Pension and Other Post-Retirement Benefit Plans (Net Periodic Benefit Costs) (Details) (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 Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	8,989	9,272	26,967	27,816
Expected return on plan assets	(11,498)	(9,970)	(34,494)	(29,910)
Amortization of prior service cost	0	0	0	0
Amortization of net (gain) loss	3,074	2,670	9,222	8,010
Net periodic benefit cost (benefit)	565	1,972	1,695	5,916
Post-Retirement Healthcare Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	69	67	207	201
Interest cost	66	95	198	285
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	(1,413)	(1,388)	(4,239)	(4,164)
Amortization of net (gain) loss	104	108	312	324
Net periodic benefit cost (benefit)	$ (1,174)	$ (1,118)	$ (3,522)	$ (3,354)