Fair Value Measurements - Impairment of Assets Measured on a Non-Recurring Basis (Details) - Fair Value, Measurements, Nonrecurring - Level 3 - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total Impairment Charges	$ 0	$ 25,781	$ 66,532	$ 25,781
Equity investments in the Managed Programs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements	37,396	0	37,396	0
Total Impairment Charges			47,112	0
Land, buildings and improvements and intangibles
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements	12,148	0	12,148	0
Total Impairment Charges			19,420	0
Net investment in direct financing leases
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements	0	24,418	0	24,418
Total Impairment Charges	$ 0	$ 25,781	$ 0	$ 25,781