Other Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Pre-Tax Amount
Other comprehensive income (loss), before tax		$ (406)	$ 5,181	$ 1,426	$ 18,014
Tax (Expense) Benefit
Other comprehensive income (loss), tax		144	(1,813)	(500)	(6,305)
Net of Tax Amount
Other Comprehensive Income (Loss), Net of Tax		(262)	3,368	926	11,709
Accumulated Net Investment Gain (Loss) Attributable to Parent
Pre-Tax Amount
Change in net unrealized gains/(losses) on securities available-for-sale		2,672	4,636	4,335	13,669
Reclassification adjustment for net (gains)/losses on securities available-for-sale included in net income	[1]	(3,617)	0	(3,987)	0
Tax (Expense) Benefit
Change in net unrealized gains/(losses) on securities available-for-sale		(938)	(1,622)	(1,523)	(4,784)
Reclassification adjustment for net (gains)/losses on securities available-for-sale included in net income	[1]	1,270	0	1,400	0
Net of Tax Amount
Change in net unrealized gains/(losses) on securities available-for-sale		1,734	3,014	2,812	8,885
Reclassification adjustment for net (gains)/losses on securities available-for-sale included in net income	[1]	(2,347)	0	(2,587)	0
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent
Pre-Tax Amount
Other comprehensive income (loss), before tax		539	545	1,078	4,345
Tax (Expense) Benefit
Other comprehensive income (loss), tax		(188)	(191)	(377)	(1,521)
Net of Tax Amount
Other Comprehensive Income (Loss), Net of Tax		$ 351	$ 354	$ 701	$ 2,824

[1] Reclassification adjustments are comprised of realized security gains or losses. The realized gains or losses have been reclassified out of accumulated other comprehensive income and have affected certain lines in the consolidated statement of comprehensive income as follows; the pre-tax amount is included in securities gains/losses-net, the tax expense amount is included in the provision for income taxes and the net of tax amount is included in net income.