Other Comprehensive Income (Loss) (Details 1) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Other Comprehensive Income Available For Sale Securities Adjustment Net Of Tax Period Increase Decrease [Roll Forward]
Beginning Balance	$ (2,744)	$ 2,867
Other comprehensive income before reclassifications	12,575	5,592
Amounts reclassified from accumulated other comprehensive loss	(139)	(174)
Net current-period other comprehensive income (loss)	12,436	5,418
Ending Balance	9,692	8,285
Other Comprehensive Income Employee Benefit Plans Adjustment Net Of Tax Period Increase Decrease [Roll Forward]
Beginning Balance	(28,257)	(26,878)
Other comprehensive income before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive (loss) income	224	331
Net current-period other comprehensive loss (income)	224	331
Ending Balance	(28,033)	(26,547)
Accumulated Other Comprehensive Income (Loss) Net Of Tax [Roll Forward]
Beginning Balance	(31,001)	(24,011)
Other comprehensive income before reclassifications	12,575	5,592
Amounts reclassified from accumulated other comprehensive (loss) income	85	157
Other comprehensive income	12,660	5,749
Ending Balance	$ (18,341)	$ (18,262)