CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Pension and other post retirement obligations:
Amortization of actuarial losses included in net periodic pension cost, gross	$ 150	$ 376	$ 625	$ 1,127
Tax effect	(57)	(144)	(240)	(432)
Amortization of actuarial losses included in net periodic pension cost, net	93	232	385	695
Amortization of prior service cost included in net periodic pension cost, gross	(32)	(34)	(91)	(101)
Tax effect	12	13	35	39
Amortization of prior service cost included in net periodic pension cost, net	(20)	(21)	(56)	(62)
Unamortized actuarial gain due to plan merger, gross (See Note H)	0	0	1,858	0
Tax effect	0	0	(710)	0
Unamortized actuarial gain due to plan merger, net	0	0	1,148	0
Other comprehensive income related to pension and other post retirement obligations, net of taxes	73	211	1,477	633
Unrealized gains on available-for-sale securities:
Net unrealized holding (losses)/gains arising during period, gross	(2,490)	(24,465)	11,163	74,332
Tax effect	952	9,310	(4,306)	(28,109)
Net unrealized holding (losses)/gains arising during period, net	(1,538)	(15,155)	6,857	46,223
Other comprehensive (loss)/income related to unrealized (losses)/gains on available-for-sale securities, net of taxes	(1,538)	(15,155)	6,857	46,223
Other comprehensive (loss)/income, net of tax	(1,465)	(14,944)	8,334	46,856
Net income	35,243	27,160	78,691	77,420
Comprehensive income	33,778	$ 12,216	87,025	$ 124,276
Accumulated Other Comprehensive Income By Component:
Unrealized loss for pension and other post-retirement obligations	(26,577)		(26,577)		$ (28,969)
Tax effect	10,093		10,093		11,008
Net unrealized loss for pension and other post-retirement obligations	(16,484)		(16,484)		(17,961)
Unrealized gain on available-for-sale securities	52,956		52,956		41,793
Tax effect	(20,295)		(20,295)		(15,989)
Net unrealized gain on available-for-sale securities	32,661		32,661		25,804
Accumulated other comprehensive income	$ 16,177		$ 16,177		$ 7,843