Balance Sheet Components - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Mar. 31, 2014	Dec. 31, 2013
Debt Disclosure [Abstract]
Construction of facility liability					$ 19.2
Interest expense capitalized	2.0	0.4	3.2	1.9
Depreciation and amortization expense	36.1	20.2	65.0	37.6
Total property and equipment assets under capital lease	31.8		31.8			23.3
Accumulated depreciation related to assets under capital lease	$ 8.6		$ 8.6			$ 5.0