Fair Value Accounting and Measurement (Financial Assets And Liabilities Accounted for Fair Value On Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	$ 5,210,134	$ 3,746,142
Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	5,210,134	3,746,142
Loans held for sale	14,760
Interest Rate Cash Flow Hedge Asset at Fair Value		14,727
Fair Value, Inputs, Level 1 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	0	0
Loans held for sale	0
Interest Rate Cash Flow Hedge Asset at Fair Value		0
Fair Value, Inputs, Level 2 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	5,210,134	3,746,142
Loans held for sale	14,760
Interest Rate Cash Flow Hedge Asset at Fair Value		14,727
Fair Value, Inputs, Level 3 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	0	0
Loans held for sale	0
Interest Rate Cash Flow Hedge Asset at Fair Value		0
U.S. Government Agency and Sponsored Enterprise Mortgage-Back Securities and Collateralized Mortgage Obligations | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	3,814,387	2,892,950
U.S. Government Agency and Sponsored Enterprise Mortgage-Back Securities and Collateralized Mortgage Obligations | Fair Value, Inputs, Level 1 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	0	0
U.S. Government Agency and Sponsored Enterprise Mortgage-Back Securities and Collateralized Mortgage Obligations | Fair Value, Inputs, Level 2 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	3,814,387	2,892,950
U.S. Government Agency and Sponsored Enterprise Mortgage-Back Securities and Collateralized Mortgage Obligations | Fair Value, Inputs, Level 3 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	0	0
Asset-backed Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	357,479	196,050
Asset-backed Securities | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	357,479	196,050
Asset-backed Securities | Fair Value, Inputs, Level 1 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	0	0
Asset-backed Securities | Fair Value, Inputs, Level 2 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	357,479	196,050
Asset-backed Securities | Fair Value, Inputs, Level 3 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	0	0
State and Municipal Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	753,572	488,802
State and Municipal Securities | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	753,572	488,802
State and Municipal Securities | Fair Value, Inputs, Level 1 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	0	0
State and Municipal Securities | Fair Value, Inputs, Level 2 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	753,572	488,802
State and Municipal Securities | Fair Value, Inputs, Level 3 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	0	0
U.S. Government Agency | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	284,696	168,340
U.S. Government Agency | Fair Value, Inputs, Level 1 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	0	0
U.S. Government Agency | Fair Value, Inputs, Level 2 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	284,696	168,340
U.S. Government Agency | Fair Value, Inputs, Level 3 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	0	0
Interest Rate Lock Commitments | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivative assets, at fair value	1,096
Interest Rate Lock Commitments | Fair Value, Inputs, Level 1 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivative assets, at fair value	0
Interest Rate Lock Commitments | Fair Value, Inputs, Level 2 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivative assets, at fair value	0
Interest Rate Lock Commitments | Fair Value, Inputs, Level 3 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivative assets, at fair value	1,096
Interest Rate Swap | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivative assets, at fair value	46,184	19,144
Interest rate derivative liabilities, at fair value	46,637	19,145
Interest Rate Swap | Fair Value, Inputs, Level 1 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivative assets, at fair value	0	0
Interest rate derivative liabilities, at fair value	0	0
Interest Rate Swap | Fair Value, Inputs, Level 2 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivative assets, at fair value	46,184	19,144
Interest rate derivative liabilities, at fair value	46,637	19,145
Interest Rate Swap | Fair Value, Inputs, Level 3 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate derivative assets, at fair value	0	0
Interest rate derivative liabilities, at fair value	0	$ 0
Forward sales contracts | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Liabilities	165
Forward sales contracts | Fair Value, Inputs, Level 1 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Liabilities	0
Forward sales contracts | Fair Value, Inputs, Level 2 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Liabilities	165
Forward sales contracts | Fair Value, Inputs, Level 3 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Liabilities	$ 0