
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	40,281	43,526
Equipment and Furniture [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	18,881	20,117
Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	29,538	29,304
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 8,549	$ 8,262