Retirement Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Contributions to Pension Plans			$ (221)	$ (160)
Employees' Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	367	339	734	679
Interest Cost	276	534	629	938
Expected Return on Plan Assets	(716)	(755)	(1,432)	(1,510)
Amortization of Prior Service Cost (Credit)	9	10	18	20
Amortization of Net Loss	312	311	624	621
Net Periodic Benefit Cost	248	439	573	748
Contributions to Pension Plans	0	0	0	0
Estimated Future Contributions in the Current Fiscal Year					0
Select Executive Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	5	19	27	38
Interest Cost	10	51	48	102
Expected Return on Plan Assets	0	0	0	0
Amortization of Prior Service Cost (Credit)	20	11	40	22
Amortization of Net Loss	38	35	76	70
Net Periodic Benefit Cost	73	116	191	232
Contributions to Pension Plans	110	80	221	160
Estimated Future Contributions in the Current Fiscal Year					221
Post-Retirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	51	45	102	90
Interest Cost	69	93	150	181
Expected Return on Plan Assets	0	0	0	0
Amortization of Prior Service Cost (Credit)	(29)	(29)	(58)	(57)
Amortization of Net Loss	42	33	83	66
Net Periodic Benefit Cost	133	142	277	280
Contributions to Pension Plans	94	158	175	231
Estimated Future Contributions in the Current Fiscal Year					$ 175