Annual report pursuant to Section 13 and 15(d)

Derivative Instruments - (Details)

v3.7.0.1
Derivative Instruments - (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Assets    
Gross amounts of commodity derivative contracts recognized at fair value $ 1,272 $ 4,644
Cash collateral 9,366 5,638
Total gross amount recognized 10,638 10,282
Gross amounts offset (3,511) (185)
Net amount reported in the Consolidated Balance Sheets 7,127 10,097
Liabilities    
Gross amounts of commodity derivative contracts recognized at fair value 3,511 185
Cash collateral 0 0
Total gross amount recognized 3,511 185
Gross amounts offset (3,511) (185)
Net amount reported in the Consolidated Balance Sheets $ 0 $ 0