Property and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 22,418,000	$ 18,929,000
Less accumulated depreciation and amortization	(12,336,000)	(10,095,000)
Property and equipment, net	10,082,000	8,834,000
Depreciation expense	3,100,000	2,700,000	2,400,000
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	11,729,000	9,902,000
Building [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,103,000	3,362,000
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	66,000	67,000
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,632,000	1,745,000
Furniture, Fixtures and Other [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 4,888,000	$ 3,853,000