Fair Value Accounting and Measurement (IRL Quantitative Information About Level 3 Fair Value Measurements) (Details) $ in Thousands	Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)
Measurement input pull through rate member | Valuation technique internal pricing model member | Interest Rate Lock Commitments Contracts | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset, Measurement Input	0.7776		0.8585
Measurement input pull through rate member | Valuation technique internal pricing model member | Interest Rate Lock Commitments Contracts | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset, Measurement Input	1.0000		0.9645
Measurement input pull through rate member | Valuation technique internal pricing model member | Interest Rate Lock Commitments Contracts | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset, Measurement Input	0.9062		0.8847
Fair Value, Recurring [Member]
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset	$ 29,139	$ 46,184
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset	0	0
Fair Value, Recurring [Member] | Interest Rate Lock Commitments Contracts
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset	482	1,096	$ 169
Fair Value, Recurring [Member] | Interest Rate Lock Commitments Contracts | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset	$ 482	$ 1,096