Schedule III - Real Estate and Accumulated Depreciation - Property Summary (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($) store	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	1,976
Debt	$ 1,013,661
Land Initial Cost	4,989,355
Building and Improvements Initial Cost	21,097,440
Adjustments and Costs to Land and Building Subsequent to Acquisition	1,839,903
Gross carrying amount - Land	4,994,642
Gross carrying amount - Building and improvements	22,932,121
Gross carrying amount - Total	27,926,763
Accumulated Depreciation	$ 3,339,136
Self storage facilities | AL
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	38
Debt	$ 5,686
Land Initial Cost	53,193
Building and Improvements Initial Cost	384,033
Adjustments and Costs to Land and Building Subsequent to Acquisition	18,063
Gross carrying amount - Land	53,191
Gross carrying amount - Building and improvements	402,098
Gross carrying amount - Total	455,289
Accumulated Depreciation	$ 28,626
Self storage facilities | AZ
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	49
Debt	$ 22,102
Land Initial Cost	147,273
Building and Improvements Initial Cost	567,989
Adjustments and Costs to Land and Building Subsequent to Acquisition	18,431
Gross carrying amount - Land	147,272
Gross carrying amount - Building and improvements	586,421
Gross carrying amount - Total	733,693
Accumulated Depreciation	$ 59,998
Self storage facilities | CA
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	219
Debt	$ 202,634
Land Initial Cost	914,399
Building and Improvements Initial Cost	2,286,177
Adjustments and Costs to Land and Building Subsequent to Acquisition	287,455
Gross carrying amount - Land	914,618
Gross carrying amount - Building and improvements	2,573,413
Gross carrying amount - Total	3,488,031
Accumulated Depreciation	$ 501,397
Self storage facilities | CO
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	27
Debt	$ 25,798
Land Initial Cost	49,985
Building and Improvements Initial Cost	192,497
Adjustments and Costs to Land and Building Subsequent to Acquisition	22,640
Gross carrying amount - Land	50,703
Gross carrying amount - Building and improvements	214,419
Gross carrying amount - Total	265,122
Accumulated Depreciation	$ 39,143
Self storage facilities | CT
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	23
Debt	$ 6,179
Land Initial Cost	43,453
Building and Improvements Initial Cost	373,628
Adjustments and Costs to Land and Building Subsequent to Acquisition	8,264
Gross carrying amount - Land	43,452
Gross carrying amount - Building and improvements	381,892
Gross carrying amount - Total	425,344
Accumulated Depreciation	$ 28,491
Self storage facilities | FL
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	256
Debt	$ 151,928
Land Initial Cost	692,608
Building and Improvements Initial Cost	3,009,106
Adjustments and Costs to Land and Building Subsequent to Acquisition	131,435
Gross carrying amount - Land	690,728
Gross carrying amount - Building and improvements	3,142,421
Gross carrying amount - Total	3,833,149
Accumulated Depreciation	$ 323,023
Self storage facilities | GA
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	120
Debt	$ 78,738
Land Initial Cost	304,982
Building and Improvements Initial Cost	1,195,949
Adjustments and Costs to Land and Building Subsequent to Acquisition	55,865
Gross carrying amount - Land	304,970
Gross carrying amount - Building and improvements	1,251,826
Gross carrying amount - Total	1,556,796
Accumulated Depreciation	$ 157,456
Self storage facilities | HI
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	14
Debt	$ 0
Land Initial Cost	29,836
Building and Improvements Initial Cost	160,978
Adjustments and Costs to Land and Building Subsequent to Acquisition	25,305
Gross carrying amount - Land	29,836
Gross carrying amount - Building and improvements	186,282
Gross carrying amount - Total	216,118
Accumulated Depreciation	$ 48,926
Self storage facilities | ID
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	2
Debt	$ 0
Land Initial Cost	4,047
Building and Improvements Initial Cost	25,235
Adjustments and Costs to Land and Building Subsequent to Acquisition	71
Gross carrying amount - Land	4,047
Gross carrying amount - Building and improvements	25,306
Gross carrying amount - Total	29,353
Accumulated Depreciation	$ 1,468
Self storage facilities | IL
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	104
Debt	$ 15,888
Land Initial Cost	203,952
Building and Improvements Initial Cost	1,082,223
Adjustments and Costs to Land and Building Subsequent to Acquisition	54,630
Gross carrying amount - Land	203,331
Gross carrying amount - Building and improvements	1,137,474
Gross carrying amount - Total	1,340,805
Accumulated Depreciation	$ 112,677
Self storage facilities | IN
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	92
Debt	$ 0
Land Initial Cost	64,877
Building and Improvements Initial Cost	508,534
Adjustments and Costs to Land and Building Subsequent to Acquisition	17,683
Gross carrying amount - Land	64,528
Gross carrying amount - Building and improvements	526,566
Gross carrying amount - Total	591,094
Accumulated Depreciation	$ 47,931
Self storage facilities | KS
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	1
Debt	$ 0
Land Initial Cost	366
Building and Improvements Initial Cost	1,897
Adjustments and Costs to Land and Building Subsequent to Acquisition	1,200
Gross carrying amount - Land	366
Gross carrying amount - Building and improvements	3,097
Gross carrying amount - Total	3,463
Accumulated Depreciation	$ 1,668
Self storage facilities | KY
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	15
Debt	$ 30,070
Land Initial Cost	10,026
Building and Improvements Initial Cost	88,389
Adjustments and Costs to Land and Building Subsequent to Acquisition	22,085
Gross carrying amount - Land	10,799
Gross carrying amount - Building and improvements	109,701
Gross carrying amount - Total	120,500
Accumulated Depreciation	$ 24,599
Self storage facilities | LA
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	10
Debt	$ 0
Land Initial Cost	16,673
Building and Improvements Initial Cost	126,604
Adjustments and Costs to Land and Building Subsequent to Acquisition	6,660
Gross carrying amount - Land	16,674
Gross carrying amount - Building and improvements	133,263
Gross carrying amount - Total	149,937
Accumulated Depreciation	$ 12,356
Self storage facilities | MA
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	65
Debt	$ 38,786
Land Initial Cost	120,291
Building and Improvements Initial Cost	546,958
Adjustments and Costs to Land and Building Subsequent to Acquisition	69,802
Gross carrying amount - Land	120,472
Gross carrying amount - Building and improvements	616,579
Gross carrying amount - Total	737,051
Accumulated Depreciation	$ 140,277
Self storage facilities | MD
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	44
Debt	$ 71,078
Land Initial Cost	157,195
Building and Improvements Initial Cost	450,952
Adjustments and Costs to Land and Building Subsequent to Acquisition	46,923
Gross carrying amount - Land	156,605
Gross carrying amount - Building and improvements	498,465
Gross carrying amount - Total	655,070
Accumulated Depreciation	$ 124,999
Self storage facilities | ME
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	5
Debt	$ 0
Land Initial Cost	2,352
Building and Improvements Initial Cost	86,339
Adjustments and Costs to Land and Building Subsequent to Acquisition	792
Gross carrying amount - Land	2,352
Gross carrying amount - Building and improvements	87,131
Gross carrying amount - Total	89,483
Accumulated Depreciation	$ 3,195
Self storage facilities | MI
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	11
Debt	$ 4,199
Land Initial Cost	13,162
Building and Improvements Initial Cost	89,881
Adjustments and Costs to Land and Building Subsequent to Acquisition	7,467
Gross carrying amount - Land	13,162
Gross carrying amount - Building and improvements	97,348
Gross carrying amount - Total	110,510
Accumulated Depreciation	$ 15,525
Self storage facilities | MN
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	7
Debt	$ 0
Land Initial Cost	9,696
Building and Improvements Initial Cost	74,960
Adjustments and Costs to Land and Building Subsequent to Acquisition	7,143
Gross carrying amount - Land	9,696
Gross carrying amount - Building and improvements	82,103
Gross carrying amount - Total	91,799
Accumulated Depreciation	$ 12,120
Self storage facilities | MO
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	29
Debt	$ 0
Land Initial Cost	33,809
Building and Improvements Initial Cost	357,853
Adjustments and Costs to Land and Building Subsequent to Acquisition	15,112
Gross carrying amount - Land	33,768
Gross carrying amount - Building and improvements	373,006
Gross carrying amount - Total	406,774
Accumulated Depreciation	$ 24,006
Self storage facilities | MS
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	7
Debt	$ 0
Land Initial Cost	9,053
Building and Improvements Initial Cost	82,098
Adjustments and Costs to Land and Building Subsequent to Acquisition	2,646
Gross carrying amount - Land	9,052
Gross carrying amount - Building and improvements	84,745
Gross carrying amount - Total	93,797
Accumulated Depreciation	$ 7,868
Self storage facilities | NC
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	54
Debt	$ 0
Land Initial Cost	93,492
Building and Improvements Initial Cost	557,728
Adjustments and Costs to Land and Building Subsequent to Acquisition	17,743
Gross carrying amount - Land	93,489
Gross carrying amount - Building and improvements	575,473
Gross carrying amount - Total	668,962
Accumulated Depreciation	$ 47,845
Self storage facilities | NH
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	17
Debt	$ 0
Land Initial Cost	50,952
Building and Improvements Initial Cost	195,719
Adjustments and Costs to Land and Building Subsequent to Acquisition	3,393
Gross carrying amount - Land	51,015
Gross carrying amount - Building and improvements	199,049
Gross carrying amount - Total	250,064
Accumulated Depreciation	$ 10,291
Self storage facilities | NJ
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	90
Debt	$ 78,795
Land Initial Cost	310,950
Building and Improvements Initial Cost	1,081,676
Adjustments and Costs to Land and Building Subsequent to Acquisition	84,560
Gross carrying amount - Land	317,420
Gross carrying amount - Building and improvements	1,159,766
Gross carrying amount - Total	1,477,186
Accumulated Depreciation	$ 242,193
Self storage facilities | NM
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	12
Debt	$ 24,572
Land Initial Cost	32,248
Building and Improvements Initial Cost	72,559
Adjustments and Costs to Land and Building Subsequent to Acquisition	8,450
Gross carrying amount - Land	32,247
Gross carrying amount - Building and improvements	81,010
Gross carrying amount - Total	113,257
Accumulated Depreciation	$ 19,464
Self storage facilities | NV
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	33
Debt	$ 15,783
Land Initial Cost	98,798
Building and Improvements Initial Cost	477,649
Adjustments and Costs to Land and Building Subsequent to Acquisition	14,252
Gross carrying amount - Land	98,973
Gross carrying amount - Building and improvements	491,726
Gross carrying amount - Total	590,699
Accumulated Depreciation	$ 35,384
Self storage facilities | NY
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	80
Debt	$ 3,235
Land Initial Cost	341,104
Building and Improvements Initial Cost	1,200,614
Adjustments and Costs to Land and Building Subsequent to Acquisition	83,904
Gross carrying amount - Land	342,924
Gross carrying amount - Building and improvements	1,282,698
Gross carrying amount - Total	1,625,622
Accumulated Depreciation	$ 140,005
Self storage facilities | OH
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	50
Debt	$ 9,920
Land Initial Cost	71,460
Building and Improvements Initial Cost	388,236
Adjustments and Costs to Land and Building Subsequent to Acquisition	27,786
Gross carrying amount - Land	71,459
Gross carrying amount - Building and improvements	416,023
Gross carrying amount - Total	487,482
Accumulated Depreciation	$ 36,109
Self storage facilities | OK
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	4
Debt	$ 0
Land Initial Cost	3,917
Building and Improvements Initial Cost	28,534
Adjustments and Costs to Land and Building Subsequent to Acquisition	458
Gross carrying amount - Land	3,917
Gross carrying amount - Building and improvements	28,992
Gross carrying amount - Total	32,909
Accumulated Depreciation	$ 1,191
Self storage facilities | OR
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	8
Debt	$ 23,319
Land Initial Cost	15,066
Building and Improvements Initial Cost	68,044
Adjustments and Costs to Land and Building Subsequent to Acquisition	3,159
Gross carrying amount - Land	15,066
Gross carrying amount - Building and improvements	71,203
Gross carrying amount - Total	86,269
Accumulated Depreciation	$ 16,087
Self storage facilities | PA
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	31
Debt	$ 10,386
Land Initial Cost	57,671
Building and Improvements Initial Cost	356,325
Adjustments and Costs to Land and Building Subsequent to Acquisition	39,082
Gross carrying amount - Land	56,997
Gross carrying amount - Building and improvements	396,080
Gross carrying amount - Total	453,077
Accumulated Depreciation	$ 57,399
Self storage facilities | RI
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	6
Debt	$ 3,585
Land Initial Cost	6,132
Building and Improvements Initial Cost	55,033
Adjustments and Costs to Land and Building Subsequent to Acquisition	2,124
Gross carrying amount - Land	6,131
Gross carrying amount - Building and improvements	57,158
Gross carrying amount - Total	63,289
Accumulated Depreciation	$ 6,045
Self storage facilities | SC
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	46
Debt	$ 27,568
Land Initial Cost	65,032
Building and Improvements Initial Cost	385,333
Adjustments and Costs to Land and Building Subsequent to Acquisition	16,162
Gross carrying amount - Land	65,036
Gross carrying amount - Building and improvements	401,491
Gross carrying amount - Total	466,527
Accumulated Depreciation	$ 52,193
Self storage facilities | TN
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	31
Debt	$ 30,338
Land Initial Cost	55,637
Building and Improvements Initial Cost	259,210
Adjustments and Costs to Land and Building Subsequent to Acquisition	17,107
Gross carrying amount - Land	55,637
Gross carrying amount - Building and improvements	276,317
Gross carrying amount - Total	331,954
Accumulated Depreciation	$ 44,087
Self storage facilities | TX
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	274
Debt	$ 61,631
Land Initial Cost	587,514
Building and Improvements Initial Cost	2,788,363
Adjustments and Costs to Land and Building Subsequent to Acquisition	117,215
Gross carrying amount - Land	587,843
Gross carrying amount - Building and improvements	2,905,249
Gross carrying amount - Total	3,493,092
Accumulated Depreciation	$ 285,874
Self storage facilities | UT
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	10
Debt	$ 15,895
Land Initial Cost	9,008
Building and Improvements Initial Cost	39,295
Adjustments and Costs to Land and Building Subsequent to Acquisition	10,751
Gross carrying amount - Land	9,008
Gross carrying amount - Building and improvements	50,046
Gross carrying amount - Total	59,054
Accumulated Depreciation	$ 16,988
Self storage facilities | VA
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	73
Debt	$ 43,618
Land Initial Cost	198,998
Building and Improvements Initial Cost	842,848
Adjustments and Costs to Land and Building Subsequent to Acquisition	46,577
Gross carrying amount - Land	198,998
Gross carrying amount - Building and improvements	889,425
Gross carrying amount - Total	1,088,423
Accumulated Depreciation	$ 152,288
Self storage facilities | WA
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	16
Debt	$ 4,729
Land Initial Cost	68,560
Building and Improvements Initial Cost	188,949
Adjustments and Costs to Land and Building Subsequent to Acquisition	15,257
Gross carrying amount - Land	68,562
Gross carrying amount - Building and improvements	204,204
Gross carrying amount - Total	272,766
Accumulated Depreciation	$ 24,049
Self storage facilities | WI
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	2
Debt	$ 0
Land Initial Cost	2,192
Building and Improvements Initial Cost	31,270
Adjustments and Costs to Land and Building Subsequent to Acquisition	463
Gross carrying amount - Land	2,192
Gross carrying amount - Building and improvements	31,733
Gross carrying amount - Total	33,925
Accumulated Depreciation	$ 706
Self storage facilities | DC
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	1
Debt	$ 7,201
Land Initial Cost	14,394
Building and Improvements Initial Cost	18,172
Adjustments and Costs to Land and Building Subsequent to Acquisition	739
Gross carrying amount - Land	14,394
Gross carrying amount - Building and improvements	18,911
Gross carrying amount - Total	33,305
Accumulated Depreciation	4,429
Other corporate assets
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Debt	0
Land Initial Cost	0
Building and Improvements Initial Cost	11,037
Adjustments and Costs to Land and Building Subsequent to Acquisition	270,344
Gross carrying amount - Land	0
Gross carrying amount - Building and improvements	281,381
Gross carrying amount - Total	281,381
Accumulated Depreciation	96,203
Intangible tenant relationships and lease rights
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Debt	0
Land Initial Cost	0
Building and Improvements Initial Cost	354,183
Adjustments and Costs to Land and Building Subsequent to Acquisition	0
Gross carrying amount - Land	0
Gross carrying amount - Building and improvements	354,183
Gross carrying amount - Total	354,183
Accumulated Depreciation	317,639
Construction in Progress/Undeveloped Land
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Debt	0
Land Initial Cost	25,002
Building and Improvements Initial Cost	4,383
Adjustments and Costs to Land and Building Subsequent to Acquisition	100,446
Gross carrying amount - Land	23,712
Gross carrying amount - Building and improvements	106,188
Gross carrying amount - Total	129,900
Accumulated Depreciation	1,191
Right of use asset - finance lease
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Debt	0
Land Initial Cost	0
Building and Improvements Initial Cost	0
Adjustments and Costs to Land and Building Subsequent to Acquisition	140,259
Gross carrying amount - Land	0
Gross carrying amount - Building and improvements	140,259
Gross carrying amount - Total	140,259
Accumulated Depreciation	15,727
Real estate under development/redevelopment
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Gross carrying amount - Total	$ 101,293	$ 118,745	$ 52,348	$ 59,248