Fair Value (Financial instruments Measured at Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	$ 2,685,048	$ 2,630,414
Foreclosed properties	2,750	3,071
US Treasuries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	149,391	0
Government-sponsored enterprise securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	64,168	69,179
Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	2,425,911	2,514,805
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Presold mortgages in process of settlement	5,672	19,257
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring | US Treasuries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring | Government-sponsored enterprise securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Individually evaluated loans	0	0
Foreclosed properties		0
Significant Other Observable Inputs (Level 2) | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	2,685,048	2,630,414
Presold mortgages in process of settlement	0	0
Significant Other Observable Inputs (Level 2) | Recurring | US Treasuries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	149,391
Significant Other Observable Inputs (Level 2) | Recurring | Government-sponsored enterprise securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	64,168	69,179
Significant Other Observable Inputs (Level 2) | Recurring | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	2,425,911	2,514,805
Significant Other Observable Inputs (Level 2) | Recurring | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	45,578	46,430
Significant Other Observable Inputs (Level 2) | Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Individually evaluated loans	0	0
Foreclosed properties		0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed properties		364
Significant Unobservable Inputs (Level 3) | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Presold mortgages in process of settlement	0	0
Significant Unobservable Inputs (Level 3) | Recurring | US Treasuries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0
Significant Unobservable Inputs (Level 3) | Recurring | Government-sponsored enterprise securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Significant Unobservable Inputs (Level 3) | Recurring | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Significant Unobservable Inputs (Level 3) | Recurring | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Significant Unobservable Inputs (Level 3) | Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Individually evaluated loans	12,590	11,583
Foreclosed properties		364
Estimated Fair Value | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	2,685,048	2,630,414
Presold mortgages in process of settlement	5,672	19,257
Estimated Fair Value | Recurring | US Treasuries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	149,391
Estimated Fair Value | Recurring | Government-sponsored enterprise securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	64,168	69,179
Estimated Fair Value | Recurring | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	2,425,911	2,514,805
Estimated Fair Value | Recurring | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	45,578	46,430
Estimated Fair Value | Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Individually evaluated loans	$ 12,590	11,583
Foreclosed properties		$ 364