Income Tax Provision - Effective tax rate based upon total income tax provision (benefit) from continuing operations (Details 2)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Federal statutory rate	34.00%	34.00%
Deferred tax adjustment		(3.30%)
Business credits	1.80%	(2.80%)
ESOP dividend	(2.80%)	(1.50%)
Domestic production activities deduction	(1.80%)	(2.30%)
Other		0.20%
State income taxes (less federal effect)	0.10%	(0.60%)
Effective tax rate	31.30%	23.70%