|12 Months Ended|
Dec. 31, 2017
|Derivative Instruments and Hedging Activities Disclosure [Abstract]|
|Schedule of (gains) losses on derivatives||
The following table summarizes (gains) losses recorded in relation to derivatives:
Tabular disclosure of the location and amount of derivative instruments and nonderivative instruments designated as hedging instruments reported before netting adjustments, and the amount of gain (loss) on derivative instruments and nonderivative instruments designated and qualified as hedging instruments.
Reference 1: http://www.xbrl.org/2003/role/presentationRef