XML 59 R46.htm IDEA: XBRL DOCUMENT v3.8.0.1
Derivatives - Foreign Currency Derivative Contracts Outstanding (Details) - Not Designated as Hedging Instrument - Foreign currency contracts
$ in Thousands
Mar. 31, 2018
USD ($)
$ / $
$ / €
$ / £
$ / kr
Dec. 31, 2017
USD ($)
$ / $
$ / €
$ / £
$ / kr
Canadian dollar    
Derivative [Line Items]    
Notional Amount $ 5,025 $ 6,226
Contractual Exchange Rate | $ / $ 1.2935 1.2850
Euro    
Derivative [Line Items]    
Notional Amount $ 9,080 $ 5,326
Contractual Exchange Rate | $ / € 1.2438 1.1836
Norwegian krone    
Derivative [Line Items]    
Notional Amount $ 5,575 $ 6,212
Contractual Exchange Rate | $ / kr 7.7127 8.3704
Pound sterling    
Derivative [Line Items]    
Notional Amount $ 6,105 $ 6,039
Contractual Exchange Rate | $ / £ 1.4035 1.3419