Description of Operations and Summary of Significant Accounting Policies (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Capitalized Fees Paid to a Related Party
Capitalized fees paid to a related party, useful life	15 years
Deferred rent
Operating lease rent expenses	$ 3.0	$ 6.0	$ 5.7
Lease incentives		$ 2.6
Equipment, furniture and fixtures | Minimum
Information related to useful life of property and equipment
Estimated useful life	5 years
Equipment, furniture and fixtures | Maximum
Information related to useful life of property and equipment
Estimated useful life	7 years
Software and computer equipment
Information related to useful life of property and equipment
Estimated useful life	3 years
Capitalized software
Information related to useful life of property and equipment
Estimated useful life	3 years