Retirement Plans Components of Net Periodic Benefit Cost (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Retirement Plans (Textuals) [Abstract]
Retirement eligible age for participation			55
Years of service for pension plan eligibility			5
Pension Contributions			$ 21,270	$ 28,000
Pension Plans, Defined Benefit [Member]
Net period benefit cost for the pension and postretirement plans
Service cost	2,975	2,975	8,925	8,925	12,078
Interest cost	1,790	1,548	5,370	4,643	6,237
Expected return on plan assets	(4,855)	(4,305)	(14,565)	(12,915)	(17,647)
Amortization of prior service cost	15	17	45	52	72
Amortization of actuarial (gain) loss	326	1,073	975	3,218	4,344
Settlement charge	0	0	0	0	0
Total net periodic benefit cost	251	1,308	750	3,923	5,084
Other Postretirement Benefit Plans, Defined Benefit [Member]
Net period benefit cost for the pension and postretirement plans
Interest cost	39	40	116	120	142
Amortization of prior service cost	0	0	0	0	0
Amortization of actuarial (gain) loss	(9)	0	(26)	0
Total net periodic benefit cost	$ 30	$ 40	$ 90	$ 120	$ 142