Acquisition of Real Estate - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014
Business Acquisition [Line Items]
Lease period	10 years
Renewal of lease period	15 years
New Jersey Facility [Member]
Business Acquisition [Line Items]
Aggregate costs related to acquisition	$ 73.3
Acres of real estate property	194
Area of facility	560,000
New Jersey Facility [Member] | Raised Floor With Twelve MW Gross Power [Member]
Business Acquisition [Line Items]
Area of facility	58,000
Capacity of the plant	12