Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014
Summary Of Significant Accounting Policies [Line Items]
Balance in excess of FDIC-insured limits		$ 64,000,000
Chemical [Member] | Scenario Adjustment [Member]
Summary Of Significant Accounting Policies [Line Items]
Additional repairs and maintenance expenses classified as cost of sales	405,000
Repair part average cost		100
Additional obsolescence expenses classified as cost of sales	$ 324,000	$ 324,000
Effect of adjustment in basic and diluted net loss per share	$ 0.02
Effect of adjustment in basic and diluted net income per share		$ 0.01
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Ownership interest in equity method investment	20.00%	20.00%
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Ownership interest in equity method investment	50.00%	50.00%
Short-Term Investments [Member]
Summary Of Significant Accounting Policies [Line Items]
Original maturity period		26 weeks
Noncurrent Restricted Investments [Member] | CD [Member]
Summary Of Significant Accounting Policies [Line Items]
Original maturity period		No longer than approximately 26 weeks