Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Reconciliation of income tax expense:
Computed income tax expense at statutory federal income tax rate of 35%			$ 3,079	$ 7,839
State income taxes, net of federal provision			158	563
Change in valuation allowance			33
Nontaxable income items			(373)
Other, net			(117)	86
Income tax expense	$ 2,253	$ 2,588	$ 2,780	$ 8,488
Computed income tax expense at statutory federal income tax rate of 35%, tax rate			35.00%	35.00%
State income taxes, net of federal provision, tax rate			1.80%	2.50%
Change in valuation allowance, tax rate			0.40%	0.00%
Nontaxable income items, tax rate			(4.20%)	0.00%
Other, net, tax rate			(1.40%)	0.40%
Income tax expense, tax rate			31.60%	37.90%