Summary of Significant Accounting Policies Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2012
Furniture and Fixtures [Member] | Minimum [Member]
Property and Equipment [Line Items]
Estimated useful lives, years	3
Furniture and Fixtures [Member] | Maximum [Member]
Property and Equipment [Line Items]
Estimated useful lives, years	5
Computer Hardware and Software [Member] | Minimum [Member]
Property and Equipment [Line Items]
Estimated useful lives, years	3
Computer Hardware and Software [Member] | Maximum [Member]
Property and Equipment [Line Items]
Estimated useful lives, years	5
Leasehold Improvements [Member] | Minimum [Member]
Property and Equipment [Line Items]
Estimated useful lives, years	2
Leasehold Improvements [Member] | Maximum [Member]
Property and Equipment [Line Items]
Estimated useful lives, years	5