Risk Management And Derivatives (Changes In Foreign Currency Exchange Rates And Derivative Foreign Currency Forward Contracts) (Detail) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2015 |
Jun. 30, 2014 |
Jun. 30, 2015 |
Jun. 30, 2014 |
Dec. 31, 2014 |
|
| Foreign Currency Exchange Gain Loss [Line Items] | |||||
| Maturity of foreign currency forward contract | 8 months | ||||
| Unrealized foreign currency exchange rate gains (losses) | $ 2,193 | $ 755 | $ (19,223) | $ 100 | |
| Realized foreign currency exchange rate gains (losses) | 2,516 | (229) | 8,857 | 222 | |
| Unrealized derivative gains (losses) | (287) | (88) | (70) | (18) | |
| Realized derivative gains (losses) | 4,381 | $ 191 | (8,637) | $ 931 | |
| Fair Value, Inputs, Level 2 [Member] | |||||
| Foreign Currency Exchange Gain Loss [Line Items] | |||||
| Foreign Currency Contract, Asset, Fair Value Disclosure | $ 1,396 | $ 1,396 | $ 806 | ||