Annual report pursuant to Section 13 and 15(d)

Investment in Storage Facilities and Intangible Assets - Summary of Activity in Storage Facilities (Detail)

v3.10.0.1
Investment in Storage Facilities and Intangible Assets - Summary of Activity in Storage Facilities (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Cost:    
Beginning balance $ 4,321,410 $ 4,243,308
Acquisition of storage facilities 76,582 22,638
Improvements and equipment additions 54,482 84,332
Net increase (decrease) in construction in progress 12,809 (141)
Dispositions (66,344) (28,727)
Ending balance 4,398,939 4,321,410
Accumulated Depreciation:    
Beginning balance 624,314 535,704
Additions during the year 102,361 102,674
Dispositions (21,994) (14,064)
Ending balance $ 704,681 $ 624,314