Pension and Employee Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Pension plan [Member]
Pension plan:
Service cost	$ 15	$ 10	$ 30	$ 20
Interest cost	82	92	164	184
Expected return on plan assets	(94)	(97)	(188)	(194)
Amortization of net actuarial loss	83	63	166	126
Net periodic benefit cost	86	68	172	136
Health care plan [Member]
Pension plan:
Interest cost	1		2
Amortization of prior service cost	(2)	(1)	(4)	(2)
Net periodic benefit cost	$ (1)	$ (1)	$ (2)	$ (2)