Quarterly report pursuant to Section 13 or 15(d)

DEBT FINANCING - Narrative (Details)

v3.8.0.1
DEBT FINANCING - Narrative (Details)
1 Months Ended
Feb. 08, 2017
USD ($)
Aug. 31, 2017
USD ($)
property
Sep. 30, 2017
USD ($)
Credit Facility [Member]      
Debt Instrument [Line Items]      
Maximum borrowing capacity $ 1,000,000,000    
Unsecured Debt [Member] | Amended Credit Facility [Member]      
Debt Instrument [Line Items]      
Maximum borrowing capacity 895,000,000    
Increase in credit facility 170,000,000.0    
Unsecured Debt [Member] | Amended Credit Facility [Member] | Tranche A Term Loan [Member]      
Debt Instrument [Line Items]      
Increase to maximum borrowing capacity 10,000,000    
Maximum borrowing capacity 235,000,000    
Unsecured Debt [Member] | Amended Credit Facility [Member] | Tranche B Term Loan [Member]      
Debt Instrument [Line Items]      
Increase to maximum borrowing capacity 55,000,000    
Maximum borrowing capacity 155,000,000    
Unsecured Debt [Member] | Amended Credit Facility [Member] | Tranche C Term Loan [Member]      
Debt Instrument [Line Items]      
Maximum borrowing capacity $ 105,000,000    
Debt instrument, prepayment premium, first term, rate 2.00%    
Debt instrument, prepayment premium, second term, rate 1.00%    
Unsecured Debt [Member] | Amended Credit Facility [Member] | Tranche C Term Loan [Member] | Federal Funds Effective Swap Rate [Member]      
Debt Instrument [Line Items]      
Borrowing rate spread 0.50%    
Unsecured Debt [Member] | Amended Credit Facility [Member] | Tranche C Term Loan [Member] | LIBOR [Member]      
Debt Instrument [Line Items]      
Borrowing rate spread 1.00%    
Unsecured Debt [Member] | Amended Credit Facility [Member] | Tranche C Term Loan [Member] | Minimum [Member] | LIBOR [Member]      
Debt Instrument [Line Items]      
Leverage based margin threshold 1.70%    
Elective leverage based margin threshold 1.50%    
Unsecured Debt [Member] | Amended Credit Facility [Member] | Tranche C Term Loan [Member] | Minimum [Member] | Base Rate [Member]      
Debt Instrument [Line Items]      
Leverage based margin threshold 0.70%    
Elective leverage based margin threshold 0.50%    
Unsecured Debt [Member] | Amended Credit Facility [Member] | Tranche C Term Loan [Member] | Maximum [Member] | LIBOR [Member]      
Debt Instrument [Line Items]      
Leverage based margin threshold 2.25%    
Elective leverage based margin threshold 2.45%    
Unsecured Debt [Member] | Amended Credit Facility [Member] | Tranche C Term Loan [Member] | Maximum [Member] | Base Rate [Member]      
Debt Instrument [Line Items]      
Leverage based margin threshold 1.25%    
Elective leverage based margin threshold 1.45%    
Line of Credit [Member] | Amended Credit Facility [Member] | Revolving line of credit [Member]      
Debt Instrument [Line Items]      
Maximum borrowing capacity $ 400,000,000    
Line of Credit [Member] | Credit Facility [Member] | Revolving line of credit [Member]      
Debt Instrument [Line Items]      
Remaining borrowing capacity     $ 194,300,000
Line of Credit [Member] | Credit Facility [Member] | Letter of Credit [Member]      
Debt Instrument [Line Items]      
Outstanding letters of credit     $ 4,700,000
Secured Debt [Member]      
Debt Instrument [Line Items]      
Fixed rate mortgages payable, face amount   $ 84,900,000  
Fixed rate mortgages payable, collateral properties | property   22  
Fixed rate mortgages payable, fixed interest rate (percent)   4.14%