Commitments and Contingencies (Details-1) - EPA [Member]	9 Months Ended
	Sep. 30, 2016 ppb pollutant state MW
Effluent Limitations Guidelines and Standards for Steam Electric Power Generating Source Category [Abstract]
Air pollution control and ash handling systems capacity at coal burning power plants, minimum (in MW) | MW	50
EPA's National Ambient Air Quality Standards
Number of pollutants monitored by the National Ambient Air Quality Standards | pollutant	6
Ozone NAAQS
Current primary regulated level of Ozone NAAQS (in parts per billion)	70
Current secondary regulated level of Ozone NAAQS (in parts per billion)	70
EPA's Cross State Air Pollution Rule
Number of states incorporating 2008 ozone NAAQS attainment levels | state	22