Fair Value Measurements (Unobservable Quantitative Input Ratios) (Details)	Jun. 30, 2021	Dec. 31, 2020
Discount Rate
Unobservable Quantitative Input
Other real estate owned, measurement input		0.070
Discount Rate | Recurring | Level 3 | Real estate fund investments | Minimum
Unobservable Quantitative Input
Other real estate owned, measurement input	0.072	0.076
Discount Rate | Recurring | Level 3 | Real estate fund investments | Maximum
Unobservable Quantitative Input
Other real estate owned, measurement input	0.150	0.150
Discount Rate | Recurring | Level 3 | Real estate fund investments | Weighted Average
Unobservable Quantitative Input
Other real estate owned, measurement input	0.118	0.127
Terminal Capitalization Rate | Recurring | Level 3 | Real estate fund investments | Minimum
Unobservable Quantitative Input
Other real estate owned, measurement input	0.053	0.055
Terminal Capitalization Rate | Recurring | Level 3 | Real estate fund investments | Maximum
Unobservable Quantitative Input
Other real estate owned, measurement input	0.106	0.103
Terminal Capitalization Rate | Recurring | Level 3 | Real estate fund investments | Weighted Average
Unobservable Quantitative Input
Other real estate owned, measurement input	0.078	0.079
Loans Receivable | Discount Rate | Recurring | Level 3
Unobservable Quantitative Input
Loans receivable, measurement input	0.065	0.065
Loans Receivable | Discount Rate | Recurring | Level 3 | Weighted Average
Unobservable Quantitative Input
Loans receivable, measurement input	0.065	0.065
Loans Receivable | Terminal Capitalization Rate | Recurring | Level 3
Unobservable Quantitative Input
Loans receivable, measurement input	0.050	0.050
Loans Receivable | Terminal Capitalization Rate | Recurring | Level 3 | Weighted Average
Unobservable Quantitative Input
Loans receivable, measurement input	0.050	0.050