v3.5.0.2
Commitments and Contingencies - Environmental Laws and Regulations - Additional Information (Detail)
6 Months Ended
Jun. 30, 2016
USD ($)
Loss Contingencies [Line Items]  
Penalties imposed on inspections $ 100,000
Minimum [Member] | Natrium West Virginia And Lake Charles South Facility [Member]  
Loss Contingencies [Line Items]  
Period during which facilities are operational 65 years