SELF STORAGE PROPERTY ACQUISITIONS AND DISPOSITIONS - Business Combination Consideration (Details) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2016
USD ($)
property
|
Sep. 30, 2016
USD ($)
property
|
Jun. 30, 2016
USD ($)
property
|
Mar. 31, 2016
USD ($)
property
|
Dec. 31, 2015
USD ($)
property
|
Sep. 30, 2015
USD ($)
property
|
Jun. 30, 2015
USD ($)
property
|
Mar. 31, 2015
USD ($)
property
|
Dec. 31, 2016
USD ($)
property
|
Dec. 31, 2015
USD ($)
property
|
Dec. 31, 2014
USD ($)
property
|
|
| Business Acquisition [Line Items] | |||||||||||
| Number of self storage properties acquired | property | 107 | 58 | 83 | ||||||||
| Consideration given, cash | $ 19,943 | $ 0 | $ 0 | ||||||||
| Business combination, debt adjustment on assumed mortgages | $ 7,200 | $ 2,200 | $ 7,200 | $ 2,200 | |||||||
| 2016 Acquisitions [Member] | |||||||||||
| Business Acquisition [Line Items] | |||||||||||
| Number of self storage properties acquired | property | 31 | 34 | 25 | 17 | 107 | ||||||
| Consideration given, cash | $ 208,707 | $ 199,890 | $ 61,263 | $ 63,300 | $ 533,160 | ||||||
| Consideration given, value of OP Equity | 16,871 | 4,841 | 80,986 | 19,068 | 121,766 | ||||||
| Consideration given, settlement of note receivable | 0 | 0 | 0 | 0 | 0 | ||||||
| Liabilities assumed, mortgages | 0 | 0 | 55,767 | 5,861 | 61,628 | ||||||
| Liabilities assumed, other | 2,125 | 896 | 1,212 | 584 | 4,817 | ||||||
| Noncontrolling interests acquired | 0 | 0 | 0 | 0 | 0 | ||||||
| Total consideration given and liabilities assumed | $ 227,703 | $ 205,627 | $ 199,228 | $ 88,813 | $ 721,371 | ||||||
| 2015 Acquisitions [Member] | |||||||||||
| Business Acquisition [Line Items] | |||||||||||
| Number of self storage properties acquired | property | 16 | 15 | 21 | 6 | 58 | ||||||
| Consideration given, cash | $ 39,626 | $ 84,673 | $ 41,277 | $ 6,991 | $ 172,567 | ||||||
| Consideration given, value of OP Equity | 1,402 | 10,188 | 22,971 | 8,954 | 43,515 | ||||||
| Consideration given, settlement of note receivable | 0 | 0 | 0 | 1,778 | 1,778 | ||||||
| Liabilities assumed, mortgages | 23,643 | 2,866 | 30,547 | 16,442 | 73,498 | ||||||
| Liabilities assumed, other | (359) | 512 | 288 | 70 | 511 | ||||||
| Noncontrolling interests acquired | 6,040 | 8,327 | 0 | 6,770 | 21,137 | ||||||
| Total consideration given and liabilities assumed | $ 70,352 | $ 106,566 | $ 95,083 | $ 41,005 | $ 313,006 | ||||||