Pension 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
Service cost - benefits earned during the period		$ 533		$ 1,231
Interest cost	369	433	814	956
Expected return on plan assets	(574)	(492)	(1,159)	(984)
Amortization of transition obligation		1		2
Amortization of net (gain)/loss	15	136	18	437
Amortization of prior service cost		8		16
Net periodic pension cost	(190)	619	(327)	1,658
Pension Plan
Service cost - benefits earned during the period		457		1,061
Interest cost	302	363	680	799
Expected return on plan assets	(574)	(492)	(1,159)	(984)
Amortization of transition obligation		1		2
Amortization of net (gain)/loss	15	136	18	403
Amortization of prior service cost		3		6
Net periodic pension cost	(257)	468	(461)	1,287
SERP
Service cost - benefits earned during the period		76		170
Interest cost	67	70	134	157
Expected return on plan assets
Amortization of transition obligation
Amortization of net (gain)/loss				34
Amortization of prior service cost		5		10
Net periodic pension cost	$ 67	$ 151	$ 134	$ 371