Property, Plant and Equipment - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Accumulated amortization for assets capitalized under capital leases	$ 567,000	$ 718,000
Interest cost capitalized in PP&E	$ 398,000
Minimum [Member] | Chemical processing plants and plant infrastructure [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives in years	15 years
Minimum [Member] | Production, fabrication, and assembly equipment [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives in years	7 years
Minimum [Member] | Processing plant components [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives in years	3 years
Minimum [Member] | Trucks, automobiles, trailers, and other rolling stock [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives in years	3 years
Maximum [Member] | Chemical processing plants and plant infrastructure [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives in years	30 years
Maximum [Member] | Production, fabrication, and assembly equipment [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives in years	15 years
Maximum [Member] | Processing plant components [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives in years	10 years
Maximum [Member] | Trucks, automobiles, trailers, and other rolling stock [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives in years	7 years