Contractual interest rate for funds borrowed, under the debt agreement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
-Number 210
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-Paragraph 19, 20, 22
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16(a))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Fair Value of Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016	Feb. 29, 2016	Dec. 31, 2015
Fair Value of Financial Instruments
Mortgage notes payable, net	$ 28,655			$ 136,299
Senior Notes	$ 646,272			$ 345,809
3.75% Senior unsecured note due In 2019
Fair Value of Financial Instruments
Interest rate (as a percent)	3.75%			3.75%
5.875% Senior unsecured notes due In 2046
Fair Value of Financial Instruments
Interest rate (as a percent)	5.875%
6.21% Mortgage notes due in 2016
Fair Value of Financial Instruments
Interest rate (as a percent)			6.21%	6.21%
5.55% Mortgage notes due in 2016
Fair Value of Financial Instruments
Interest rate (as a percent)		5.55%		5.55%
5.88% Mortgage notes due in 2021
Fair Value of Financial Instruments
Interest rate (as a percent)	5.88%			5.88%
7% Mortgage notes due in 2019
Fair Value of Financial Instruments
Interest rate (as a percent)	7.00%			7.00%
8.15% Mortgage notes due in 2021
Fair Value of Financial Instruments
Interest rate (as a percent)	8.15%			8.15%
Carrying Amount
Fair Value of Financial Instruments
Mortgage notes payable, net	$ 674,927			$ 482,108
Carrying Amount \| 3.75% Senior unsecured note due In 2019
Fair Value of Financial Instruments
Senior Notes	346,381			345,809
Carrying Amount \| 5.875% Senior unsecured notes due In 2046
Fair Value of Financial Instruments
Senior Notes	299,891
Carrying Amount \| 6.21% Mortgage notes due in 2016
Fair Value of Financial Instruments
Mortgage notes payable, net				23,476
Carrying Amount \| 5.55% Mortgage notes due in 2016
Fair Value of Financial Instruments
Mortgage notes payable, net				83,375
Carrying Amount \| 5.88% Mortgage notes due in 2021
Fair Value of Financial Instruments
Mortgage notes payable, net	13,944			14,045
Carrying Amount \| 7% Mortgage notes due in 2019
Fair Value of Financial Instruments
Mortgage notes payable, net	8,964			9,145
Carrying Amount \| 8.15% Mortgage notes due in 2021
Fair Value of Financial Instruments
Mortgage notes payable, net	5,747			6,258
Fair Value
Fair Value of Financial Instruments
Mortgage notes payable, net	705,444			490,221
Fair Value \| 3.75% Senior unsecured note due In 2019
Fair Value of Financial Instruments
Senior Notes	358,351			351,692
Fair Value \| 5.875% Senior unsecured notes due In 2046
Fair Value of Financial Instruments
Senior Notes	316,200
Fair Value \| 6.21% Mortgage notes due in 2016
Fair Value of Financial Instruments
Mortgage notes payable, net				24,038
Fair Value \| 5.55% Mortgage notes due in 2016
Fair Value of Financial Instruments
Mortgage notes payable, net				83,457
Fair Value \| 5.88% Mortgage notes due in 2021
Fair Value of Financial Instruments
Mortgage notes payable, net	15,100			14,678
Fair Value \| 7% Mortgage notes due in 2019
Fair Value of Financial Instruments
Mortgage notes payable, net	9,551			9,645
Fair Value \| 8.15% Mortgage notes due in 2021
Fair Value of Financial Instruments
Mortgage notes payable, net	$ 6,242			$ 6,711