Fair Value - Quantitative Information about Significant Unobservable Inputs Used in Fair Value Measurements (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investment securities - available-for-sale	$ 7,567,701	$ 7,382,066
Pooled trust preferred securities | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of adjusted specific issuer evaluation defaults	0.00%
Percentage of adjusted specific issuer evaluation recoveries	0.00%
Pooled trust preferred securities | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of adjusted specific issuer evaluation defaults	100.00%
Percentage of adjusted specific issuer evaluation recoveries	100.00%
Pooled trust preferred securities | Median
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of adjusted specific issuer evaluation defaults	50.00%
Percentage of adjusted specific issuer evaluation recoveries	25.00%
Significant Unobservable Inputs (Level 3) | Pooled trust preferred securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investment securities - available-for-sale		$ 9,496
Significant Unobservable Inputs (Level 3) | Pooled trust preferred securities | Constant prepayment rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input		0.0000
Significant Unobservable Inputs (Level 3) | Pooled trust preferred securities | Minimum | Additional asset defaults
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input		0.057
Significant Unobservable Inputs (Level 3) | Pooled trust preferred securities | Minimum | Expected asset recoveries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input		0.000
Significant Unobservable Inputs (Level 3) | Pooled trust preferred securities | Maximum | Additional asset defaults
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input		0.085
Significant Unobservable Inputs (Level 3) | Pooled trust preferred securities | Maximum | Expected asset recoveries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input		0.460
Significant Unobservable Inputs (Level 3) | Pooled trust preferred securities | Weighted Average | Additional asset defaults
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input		0.065
Significant Unobservable Inputs (Level 3) | Pooled trust preferred securities | Weighted Average | Expected asset recoveries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input		0.141
Significant Unobservable Inputs (Level 3) | Collateral Dependent Loans | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 15,443	$ 2,634
Significant Unobservable Inputs (Level 3) | Collateral Dependent Loans | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 54,248	$ 16,308
Significant Unobservable Inputs (Level 3) | Collateral Dependent Loans | Minimum | Discount for type of property, age of appraisal, and current status | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	0.03	0.14
Significant Unobservable Inputs (Level 3) | Collateral Dependent Loans | Minimum | Discount for type of property, age of appraisal, and current status | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	0.02	0.06
Significant Unobservable Inputs (Level 3) | Collateral Dependent Loans | Maximum | Discount for type of property, age of appraisal, and current status | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	0.30	0.15
Significant Unobservable Inputs (Level 3) | Collateral Dependent Loans | Maximum | Discount for type of property, age of appraisal, and current status | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	0.37	0.10
Significant Unobservable Inputs (Level 3) | Collateral Dependent Loans | Weighted Average | Discount for type of property, age of appraisal, and current status | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	0.12	0.14
Significant Unobservable Inputs (Level 3) | Collateral Dependent Loans | Weighted Average | Discount for type of property, age of appraisal, and current status | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	0.16	0.08
Significant Unobservable Inputs (Level 3) | Foreclosed Assets | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 520
Significant Unobservable Inputs (Level 3) | Foreclosed Assets | Discount for type of property, age of appraisal, and current status | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	0.19