Balance Sheet Components - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Debt Disclosure [Abstract]
Inventories write-downs in cost of automotive sales	$ 8,648,000	$ 4,929,000	$ 1,828,000
Interest expense capitalized	3,500,000	7,600,000
Depreciation and amortization expense	83,900,000	25,300,000	14,600,000
Total property and equipment assets under capital lease	23,300,000	8,100,000
Accumulated depreciation related to assets under capital lease	$ 5,000,000	$ 1,000,000