XML 76 R65.htm IDEA: XBRL DOCUMENT v3.7.0.1
Derivatives - Gain (loss) on derivatives (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Derivative financial instruments    
Cash settlements received for early terminations of derivatives, net $ 0 $ 80,000
Derivatives not designated as hedges | Commodity derivatives    
Derivative financial instruments    
Cash settlements received for matured derivatives, net(1) 7,451 65,937
Cash settlements received for early terminations of derivatives, net 0 80,000
Cash settlements received for derivatives, net $ 7,451 145,937
Deferred premium   $ 4,000