Agreements and Transactions with Related Parties - Narratives (Details) - USD ($)			1 Months Ended	2 Months Ended	12 Months Ended
	Dec. 29, 2016	Feb. 02, 2016	Feb. 28, 2014	Feb. 24, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Feb. 22, 2017	Oct. 31, 2016	Jul. 31, 2016	May 31, 2016	Apr. 30, 2016	Jan. 20, 2016
Distributions Of Available Cash and Deferred Revenue Earned
Revenue from the managed programs					$ 186,169,000	$ 202,935,000	$ 263,063,000
Percentage of available cash distribution to advisor					10.00%
Other Transactions with Affiliates
Loans to affiliates					$ 257,500,000	185,447,000	11,000,000
Proceeds from repayment of short-term loans to affiliates					37,053,000	185,447,000	11,000,000
Share Purchase Agreement
Stock repurchased during period, shares			11,037
Repurchase of common stock			$ 700,000		0	0	679,000
Proceeds from sales of real estate					$ 542,422,000	35,557,000	285,742,000
Subsequent Event
Other Transactions with Affiliates
Line of credit, maximum borrowing amount								$ 1,850,000,000.00
Self-storage
Share Purchase Agreement
Ownership interest in joint ventures		38.30%
Self-storage | Third Party
Share Purchase Agreement
Ownership interest in joint ventures		61.20%
Maximum
Share Purchase Agreement
Ownership interest in joint ventures					90.00%
Minimum
Share Purchase Agreement
Ownership interest in joint ventures					3.00%
CCIF
Distributions Of Available Cash and Deferred Revenue Earned
Reimbursement percentage					50.00%
Other Transactions with Affiliates
Line of credit, maximum borrowing amount						50,000,000
CCIF | Average adjusted capital | Maximum
Distributions Of Available Cash and Deferred Revenue Earned
Incentive fees					2.344%
CCIF | Average adjusted capital | Minimum
Distributions Of Available Cash and Deferred Revenue Earned
Incentive fees					1.875%
CCIF | Net investment income | Minimum
Distributions Of Available Cash and Deferred Revenue Earned
Incentive fees					20.00%
CCIF | Capital gain | Minimum
Distributions Of Available Cash and Deferred Revenue Earned
Incentive fees					20.00%
CCIF | Front-end fees
Distributions Of Available Cash and Deferred Revenue Earned
Maximum personnel and overhead reimbursement, percentage					18.00%
CCIF | Gross proceeds
Distributions Of Available Cash and Deferred Revenue Earned
Maximum personnel and overhead reimbursement, percentage					82.00%
CCIF | Average net asset
Distributions Of Available Cash and Deferred Revenue Earned
Reimbursement percentage					1.75%
CESH I
Distributions Of Available Cash and Deferred Revenue Earned
Revenue from the managed programs					$ 2,400,000
Other Transactions with Affiliates
Line of credit, maximum borrowing amount												$ 35,000,000
Loans receivable from related party											$ 17,100,000
CESH I | Gross proceeds
Distributions Of Available Cash and Deferred Revenue Earned
Advisory fee percentage					2.50%
CPA: 17 - Global
Other Transactions with Affiliates
Line of credit, maximum borrowing amount						75,000,000	75,000,000
CPA:18 - Global
Other Transactions with Affiliates
Line of credit, maximum borrowing amount						100,000,000	100,000,000			$ 50,000,000
Loans receivable from related party									$ 27,500,000
CWI
Other Transactions with Affiliates
Line of credit, maximum borrowing amount							110,000,000
Interest rate on loan					1.10%
CWI 2
Other Transactions with Affiliates
Line of credit, maximum borrowing amount					$ 250,000,000	110,000,000	110,000,000.0
Loans receivable from related party	$ 210,000,000												$ 20,000,000
Accrued interest					$ 100,000
CWI 2 | Subsequent Event
Other Transactions with Affiliates
Proceeds from repayment of short-term loans to affiliates				$ 210,000,000
CWI 2 | LIBOR
Other Transactions with Affiliates
Interest rate on loan	1.10%
Managed Programs
Other Transactions with Affiliates
Loans to affiliates						$ 185,400,000	$ 11,000,000
Managed Programs | LIBOR
Other Transactions with Affiliates
Interest rate on loan						1.10%
Employee | Self-storage
Share Purchase Agreement
Ownership interest in joint ventures		0.50%
Proceeds from sales of real estate		$ 100,000