Fair Value of Assets and Liabilities (Schedule of Valuation Techniques and Significant Unobservable Inputs Used to Measure Both Recurring and Nonrecurring) (Details) $ in Thousands	Dec. 31, 2021 USD ($)	Dec. 31, 2021	Dec. 31, 2021 $ / shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available-for-sale securities	$ 2,327,793			$ 3,055,839
Loans held-for-investment	38,598			55,134
MSRs	147,571			92,081	$ 85,638	$ 75,183
Impaired loans—collateral based	93,270			139,662
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans—collateral based	93,300
Measured at fair value on a recurring basis:
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-investment	38,598			55,134
MSRs	147,571			92,081
Derivative assets	165,008			278,423
Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-investment	15,891			10,280
MSRs	147,571			92,081
Derivative assets	10,560			48,091
Measured at fair value on a non-recurring basis:
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans—collateral based	63,415
Other real estate owned	4,271
Measured at fair value on a non-recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans—collateral based	63,415
Other real estate owned	4,271
Municipal
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available-for-sale securities	165,594			146,910
Municipal | Measured at fair value on a recurring basis:
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available-for-sale securities	165,594			146,910
Municipal | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available-for-sale securities	$ 105,687			$ 109,876
Discount rate | Discounted cash flows | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-investment, measurement input		0.0300
Discount rate | Discounted cash flows | Minimum | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
MSRs, measurement input		0.06
Discount rate | Discounted cash flows | Maximum | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
MSRs, measurement input		0.19
Discount rate | Discounted cash flows | Weighted Average | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-investment, measurement input		0.0300
MSRs, measurement input		0.0980
Credit discount | Discounted cash flows | Minimum | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-investment, measurement input		0
Credit discount | Discounted cash flows | Maximum | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-investment, measurement input		0.03
Credit discount | Discounted cash flows | Weighted Average | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-investment, measurement input		0.0057
Constant prepayment rate (CPR) | Discounted cash flows | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-investment, measurement input		0.1164
Constant prepayment rate (CPR) | Discounted cash flows | Minimum | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
MSRs, measurement input		0
Constant prepayment rate (CPR) | Discounted cash flows | Maximum | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
MSRs, measurement input		0.83
Constant prepayment rate (CPR) | Discounted cash flows | Weighted Average | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-investment, measurement input		0.1164
MSRs, measurement input		0.1164
Cost of servicing | Discounted cash flows | Minimum | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
MSRs, measurement input | $ / shares			70
Cost of servicing | Discounted cash flows | Maximum | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
MSRs, measurement input | $ / shares			200
Cost of servicing | Discounted cash flows | Weighted Average | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
MSRs, measurement input		75	75
Cost of servicing - delinquent | Discounted cash flows | Minimum | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
MSRs, measurement input | $ / shares			200
Cost of servicing - delinquent | Discounted cash flows | Maximum | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
MSRs, measurement input | $ / shares			1,000
Cost of servicing - delinquent | Discounted cash flows | Weighted Average | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
MSRs, measurement input		312	312
Pull-through rate | Discounted cash flows | Minimum | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives, measurement input		0.26
Pull-through rate | Discounted cash flows | Maximum | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives, measurement input		1
Pull-through rate | Discounted cash flows | Weighted Average | Measured at fair value on a recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives, measurement input		0.8578
Appraisal adjustment - cost of sale | Appraisal value | Measured at fair value on a non-recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans - collateral based, measurement input		0.10
Other real estate owned, measurement input		0.10
Appraisal adjustment - cost of sale | Appraisal value | Weighted Average | Measured at fair value on a non-recurring basis: | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans - collateral based, measurement input		0.1000
Other real estate owned, measurement input		0.1000