Employee Benefit and Deferred Compensation Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Pension Benefits [Member]
Plan expense for noncontributory benefit pension plan and post-retirement health and life plans
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	187	215	375	430
Expected return on plan assets	(309)	(298)	(620)	(596)
Prior service cost recognized	0	0	0	0
Recognized actuarial loss	102	89	199	178
Net periodic benefit cost	(20)	6	(46)	12
Other Benefits [Member]
Plan expense for noncontributory benefit pension plan and post-retirement health and life plans
Service cost	6	6	13	12
Interest cost	15	16	27	32
Expected return on plan assets	0	0	0	0
Prior service cost recognized	0	0	0	0
Recognized actuarial loss	36	18	55	36
Net periodic benefit cost	$ 57	$ 40	$ 95	$ 80