CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Pension and other post retirement obligations:
Amortization of actuarial losses included in net periodic pension cost, gross	$ 304	$ 150	$ 910	$ 625
Tax effect	(74)	(57)	(221)	(240)
Amortization of actuarial losses included in net periodic pension cost, net	230	93	689	385
Amortization of prior service cost included in net periodic pension cost, gross	(105)	(32)	(359)	(91)
Tax effect	25	12	87	35
Amortization of prior service cost included in net periodic pension cost, net	(80)	(20)	(272)	(56)
Initial projected benefit obligation recognized upon plan adoption, gross (See Note H)	(775)	0	(775)	0
Tax effect	189	0	189	0
Initial projected benefit obligation recognized upon plan adoption, net	(586)	0	(586)	0
Unamortized actuarial gain due to plan merger, gross (See Note H)	0	0	0	1,858
Tax effect	0	0	0	(710)
Unamortized actuarial gain due to plan merger, net	0	0	0	1,148
Other comprehensive (loss) income related to pension and other post retirement obligations, net of taxes	(436)	73	(169)	1,477
Unrealized (losses) gains on available-for-sale securities:
Net unrealized holding (losses)/gains arising during period, gross	(20,094)	(2,490)	(76,705)	11,163
Tax effect	4,879	952	18,639	(4,306)
Net unrealized holding (losses)/gains arising during period, net	(15,215)	(1,538)	(58,066)	6,857
Reclassification of other comprehensive income due to change in accounting principle - equity securities	0	0	(208)	0
Other comprehensive (loss)/income related to unrealized (losses)/gains on available-for-sale securities, net of taxes	(15,215)	(1,538)	(58,274)	6,857
Other comprehensive (loss)/income, net of tax	(15,651)	(1,465)	(58,443)	8,334
Net income	43,106	35,243	127,818	78,691
Comprehensive income	27,455	$ 33,778	69,375	$ 87,025
Accumulated Other Comprehensive Loss By Component:
Unrealized loss for pension and other post-retirement obligations	(28,901)		(28,901)		$ (28,677)
Tax effect	7,099		7,099		7,044
Net unrealized loss for pension and other post-retirement obligations	(21,802)		(21,802)		(21,633)
Unrealized (loss) gain on available-for-sale securities	(53,040)		(53,040)		23,940
Tax effect	12,908		12,908		(6,006)
Reclassification of other comprehensive income due to change in accounting principle - equity securities	(208)		(208)		0
Net unrealized (loss) gain on available-for-sale securities	(40,340)		(40,340)		17,934
Accumulated other comprehensive loss	$ (62,142)		$ (62,142)		$ (3,699)