Fair Value Measurement and Fair Value of Financial Instruments (Quantitative Information for Significant Unobservable Inputs) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Quantitative information
Derivative assets - Fair value	$ 694,010	$ 602,754
Fair Value, Measurements, Recurring
Quantitative information
Derivative assets - Fair value	694,010	602,754
Fair Value, Measurements, Nonrecurring
Quantitative information
Loans held-for-investment, fair value disclosure	138,330	189,862
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Quantitative information
Derivative assets - Fair value	220	273
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Nonrecurring
Quantitative information
Loans held-for-investment, fair value disclosure	138,330	189,862
Significant Unobservable Inputs (Level 3) | Discounted cash flows | Fair Value, Measurements, Nonrecurring
Quantitative information
Loans held-for-investment, fair value disclosure	89,442	104,783
Significant Unobservable Inputs (Level 3) | Fair value of collateral, discount | Fair Value, Measurements, Nonrecurring
Quantitative information
Loans held-for-investment, fair value disclosure	32,636	22,207
Significant Unobservable Inputs (Level 3) | Fair value of property, selling cost | Fair Value, Measurements, Nonrecurring
Quantitative information
Loans held-for-investment, fair value disclosure	15,252	46,993
Significant Unobservable Inputs (Level 3) | Fair value of collateral, contract value | Fair Value, Measurements, Nonrecurring
Quantitative information
Loans held-for-investment, fair value disclosure	1,000	15,879
OREO | Fair Value, Measurements, Nonrecurring
Quantitative information
Assets, fair value disclosure		15,824
OREO | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Nonrecurring
Quantitative information
Assets, fair value disclosure		15,824
OREO | Significant Unobservable Inputs (Level 3) | Fair value of property, selling cost | Fair Value, Measurements, Nonrecurring
Quantitative information
Assets, fair value disclosure		15,824
Other nonperforming assets | Fair Value, Measurements, Nonrecurring
Quantitative information
Assets, fair value disclosure	699
Other nonperforming assets | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Nonrecurring
Quantitative information
Assets, fair value disclosure	699
Other nonperforming assets | Significant Unobservable Inputs (Level 3) | Fair value of collateral, contract value | Fair Value, Measurements, Nonrecurring
Quantitative information
Assets, fair value disclosure	699
Investments in tax credit and other investments, net | Fair Value, Measurements, Nonrecurring
Quantitative information
Assets, fair value disclosure		3,140
Investments in tax credit and other investments, net | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Nonrecurring
Quantitative information
Assets, fair value disclosure		3,140
Investments in tax credit and other investments, net | Significant Unobservable Inputs (Level 3) | Individual analysis of each investment, expected future tax benefits and distributions | Fair Value, Measurements, Nonrecurring
Quantitative information
Assets, fair value disclosure		3,140
Equity contracts | Fair Value, Measurements, Recurring
Quantitative information
Derivative assets - Fair value	226	858
Equity contracts | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Quantitative information
Derivative assets - Fair value	$ 220	$ 273
Equity volatility | Equity contracts | Significant Unobservable Inputs (Level 3) | Black-Scholes option pricing model | Fair Value, Measurements, Recurring | Weighted Average
Quantitative information
Measurement input	49.00%	53.00%
Equity volatility | Equity contracts | Significant Unobservable Inputs (Level 3) | Black-Scholes option pricing model | Fair Value, Measurements, Recurring | Minimum
Quantitative information
Measurement input	45.00%	46.00%
Equity volatility | Equity contracts | Significant Unobservable Inputs (Level 3) | Black-Scholes option pricing model | Fair Value, Measurements, Recurring | Maximum
Quantitative information
Measurement input	54.00%	61.00%
Liquidity discount | Equity contracts | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Quantitative information
Measurement input	47.00%	47.00%
Liquidity discount | Equity contracts | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Weighted Average
Quantitative information
Measurement input	47.00%	47.00%
Discount | Significant Unobservable Inputs (Level 3) | Discounted cash flows | Fair Value, Measurements, Nonrecurring | Weighted Average
Quantitative information
Loans held-for-investment, measurement input	7.00%	11.00%
Discount | Significant Unobservable Inputs (Level 3) | Discounted cash flows | Fair Value, Measurements, Nonrecurring | Minimum
Quantitative information
Loans held-for-investment, measurement input	4.00%	3.00%
Discount | Significant Unobservable Inputs (Level 3) | Discounted cash flows | Fair Value, Measurements, Nonrecurring | Maximum
Quantitative information
Loans held-for-investment, measurement input	15.00%	15.00%
Discount | Significant Unobservable Inputs (Level 3) | Fair value of collateral, discount | Fair Value, Measurements, Nonrecurring | Weighted Average
Quantitative information
Loans held-for-investment, measurement input	40.00%	15.00%
Discount | Significant Unobservable Inputs (Level 3) | Fair value of collateral, discount | Fair Value, Measurements, Nonrecurring | Minimum
Quantitative information
Loans held-for-investment, measurement input	15.00%	10.00%
Discount | Significant Unobservable Inputs (Level 3) | Fair value of collateral, discount | Fair Value, Measurements, Nonrecurring | Maximum
Quantitative information
Loans held-for-investment, measurement input	81.00%	26.00%
Selling cost | Significant Unobservable Inputs (Level 3) | Fair value of property, selling cost | Fair Value, Measurements, Nonrecurring
Quantitative information
Loans held-for-investment, measurement input	8.00%
OREO, measurement input		0.08
Selling cost | Significant Unobservable Inputs (Level 3) | Fair value of property, selling cost | Fair Value, Measurements, Nonrecurring | Weighted Average
Quantitative information
Loans held-for-investment, measurement input	8.00%	10.00%
OREO, measurement input		0.08
Selling cost | Significant Unobservable Inputs (Level 3) | Fair value of property, selling cost | Fair Value, Measurements, Nonrecurring | Minimum
Quantitative information
Loans held-for-investment, measurement input		7.00%
Selling cost | Significant Unobservable Inputs (Level 3) | Fair value of property, selling cost | Fair Value, Measurements, Nonrecurring | Maximum
Quantitative information
Loans held-for-investment, measurement input		26.00%