Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net Income	$ 16,981	$ 15,426	$ 41,249	$ 41,750
Unrealized Gains on Available-for-Sale Securities:
Reversal of Previously Recognized Losses (Gains) Realized on Sale of Investments and Included in Other Income During Period	32	(4)	34	(4)
Unrealized Gains Arising During Period	92	66	218	157
Income Tax Expense	(26)	(13)	(53)	(32)
Change in Unrealized Gains on Available-for-Sale Securities – net-of-tax	98	49	199	121
Pension and Postretirement Benefit Plans:
Amortization of Unrecognized Postretirement Benefit Losses and Costs (note 11)	137	129	275	259
Income Tax Expense	(36)	(33)	(72)	(67)
Pension and Postretirement Benefit Plans – net-of-tax	101	96	203	192
Total Other Comprehensive Income	199	145	402	313
Total Comprehensive Income	$ 17,180	$ 15,571	$ 41,651	$ 42,063