Securities - Schedule of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Equity and Other Securities, Amortized Cost [Abstract]
Equity and Other Securities, Due after ten years, Amortized Cost	$ 697
Equity and Other Securities, Not due at single maturity, Amortized Cost	6,951
Equity and Other Securities, Amortized Cost	7,648
Available-for-sale Securities Debt Maturities, Amortized Cost [Abstract]
Available-for-sale Securities, Due in one year or less, Amortized Cost	59,697
Available-for-sale Securities, Due from one to five years, Amortized Cost	123,941
Available-for-sale Securities, Due from five to ten years, Amortized Cost	136,438
Available-for-sale Securities, Due after ten years, Amortized Cost	75,727
Available-for-sale Securities, Amortized Cost	1,026,724	$ 834,254
Held-to-maturity Securities Debt Maturities, Amortized Cost [Abstract]
Held-to-maturity Securities, Due from one to five years, Amortized Cost	3,805
Held-to-maturity Securities, Due from five to ten years, Amortized Cost	612
Held-to-maturity Securities, Amortized Cost	4,417	99,266
Equity and Other Securities, Fair Value [Abstract]
Equity and Other Securities, Due after ten years, Fair Value	697
Equity and Other Securities, Not due at single maturity, Fair Value	6,951
Equity and Other Securities, Fair Value	7,648
Available-for-sale Securities Debt Maturities, Fair Value [Abstract]
Available-for-sale Securities, Due in one year or less, Fair Value	59,875
Available-for-sale Securities, Due from one to five years, Fair Value	125,158
Available-for-sale Securities, Due from five to ten years, Fair Value	137,993
Available-for-sale Securities, Due after ten years, Fair Value	76,304
Available-for-sale Securities, Fair Value, Total	1,031,933	817,656
Held-to-maturity Securities Debt Maturities, Fair Value [Abstract]
Held-to-maturity Securities, Due from one to five years, Fair Value	3,873
Held-to-maturity Securities, Due from five to ten years, Fair Value	629
Held-to-maturity securities, Fair Value, Total	4,502	$ 97,739
Mortgage-Backed Securities
Available-for-sale Securities Debt Maturities, Amortized Cost [Abstract]
Available-for-sale Securities, Not due at single maturity, Amortized Cost	630,921
Available-for-sale Securities Debt Maturities, Fair Value [Abstract]
Available-for-sale Securities, Not due at single maturity, Fair Value	$ 632,603

Equity and other securities at amortized cost.

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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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