Accumulated Other Comprehensive Income (Loss) by Component (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Balance	$ 639,201	$ 618,997	$ 549,683	$ 579,672	$ 618,997	$ 579,672
Total other comprehensive income (loss), net of tax	2,286	5,563	8,918	(22,633)	7,849	(13,715)
Balance	655,167	639,201	571,921	549,683	655,167	571,921
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Balance	(927)	1,290	(14,159)	(3,982)	1,290	(3,982)
Other comprehensive income before reclassifications, net of tax	1,497		11,414		(720)	1,212
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(85)		37		(85)	62
Total other comprehensive income (loss), net of tax	1,412		11,451		(805)	1,274
Balance	485	(927)	(2,708)	(14,159)	485	(2,708)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Balance	(9,723)	(17,521)	(19,468)	(5,863)	(17,521)	(5,863)
Other comprehensive income before reclassifications, net of tax	(1,267)		(2,404)		4,706	(16,152)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	1,788		399		3,613	542
Total other comprehensive income (loss), net of tax	521		(2,005)		8,319	(15,610)
Balance	(9,202)	(9,723)	(21,473)	(19,468)	(9,202)	(21,473)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance	(1,818)	(1,884)	(930)	(983)	(1,884)	(983)
Other comprehensive income before reclassifications, net of tax	0		0
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	77		52		143	105
Total other comprehensive income (loss), net of tax	77		52		143	105
Balance	(1,741)	(1,818)	(878)	(930)	(1,741)	(878)
Accumulated Gain (Loss), Financial Liability, Fair Value Option, Attributable to Parent [Member]
Balance	1,765	1,849	2,117	1,021	1,849	1,021
Other comprehensive income before reclassifications, net of tax	276		(580)		192	516
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0		0
Total other comprehensive income (loss), net of tax	276		(580)		192	516
Balance	2,041	1,765	1,537	2,117	2,041	1,537
AOCI Attributable to Parent [Member]
Balance	(10,703)	(16,266)	(32,440)	(9,807)	(16,266)	(9,807)
Other comprehensive income before reclassifications, net of tax	506		8,430		4,178	(14,424)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	1,780		488		3,671	709
Total other comprehensive income (loss), net of tax	2,286	5,563	8,918	(22,633)	7,849	(13,715)
Balance	$ (8,417)	$ (10,703)	$ (23,522)	$ (32,440)	$ (8,417)	$ (23,522)