Summary of Reportable Segments (Detail) - USD ($)
 3 Months Ended 9 Months Ended
Sep. 30, 2020
Jun. 30, 2020
Mar. 31, 2020
Dec. 31, 2019
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Revenues:              
Total revenues $ 31,363,122       $ 29,588,014 $ 91,130,790 $ 79,451,856
Operating expenses:              
General and administrative 4,012,072       3,519,557 11,829,732 7,000,627
Depreciation 8,003,587       7,639,190 23,562,701 21,928,108
Intangible amortization expense 1,587,899       3,741,046 8,475,682 7,822,354
Self administration transaction expenses 0       107,100 0 1,595,371
Acquisition expenses – affiliates             84,061
Other acquisition expenses 468,577       25,529 593,903 109,765
Contingent earnout adjustment 1,600,000       300,000 (5,100,000) 300,000
Contingent earnout expense 1,600,000            
Total operating expenses 26,992,137 $ 27,497,027 $ 61,368,274 $ 26,965,933 27,773,486 115,857,438 74,919,300
Impairment of goodwill and intangible assets           36,465,732  
Impairment of investments in Managed REITs 0       0 4,376,879 0
Operating income (loss) 4,370,985 1,972,518 (31,070,151) 7,055,456 1,814,528 (24,726,648) 4,532,556
Other income (expense):              
Interest expense (8,093,476)       (10,260,936) (24,717,208) (28,584,740)
Net loss on extinguishment of debt 0       0 0 (1,487,867)
Interest expense – accretion of fair market value of secured debt 32,788       33,191 98,337 98,850
Interest expense – debt issuance costs (952,479)       (1,082,543) (2,832,240) (2,997,801)
Gain resulting from acquisition of           0 8,017,353
Other 185,685       (45,819) 2,914,840 (352,219)
Net loss (4,456,497) $ (7,062,841) $ (37,743,581) $ (4,321,670) (9,541,579) (49,262,919) (20,773,868)
Self Storage Rental Revenue              
Revenues:              
Total revenues 26,706,201       25,669,615 77,221,013 74,056,235
Ancillary Operating Revenue              
Revenues:              
Total revenues 1,431,952       1,188,934 3,768,213 2,589,985
Managed REIT Platform Revenue              
Revenues:              
Total revenues 2,051,021       1,192,665 5,687,701 1,221,727
Reimbursable Costs from Managed REITs              
Revenues:              
Total revenues 1,173,948       1,536,800 4,453,863 1,583,909
Operating expenses:              
Operating expenses 1,173,948       1,536,800 4,453,863 1,583,909
Property Operating Expenses              
Operating expenses:              
Operating expenses 9,816,774       9,655,599 28,686,843 26,630,201
Property operating expenses – Affiliates              
Operating expenses:              
Operating expenses 0       0 0 6,605,670
Managed REIT Platform Expenses              
Operating expenses:              
Operating expenses 329,280       1,248,665 2,512,103 1,259,234
Self Storage              
Revenues:              
Total revenues 28,138,153       26,858,549 80,989,226 76,646,220
Operating expenses:              
Depreciation 7,863,351       7,470,184 23,185,178 21,750,206
Intangible amortization expense 561,601       2,503,987 4,950,285 6,524,347
Acquisition expenses – affiliates             84,061
Other acquisition expenses 468,577       25,529 593,903 109,765
Total operating expenses 18,710,303       19,655,299 57,416,209 61,704,250
Operating income (loss) 9,427,850       7,203,250 23,573,017 14,941,970
Other income (expense):              
Interest expense (8,048,225)       (10,214,822) (24,581,790) (28,537,117)
Net loss on extinguishment of debt             (1,487,867)
Interest expense – accretion of fair market value of secured debt 32,788       33,191 98,337 98,850
Interest expense – debt issuance costs (950,120)       (1,082,543) (2,825,162) (2,997,801)
Gain resulting from acquisition of             8,017,353
Other (139,829)       (106,450) (544,296) (414,871)
Net loss 322,464       (4,167,374) (4,279,894) (10,379,483)
Self Storage | Self Storage Rental Revenue              
Revenues:              
Total revenues 26,706,201       25,669,615 77,221,013 74,056,235
Self Storage | Ancillary Operating Revenue              
Revenues:              
Total revenues 1,431,952       1,188,934 3,768,213 2,589,985
Self Storage | Property Operating Expenses              
Operating expenses:              
Operating expenses 9,816,774       9,655,599 28,686,843 26,630,201
Self Storage | Property operating expenses – Affiliates              
Operating expenses:              
Operating expenses             6,605,670
Managed REIT Platform              
Revenues:              
Total revenues 3,224,969       2,729,465 10,141,564 2,805,636
Operating expenses:              
Intangible amortization expense 1,026,298       1,237,059 3,525,397 1,298,007
Contingent earnout adjustment         300,000 (5,100,000) 300,000
Contingent earnout expense 1,600,000            
Total operating expenses 4,129,526       4,322,524 46,233,974 4,441,150
Impairment of goodwill and intangible assets           36,465,732  
Impairment of investments in Managed REITs           4,376,879  
Operating income (loss) (904,557)       (1,593,059) (36,092,410) (1,635,514)
Other income (expense):              
Other 325,514       60,631 3,312,206 62,652
Net loss (579,043)       (1,532,428) (32,780,204) (1,572,862)
Managed REIT Platform | Managed REIT Platform Revenue              
Revenues:              
Total revenues 2,051,021       1,192,665 5,687,701 1,221,727
Managed REIT Platform | Reimbursable Costs from Managed REITs              
Revenues:              
Total revenues 1,173,948       1,536,800 4,453,863 1,583,909
Operating expenses:              
Operating expenses 1,173,948       1,536,800 4,453,863 1,583,909
Managed REIT Platform | Managed REIT Platform Expenses              
Operating expenses:              
Operating expenses 329,280       1,248,665 2,512,103 1,259,234
Corporate and Other              
Operating expenses:              
General and administrative 4,012,072       3,519,557 11,829,732 7,000,627
Depreciation 140,236       169,006 377,523 177,902
Self administration transaction expenses         107,100   1,595,371
Total operating expenses 4,152,308       3,795,663 12,207,255 8,773,900
Operating income (loss) (4,152,308)       (3,795,663) (12,207,255) (8,773,900)
Other income (expense):              
Interest expense (45,251)       (46,114) (135,418) (47,623)
Interest expense – debt issuance costs (2,359)         (7,078)  
Other           146,930  
Net loss $ (4,199,918)       $ (3,841,777) $ (12,202,821) $ (8,821,523)