Other Comprehensive Income/Loss (Components of Accumulated Other Comprehensive Loss, Net of Related Tax Effects) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Changes in accumulated other comprehensive loss components
Balance at the beginning of the period	$ (63,460)	$ (35,092)	$ (65,951)	$ (38,250)
Other comprehensive income, net of tax	(2,347)	4,891	144	8,049
Balance at the end of the period	(65,807)	(30,201)	(65,807)	(30,201)
Net unrealized (loss) gain on securities available-for-sale
Changes in accumulated other comprehensive loss components
Balance at the beginning of the period	6,679	(1,373)	4,686	(4,366)
Other comprehensive income, net of tax	(2,791)	4,699	(798)	7,692
Balance at the end of the period	3,888	3,326	3,888	3,326
Net actuarial loss on pension plans and other postretirement benefits
Changes in accumulated other comprehensive loss components
Balance at the beginning of the period	(67,007)	(30,465)	(67,476)	(30,600)
Other comprehensive income, net of tax	417	161	886	296
Balance at the end of the period	(66,590)	(30,304)	(66,590)	(30,304)
Prior service cost on pension plans and other postretirement benefits
Changes in accumulated other comprehensive loss components
Balance at the beginning of the period	(3,132)	(3,254)	(3,161)	(3,284)
Other comprehensive income, net of tax	27	31	56	61
Balance at the end of the period	$ (3,105)	$ (3,223)	$ (3,105)	$ (3,223)