Schedule III - Real Estate Assets and Accumulated Depreciation - 6 (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	$ 1,892,744
Land	994,149
Buildings Improvements	2,825,703
Total Adjustment to Basis	(1,457,677)
Gross Amount at Which Carried	2,362,175	$ 3,371,926	$ 2,530,311	$ 4,444,041
Accumulated Depreciation	158,354	$ 298,364	$ 243,122	$ 385,245
United Oil: | Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	4,205
Land	2,016
Buildings Improvements	3,486
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,502
Accumulated Depreciation	97
United Oil: | Madera, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	1,500
Buildings Improvements	3,804
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,304
Accumulated Depreciation	447
United Oil: | Norco, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	3,224
Land	1,852
Buildings Improvements	1,489
Total Adjustment to Basis	0
Gross Amount at Which Carried	3,341
Accumulated Depreciation	273
United Oil: | Poway, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	3,072
Buildings Improvements	705
Total Adjustment to Basis	0
Gross Amount at Which Carried	3,777
Accumulated Depreciation	129
United Oil: | San Clemente, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	4,272
Land	2,036
Buildings Improvements	3,561
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,597
Accumulated Depreciation	101
United Oil: | San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	2,312
Land	1,362
Buildings Improvements	1,662
Total Adjustment to Basis	0
Gross Amount at Which Carried	3,024
Accumulated Depreciation	50
United Oil: | San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	3,643
Land	1,547
Buildings Improvements	3,218
Total Adjustment to Basis	0
Gross Amount at Which Carried	4,765
Accumulated Depreciation	91
United Oil: | San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	4,975
Land	2,409
Buildings Improvements	4,105
Total Adjustment to Basis	0
Gross Amount at Which Carried	6,514
Accumulated Depreciation	122
United Oil: | San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	2,977
Buildings Improvements	1,448
Total Adjustment to Basis	0
Gross Amount at Which Carried	4,425
Accumulated Depreciation	265
United Oil: | San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	2,663
Land	1,877
Buildings Improvements	883
Total Adjustment to Basis	0
Gross Amount at Which Carried	2,760
Accumulated Depreciation	161
United Oil: | San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	1,824
Buildings Improvements	382
Total Adjustment to Basis	0
Gross Amount at Which Carried	2,206
Accumulated Depreciation	71
United Oil: | Santa Ana, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	2,596
Land	1,629
Buildings Improvements	1,766
Total Adjustment to Basis	0
Gross Amount at Which Carried	3,395
Accumulated Depreciation	53
United Oil: | Santa Clarita, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	4,787
Buildings Improvements	733
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,520
Accumulated Depreciation	134
United Oil: | Sun City, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	1,136
Buildings Improvements	1,421
Total Adjustment to Basis	0
Gross Amount at Which Carried	2,557
Accumulated Depreciation	260
United Oil: | Vista, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	2,312
Land	2,063
Buildings Improvements	334
Total Adjustment to Basis	0
Gross Amount at Which Carried	2,397
Accumulated Depreciation	61
United Oil: | Vista (Vista), CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	2,244
Land	2,028
Buildings Improvements	418
Total Adjustment to Basis	0
Gross Amount at Which Carried	2,446
Accumulated Depreciation	77
United Oil: | Whittier, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	2,521
Land	1,629
Buildings Improvements	985
Total Adjustment to Basis	0
Gross Amount at Which Carried	2,614
Accumulated Depreciation	181
University Marketplace: | Marion, IN
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	3,400
Land	850
Buildings Improvements	6,722
Total Adjustment to Basis	(7,572)
Gross Amount at Which Carried	0
Accumulated Depreciation	0
Urban Air Adventure Park: | Waukesha, WI
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	7,115
Land	3,408
Buildings Improvements	12,918
Total Adjustment to Basis	666
Gross Amount at Which Carried	16,992
Accumulated Depreciation	2,428
Vacant: | Appleton, WI
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	895
Buildings Improvements	1,026
Total Adjustment to Basis	(1,194)
Gross Amount at Which Carried	727
Accumulated Depreciation	22
Vacant: | Cherokee, IA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	217
Buildings Improvements	3,326
Total Adjustment to Basis	(2,867)
Gross Amount at Which Carried	676
Accumulated Depreciation	4
Vacant: | Richmond, VA
Real Estate and Accumulated Depreciation [Line Items]
Land	925
Buildings Improvements	10
Total Adjustment to Basis	0
Gross Amount at Which Carried	935
Accumulated Depreciation	0
Vacant: | Sanford, FL
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	1,031
Buildings Improvements	1,807
Total Adjustment to Basis	(1,858)
Gross Amount at Which Carried	980
Accumulated Depreciation	33
Vacant: | Valentine, NE
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	395
Buildings Improvements	3,549
Total Adjustment to Basis	(2,765)
Gross Amount at Which Carried	1,179
Accumulated Depreciation	8
Vacant: | Walker, LA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	899
Buildings Improvements	3,910
Total Adjustment to Basis	(85)
Gross Amount at Which Carried	4,724
Accumulated Depreciation	758
Vacant: | Willmar, MN
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	200
Buildings Improvements	1,279
Total Adjustment to Basis	0
Gross Amount at Which Carried	1,479
Accumulated Depreciation	220
Vacant: | York,PA
Real Estate and Accumulated Depreciation [Line Items]
Land	0
Buildings Improvements	5,145
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,145
Accumulated Depreciation	0
Valeo North American HQ: | Troy, MI
Real Estate and Accumulated Depreciation [Line Items]
Land	1,880
Buildings Improvements	9,813
Total Adjustment to Basis	0
Gross Amount at Which Carried	11,693
Accumulated Depreciation	19
Valeo Production Facility: | East Liberty,OH
Real Estate and Accumulated Depreciation [Line Items]
Land	357
Buildings Improvements	4,989
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,346
Accumulated Depreciation	7
Valvoline HQ: | Lexington, KY
Real Estate and Accumulated Depreciation [Line Items]
Land	5,558
Buildings Improvements	41,234
Total Adjustment to Basis	0
Gross Amount at Which Carried	46,792
Accumulated Depreciation	51
Ventura Place: | Albuquerque, NM
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	5,760
Land	5,203
Buildings Improvements	7,998
Total Adjustment to Basis	(13,201)
Gross Amount at Which Carried	0
Accumulated Depreciation	0
WakeMed MyCare 365: | Raleigh, NC
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	329
Buildings Improvements	556
Total Adjustment to Basis	0
Gross Amount at Which Carried	885
Accumulated Depreciation	20
Walmart: | Anderson, SC
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	9,741
Land	2,424
Buildings Improvements	9,719
Total Adjustment to Basis	0
Gross Amount at Which Carried	12,143
Accumulated Depreciation	1,495
Walmart: | Florence, SC
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	9,023
Land	2,013
Buildings Improvements	9,225
Total Adjustment to Basis	0
Gross Amount at Which Carried	11,238
Accumulated Depreciation	1,413
Walmart: | Perry, GA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	7,440
Land	2,270
Buildings Improvements	11,053
Total Adjustment to Basis	0
Gross Amount at Which Carried	13,323
Accumulated Depreciation	2,678
Walmart: | Randallstown,MD
Real Estate and Accumulated Depreciation [Line Items]
Land	8,382
Buildings Improvements	23,365
Total Adjustment to Basis	0
Gross Amount at Which Carried	31,747
Accumulated Depreciation	29
Walmart: | Summerville, SC
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	4,280
Land	2,410
Buildings Improvements	2,098
Total Adjustment to Basis	(4,508)
Gross Amount at Which Carried	0
Accumulated Depreciation	0
Walmart: | Tallahassee, FL
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	11,331
Land	14,823
Buildings Improvements	0
Total Adjustment to Basis	0
Gross Amount at Which Carried	14,823
Accumulated Depreciation	0
Walmart: | York, SC
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	8,865
Land	1,913
Buildings Improvements	11,410
Total Adjustment to Basis	0
Gross Amount at Which Carried	13,323
Accumulated Depreciation	2,746
Walgreens: | Austintown, OH
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	3,643
Land	637
Buildings Improvements	4,173
Total Adjustment to Basis	0
Gross Amount at Which Carried	4,810
Accumulated Depreciation	884
Walgreens: | Clinton, MI
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	4,139
Land	1,977
Buildings Improvements	4,232
Total Adjustment to Basis	0
Gross Amount at Which Carried	6,209
Accumulated Depreciation	130
Walgreens: | Connelly Springs, NC
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	1,349
Buildings Improvements	3,628
Total Adjustment to Basis	0
Gross Amount at Which Carried	4,977
Accumulated Depreciation	788
Walgreens: | Coweta,OK
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	2,584
Land	897
Buildings Improvements	3,303
Total Adjustment to Basis	0
Gross Amount at Which Carried	4,200
Accumulated Depreciation	4
Walgreens: | Danville, VA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	4,908
Land	989
Buildings Improvements	4,547
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,536
Accumulated Depreciation	1,100
Walgreens: | Dearborn Heights, MI
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	6,187
Land	2,236
Buildings Improvements	3,411
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,647
Accumulated Depreciation	745
Walgreens: | East Chicago, IN
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	331
Buildings Improvements	5,242
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,573
Accumulated Depreciation	970
Walgreens: | Fort Madison, IA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	3,554
Land	514
Buildings Improvements	3,723
Total Adjustment to Basis	0
Gross Amount at Which Carried	4,237
Accumulated Depreciation	796
Walgreens: | Harrison, AR
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	4,671
Land	1,237
Buildings Improvements	5,424
Total Adjustment to Basis	0
Gross Amount at Which Carried	6,661
Accumulated Depreciation	158
Walgreens: | Huntsville, AL
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	3,273
Land	1,931
Buildings Improvements	2,457
Total Adjustment to Basis	(4,388)
Gross Amount at Which Carried	0
Accumulated Depreciation	0
Walgreens: | Indianapolis, IN
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	4,526
Land	1,212
Buildings Improvements	5,484
Total Adjustment to Basis	0
Gross Amount at Which Carried	6,696
Accumulated Depreciation	159
Walgreens: | Kannapolis, NC
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	1,480
Buildings Improvements	5,031
Total Adjustment to Basis	0
Gross Amount at Which Carried	6,511
Accumulated Depreciation	1,106
Walgreens: | Las Vegas, NV
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	3,943
Land	2,325
Buildings Improvements	3,262
Total Adjustment to Basis	70
Gross Amount at Which Carried	5,657
Accumulated Depreciation	704
Walgreens: | Lawton, OK
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	2,824
Land	860
Buildings Improvements	2,539
Total Adjustment to Basis	106
Gross Amount at Which Carried	3,505
Accumulated Depreciation	563
Walgreens: | Lees Summit, MO
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	4,114
Land	1,205
Buildings Improvements	4,884
Total Adjustment to Basis	0
Gross Amount at Which Carried	6,089
Accumulated Depreciation	147
Walgreens: | Little Rock, AR
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	4,489
Land	548
Buildings Improvements	4,676
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,224
Accumulated Depreciation	885
Walgreens: | Lubbock, TX
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	3,610
Land	565
Buildings Improvements	3,257
Total Adjustment to Basis	103
Gross Amount at Which Carried	3,925
Accumulated Depreciation	774
Walgreens: | Lubbock, TX
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	3,180
Land	531
Buildings Improvements	2,951
Total Adjustment to Basis	102
Gross Amount at Which Carried	3,584
Accumulated Depreciation	697
Walgreens: | Metropolis, IL
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	4,182
Land	284
Buildings Improvements	4,991
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,275
Accumulated Depreciation	924
Walgreens: | Reidsville,NC
Real Estate and Accumulated Depreciation [Line Items]
Land	722
Buildings Improvements	5,117
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,839
Accumulated Depreciation	6
Walgreens: | Sacramento, CA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	3,299
Land	324
Buildings Improvements	2,669
Total Adjustment to Basis	0
Gross Amount at Which Carried	2,993
Accumulated Depreciation	528
Walgreens: | San Antonio, TX
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	7,051
Land	1,417
Buildings Improvements	7,932
Total Adjustment to Basis	0
Gross Amount at Which Carried	9,349
Accumulated Depreciation	218
Walgreens: | Siloam Springs, AR
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	3,776
Land	936
Buildings Improvements	4,367
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,303
Accumulated Depreciation	131
Walgreens: | Slidell, LA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	2,977
Land	757
Buildings Improvements	3,557
Total Adjustment to Basis	0
Gross Amount at Which Carried	4,314
Accumulated Depreciation	111
Walgreens: | Springfield, IL
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	830
Buildings Improvements	3,619
Total Adjustment to Basis	0
Gross Amount at Which Carried	4,449
Accumulated Depreciation	896
Walgreens: | St. Louis, MO
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	2,534
Land	355
Buildings Improvements	3,149
Total Adjustment to Basis	0
Gross Amount at Which Carried	3,504
Accumulated Depreciation	4
Walgreens: | Suffolk, VA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	4,115
Land	1,261
Buildings Improvements	3,461
Total Adjustment to Basis	0
Gross Amount at Which Carried	4,722
Accumulated Depreciation	901
Walgreens: | Whiteville, NC
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	0
Land	829
Buildings Improvements	4,090
Total Adjustment to Basis	0
Gross Amount at Which Carried	4,919
Accumulated Depreciation	120
Walgreens/KeyBank: | Newburgh, NY
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	5,000
Land	3,280
Buildings Improvements	5,441
Total Adjustment to Basis	(8,721)
Gross Amount at Which Carried	0
Accumulated Depreciation	0
Wallace Commons: | Salisbury, NC
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	7,590
Land	3,265
Buildings Improvements	8,058
Total Adjustment to Basis	(11,323)
Gross Amount at Which Carried	0
Accumulated Depreciation	0
Wallace Commons II: | Salisbury, NC
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	5,990
Land	2,231
Buildings Improvements	8,479
Total Adjustment to Basis	(10,710)
Gross Amount at Which Carried	0
Accumulated Depreciation	0
Waterford South Park: | Clarksville, IN
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	7,114
Land	2,946
Buildings Improvements	8,564
Total Adjustment to Basis	(11,510)
Gross Amount at Which Carried	0
Accumulated Depreciation	0
Weasler Engineering | West Bend, WI
Real Estate and Accumulated Depreciation [Line Items]
Land	1,019
Buildings Improvements	13,390
Total Adjustment to Basis	0
Gross Amount at Which Carried	14,409
Accumulated Depreciation	19
Wendy's: | Grafton, VA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	1,616
Land	539
Buildings Improvements	894
Total Adjustment to Basis	0
Gross Amount at Which Carried	1,433
Accumulated Depreciation	176
Wendy's: | Westminster, CO
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	1,010
Land	596
Buildings Improvements	1,108
Total Adjustment to Basis	0
Gross Amount at Which Carried	1,704
Accumulated Depreciation	217
Western Crossing: | Jacksonville, NC
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	6,190
Land	3,382
Buildings Improvements	7,775
Total Adjustment to Basis	(11,157)
Gross Amount at Which Carried	0
Accumulated Depreciation	0
West Marine: | Chicago, IL
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	5,370
Land	4,442
Buildings Improvements	8,698
Total Adjustment to Basis	0
Gross Amount at Which Carried	13,140
Accumulated Depreciation	248
West Marine: | Mystic,CT
Real Estate and Accumulated Depreciation [Line Items]
Land	1,966
Buildings Improvements	1,968
Total Adjustment to Basis	0
Gross Amount at Which Carried	3,934
Accumulated Depreciation	4
West Marine: | Panama City, FL
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	1,930
Land	676
Buildings Improvements	2,220
Total Adjustment to Basis	0
Gross Amount at Which Carried	2,896
Accumulated Depreciation	469
West Marine: | Pensacola, FL
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	1,960
Land	1,107
Buildings Improvements	3,397
Total Adjustment to Basis	0
Gross Amount at Which Carried	4,504
Accumulated Depreciation	696
Westover Market: | San Antonio, TX
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	2,790
Land	2,705
Buildings Improvements	7,959
Total Adjustment to Basis	(10,664)
Gross Amount at Which Carried	0
Accumulated Depreciation	0
Winn-Dixie: | Amite, LA
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	1,670
Land	1,479
Buildings Improvements	1,691
Total Adjustment to Basis	0
Gross Amount at Which Carried	3,170
Accumulated Depreciation	98
H&E Equipment Services | Albuquerque, NM
Real Estate and Accumulated Depreciation [Line Items]
Land	1,355
Buildings Improvements	4,622
Total Adjustment to Basis	0
Gross Amount at Which Carried	5,977
Accumulated Depreciation	$ 6