Long-Term Debt - Schedule of Long-Term Debt (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Long-term debt	$ 460,328	$ 462,967
Less current portion of long-term debt	10,530	9,262
Long-term debt due after one year	449,798	453,705
Working Capital Revolver Loan [Member]
Debt Instrument [Line Items]
Long-term debt
7.75% Senior Secured Notes due 2019 [Member]
Debt Instrument [Line Items]
Long-term debt	425,000	425,000
Secured Promissory Note [Member]
Debt Instrument [Line Items]
Long-term debt	26,211	29,555
Other, with a current weighted-average interest rate of 4.05%, most of which is secured by machinery and equipment [Member]
Debt Instrument [Line Items]
Long-term debt	$ 9,117	$ 8,412