Blount Station (Details) (USD $)	6 Months Ended		12 Months Ended
	Jun. 30, 2011 MW Tons Dth MWh	Jun. 30, 2010	Dec. 31, 2013	Dec. 31, 2012
Blount Capacity Megawatts [Abstract]
Blount capacity current - MW	190
Blount capacity future - MW	100
Blount capacity reduction - MW	90
Restructuring And Related Cost [Abstract]
Benefits expected to be paid			$ 300,000	$ 300,000
Restructuring accrual activity [Roll forward]
Balance at December 31, 2010	259,000
Additional expense, net	56,000
Cash payments during the period	(24,000)
Balance at June 30, 2011	291,000
Accelerated Depreciation Recovered [Abstract]
Accelerated depreciation recovered	$ 1,700,000	$ 1,700,000