Employee Benefit Plans (Schedule Of Net Periodic Benefit Cost) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 491,000	$ 789,000	$ 1,389,000	$ 1,931,000
Interest cost	969,000	724,000	2,067,000	1,890,000
Expected return on plan assets	(667,000)	(405,000)	(1,769,000)	(1,225,000)
Prior service cost	(35,000)	(21,000)	(93,000)	(70,000)
Recognized loss	467,000	151,000	856,000	462,000
Total	1,225,000	1,238,000	2,450,000	2,988,000
Employer contributions to qualified retirement plan			$ 2,500,000	$ 2,200,000