Commitments and Contingencies - Lease Financing Obligation (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Lease Financing Obligation, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2014		$ 4,991
2015		5,601
2016		5,769
2017		5,948
2018		6,128
Thereafter		31,059
Total payments		59,496
Less: interest and land lease expense		(38,962)
Total payments under facility financing obligations		20,534
Property reverting to landlord		23,436
Present value of obligation		43,970
Less current portion		(818)
Long-term portion of obligation	$ 42,831	$ 43,152