Income Taxes (Details 2)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of statutory federal income tax rate
Federal statutory rate	35.00%	35.00%	35.00%
State income taxes, net of federal benefit	4.80%	3.03%	7.10%
State valuation allowance	(0.06%)	(0.07%)	(4.27%)
Nondeductible expenses and other	(0.61%)	0.54%	0.44%
Effective income tax rate	39.13%	38.50%	38.27%