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Long-Term Debt - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2017
Dec. 31, 2016
6.0% Senior Notes Due 2022    
Debt Instrument [Line Items]    
Debt maturity period 2022 2022
Senior Bank Credit Facility    
Debt Instrument [Line Items]    
Credit facility $ 107,000 $ 70,000
Credit facility expiration date Jun. 26, 2020  
Letters of Credit Outstanding, Amount $ 700