Employee Benefit Plans Employee Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service Cost	$ 213	$ 191
Interest Cost	742	742
Expected Return on Plan Assets	(941)	(785)
Prior Service Cost (Benefit)	11	14
Net Loss (Gain)	652	650
Net Periodic Benefit Cost	677	812
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions made by Employer	0
Remaining Anticipated Employer Contributions in Current Fiscal Year	1,582
Anticipated Future Employer Contributions in Next Fiscal Year	3,483
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service Cost	54	53
Interest Cost	60	86
Prior Service Cost (Benefit)	(69)	(69)
Net Loss (Gain)	2	35
Net Periodic Benefit Cost	47	105
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions made by Employer	109
Remaining Anticipated Employer Contributions in Current Fiscal Year	329
Anticipated Future Employer Contributions in Next Fiscal Year	489
Other Pension Plans, Postretirement or Supplemental Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Interest Cost	33	26
Net Loss (Gain)	17	14
Net Periodic Benefit Cost	50	40
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions made by Employer	54
Remaining Anticipated Employer Contributions in Current Fiscal Year	162
Anticipated Future Employer Contributions in Next Fiscal Year	$ 215