Investment in Mortgage Notes and Notes Receivable (Details) | 3 Months Ended | 9 Months Ended | | |
Sep. 30, 2021USD ($) | Mar. 31, 2021USD ($) | Sep. 30, 2020USD ($) | Sep. 30, 2021USD ($) | Sep. 30, 2020USD ($) | Jan. 01, 2021USD ($) | Dec. 31, 2020USD ($) |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | $ 368,684,000 | | | $ 368,684,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 369,134,000 | | | 369,134,000 | | | $ 365,628,000 |
Mortgage Note and Notes Receivable Commitments | 12,800,000 | | | 12,800,000 | | | |
Proceeds from Sale and Collection of Mortgage Notes Receivable | | | | 8,106,000 | $ 414,000 | | |
Notes Receivable | 7,300,000 | | | 7,300,000 | | | 7,300,000 |
Financing Receivable, Allowance for Credit Loss | 13,181,000 | | $ 2,163,000 | 13,181,000 | 2,163,000 | $ 0 | 32,858,000 |
Provision for Loan, Lease, and Other Losses | | | | (19,677,000) | | | |
Financing Receivable, Allowance for Credit Loss, Writeoff | | | | 0 | | | |
Financing Receivable, Allowance for Credit Loss, Recovery | | | | 0 | | | |
Financing Receivable, Credit Loss, Expense (Reversal) | $ (14,096,000) | | $ 5,707,000 | (19,677,000) | $ 10,383,000 | | |
Note, 8.0%, due May 2, 2024 [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
Proceeds from Sale and Collection of Mortgage Notes Receivable | | | | $ 6,800,000 | | | |
Number of Notes Receivable | 1 | | | 1 | | | |
Provision for Loan, Lease, and Other Losses | | | | $ 10,200,000 | | | |
Unrecorded Unconditional Purchase Obligation, Change of Amount as Result of Variable Components | $ 8,500,000 | | | 8,500,000 | | | |
Financing Receivable, Credit Loss, Expense (Reversal) | | | | 15,300,000 | | | |
Mortgage Receivable [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
Mortgage Note and Notes Receivable Commitments | 12,774,000 | | | 12,774,000 | | | |
Financing Receivable, Allowance for Credit Loss | 2,848,000 | | | 2,848,000 | | | 7,000,000 |
Provision for Loan, Lease, and Other Losses | | | | (4,152,000) | | | |
Financing Receivable, Allowance for Credit Loss, Writeoff | | | | 0 | | | |
Financing Receivable, Allowance for Credit Loss, Recovery | | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 9.02%, Prepaid in Full | Private School | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 9.02% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 0 | | | $ 0 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 0 | | | 0 | | | 5,278,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Proceeds from Sale and Collection of Mortgage Notes Receivable | | $ 5,100,000 | | | | | |
Prepaymentfee | | $ 0 | | | | | |
Mortgage Receivable [Member] | Mortgage Note, 7.75%, due June 30, 2025 [Member] | Attraction Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 7.75% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 28,521,000 | | | $ 28,521,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 27,908,000 | | | 27,908,000 | | | 27,045,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 7.85%, due January 3, 2027 [Member] | Fitness & Wellness Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 7.85% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 10,905,000 | | | $ 10,905,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 11,278,000 | | | 11,278,000 | | | 11,225,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 7.55%, due July 31, 2029 [Member] | Fitness & Wellness Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 7.55% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 9,090,000 | | | $ 9,090,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 9,398,000 | | | 9,398,000 | | | 9,355,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 8.23%, December 31, 2029 [Member] | Ski Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 8.21% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 44,605,000 | | | $ 44,605,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 44,537,000 | | | 44,537,000 | | | 40,680,000 |
Mortgage Note and Notes Receivable Commitments | 12,395,000 | | | $ 12,395,000 | | | |
Mortgage Receivable [Member] | Mortgage Note, 7.85%, due June 30, 2030 [Member] | Fitness & Wellness Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 7.85% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 10,539,000 | | | $ 10,539,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 10,797,000 | | | 10,797,000 | | | 8,630,000 |
Mortgage Note and Notes Receivable Commitments | 379,000 | | | $ 379,000 | | | |
Mortgage Receivable [Member] | Mortgage Note, 7.01%, due September 30, 2031 [Member] | Experiential Lodging Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 7.01% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 71,223,000 | | | $ 71,223,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 70,422,000 | | | 70,422,000 | | | 67,235,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 11.31%, due June 1, 2033 [Member] | Eat & Play Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 11.31% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 10,915,000 | | | $ 10,915,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 11,073,000 | | | 11,073,000 | | | 11,929,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 11.96%, due December 1, 2034 [Member] | Ski Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 11.96% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 51,050,000 | | | $ 51,050,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 51,045,000 | | | 51,045,000 | | | 51,031,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 10.91%, due December 1, 2034 [Member] | Ski Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 10.91% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 37,562,000 | | | $ 37,562,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 37,506,000 | | | 37,506,000 | | | 37,413,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 11.38%, due December 1, 2034 [Member] | Ski Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 11.38% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 4,550,000 | | | $ 4,550,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 4,509,000 | | | 4,509,000 | | | 4,396,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 8.72%, due January 5, 2036 [Member] | Ski Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 8.72% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 21,000,000 | | | $ 21,000,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 21,000,000 | | | 21,000,000 | | | 21,000,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, due May 31, 2036 [Member] | Eat & Play Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 10.25% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 17,505,000 | | | $ 17,505,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 17,729,000 | | | 17,729,000 | | | 18,289,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 9.75% due August 1, 2036 [Member] | Eat & Play Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 9.75% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 18,068,000 | | | $ 18,068,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 18,285,000 | | | 18,285,000 | | | 18,830,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 7.85% due January 31, 2038 [Member] | Fitness & Wellness Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 7.85% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 10,292,000 | | | $ 10,292,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 10,568,000 | | | 10,568,000 | | | 10,408,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 7.98%, due May 9, 2039 [Member] | early childhood education center [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 7.98% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 4,200,000 | | | $ 4,200,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 4,321,000 | | | 4,321,000 | | | 4,348,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 8.125%, due June 17, 2039 [Member] | Eat & Play Properties [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 8.13% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 14,700,000 | | | $ 14,700,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 14,759,000 | | | 14,759,000 | | | 14,799,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | $ 0 | | | |
Mortgage Receivable [Member] | Mortgage Note, 8.42%, due October 31, 2019 [Member] | early childhood education center [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate | | | | 8.42% | | | |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages | 3,959,000 | | | $ 3,959,000 | | | |
Mortgage Loans on Real Estate, Commercial and Consumer, Net | 3,999,000 | | | 3,999,000 | | | 3,737,000 |
Mortgage Note and Notes Receivable Commitments | 0 | | | 0 | | | |
Unfunded Loan Commitment [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
Financing Receivable, Allowance for Credit Loss | 84,000 | | | 84,000 | | | 138,000 |
Provision for Loan, Lease, and Other Losses | | | | (54,000) | | | |
Financing Receivable, Allowance for Credit Loss, Writeoff | | | | 0 | | | |
Financing Receivable, Allowance for Credit Loss, Recovery | | | | 0 | | | |
Notes Receivable [Member] | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
Financing Receivable, Allowance for Credit Loss | 10,249,000 | | | 10,249,000 | | | 12,854,000 |
Provision for Loan, Lease, and Other Losses | | | | (2,605,000) | | | |
Financing Receivable, Allowance for Credit Loss, Writeoff | | | | 0 | | | |
Financing Receivable, Allowance for Credit Loss, Recovery | | | | 0 | | | |
Note Receivable Unfunded Loan Commitment | | | | | | | |
Financing Receivable, Allowance for Credit Loss [Line Items] | | | | | | | |
Financing Receivable, Allowance for Credit Loss | $ 0 | | | 0 | | | $ 12,866,000 |
Provision for Loan, Lease, and Other Losses | | | | (12,866,000) | | | |
Financing Receivable, Allowance for Credit Loss, Writeoff | | | | 0 | | | |
Financing Receivable, Allowance for Credit Loss, Recovery | | | | $ 0 | | | |