DEBT (Details) (USD $)	12 Months Ended								0 Months Ended							12 Months Ended	0 Months Ended		12 Months Ended	0 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Revolving Credit Facility	Sep. 20, 2012 Revolving Credit Facility	Feb. 10, 2012 Revolving Credit Facility	Feb. 09, 2012 Revolving Credit Facility	Feb. 10, 2012 Letter of Credit	Jan. 23, 2014 Senior Unsecured Notes due 2021 Subsequent Event	Jan. 23, 2014 Senior Unsecured Notes due 2021 Revolving Credit Facility Subsequent Event	Jan. 23, 2014 Senior Unsecured Notes due 2021 Prior to February 1, 2017 Subsequent Event	May 23, 2013 Senior Unsecured Notes Due 2023 [Member]	May 23, 2013 Senior Unsecured Notes Due 2023 [Member] Prior to June 2018 [Member]	May 23, 2013 Senior Unsecured Notes Due 2023 [Member] Prior to June 2016 [Member]	Oct. 27, 2010 Senior Notes due 2018	Dec. 31, 2013 Senior Notes due 2018	Feb. 11, 2014 Senior Notes due 2018 Subsequent Event	Jan. 08, 2014 Senior Notes due 2018 Subsequent Event	Dec. 31, 2013 Senior Notes due 2018 Prior to November 2013	Jul. 26, 2012 Additional Senior Notes [Member]	Nov. 24, 2012 Additional Senior Notes [Member]	Dec. 31, 2013 2013 Revolving Credit Facility [Member] Revolving Credit Facility	Jul. 29, 2013 2013 Revolving Credit Facility [Member] Revolving Credit Facility	Dec. 31, 2013 2013 Revolving Credit Facility [Member] Revolving Credit Facility Minimum	Dec. 31, 2013 2013 Revolving Credit Facility [Member] Revolving Credit Facility Maximum	Dec. 31, 2013 2013 Revolving Credit Facility [Member] Revolving Credit Facility Federal Funds Rate	Dec. 31, 2013 2013 Revolving Credit Facility [Member] Revolving Credit Facility London Interbank Offered Rate (LIBOR)	Dec. 31, 2013 2013 Revolving Credit Facility [Member] Revolving Credit Facility London Interbank Offered Rate (LIBOR) Minimum	Dec. 31, 2013 2013 Revolving Credit Facility [Member] Revolving Credit Facility London Interbank Offered Rate (LIBOR) Maximum	Dec. 31, 2013 2013 Revolving Credit Facility [Member] Revolving Credit Facility Base Rate Minimum	Dec. 31, 2013 2013 Revolving Credit Facility [Member] Revolving Credit Facility Base Rate Maximum	Dec. 31, 2013 Mortgage Indebtedness		Dec. 31, 2012 Mortgage Indebtedness	Jan. 21, 2014 Mortgage Indebtedness Subsequent Event	Dec. 31, 2013 Mortgage Indebtedness Fixed Rate Mortgages	Dec. 31, 2013 Mortgage Indebtedness Variable Rate Mortgages	Dec. 31, 2013 Senior Notes		Dec. 31, 2012 Senior Notes
Debt Instrument
Principal Outstanding, Fixed Rate																																$ 54,688,000		$ 94,373,000
Principal Outstanding, Variable Rate																																86,640,000		57,949,000
Total Principal Outstanding																																141,328,000		152,322,000
Weighted Average Interest Rate																																4.08%			3.97%	2.62%	5.00%
Debt Instrument, Description of Variable Rate Basis																										federal funds rate	one-month LIBOR					90-day LIBOR
Debt Instrument, Basis Spread on Variable Rate																										0.50%	1.00%					4.00%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum																																1.00%
Stated interest rate									5.50%			5.375%			8.125%																				4.25%
Aggregate principal amount of debt									350,000,000			200,000,000			225,000,000					100,000,000	100,000,000														44,800,000			411,250,000	[1]	325,000,000	[1]
Repayment of outstanding amount under revolving credit facility	100,500,000	42,500,000	0							4,500,000
Debt Instrument, Unamortized Premium																																						3,200,000
Debt Instrument, Redemption Price, Percentage											100.00%		100.00%				109.485%	109.837%
Expected Tender Offer and Redemption Related Costs and Write Offs in First Quarter of Next Fiscal Year																	21,600,000
Expected Tender Offer and Redemption Related Costs and Write Offs in First Quarter of Next Fiscal Year, Payments Made to Noteholders for Early Redemption																	20,800,000
Expected Tender Offer and Redemption Related Costs and Write Offs in First Quarter of Next Fiscal Year, Write-Offs Associated With Unamortized Deferred Financing and Premium Costs																	800,000
Debt Instrument, Percent to Par Value																				106.00%
Proceeds from Issuance of Debt									350,000,000			200,000,000			225,000,000					103,000,000
Debt Instrument, Interest Rate, Effective Percentage																				6.92%
Proceeds from Debt, Net of Issuance Costs									341,400,000			194,600,000			219,900,000
Debt Instrument, Redeemable, Redemption Price of Principal Amount, Percentage																			108.125%
Line of Credit Facility, Maximum Borrowing Capacity						200,000,000	100,000,000	20,000,000															375,000,000
Line of Credit Facility, Commitment Fee Amount				1,200,000
Line of Credit Facility, Accordion Feature, Additional Borrowing Capacity						150,000,000																	225,000,000
Line of Credit Facility, Accordion Feature, Increased Borrowing Capacity					230,000,000
Line of Credit Facility, Optional Extension Period				1 year																		1 year
Secured revolving credit facility	135,500,000	92,500,000
Line of Credit Facility, Current Borrowing Capacity																						135,100,000
Line of Credit Facility, Interest Rate During Period																												2.50%	3.50%	1.50%	2.50%
Line of Credit Facility, Interest Rate at Period End																						3.17%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage																								0.35%	0.50%
Interest Expense	40,460,000	34,335,000	30,319,000	1,700,000
Amortization of deferred financing costs	3,280,000	2,685,000	1,998,000
Interest Payable	4,700,000	5,400,000
Loss on extinguishment of debt	(10,101,000)	(2,670,000)	0													(9,800,000)
Debt Instrument, Redemption Price, Principal Amount Redeemed																113,800,000
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed											35.00%			35.00%		35.00%
Debt Instrument, Redemption Price, Percentage, Using Proceeds of Specific Kinds of Equity Offerings											105.50%			105.375%
Gains (Losses) on Extinguishment of Debt, before Write off of Deferred Debt Issuance Cost																(9,300,000)
Write off of Deferred Debt Issuance Cost																500,000
Long-term Debt	688,078,000																	211,300,000														141,328,000	[2]					411,250,000
Extinguishment of Debt, Amount																	$ 400,000	$ 210,900,000

[1] Face value represents amounts contractually due under the terms of the respective agreements.

[2] Outstanding principal balance for Senior Notes does not include premium of $3.2 million as of December 31, 2013.