Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net income	$ 13,923	$ 12,725	$ 25,335	$ 24,985
Other comprehensive income (loss), net of tax:
Amortization of actuarial losses, net of taxes of $(43) and ($64) for the three months ended June 30, 2018 and 2017, respectively and of ($84) and ($128) for six months ended June 30, 2018 and 2017, respectively.	90	87	181	174
Amortization of prior service credits, net of taxes of $3 and $5 for the three months ended June 30, 2018 and 2017, respectively and of $6 and $9 for six months ended June 30, 2018 and 2017, respectively.	(6)	(6)	(13)	(13)
Net unrealized (losses) gains on securities, net of taxes of $1,388 and ($436) for three months ended June 30, 2018 and 2017, respectively and of $4,443 and ($1,247) for six months ended June 30, 2018 and 2017, respectively.	(3,014)	601	(9,654)	1,749
Net unrealized gains (losses) on cash flow hedges, net of taxes of ($961) and $90 three months ended June 30, 2018 and 2017, respectively and of ($3,565) and $90 for six months ended June 30, 2018 and 2017, respectively.	2,085	(124)	7,746	(124)
Change in fair value of liabilities related to instrument-specific credit risk,net of taxes of ($6) for the three and six months ended June 30, 2018.	13		13
Total other comprehensive income (loss), net of tax	(832)	558	(1,727)	1,786
Comprehensive income	$ 13,091	$ 13,283	$ 23,608	$ 26,771