Securities, Available-for-sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Abstract]
Amortized cost	$ 582,983	$ 565,199
Gross unrealized gains	626	2,544
Gross unrealized losses	(14,401)	(6,340)
Fair value	569,208	561,403
Equity Securities, Available-for-sale [Abstract]
Amortized cost		25,000
Available-for-sale [Abstract]
Amortized cost	582,983	590,199
Gross unrealized gains	626	2,620
Gross unrealized losses	(14,401)	(7,058)
Available-for-sale securities	569,208	585,761
U.S. Treasury and Government Agencies [Member]
Debt Securities, Available-for-sale [Abstract]
Amortized cost	246,153	211,574
Gross unrealized gains	0	170
Gross unrealized losses	(3,354)	(1,172)
Fair value	242,799	210,572
State and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Abstract]
Amortized cost	127,423	144,159
Gross unrealized gains	480	2,017
Gross unrealized losses	(3,911)	(1,161)
Fair value	123,992	145,015
U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Debt Securities, Available-for-sale [Abstract]
Amortized cost	208,900	208,959
Gross unrealized gains	146	357
Gross unrealized losses	(7,135)	(4,007)
Fair value	201,911	205,309
Other Debt Securities [Member]
Debt Securities, Available-for-sale [Abstract]
Amortized cost	507	507
Gross unrealized gains	0	0
Gross unrealized losses	(1)	0
Fair value	506	507
CRA Investments Funds [Member]
Equity Securities, Available-for-sale [Abstract]
Amortized cost	0	25,000
Gross unrealized gains	0	76
Gross unrealized losses	0	(718)
Fair value	$ 0	$ 24,358

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in equity securities classified as available-for-sale.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in equity securities classified as available-for-sale.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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