Pension Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Service cost - benefits earned during the period		$ 698
Interest cost	439	523
Expected return on plan assets	(591)	(492)
Amortization of transition obligation		1
Amortization of net (gain)/loss	3	301
Amortization of prior service cost		8
Net periodic pension cost	(149)	1,039
Pension Plan
Service cost - benefits earned during the period		604
Interest cost	372	436
Expected return on plan assets	(591)	(492)
Amortization of transition obligation		1
Amortization of net (gain)/loss	3	267
Amortization of prior service cost		3
Net periodic pension cost	(216)	819
SERP
Service cost - benefits earned during the period		94
Interest cost	67	87
Expected return on plan assets
Amortization of transition obligation
Amortization of net (gain)/loss		34
Amortization of prior service cost		5
Net periodic pension cost	$ 67	$ 220