Fair Value Measurement and Fair Value of Financial Instruments (Quantitative Information for Significant Unobservable Inputs) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Quantitative information
Derivative assets - Fair value	$ 602,754	$ 330,316
Fair Value, Measurements, Recurring
Quantitative information
Derivative assets - Fair value	602,754	330,316
Fair Value, Measurements, Recurring | Equity contracts
Quantitative information
Derivative assets - Fair value	858	1,414
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Quantitative information
Derivative assets - Fair value	273	421
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Equity contracts
Quantitative information
Derivative assets - Fair value	273	421
Fair Value, Measurements, Nonrecurring
Quantitative information
Loans held-for-investment, Fair Value	189,862	49,679
Fair Value, Measurements, Nonrecurring | OREO
Quantitative information
Assets, fair value disclosure	15,824	125
Fair Value, Measurements, Nonrecurring | Investments in tax credit and other investments, net
Quantitative information
Assets, fair value disclosure	3,140	3,076
Fair Value, Measurements, Nonrecurring | Other nonperforming assets
Quantitative information
Assets, fair value disclosure		1,167
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3)
Quantitative information
Loans held-for-investment, Fair Value	189,862	49,679
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Discounted cash flows
Quantitative information
Loans held-for-investment, Fair Value	104,783	27,841
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Valuation Technique, Fair Value Of Collateral, Discount
Quantitative information
Loans held-for-investment, Fair Value	22,207	1,014
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Valuation Technique, Fair Value Of Collateral, Contract Value
Quantitative information
Loans held-for-investment, Fair Value	15,879	20,824
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Valuation Technique, Fair Value Of Valuation Technique, Fair Value Of Property, Selling Cost
Quantitative information
Loans held-for-investment, Fair Value	46,993
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | OREO
Quantitative information
Assets, fair value disclosure	15,824	125
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | OREO | Valuation Technique, Fair Value Of Valuation Technique, Fair Value Of Property, Selling Cost
Quantitative information
Assets, fair value disclosure	15,824	125
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Investments in tax credit and other investments, net
Quantitative information
Assets, fair value disclosure	3,140	3,076
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Investments in tax credit and other investments, net | Valuation Technique, Individual Analysis
Quantitative information
Assets, fair value disclosure	$ 3,140	3,076
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Other nonperforming assets
Quantitative information
Assets, fair value disclosure		1,167
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Other nonperforming assets | Valuation Technique, Fair Value Of Collateral, Contract Value
Quantitative information
Assets, fair value disclosure		$ 1,167
Equity volatility | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Equity contracts | Black-Scholes option pricing model | Minimum
Quantitative information
Equity contracts, measurement input	46.00%	39.00%
Equity volatility | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Equity contracts | Black-Scholes option pricing model | Maximum
Quantitative information
Equity contracts, measurement input	61.00%	44.00%
Equity volatility | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Equity contracts | Black-Scholes option pricing model | Weighted Average
Quantitative information
Equity contracts, measurement input	53.00%	42.00%
Liquidity discount | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Equity contracts
Quantitative information
Equity contracts, measurement input	47.00%	47.00%
Liquidity discount | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Equity contracts | Weighted Average
Quantitative information
Equity contracts, measurement input	47.00%	47.00%
Discount | Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Discounted cash flows | Minimum
Quantitative information
Loans held-for-investment, measurement input	3.00%	4.00%
Discount | Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Discounted cash flows | Maximum
Quantitative information
Loans held-for-investment, measurement input	15.00%	15.00%
Discount | Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Discounted cash flows | Weighted Average
Quantitative information
Loans held-for-investment, measurement input	11.00%	14.00%
Discount | Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Valuation Technique, Fair Value Of Collateral, Discount | Minimum
Quantitative information
Loans held-for-investment, measurement input	10.00%	8.00%
Discount | Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Valuation Technique, Fair Value Of Collateral, Discount | Maximum
Quantitative information
Loans held-for-investment, measurement input	26.00%	20.00%
Discount | Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Valuation Technique, Fair Value Of Collateral, Discount | Weighted Average
Quantitative information
Loans held-for-investment, measurement input	15.00%	19.00%
Selling cost | Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Valuation Technique, Fair Value Of Valuation Technique, Fair Value Of Property, Selling Cost
Quantitative information
OREO, measurement input	0.08	0.08
Selling cost | Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Valuation Technique, Fair Value Of Valuation Technique, Fair Value Of Property, Selling Cost | Minimum
Quantitative information
Loans held-for-investment, measurement input	7.00%
Selling cost | Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Valuation Technique, Fair Value Of Valuation Technique, Fair Value Of Property, Selling Cost | Maximum
Quantitative information
Loans held-for-investment, measurement input	26.00%
Selling cost | Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3) | Valuation Technique, Fair Value Of Valuation Technique, Fair Value Of Property, Selling Cost | Weighted Average
Quantitative information
Loans held-for-investment, measurement input	10.00%
OREO, measurement input	0.08	0.08