Income Taxes (Reconciliation Of Income Tax Provision At Statutory Income Tax Rate And Effective Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Taxes [Abstract]
Statutory federal rate	35.00%	35.00%	35.00%
State taxes, net of federal tax benefit	2.60%	2.70%	2.90%
Permanent differences	0.50%	0.70%	0.50%
Change in valuation allowance	0.10%	(0.10%)	(0.20%)
Changes in tax contingencies	(0.10%)	0.00%	(2.40%)
Other items, net	(0.90%)	(0.90%)	(1.40%)
Effective income tax rate, Total	37.20%	37.40%	34.40%