Pension and Other Post Retirement Benefit Plans Pension and Other Post Retirement Benefit Plans - Schedule of Changes in Benefit Obligation, and Plan Assets, Funded Status of the Plan, Assets and Liabilities Recognized in the Balance Sheets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	$ 68,769	$ 61,422
Service Cost	161	252
Interest Cost	2,990	3,208
Actuarial Loss (Gain)	3,168	7,346
Benefits paid	(5,922)	(3,459)
Benefit obligation at end of year	69,166	68,769
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	62,078	63,275
Actual return on plan assets	6,141	1,726
Employer contributions	568	536
End of Year	62,865	62,078
Funded Status at End of Year	(6,301)	(6,691)
Assets and Liabilities Recognized in the Balance Sheets:
Deferred Tax Asset	9,200	10,928
Liabilities	6,301	6,691
Amounts Recognized In Accumulated Other Comprehensive Income Not Yet Recognized As A Component of Net Periodic Pension Cost [Abstract]
Accumulated Loss	(17,085)	(16,310)
Prior Service Credit	(41)	(56)
Total	$ (17,126)	$ (16,366)