Real Estate (Rental Income) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Lease Income [Abstract]
Rental income from operating leases	$ 159,300,000	$ 160,234,000	$ 328,033,000	$ 318,632,000
Earned income from direct financing leases	162,000	208,000	326,000	420,000
Percentage rent	165,000	300,000	568,000	722,000
Real estate expense reimbursement from tenants	3,852,000	3,854,000	9,099,000	7,848,000
Total lease income	163,479,000	164,596,000	338,026,000	327,622,000
Accrued rental income	35,862,000		35,862,000
Straight line rent adjustments	30,894,000	$ 296,000	30,717,000	$ 925,000
Accrued rental income	59,459,000		59,459,000		$ 28,897,000
Accrued rental income allowance	$ 7,481,000		$ 7,481,000		$ 1,842,000