XML 94 R83.htm IDEA: XBRL DOCUMENT v3.19.2
DERIVATIVE FINANCIAL INSTRUMENTS (Details 1) - USD ($)
$ in Millions
Jun. 30, 2019
Dec. 31, 2018
Jun. 30, 2018
Derivative [Line Items]      
Notional amount $ 186.1 $ 116.5 $ 139.1
Natural Gas Commodity Forward Contracts      
Derivative [Line Items]      
Notional amount 67.1 58.4 79.6
Other Commodity Forward Contracts      
Derivative [Line Items]      
Notional amount $ 119.0 $ 58.1 $ 59.5