Accounts Receivable - Components of Accounts Receivable (Detail) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Receivables [Abstract]    
Trade receivables $ 41,469 $ 45,719
Allowance for doubtful accounts (5,376) (5,837)
Total accounts receivable $ 36,093 $ 39,882