Fair Value Measurements - Narratives (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2017 property	Dec. 31, 2016 USD ($) property	Dec. 31, 2015 USD ($) property	Dec. 31, 2014 USD ($) property
Fair value inputs
Unamortized discount (premium)		$ 8,000
Goodwill, impairment loss		$ 10,191
Number of properties disposed | property		15
Direct Financing Method
Fair value inputs
Impairment charges on properties		$ 7,000
Subsequent Event
Fair value inputs
Number of properties disposed | property	2
Fair Value, Measurements, Nonrecurring | Level 3
Fair value inputs
Impairment charges on properties		$ 52,300
Impaired properties | property		18
Fair Value, Measurements, Nonrecurring | Level 3 | Real Estate | Industrial facilities in Erlanger, KY
Fair value inputs
Impairment charges on properties			$ 8,700
Fair Value, Measurements, Nonrecurring | Level 3 | Real Estate | Industrial facilities in Erlanger, KY | Cash flows
Fair value inputs
Discount rate			9.25%
Fair Value, Measurements, Nonrecurring | Level 3 | Real Estate | Industrial facilities in Erlanger, KY | Residual discount rate
Fair value inputs
Discount rate			9.75%
Fair Value, Measurements, Nonrecurring | Level 3 | Real Estate | Industrial facilities in Erlanger, KY | Residual capitalization rates
Fair value inputs
Discount rate			8.50%
Fair Value, Measurements, Nonrecurring | Level 3 | Real Estate | Building
Fair value inputs
Impairment charges on properties			$ 6,900
Fair Value, Measurements, Nonrecurring | Level 3 | Equity method investments | Cash flows | Minimum
Fair value inputs
Discount rate				12.75%
Gen and admin to assets ratio				3.50%
Fair Value, Measurements, Nonrecurring | Level 3 | Equity method investments | Cash flows | Maximum
Fair value inputs
Discount rate				15.75%
Gen and admin to assets ratio				4.50%
Fair Value, Measurements, Nonrecurring | Level 3 | Continuing Operations
Fair value inputs
Impairment charges on properties		$ 59,303	29,906	$ 23,802
Fair Value, Measurements, Nonrecurring | Level 3 | Continuing Operations | Real Estate
Fair value inputs
Impairment charges on properties		$ 52,316	$ 26,597	21,738
Number of real estate properties | property			7
Fair Value, Measurements, Nonrecurring | Level 3 | Continuing Operations | Real Estate | Impaired Properties
Fair value inputs
Impairment charges on properties			$ 10,900	$ 7,800
Number of properties disposed | property		1	2
Number of real estate properties | property			5	13
Fair Value, Measurements, Nonrecurring | Level 3 | Continuing Operations | Real Estate | Vacant Properties
Fair value inputs
Impairment charges on properties				$ 14,000
Capitalization rate				8.00%
Fair Value, Measurements, Nonrecurring | Level 3 | Continuing Operations | Net investments in direct financing lease
Fair value inputs
Impairment charges on properties		$ 6,987	$ 3,309	$ 1,329
Number of real estate properties | property		1	5	8
Fair Value, Measurements, Nonrecurring | Level 3 | Continuing Operations | Equity method investments
Fair value inputs
Impairment charges on properties		$ 0	$ 0	$ 735
Fair Value, Measurements, Nonrecurring | Level 3 | Continuing Operations | Equity method investments | CPA 16 Operating Partnership
Fair value inputs
Impairment charges on properties				$ 700
Fair Value, Measurements, Nonrecurring | Level 3 | Noncontrolling interest
Fair value inputs
Impairment charges on properties		1,200	1,000
Impaired Portfolio | Fair Value, Measurements, Nonrecurring | Level 3
Fair value inputs
Impairment charges on properties		$ 41,000
Impaired properties | property		14
Goodwill, impairment loss		$ 10,200
Senior Unsecured Notes
Fair value inputs
Unamortized discount (premium)		7,800	7,800
Carrying Value | Senior Unsecured Notes | Level 2
Fair value inputs
Debt instrument, unamortized discount and debt issuance costs, net		12,100	10,500
Unamortized discount (premium)		7,800	7,800
Carrying Value | Non-Recourse Debt | Level 3
Fair value inputs
Debt instrument, unamortized discount and debt issuance costs, net		1,300	1,800
Unamortized discount (premium)		$ 200	$ (3,800)