Summary of Significant Accounting Policies - Additional Information (Details) $ / shares in Units, $ in Thousands														12 Months Ended
	Jan. 08, 2021 $ / shares	Oct. 09, 2020 $ / shares	Jul. 10, 2020 $ / shares	Apr. 10, 2020 $ / shares	Jan. 10, 2020 $ / shares	Oct. 15, 2019	Oct. 11, 2019 $ / shares	Jul. 12, 2019 $ / shares	Apr. 12, 2019 $ / shares	Jan. 11, 2019 $ / shares	Oct. 12, 2018 $ / shares	Jul. 13, 2018 $ / shares	Apr. 13, 2018 $ / shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Significant Accounting Policies
Stock split ratio						2
Intangibles including goodwill														$ 12,500	$ 12,100
Intangible assets														4,700	4,300
Goodwill														7,800
Accumulated amortization of identified intangible assets														3,200	3,100
Cash and cash equivalents, restricted cash														$ 24,100	25,100
Estimated membership upgrade contract term														20 years
Deferred financing costs														$ 27,900	24,000
Operating loss carryforwards														74,100	74,100
Aggregate cost in real estate U.S federal tax basis														4,000,000
Net investment in notes receivable U.S federal tax basis														40,700
Quarterly distribution paid per common share (usd per share) | $ / shares		$ 0.3425	$ 0.3425	$ 0.3425	$ 0.3063		$ 0.3063	$ 0.3063	$ 0.3063	$ 0.2750	$ 0.2750	$ 0.2750	$ 0.2750
Cumulative effect of change in accounting principle														$ 1,304,755	1,321,888	$ 1,193,344	$ 1,100,042
Minimum
Significant Accounting Policies
Lessor operating lease term														1 month
Maximum
Significant Accounting Policies
Lessor operating lease term														6 months
Cumulative Effect, Period of Adoption, Adjustment
Significant Accounting Policies
Cumulative effect of change in accounting principle															$ (3,875)		$ (15,186)
2020 Distributions
Significant Accounting Policies
Quarterly distribution paid per common share (usd per share) | $ / shares					$ 0.015462
Subsequent Event
Significant Accounting Policies
Quarterly distribution paid per common share (usd per share) | $ / shares	$ 0.3425
Quarterly distribution for tax purposes (usd per share) | $ / shares	0.087801
Subsequent Event | 2020 Distributions
Significant Accounting Policies
Quarterly distribution paid per common share (usd per share) | $ / shares	$ 0.254699
Operating Partnership
Significant Accounting Policies
Ownership interest (percent)														94.60%