Fair Value Measurements (Unobservable Quantitative Input Ratios) (Details) - Level 3	Dec. 31, 2022	Dec. 31, 2021
Discount rates | Nonrecurring | Real estate investments | Minimum
Unobservable Quantitative Input
Real estate, measurement input	0.0750
Discount rates | Nonrecurring | Real estate investments | Maximum
Unobservable Quantitative Input
Real estate, measurement input	0.0800
Discount rates | Nonrecurring | Real estate investments | Weighted Average
Unobservable Quantitative Input
Real estate, measurement input	0.0752
Terminal capitalization rates | Nonrecurring | Real estate investments | Minimum
Unobservable Quantitative Input
Real estate, measurement input	0.0475
Terminal capitalization rates | Nonrecurring | Real estate investments | Maximum
Unobservable Quantitative Input
Real estate, measurement input	0.0550
Terminal capitalization rates | Nonrecurring | Real estate investments | Weighted Average
Unobservable Quantitative Input
Real estate, measurement input	0.0478
Loans Receivable | Discount rates | Recurring
Unobservable Quantitative Input
Loans receivable, measurement input	0.075	0.065
Loans Receivable | Terminal capitalization rates | Recurring
Unobservable Quantitative Input
Loans receivable, measurement input	0.055	0.050