Pension and Postretirement Plans (Obligation, Asset, and Funding Information) (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 12,713	$ 10,876	$ 38,788	$ 28,684
Interest cost	14,242	14,828	42,776	44,248
Supplemental Executive Retirement Plan (SERP) [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	429	367	1,288	1,100
Interest cost	1,023	1,060	3,069	3,181
Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	728	778	2,183	2,335
Interest cost	$ 508	$ 684	$ 1,525	$ 2,052