Employee Benefit Plans (Schedule of Benefits Plans) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Pension Benefit Plan [Member]
Periodic costs for employee retirement benefit plans
Service Cost	$ 639	$ 474	$ 1,279	$ 947
Interest Cost	724	671	1,447	1,341
Expected Return on Assets	(980)	(884)	(1,959)	(1,767)
Amortization of Unrecognized Losses	$ 411	$ 104	$ 823	208
Amortization of Unrecognized Prior Service Cost (Credit)				1
Net Periodic Benefit Cost	$ 794	$ 365	$ 1,590	730
Other Benefits Plan [Member]
Periodic costs for employee retirement benefit plans
Service Cost	343	258	686	516
Interest Cost	480	448	961	896
Expected Return on Assets	(527)	(484)	(1,053)	(969)
Amortization of Unrecognized Losses	565	353	1,131	707
Amortization of Unrecognized Prior Service Cost (Credit)	(432)	(432)	(864)	(864)
Net Periodic Benefit Cost	$ 429	$ 143	$ 861	$ 286