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, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Pension Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	9,879	8,989	29,637	26,967
Expected return on plan assets	(11,528)	(11,498)	(34,584)	(34,494)
Amortization of prior service cost	0	0	0	0
Amortization of net (gain) loss	(1)	3,074	(2)	9,222
Net periodic benefit cost	(1,650)	565	(4,949)	1,695
Employer contributions	5,200		6,200
Post-Retirement Healthcare Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	60	69	180	207
Interest cost	71	66	213	198
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	(872)	(1,413)	(2,616)	(4,239)
Amortization of net (gain) loss	80	104	240	312
Net periodic benefit cost	$ (661)	$ (1,174)	$ (1,983)	$ (3,522)