Income Tax (tables)

6 Months Ended

Jun. 30, 2013

Income Tax Disclosure [Abstract]

Effective Tax Rate Reconciliation

	June 30,
	2013		2012
Federal statutory tax rate	35.0	%	35.0	%
Increase (decrease):
Current state income tax, net of federal tax benefit	4.6		4.8
Amortization of investment and energy tax credits	(0.3	)	(0.3	)
Differences required to be flowed-through by regulatory commissions	2.3		1.5
Gains on company and trust-owned life insurance	(0.8	)	(0.7	)
Other, net	(0.1	)	0.3
Effective income tax rate	40.7	%	40.6	%