DERIVATIVE AND HEDGING ACTIVITIES (Details) (USD $) In Thousands, unless otherwise specified		3 Months Ended		9 Months Ended		1 Months Ended	9 Months Ended					0 Months Ended			9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013 Cash flow hedges	Sep. 30, 2012 Cash flow hedges	Sep. 30, 2013 Cash flow hedges	Sep. 30, 2012 Cash flow hedges	Dec. 31, 2011 Unsecured Term Loan	Sep. 30, 2013 Unsecured Term Loan	Sep. 30, 2013 Unsecured Term Loan Minimum	Sep. 30, 2013 Unsecured Term Loan Maximum	Sep. 30, 2013 Interest rate swap	Dec. 31, 2012 Interest rate swap	Jul. 19, 2012 Interest rate swap Unsecured Term Loan	Jul. 19, 2012 Interest rate swap Unsecured Term Loan Minimum	Jul. 19, 2012 Interest rate swap Unsecured Term Loan Maximum	Sep. 30, 2013 0.6800% Interest rate swap Cash flow hedges	Sep. 30, 2013 0.6925% Interest rate swap Cash flow hedges
Derivative and hedging activities
Unsecured term Loan						$ 250,000						$ 250,000
Unsecured term Loan, maturity term						5 years						5 years
Variable rate basis							one-month LIBOR					one-month LIBOR
Interest rate spread (as a percent)							1.15%	1.00%	2.00%				1.00%	2.00%
Interest rate (as a percent)												0.685%
Minimum aggregate principal amount of indebtedness in default upon which counterparties could declare the Company in default on its derivative obligations	20,000
Notional Amount															150,000	100,000
Fixed Interest Rate (as a percent)															0.68%	0.6925%
Variable Interest Rate															one-month LIBOR	one-month LIBOR
Fair value of derivative assets										474	0
Fair value of derivative liability										0	(1,296)
Estimated amount reclassified from accumulated other comprehensive income to interest expense over the next twelve months										1,112
Amount of gain (loss) recognized in accumulated other comprehensive income on interest rate derivatives (effective portion)		(1,519)	(1,616)	923	(1,616)
Amount of gain (loss) reclassified from accumulated other comprehensive income into income as interest expense (effective portion)		(300)	(148)	(847)	(148)
Amount of gain (loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)		0		0
Fair value of derivatives in net liability position	$ 0