Schedule III - Real Estate and Accumulated Depreciation and Amortization Part 5 (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule Of Investments In Real Estate [Line Items]
Total Investment in Real Estate	$ 1,721,404	$ 1,514,750	$ 1,410,051	$ 1,246,588
Accumulated Depreciation And Amortization Description [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	1,662,484
Cost Capitalized Subsequent to Initial Investment	58,920
Land	870,119
Building and Improvements	851,285
Total Investment in Real Estate	1,721,404
Accumulated Depreciation and Amortization	$ 268,919
Date of Initial Leasehold or Acquisition Investment	2015
Accumulated Depreciation And Amortization Description [Member] | KENTUCKY [Member] | Louisville One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 1,488
Cost Capitalized Subsequent to Initial Investment	0
Land	513
Building and Improvements	975
Total Investment in Real Estate	1,488
Accumulated Depreciation and Amortization	$ 11
Date of Initial Leasehold or Acquisition Investment	2023
Accumulated Depreciation And Amortization Description [Member] | KENTUCKY [Member] | Louisville Two [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 3,356
Land	818
Building and Improvements	2,538
Total Investment in Real Estate	3,356
Accumulated Depreciation and Amortization	$ 611
Date of Initial Leasehold or Acquisition Investment	2019
Accumulated Depreciation And Amortization Description [Member] | KENTUCKY [Member] | Louisville Three [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 4,450
Land	1,354
Building and Improvements	3,096
Total Investment in Real Estate	4,450
Accumulated Depreciation and Amortization	$ 575
Date of Initial Leasehold or Acquisition Investment	2021
Accumulated Depreciation And Amortization Description [Member] | KENTUCKY [Member] | Owensboro One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 3,811
Land	1,012
Building and Improvements	2,799
Total Investment in Real Estate	3,811
Accumulated Depreciation and Amortization	$ 944
Date of Initial Leasehold or Acquisition Investment	2019
Accumulated Depreciation And Amortization Description [Member] | LOUISIANA [Member] | Bossier City [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 2,182
Land	1,334
Building and Improvements	848
Total Investment in Real Estate	2,182
Accumulated Depreciation and Amortization	$ 337
Date of Initial Leasehold or Acquisition Investment	2017
Accumulated Depreciation And Amortization Description [Member] | LOUISIANA [Member] | W. Monroe [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 2,387
Land	674
Building and Improvements	1,713
Total Investment in Real Estate	2,387
Accumulated Depreciation and Amortization	$ 47
Date of Initial Leasehold or Acquisition Investment	2023
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Arlington One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 518
Cost Capitalized Subsequent to Initial Investment	27
Land	337
Building and Improvements	208
Total Investment in Real Estate	545
Accumulated Depreciation and Amortization	$ 208
Date of Initial Leasehold or Acquisition Investment	1985
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Auburn One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 369
Cost Capitalized Subsequent to Initial Investment	160
Land	240
Building and Improvements	289
Total Investment in Real Estate	529
Accumulated Depreciation and Amortization	$ 267
Date of Initial Leasehold or Acquisition Investment	1991
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Auburn Two [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 600
Land	600
Total Investment in Real Estate	$ 600
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Auburn Three [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 625
Land	625
Total Investment in Real Estate	$ 625
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Auburn Four [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 725
Land	725
Total Investment in Real Estate	$ 725
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Barre One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 536
Cost Capitalized Subsequent to Initial Investment	12
Land	348
Building and Improvements	200
Total Investment in Real Estate	548
Accumulated Depreciation and Amortization	$ 167
Date of Initial Leasehold or Acquisition Investment	1991
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Bedford One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 1,350
Land	1,350
Total Investment in Real Estate	$ 1,350
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Bellingham One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 734
Cost Capitalized Subsequent to Initial Investment	73
Land	476
Building and Improvements	331
Total Investment in Real Estate	807
Accumulated Depreciation and Amortization	$ 331
Date of Initial Leasehold or Acquisition Investment	1985
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Bradford One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 650
Land	650
Total Investment in Real Estate	$ 650
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Burlington One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 600
Land	600
Total Investment in Real Estate	$ 600
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Burlington Two [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 1,250
Land	1,250
Total Investment in Real Estate	$ 1,250
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Foxborough One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 427
Cost Capitalized Subsequent to Initial Investment	98
Land	325
Building and Improvements	200
Total Investment in Real Estate	525
Accumulated Depreciation and Amortization	$ 192
Date of Initial Leasehold or Acquisition Investment	1990
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Gardner One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 550
Land	550
Total Investment in Real Estate	$ 550
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Gardner Two [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 787
Land	638
Building and Improvements	149
Total Investment in Real Estate	787
Accumulated Depreciation and Amortization	$ 89
Date of Initial Leasehold or Acquisition Investment	2014
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Gardner Three [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 1,008
Cost Capitalized Subsequent to Initial Investment	426
Land	657
Building and Improvements	777
Total Investment in Real Estate	1,434
Accumulated Depreciation and Amortization	$ 655
Date of Initial Leasehold or Acquisition Investment	1985
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Hyde Park One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 499
Cost Capitalized Subsequent to Initial Investment	220
Land	322
Building and Improvements	397
Total Investment in Real Estate	719
Accumulated Depreciation and Amortization	$ 345
Date of Initial Leasehold or Acquisition Investment	1985
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Leominster One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 571
Land	199
Building and Improvements	372
Total Investment in Real Estate	571
Accumulated Depreciation and Amortization	$ 223
Date of Initial Leasehold or Acquisition Investment	2012
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Littleton One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 1,357
Land	759
Building and Improvements	598
Total Investment in Real Estate	1,357
Accumulated Depreciation and Amortization	$ 213
Date of Initial Leasehold or Acquisition Investment	2017
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Lowell One [Member]
Schedule Of Investments In Real Estate [Line Items]
Cost Capitalized Subsequent to Initial Investment	$ 636
Land	429
Building and Improvements	207
Total Investment in Real Estate	636
Accumulated Depreciation and Amortization	$ 153
Date of Initial Leasehold or Acquisition Investment	1996
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Lowell Two [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 3,961
Land	2,042
Building and Improvements	1,919
Total Investment in Real Estate	3,961
Accumulated Depreciation and Amortization	$ 428
Date of Initial Leasehold or Acquisition Investment	2019
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Lynn One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 850
Land	850
Total Investment in Real Estate	$ 850
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Marlborough One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 550
Land	550
Total Investment in Real Estate	$ 550
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Maynard One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 735
Cost Capitalized Subsequent to Initial Investment	98
Land	478
Building and Improvements	355
Total Investment in Real Estate	833
Accumulated Depreciation and Amortization	$ 346
Date of Initial Leasehold or Acquisition Investment	1985
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Melrose One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 600
Land	600
Total Investment in Real Estate	$ 600
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Methuen One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 650
Land	650
Total Investment in Real Estate	$ 650
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Newton One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 691
Cost Capitalized Subsequent to Initial Investment	90
Land	450
Building and Improvements	331
Total Investment in Real Estate	781
Accumulated Depreciation and Amortization	$ 331
Date of Initial Leasehold or Acquisition Investment	1985
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Peabody One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 550
Land	550
Total Investment in Real Estate	$ 550
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Peabody Two [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 650
Land	650
Total Investment in Real Estate	$ 650
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Randolph One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 574
Cost Capitalized Subsequent to Initial Investment	245
Land	430
Building and Improvements	389
Total Investment in Real Estate	819
Accumulated Depreciation and Amortization	$ 380
Date of Initial Leasehold or Acquisition Investment	1985
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Revere One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 1,300
Land	1,300
Total Investment in Real Estate	$ 1,300
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Rockland One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 579
Cost Capitalized Subsequent to Initial Investment	45
Land	377
Building and Improvements	247
Total Investment in Real Estate	624
Accumulated Depreciation and Amortization	$ 247
Date of Initial Leasehold or Acquisition Investment	1985
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Salem One
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 600
Land	600
Total Investment in Real Estate	$ 600
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Tewksbury One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 125
Cost Capitalized Subsequent to Initial Investment	596
Land	75
Building and Improvements	646
Total Investment in Real Estate	721
Accumulated Depreciation and Amortization	$ 545
Date of Initial Leasehold or Acquisition Investment	1986
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Tewksbury Two [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 1,200
Land	1,200
Total Investment in Real Estate	$ 1,200
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Wakefield One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 900
Land	900
Total Investment in Real Estate	$ 900
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Webster One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 1,012
Cost Capitalized Subsequent to Initial Investment	1,157
Land	659
Building and Improvements	1,510
Total Investment in Real Estate	2,169
Accumulated Depreciation and Amortization	$ 1,203
Date of Initial Leasehold or Acquisition Investment	1985
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | West Roxbury One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 490
Cost Capitalized Subsequent to Initial Investment	226
Land	319
Building and Improvements	397
Total Investment in Real Estate	716
Accumulated Depreciation and Amortization	$ 145
Date of Initial Leasehold or Acquisition Investment	1985
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Wilmington One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 600
Land	600
Total Investment in Real Estate	$ 600
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Wilmington Two [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 1,300
Land	1,300
Total Investment in Real Estate	$ 1,300
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Woburn One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 508
Cost Capitalized Subsequent to Initial Investment	314
Land	508
Building and Improvements	314
Total Investment in Real Estate	822
Accumulated Depreciation and Amortization	$ 314
Date of Initial Leasehold or Acquisition Investment	1985
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Seekonk One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 1,073
Cost Capitalized Subsequent to Initial Investment	(373)
Land	576
Building and Improvements	124
Total Investment in Real Estate	700
Accumulated Depreciation and Amortization	$ 119
Date of Initial Leasehold or Acquisition Investment	1985
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Sutton One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 714
Cost Capitalized Subsequent to Initial Investment	57
Land	464
Building and Improvements	307
Total Investment in Real Estate	771
Accumulated Depreciation and Amortization	$ 264
Date of Initial Leasehold or Acquisition Investment	1993
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Worcester One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 550
Cost Capitalized Subsequent to Initial Investment	0
Land	550
Building and Improvements	0
Total Investment in Real Estate	550
Accumulated Depreciation and Amortization	$ 0
Date of Initial Leasehold or Acquisition Investment	2011
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Worcester Two [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 547
Cost Capitalized Subsequent to Initial Investment	10
Land	355
Building and Improvements	202
Total Investment in Real Estate	557
Accumulated Depreciation and Amortization	$ 168
Date of Initial Leasehold or Acquisition Investment	1991
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Worcester Three [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 196
Cost Capitalized Subsequent to Initial Investment	790
Building and Improvements	986
Total Investment in Real Estate	986
Accumulated Depreciation and Amortization	$ 324
Date of Initial Leasehold or Acquisition Investment	2017
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Falmouth One [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 415
Cost Capitalized Subsequent to Initial Investment	2,389
Land	458
Building and Improvements	2,346
Total Investment in Real Estate	2,804
Accumulated Depreciation and Amortization	$ 753
Date of Initial Leasehold or Acquisition Investment	1988
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Worcester Four [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 979
Cost Capitalized Subsequent to Initial Investment	8
Land	637
Building and Improvements	350
Total Investment in Real Estate	987
Accumulated Depreciation and Amortization	$ 291
Date of Initial Leasehold or Acquisition Investment	1991
Accumulated Depreciation And Amortization Description [Member] | MASSACHUSETTS [Member] | Worcester Five [Member]
Schedule Of Investments In Real Estate [Line Items]
Initial Cost of Leasehold or Acquisition Investment to Company	$ 498
Cost Capitalized Subsequent to Initial Investment	539
Land	322
Building and Improvements	715
Total Investment in Real Estate	1,037
Accumulated Depreciation and Amortization	$ 530
Date of Initial Leasehold or Acquisition Investment	1985