Equity Investments in the Managed Programs and Real Estate - Narratives (Details) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Apr. 13, 2020	Dec. 31, 2019
Investments in REITs
Distributions of earnings from equity method investments	$ 7,286,000	$ 19,472,000
Real Estate | Unconsolidated Real Estate Investment
Investments in REITs
Distributions of earnings from equity method investments	11,200,000	14,600,000
Aggregate unamortized basis difference on equity investments	24,700,000			$ 25,200,000
Affiliated Entity | CPA:18 – Global
Investments in REITs
Distributions of earnings from equity method investments	$ 2,200,000	2,500,000
Affiliated Entity | CPA:18 – Global | Class A
Investments in REITs
Asset management fees receivable, shares	125,869
Affiliated Entity | CPA:18 – Global operating partnership
Investments in REITs
Distributions of earnings from equity method investments	$ 5,100,000	5,600,000
Affiliated Entity | CWI 1
Investments in REITs
Distributions of earnings from equity method investments	800,000	2,000,000.0
Affiliated Entity | CWI 1 operating partnership
Investments in REITs
Distributions of earnings from equity method investments	0	4,900,000
Affiliated Entity | CWI 2
Investments in REITs
Distributions of earnings from equity method investments	500,000	1,200,000
Affiliated Entity | CWI 2 operating partnership
Investments in REITs
Distributions of earnings from equity method investments	0	$ 4,500,000
Affiliated Entity | Managed Programs
Investments in REITs
Aggregate unamortized basis difference on equity investments	$ 17,700,000			$ 47,000,000.0
WLT
Investments in REITs
Shares owned (shares)			5,531,025
Affiliated Entity | WLT | Common Stock
Investments in REITs
Shares owned (shares)			12,208,243