Foreign Currency Gain, Net - Additional Information (Detail) $ in Thousands |
3 Months Ended | ||
|---|---|---|---|
|
Mar. 31, 2017
USD ($)
|
Jun. 30, 2017
USD ($)
₩ / $
|
Dec. 31, 2016
₩ / $
|
|
| Foreign Currency Transaction [Abstract] | |||
| Intercompany loan balances | $ 670,992 | ||
| Exchange rates using first base rate | ₩ / $ | 1,139.6 | 1,208.5 | |
| New issue of intercompany loans | $ 75,000 |