Employee Benefits (Retirement Plans And Other Postretirement Benefits) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Retirement Plans
Service cost	$ 1,712	$ 1,516	$ 5,137	$ 4,548	$ 6,653	$ 5,932
Interest cost	3,497	3,407	10,491	10,222	13,898	13,518
Amendments	0	0	0	0	838	0
Expected return on plan assets	(3,523)	(3,467)	(10,571)	(10,400)	(14,038)	(14,259)
Amortization of net loss	1,636	887	4,908	2,661	5,796	3,067
Amortization of prior service cost	29	29	87	87	115	115
Net periodic benefit cost	3,351	2,372	10,052	7,118	13,262	8,373
Other Postretirement Benefits
Service cost	747	889	2,241	2,668	3,131	3,516
Interest cost	1,345	1,666	4,034	4,998	5,700	6,621
Expected return on plan assets	(455)	(382)	(1,367)	(1,147)	(1,749)	(1,521)
Amortization of prior service benefit	(1,482)	(717)	(4,445)	(2,152)	(5,162)	(2,869)
Amortization of net gain	(11)	(44)	(30)	(131)	(74)	(131)
Net periodic benefit cost	$ 144	$ 1,412	$ 433	$ 4,236	$ 1,846	$ 5,616