Annual report pursuant to Section 13 and 15(d)

Summary Of Significant Accounting Policies (Rollforward Analysis Of The Allowance Against Accounts Receivable Balance) (Detail)

v3.3.1.900
Summary Of Significant Accounting Policies (Rollforward Analysis Of The Allowance Against Accounts Receivable Balance) (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Allowance for Bad Debt, Beginning Balance $ (10,031) $ (7,631) $ (6,069)
Allowance for Bad Debt, Charged to costs and expenses (2,699) (2,400) (1,562)
Allowance for Bad Debts, Foreign currency gain 880    
Allowance for Bad Debt, Ending Balance (11,850) (10,031) $ (7,631)
Gabon [Member]      
Allowance for Bad Debt, Charged to costs and expenses $ (2,700) $ (2,400)