Investment in Mortgage Notes (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2019 USD ($) loans mortgagenotes	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 357,391	$ 517,467
Mortgage notes and related accrued interest receivable, net		356,183
Proceeds from mortgage note receivable paydown		$ 217,459	335,168	$ 21,784
Number Of Mortgage Notes Receivable | mortgagenotes		2
Mortgage Receivable [Member] | Public Charter School Portfolio Sale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of properties securing debt		14
Proceeds from Maturities, Prepayments and Calls of Securities, Operating Activities		$ 0
Number Of Mortgage Notes Receivable		7
Mortgage Receivable [Member] | mortgage note paid in full July 1, 2019 [Member] | Attraction Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net	[1]	$ 0	179,846
Mortgage notes and related accrued interest receivable, net		$ 0
Number of properties securing debt		3
Mortgage Receivable [Member] | Mortgage Note paid in full July 10, 2019 [Member] | Public charter school properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net	[2]	$ 0	15,652
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		10.00%
Mortgage notes and related accrued interest receivable, net		$ 0
Proceeds from mortgage note receivable paydown		17,800
Proceeds from Maturities, Prepayments and Calls of Securities, Operating Activities		1,800
Mortgage Receivable [Member] | Mortgage Note paid in full November 1, 2019 [Member] | Public charter school properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net	[3]	$ 0	9,839
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		9.95%
Mortgage notes and related accrued interest receivable, net		$ 0
Proceeds from mortgage note receivable paydown		9,800
Proceeds from Maturities, Prepayments and Calls of Securities, Operating Activities		0
Mortgage Receivable [Member] | Mortgage Note, 7.00% due December 20, 2021 [Member] | Public Charter School Portfolio Sale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net	[4]	$ 0	54,535
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		7.00%
Mortgage notes and related accrued interest receivable, net		$ 0
Number of properties securing debt		8
Mortgage Receivable [Member] | Mortgage Note, 8.93% to 9.38%, sold [Member] | Public Charter School Portfolio Sale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net	[4]	$ 0	8,835
Mortgage notes and related accrued interest receivable, net		0
Mortgage Receivable [Member] | Mortgage Note, 10.35%, sold [Member] | Public Charter School Portfolio Sale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net	[4]	$ 0	6,383
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		10.35%
Mortgage notes and related accrued interest receivable, net		$ 0
Mortgage Receivable [Member] | Mortgage Note, 9.10%, sold [Member] | Public Charter School Portfolio Sale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net	[4]	$ 0	4,165
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		9.10%
Mortgage notes and related accrued interest receivable, net		$ 0
Mortgage Receivable [Member] | Mortgage Note, 8.84%, sold [Member] | Public Charter School Portfolio Sale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net	[4]	$ 0	4,236
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		8.84%
Mortgage notes and related accrued interest receivable, net		$ 0
Mortgage Receivable [Member] | Mortgage Note, 8.75%, sold [Member] | Public Charter School Portfolio Sale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net	[4]	$ 0	23,718
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		8.75%
Mortgage notes and related accrued interest receivable, net		$ 0
Mortgage Receivable [Member] | Mortgage Note, 9.02%, sold [Member] | Public Charter School Portfolio Sale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net	[4]	$ 0	14,325
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		9.02%
Mortgage notes and related accrued interest receivable, net		$ 0
Mortgage Receivable [Member] | Mortgage Note, 7.75%, due June 30, 2025 [Member] | Attraction Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 27,423	0
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		7.75%
Mortgage notes and related accrued interest receivable, net		$ 27,423
Mortgage Receivable [Member] | Mortgage Note, 7.85%, due December 28, 2018 | Fitness & Wellness Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 5,803	5,803
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		7.85%
Mortgage notes and related accrued interest receivable, net		$ 5,766
Mortgage Receivable [Member] | Mortgage Note, 7.85%, due January 3, 2027 [Member] | Fitness & Wellness Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 10,977	10,977
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		7.85%
Mortgage notes and related accrued interest receivable, net		$ 10,905
Mortgage Receivable [Member] | Mortgage Note, 7.55%, due July 31, 2029 [Member] | Fitness & Wellness Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 5,985	0
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		7.55%
Mortgage notes and related accrued interest receivable, net		$ 5,950
Mortgage Receivable [Member] | Mortgage Note, 8.25%, December 31, 2029 [Member] | Ski Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 37,000	0
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		8.25%
Mortgage notes and related accrued interest receivable, net		$ 37,000
Mortgage Receivable [Member] | Mortgage Note, 6.99%, due September 30, 2031 [Member] | Experiential Lodging Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 70,396	0
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		6.99%
Mortgage notes and related accrued interest receivable, net		$ 70,000
Mortgage Receivable [Member] | Mortgage Note, 11.31%, due June 1, 2033 [Member] | Eat & Play Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 11,582	11,934
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		11.31%
Mortgage notes and related accrued interest receivable, net		$ 11,582
Mortgage Receivable [Member] | Mortgage Note, 11.61%, due December 1, 2034 | Ski Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 51,050	51,050
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		11.61%
Mortgage notes and related accrued interest receivable, net		$ 51,050
Mortgage Receivable [Member] | Mortgage note, 10.75%, due December 1, 2034 | Ski Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 37,562	37,562
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		10.75%
Mortgage notes and related accrued interest receivable, net		$ 37,562
Mortgage Receivable [Member] | Mortgage Note, 11.21%, due December 1, 2034 [Member] | Ski Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 4,550	4,550
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		11.21%
Mortgage notes and related accrued interest receivable, net		$ 4,550
Mortgage Receivable [Member] | Mortgage Note, 8.43%, due January 5, 2036 | Ski Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 21,000	21,000
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		8.43%
Mortgage notes and related accrued interest receivable, net		$ 21,000
Mortgage Receivable [Member] | Mortgage Note, due May 31, 2036 | Eat & Play Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 17,505	17,505
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		10.25%
Mortgage notes and related accrued interest receivable, net		$ 17,505
Mortgage Receivable [Member] | Mortgage Note, 9.75% due August 1, 2036 | Eat & Play Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 18,068	18,068
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		9.75%
Mortgage notes and related accrued interest receivable, net		$ 18,068
Mortgage Receivable [Member] | Mortgage Notes, 8.67%, due April 30, 2037 [Member] | Education Property [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 5,048	4,952
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		8.84%
Mortgage notes and related accrued interest receivable, net		$ 4,674
Mortgage Receivable [Member] | Mortgage Note, 7.85% due January 31, 2038 [Member] | Fitness & Wellness Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 10,360	10,360
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		7.85%
Mortgage notes and related accrued interest receivable, net		$ 10,292
Mortgage Receivable [Member] | Mortgage Note, 7.75%, due May 9, 2039 [Member] | early childhood education center [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 4,258	0
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		7.75%
Mortgage notes and related accrued interest receivable, net		$ 4,200
Mortgage Receivable [Member] | Mortgage Note, 8.125%, due June 17, 2039 [Member] | Eat & Play Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 14,800	0
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		8.125%
Mortgage notes and related accrued interest receivable, net		$ 14,700
Mortgage Receivable [Member] | Mortgage Note, 8.25%, due October 31, 2019 [Member] | early childhood education center [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Notes and Related Accrued Interest Receivable, Net		$ 4,024	$ 2,172
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		8.25%
Mortgage notes and related accrued interest receivable, net		$ 3,956
Minimum [Member] | Mortgage Receivable [Member] | mortgage note paid in full July 1, 2019 [Member] | Attraction Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		7.00%
Minimum [Member] | Mortgage Receivable [Member] | Mortgage Note, 8.93% to 9.38%, sold [Member] | Public Charter School Portfolio Sale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		8.93%
Maximum [Member] | Mortgage Receivable [Member] | mortgage note paid in full July 1, 2019 [Member] | Attraction Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		10.00%
Maximum [Member] | Mortgage Receivable [Member] | Mortgage Note, 8.93% to 9.38%, sold [Member] | Public Charter School Portfolio Sale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate		9.38%
Experiential Reportable Operating Segment [Member] | mortgage note paid in full July 1, 2019 [Member] | Attraction Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of properties securing debt | loans		3
Proceeds from mortgage note receivable paydown		$ 189,800
Proceeds from Maturities, Prepayments and Calls of Securities, Operating Activities		$ 0

[1] On July 1, 2019, the Company received $189.8 million in proceeds representing payment in full on mortgage notes receivable from SVVI, LLC (Schlitterbahn Group) that were secured by three attraction properties. There were no prepayment fees received in connection with these note payoffs.

[2] On July 10, 2019, the Company received $17.8 million in proceeds representing prepayment in full on a mortgage note receivable that was secured by one public charter school located in Jersey City, New Jersey. In connection with the prepayment of this note, the Company recognized a prepayment fee of $1.8 million that is included in mortgage and other financing income in the accompanying consolidated statements of income and comprehensive income for the year ended December 31, 2019.

[3] On November 1, 2019, the Company received $9.8 million in proceeds representing prepayment in full on a mortgage note receivable that was secured by one public charter school located in Vineland, New Jersey. No prepayment fee was received in connection with this note payoff.

[4] On November 22, 2019, the Company completed the sale of substantially all of its public charter school portfolio which included seven mortgage notes receivable that were secured by 14 public charter school properties. No prepayment fees were received in connection with the sale of these notes. See Note 3 for additional information related to the sale and Note 4 for additional information related to the impairment recognized related to this sale.