Income Tax (Tables)

6 Months Ended

Jun. 30, 2016

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Three Months Ended June 30,						Six Months Ended June 30,
Dollars in thousands	2016			2015			2016			2015
Income taxes at statutory rates (federal and state)	$	1,351		$	1,429		$	25,959		$	20,321
Increase (decrease):
Differences required to be flowed-through by regulatory commissions	65			85			1,583			1,414
Other, net	(34		)	(100		)	(774		)	(1,238		)
Total provision for income taxes	$	1,382		$	1,414		$	26,768		$	20,497
Effective tax rate	40.6		%	39.2		%	40.9		%	40.0		%