Fair Values of Financial Instruments - Fair Value Measurements of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	$ 1,790,025	$ 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	1,787,132	1,138,867
Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	2,893	3,328
Fair Value, Measurements, Recurring | Interest rate swap liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap liability	29,299	12,636
Fair Value, Measurements, Recurring | U.S. Government-sponsored agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	38,875	13,582
Fair Value, Measurements, Recurring | State and municipal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	899,796	606,135
Fair Value, Measurements, Recurring | U.S. Government-sponsored mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	851,323	522,447
Fair Value, Measurements, Recurring | Corporate obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	31	31
Fair Value, Measurements, Recurring | Interest rate swap asset
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Asset derivatives	27,855	11,948
Fair Value, Measurements, Recurring | Interest rate cap
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Asset derivatives		135
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest rate swap liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap liability	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Government-sponsored agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | State and municipal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Government-sponsored mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest rate swap asset
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Asset derivatives	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest rate cap
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Asset derivatives		0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Interest rate swap liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap liability	29,299	12,636
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | U.S. Government-sponsored agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	38,875	13,582
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | State and municipal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	896,938	602,842
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | U.S. Government-sponsored mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	851,319	522,443
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Corporate obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Interest rate swap asset
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Asset derivatives	27,855	11,948
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Interest rate cap
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Asset derivatives		135
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Interest rate swap liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap liability	0	0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | U.S. Government-sponsored agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | State and municipal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	2,858	3,293
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | U.S. Government-sponsored mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	4	4
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Corporate obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	31	31
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Interest rate swap asset
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Asset derivatives	$ 0	0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Interest rate cap
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Asset derivatives		$ 0