Employee Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Pension Benefit Plan [Member]
Periodic costs for employee retirement benefit plans
Service Cost	$ 473	$ 575
Interest Cost	670	617
Expected Return on Assets	(883)	(724)
Amortization of Unrecognized Losses	104	408
Amortization of Unrecognized Prior Service Cost	1	2
Net Periodic Benefit Cost	365	878
Other Benefits Plan [Member]
Periodic costs for employee retirement benefit plans
Service Cost	258	334
Interest Cost	448	399
Expected Return on Assets	(484)	(406)
Amortization of Unrecognized Losses	353	516
Amortization of Unrecognized Prior Service Cost	(432)	(432)
Net Periodic Benefit Cost	$ 143	$ 411