Income Taxes (Schedule Of Effective Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Abstract]
Statutory U.S. federal income tax rate	35.00%	35.00%	35.00%
State income tax, net of related federal income tax benefit	13.30%	3.60%	3.70%
Federal credits	(10.10%)	(0.40%)	(0.50%)
Enhanced deduction for food donation	(2.40%)	(0.20%)	(0.10%)
Valuation allowance	6.00%	0.30%	0.40%
Other	6.20%	0.00%	0.10%
Return to provision and other discrete items	(7.20%)	(0.10%)	(1.00%)
Effective income tax rate	40.80%	38.20%	37.60%