Fair Value (Details 1) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Jun. 30, 2018	Dec. 31, 2017
Fair value measurement using significant unobservable input
Securities available-for-sale	$ 782,609	$ 814,931
Reconciliation and income statement classification of gains and losses for all assets measured at fair value on a recurring basis using significant unobservable inputs
Beginning balance	18,665	16,578
Total realized/unrealized gains or losses - Included in earnings	0	0
Total realized/unrealized gains or losses - Included in other comprehensive income	3,072	2,773
Transfers	0
Purchases		0
Settlements	(15,152)	(1,066)
Ending balance	6,585	18,285
US Government Agencies Debt Securities [Member]
Fair value measurement using significant unobservable input
Securities available-for-sale	12,777	13,695
State and Municipal Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	231,156	231,622
Reconciliation and income statement classification of gains and losses for all assets measured at fair value on a recurring basis using significant unobservable inputs
Beginning balance	3,135	4,210
Total realized/unrealized gains or losses - Included in earnings	0	0
Total realized/unrealized gains or losses - Included in other comprehensive income	0	0
Transfers	0
Purchases		0
Settlements	0	(530)
Ending balance	3,135	3,680
Collateralized Debt Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	3,450	14,605
Reconciliation and income statement classification of gains and losses for all assets measured at fair value on a recurring basis using significant unobservable inputs
Beginning balance	15,530	12,368
Total realized/unrealized gains or losses - Included in earnings	0	0
Total realized/unrealized gains or losses - Included in other comprehensive income	3,072	2,773
Transfers	0
Purchases		0
Settlements	(15,152)	(536)
Ending balance	3,450	14,605
Mortgage Backed Securities - Residential
Fair value measurement using significant unobservable input
Securities available-for-sale	190,739	215,338
Mortgage Backed Securities - Commercial
Fair value measurement using significant unobservable input
Securities available-for-sale		1
Collateralized Mortgage Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	344,487	339,670
Fair Value, Inputs, Level 3 [Member]
Fair value measurement using significant unobservable input
Securities available-for-sale	6,585	18,285
Fair Value, Inputs, Level 3 [Member] \| US Government Agencies Debt Securities [Member]
Fair value measurement using significant unobservable input
Securities available-for-sale	0	0
Fair Value, Inputs, Level 3 [Member] \| State and Municipal Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	3,135	3,680
Fair Value, Inputs, Level 3 [Member] \| Collateralized Debt Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	3,450	14,605
Fair Value, Inputs, Level 3 [Member] \| Mortgage Backed Securities - Residential
Fair value measurement using significant unobservable input
Securities available-for-sale	0	0
Fair Value, Inputs, Level 3 [Member] \| Mortgage Backed Securities - Commercial
Fair value measurement using significant unobservable input
Securities available-for-sale		0
Fair Value, Inputs, Level 3 [Member] \| Collateralized Mortgage Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	0	0
Fair Value, Inputs, Level 1 [Member]
Fair value measurement using significant unobservable input
Securities available-for-sale	0	0
Fair Value, Inputs, Level 1 [Member] \| US Government Agencies Debt Securities [Member]
Fair value measurement using significant unobservable input
Securities available-for-sale	0	0
Fair Value, Inputs, Level 1 [Member] \| State and Municipal Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	0	0
Fair Value, Inputs, Level 1 [Member] \| Collateralized Debt Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	0	0
Fair Value, Inputs, Level 1 [Member] \| Mortgage Backed Securities - Residential
Fair value measurement using significant unobservable input
Securities available-for-sale	0	0
Fair Value, Inputs, Level 1 [Member] \| Mortgage Backed Securities - Commercial
Fair value measurement using significant unobservable input
Securities available-for-sale		0
Fair Value, Inputs, Level 1 [Member] \| Collateralized Mortgage Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	0	0
Fair Value, Inputs, Level 2 [Member]
Fair value measurement using significant unobservable input
Securities available-for-sale	776,024	796,646
Reconciliation and income statement classification of gains and losses for all assets measured at fair value on a recurring basis using significant unobservable inputs
Derivative Assets	482	298
Derivative Liability	482	298
Fair Value, Inputs, Level 2 [Member] \| US Government Agencies Debt Securities [Member]
Fair value measurement using significant unobservable input
Securities available-for-sale	12,777	13,695
Fair Value, Inputs, Level 2 [Member] \| State and Municipal Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	228,021	227,942
Fair Value, Inputs, Level 2 [Member] \| Collateralized Debt Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	0	0
Fair Value, Inputs, Level 2 [Member] \| Mortgage Backed Securities - Residential
Fair value measurement using significant unobservable input
Securities available-for-sale	190,739	215,338
Fair Value, Inputs, Level 2 [Member] \| Mortgage Backed Securities - Commercial
Fair value measurement using significant unobservable input
Securities available-for-sale		1
Fair Value, Inputs, Level 2 [Member] \| Collateralized Mortgage Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	$ 344,487	$ 339,670

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of gain (loss) recognized in other comprehensive income (loss) for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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