Income Taxes (Schedule Of Effective Reconciliation Of The U.S. Statutory Federal Income Tax Rates) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Tax provision at statutory rate on income before income taxes	$ 115,040	$ 95,584	$ 77,029
State income taxes, net of federal benefit	12,083	10,211	7,480
Meals and entertainment disallowance	872	828	721
Tax credits	(5,422)	(2,609)	(4,453)
Other, net	0	(368)	(163)
Total provision for income taxes	$ 122,573	$ 103,646	$ 80,614