Commitment and Contingencies - Lease Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2014 sqft	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
Expiration of lease	Nov. 30, 2020
Operating Leases, Rent Expense	$ 2,000,000
Rent expense	1,800,000	1,300,000	1,300,000
Area of rentable square feet	50,400
Sublease rentals, to be received in 2015	455,000
Sublease rentals, to be received in 2016	523,000
Sublease rentals, to be received in 2017	$ 316,000