DEBT (Details) (USD $)	3 Months Ended		9 Months Ended			3 Months Ended	9 Months Ended	0 Months Ended							9 Months Ended	12 Months Ended		0 Months Ended	9 Months Ended		9 Months Ended									0 Months Ended	9 Months Ended					0 Months Ended	9 Months Ended						0 Months Ended		0 Months Ended		0 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 Revolving Credit Facility [Member]	Sep. 30, 2014 Revolving Credit Facility [Member]	Jan. 23, 2014 Senior Unsecured Notes due 2021 [Member]	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]	Feb. 11, 2014 Senior Notes due 2018 [Member]	Jan. 08, 2014 Senior Notes due 2018 [Member]	Jun. 24, 2013 Senior Notes due 2018 [Member]	Sep. 30, 2014 Senior Notes due 2018 [Member]	Dec. 31, 2013 Senior Notes due 2018 [Member]	Oct. 27, 2010 Senior Notes due 2018 [Member]	Jun. 24, 2013 Senior Notes due 2018 [Member] Prior to November 2013 [Member]	Sep. 30, 2014 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member]	Sep. 10, 2014 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member]	Sep. 30, 2014 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] Minimum [Member]	Sep. 30, 2014 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] Maximum [Member]	Sep. 30, 2014 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] Federal Funds Rate [Member]	Sep. 30, 2014 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] London Interbank Offered Rate (LIBOR) [Member]	Sep. 30, 2014 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] London Interbank Offered Rate (LIBOR) [Member] Minimum [Member]	Sep. 30, 2014 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] London Interbank Offered Rate (LIBOR) [Member] Maximum [Member]	Sep. 30, 2014 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] Base Rate [Member] Minimum [Member]	Sep. 30, 2014 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] Base Rate [Member] Maximum [Member]	Jul. 26, 2012 Additional Senior Notes [Member]	May 01, 2014 Mortgage Indebtedness [Member]	Sep. 30, 2014 Mortgage Indebtedness [Member]	Apr. 08, 2014 Mortgage Indebtedness [Member]	Jan. 21, 2014 Mortgage Indebtedness [Member]	Dec. 31, 2013 Mortgage Indebtedness [Member]	Sep. 30, 2014 Mortgage Indebtedness [Member] Fixed Rate Mortgages [Member]	Jan. 23, 2014 Debt Instrument, Redemption, Period One [Member] Senior Unsecured Notes due 2021 [Member]	Sep. 30, 2014 Investment Grade Credit Rating [Member] 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] Minimum [Member]	Sep. 30, 2014 Investment Grade Credit Rating [Member] 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] Maximum [Member]	Sep. 30, 2014 Investment Grade Credit Rating [Member] 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] London Interbank Offered Rate (LIBOR) [Member] Minimum [Member]	Sep. 30, 2014 Investment Grade Credit Rating [Member] 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] London Interbank Offered Rate (LIBOR) [Member] Maximum [Member]	Sep. 30, 2014 Investment Grade Credit Rating [Member] 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] Base Rate [Member] Minimum [Member]	Sep. 30, 2014 Investment Grade Credit Rating [Member] 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member] Base Rate [Member] Maximum [Member]	Oct. 10, 2014 Subsequent Event [Member] Additional Senior Unsecured Notes due 2021 [Member]	Oct. 10, 2014 Subsequent Event [Member] Additional Senior Unsecured Notes due 2021 [Member]	Oct. 10, 2014 Subsequent Event [Member] 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member]	Oct. 10, 2014 Subsequent Event [Member] 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member]	Oct. 10, 2014 London Interbank Offered Rate (LIBOR) [Member] Subsequent Event [Member] 2014 Revolving Credit Facility [Member] Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Principal Outstaning, Fixed Rate																															$ 124,714,000			$ 54,688,000
Principal Outstaning, Variable Rate																															0			86,640,000
Total Principal Outstanding																															124,714,000			141,328,000
Debt Instrument, Description of Variable Rate Basis																							federal funds rate	one-month LIBOR
Debt Instrument, Basis Spread on Variable Rate																							0.50%	1.00%																							2.00%
Debt Instrument, Interest Rate, Stated Percentage								5.50%	5.375%								8.125%															4.10%	4.25%
Debtor Reorganization Items, Write-off of Deferred Financing Costs and Debt Discounts			500,000																												100,000
Repayments of Long-term Debt																														29,800,000
Debt Instrument, Face Amount								350,000,000	200,000,000								225,000,000												100,000,000			11,600,000	44,800,000											150,000,000
Debt Instrument, Issued Price, Percentage																																												99.50%
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%
Proceeds from Issuance of Debt								350,000,000	200,000,000
Proceeds from Debt, Net of Issuance Costs								340,800,000	194,600,000																																		145,800,000
Debt Instrument, Yield-to-Maturity																																												5.593%
Debt Instrument, Redeemable, Redemption Price of Principal Amount, Percentage											105.375%							108.125%
Line of Credit Facility, Maximum Borrowing Capacity																				750,000,000.0
Line of Credit Facility, Revolving Credit Conversion to Term Loan, Amount																				200,000,000.0																										200,000,000.0
Debt Instrument, Term																																													5 years
Line of Credit Facility, Accordion Feature, Additional Borrowing Capacity																				100,000,000
Line of Credit Facility, Optional Extension Period																			1 year
Secured revolving credit facility	614,000,000		614,000,000		135,500,000														614,000,000
Debt Instrument, Refianced, Write-off of Unamortized Financing Costs							200,000
Line of Credit Facility, Current Borrowing Capacity																				650,000,000
Line of Credit Facility, Interest Rate During Period																									2.00%	2.60%	1.00%	1.60%											0.90%	1.70%	0.00%	0.70%
Line of Credit Facility, Commitment Fee Percentage																																					0.125%	0.30%
Line of Credit Facility, Interest Rate at Period End																			2.46%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage																					0.25%	0.35%
Interest Expense	10,540,000	9,739,000	32,668,000	29,884,000		300,000	2,300,000
Line of Credit Facility, Commitment Fee Amount						500,000	1,100,000
Amortization of deferred financing costs	900,000	800,000	2,812,000	2,395,000
Interest Payable	7,900,000		7,900,000		4,700,000
Gain (Loss) on extinguishment of debt	(158,000)	(351,000)	(22,454,000)	(10,101,000)											21,600,000	(9,800,000)
Gains (Losses) on Extinguishment of Debt, before Write off of Deferred Debt Issuance Cost															(20,800,000)	9,300,000
Write off of Deferred Debt Issuance Cost															800,000	500,000
Debt, Weighted Average Interest Rate																														5.00%	3.96%				3.96%
Long-term Debt	1,288,714,000		1,288,714,000										211,300,000																		124,714,000
Extinguishment of Debt, Amount												$ 400,000	$ 210,900,000
Debt Instrument, Redemption Price, Percentage										100.00%		109.485%	109.837%																							100.00%