Fair Value (Details 1) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Fair value measurement using significant unobservable input
Securities available-for-sale	$ 786,211	$ 784,916
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	6,393	18,285
Total realized/unrealized gains or losses - Included in earnings	0	0
Total realized/unrealized gains or losses - Included in other comprehensive income	77	(2,840)
Transfers	0
Purchases		0
Settlements	(286)	(9,052)
Ending balance	6,184	6,393
US Government Agencies Debt Securities [Member]
Fair value measurement using significant unobservable input
Securities available-for-sale	29,450	25,364
State and Municipal Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	235,747	233,935
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	3,680
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	(245)	(545)
Ending balance	2,890	3,135
Collateralized Debt Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	3,294	3,258
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	3,258	14,605
Total realized/unrealized gains or losses - Included in earnings	0	0
Total realized/unrealized gains or losses - Included in other comprehensive income	77	(2,840)
Transfers	0
Purchases		0
Settlements	(41)	(8,507)
Ending balance	3,294	3,258
Mortgage Backed Securities - Residential
Fair value measurement using significant unobservable input
Securities available-for-sale	181,853	178,743
Mortgage Backed Securities - Commercial
Fair value measurement using significant unobservable input
Securities available-for-sale		0
Collateralized Mortgage Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	335,867	343,616
Fair Value, Inputs, Level 3 [Member]
Fair value measurement using significant unobservable input
Securities available-for-sale	6,184	6,393
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	2,890	3,135
Fair Value, Inputs, Level 3 [Member] \| Collateralized Debt Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	3,294	3,258
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	780,027	778,523
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	304	218
Derivative Liability	304	218
Fair Value, Inputs, Level 2 [Member] \| US Government Agencies Debt Securities [Member]
Fair value measurement using significant unobservable input
Securities available-for-sale	29,450	25,364
Fair Value, Inputs, Level 2 [Member] \| State and Municipal Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	232,857	230,800
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	181,853	178,743
Fair Value, Inputs, Level 2 [Member] \| Mortgage Backed Securities - Commercial
Fair value measurement using significant unobservable input
Securities available-for-sale		0
Fair Value, Inputs, Level 2 [Member] \| Collateralized Mortgage Obligations
Fair value measurement using significant unobservable input
Securities available-for-sale	$ 335,867	$ 343,616

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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