Property and Equipment, net (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net	$ 12,788,000	$ 4,703,000
Depreciation	2,200,000	1,609,000	1,361,000
Disposal of Property Plant and Equipment	800,000	3,200,000	800,000
Full Depreciated Assets in Use	4,200,000	5,200,000
Internal-use software development costs capitalized	(2,013,000)	0	0
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(9,278,000)	(8,209,000)
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net	2,371,000	1,899,000
Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net	7 years
Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net	10 years
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net	9,477,000	7,421,000
Computer Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net	3 years
Computer Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net	10 years
Software [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net	4,123,000	2,243,000
Software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net	2 years
Software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net	5 years
Software Development [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	3 years
Property, Plant and Equipment, Net	2,013,000	0
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	Shorter of lease term or useful life
Property, Plant and Equipment, Net	3,550,000	1,037,000
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net	$ 532,000	$ 312,000