Pension Plans And Other Postretirement Benefits (Components Of Net Periodic Benefit Costs) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,287	$ 1,044	$ 2,536	$ 2,087
Interest cost	3,258	2,964	6,523	5,928
Expected return on plan assets	(3,482)	(2,596)	(6,732)	(5,191)
Amortization of prior service cost	72	43	119	87
Amortization of actuarial loss	1,654	1,016	3,516	2,033
Capitalized costs	(924)	(951)	(1,808)	(1,808)
Settlement charge	4,980		4,980
Curtailment credit	(480)		(480)
Net periodic benefit cost including discontinued operations	6,365	1,520	8,654	3,136
Less discontinued operations	4,594	287	4,876	574
Net periodic benefit cost	1,771	1,233	3,778	2,562
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	322	376	659	751
Interest cost	616	812	1,316	1,623
Expected return on plan assets	(529)	(621)	(1,067)	(1,243)
Amortization of transition obligation		34	18	69
Amortization of prior service cost	(36)	(89)	(104)	(178)
Amortization of actuarial loss	268	206	536	411
Amortization of regulatory asset	34	34	68	68
Capitalized costs	(167)	(188)	(330)	(343)
Settlement charge	325		325
Net periodic benefit cost including discontinued operations	833	564	1,421	1,158
Less discontinued operations	337	49	390	98
Net periodic benefit cost	$ 496	$ 515	$ 1,031	$ 1,060