Balance Sheet Components - Property, Plant, and Equipment (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment
Property, plant and equipment, gross	$ 44,721	$ 44,053
Less: Accumulated depreciation and amortization	(12,580)	(11,577)
Property and equipment, net	32,141	32,476
Equipment [Member]
Property, Plant and Equipment
Property, plant and equipment, gross	20,075	13,363
Leasehold improvements [Member]
Property, Plant and Equipment
Property, plant and equipment, gross	21,677	9,951
Furniture and fixtures [Member]
Property, Plant and Equipment
Property, plant and equipment, gross	1,278	1,278
Construction in Progress [Member]
Property, Plant and Equipment
Property, plant and equipment, gross	$ 1,691	$ 19,461