Commitments and Contingencies (Details) $ in Millions, ₩ in Billions |
Jun. 30, 2017
USD ($)
|
Jun. 30, 2017
KRW (₩)
|
Dec. 31, 2016
USD ($)
|
Dec. 31, 2016
KRW (₩)
|
|---|---|---|---|---|
| Assessment | ||||
| Loss Contingencies [Line Items] | ||||
| Estimate of possible loss | $ 10.6 | ₩ 11.9 | ||
| Additional Assessment | ||||
| Loss Contingencies [Line Items] | ||||
| Estimate of possible loss | $ 17.9 | ₩ 20.1 |