Employee Benefit Plans Components of Net Periodic Expense (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 765	$ 798	$ 1,214
Defined Benefit Plan, Interest Cost	2,969	3,092	3,280
Defined Benefit Plan, Expected Return on Plan Assets	(3,139)	(3,619)	(3,008)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	57	62	62
Defined Benefit Plan, Amortization of Transition Obligations (Assets)	0	0	0
Defined Benefit Plan, Recognition of Net Actuarial Loss (Gain)	2,599	1,486	1,378
Defined Benefit Plan, Curtailment Expense	0	0	57
Defined Benefit Plan, Net Periodic Benefit Cost	3,251	1,819	2,983
Supplemental Employee Retirement Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	0	0	0
Defined Benefit Plan, Interest Cost	104	114	100
Defined Benefit Plan, Expected Return on Plan Assets	0	0	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	0
Defined Benefit Plan, Amortization of Transition Obligations (Assets)	0	0	0
Defined Benefit Plan, Recognition of Net Actuarial Loss (Gain)	55	48	30
Defined Benefit Plan, Curtailment Expense	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	159	162	130
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	214	210	340
Defined Benefit Plan, Interest Cost	343	365	547
Defined Benefit Plan, Expected Return on Plan Assets	0	0	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(278)	(314)	(141)
Defined Benefit Plan, Amortization of Transition Obligations (Assets)	0	0	171
Defined Benefit Plan, Recognition of Net Actuarial Loss (Gain)	139	163	0
Defined Benefit Plan, Curtailment Expense	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	$ 418	$ 424	$ 917