Disclosures About Fair Value of Assets and Liabilities - Fair Value Measurements of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	$ 1,247,632	$ 1,142,195
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	1,244,697	1,138,867
Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	2,936	3,328
Fair Value, Measurements, Recurring | Interest rate swap liability | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap liability	0	0
Fair Value, Measurements, Recurring | Interest rate swap liability | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap liability	15,166	12,636
Fair Value, Measurements, Recurring | Interest rate swap liability | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap liability	0	0
Fair Value, Measurements, Recurring | Fair Value | Interest rate swap liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap liability	15,166	12,636
U.S. Government-sponsored agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	33,703	13,582
U.S. Government-sponsored agency securities | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
U.S. Government-sponsored agency securities | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	33,703	13,582
U.S. Government-sponsored agency securities | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
U.S. Government-sponsored agency securities | Fair Value, Measurements, Recurring | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	33,703	13,582
State and municipal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	651,858	606,135
State and municipal | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
State and municipal | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	648,957	602,842
State and municipal | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	2,901	3,293
State and municipal | Fair Value, Measurements, Recurring | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	651,858	606,135
U.S. Government-sponsored mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	562,040	522,447
U.S. Government-sponsored mortgage-backed securities | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
U.S. Government-sponsored mortgage-backed securities | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	562,036	522,443
U.S. Government-sponsored mortgage-backed securities | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	4	4
U.S. Government-sponsored mortgage-backed securities | Fair Value, Measurements, Recurring | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	562,040	522,447
Corporate obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	31	31
Corporate obligations | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Corporate obligations | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Corporate obligations | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	31	31
Corporate obligations | Fair Value, Measurements, Recurring | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	31	31
Interest rate swap asset | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	0	0
Interest rate swap asset | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	14,194	11,948
Interest rate swap asset | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	0	0
Interest rate swap asset | Fair Value, Measurements, Recurring | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	14,194	11,948
Interest rate cap | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	0	0
Interest rate cap | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	35	135
Interest rate cap | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	0	0
Interest rate cap | Fair Value, Measurements, Recurring | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivatives	$ 35	$ 135