Retirement Plans (Summary Of Change In Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	$ 174,223	$ 152,696
Actual return on plan assets	23,399	(1,499)
Employer contribution	25,000	27,500
Gross benefits paid	(4,811)	(4,474)
Fair value of plan assets at end of year	217,811	174,223
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contribution	103	103
Gross benefits paid	(103)	(103)
Fair value of plan assets at end of year	0	0
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contribution	58	122
Gross benefits paid	(58)	(122)
Fair value of plan assets at end of year	$ 0	$ 0